Ohta Hiromichi
| Research Institute for Electronic Science Green Nanotechnology Research Center | Professor |
Last Updated :2025/07/05
■Researcher basic information
Profile Information
I think that the approach for materials research could be divided into two main ways. One is a long-term diligent search for new substances, and the other is process development where a known substance is developed to be available as "a material." I have been closely watching the whole process of making furniture by my father, so that I seem to be better at process development in order to "make fine products." Firstly, I will fabricate high-quality thin films to know the intrinsic property which has been unable to be extracted from the data measured with dirty polycrystal such as ceramics or extremely small single crystal. My most interest in process development for now is to design electronic devices with the high-quality epitaxial thin films.
Researchmap personal page
Home Page URL
Researcher number
- 80372530
Researcher ID
- H-4468-2012
J-Global ID
Research Keyword
Research Field
Educational Organization
- Master's degree program, Graduate School of Information Science and Technology
- Doctoral (PhD) degree program, Graduate School of Information Science and Technology
■Career
Career
- Apr. 2025 - Present
Hokkaido University, Research Institute for Electronic Science, Director, Japan - Sep. 2012 - Present
Hokkaido University, RIES, Professor - Apr. 2021 - Mar. 2025
Deputy Director, RIES, Hokkaido University, Japan - Oct. 2003 - Aug. 2012
Graduate School of Engineering, Nagoya University, Associate Professor - Oct. 2008 - Mar. 2012
PRESTO, JST - Nov. 1999 - Sep. 2004
ERATO, JST - Jan. 1998 - Sep. 2003
HOYA Co. - Apr. 1996 - Dec. 1997
SANYO Electric Co.
Educational Background
- Oct. 1998 - Sep. 2001, Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Engineering, Innovative and Engineered Materials, Japan
- Apr. 1994 - Mar. 1996, Nagoya University, Graduate School of Engineering, Applied Chemistry
- Apr. 1990 - Mar. 1994, Saitama University, Faculty of Engineering, Applied Chemistry, Japan
- Apr. 1987 - Mar. 1990, Meiwa High School, Japan
Committee Memberships
- Sep. 2024 - Present
一般社団法人 日本熱電学会, 理事, Society - Aug. 2024 - Present
公益社団法人日本セラミックス協会 東北・北海道支部, 常任委員, Society - Apr. 2021 - Present
JSTさきがけ [未来材料] 物質探索空間の拡大による未来材料の創製（陰山領域）, 領域アドバイザー, Others - Apr. 2022 - Mar. 2025
薄膜材料デバイス研究会, 組織委員 - Apr. 2008 - Aug. 2024
一般社団法人 日本熱電学会, 評議員, Society - Apr. 2017 - Jul. 2024
公益社団法人日本セラミックス協会 東北・北海道支部, 幹事, Society - Apr. 2004 - Mar. 2006
公益社団法人日本セラミックス協会, 学術論文誌編集委員, Society
■Research activity information
Awards
Papers
- Millimeter-Sized Epitaxial Ferroelectric BaTiO3 Freestanding Sheets Peeled from Al2O3 Substrates
Weikun Zhou, Diwen Chen, Ren Mitsuya, Hiromichi Ohta, Tsukasa Katayama
ACS Applied Electronic Materials, 7, 4552, 4556, 27 May 2025, [Peer-reviewed]
English, Scientific journal - Controlling Thermal Conductivity of Amorphous SiOx Films through Structural Engineering Utilizing Single Crystal Substrate Surfaces
Katelyn A. Kirchner, Sohei Ogasawara, Melbert Jeem, Hiromichi Ohta, Akihiro Suzuki, Hiroo Tajiri, Tomoyuki Koganezawa, Loku Singgappulige Rosantha Kumara, Junji Nishii, John C. Mauro, Yasutaka Matsuo, Madoka Ono
Nano Letters, 14 May 2025, [Peer-reviewed]
English, Scientific journal, 41337912 - Epitaxial Growth of Triple-Layered Brownmillerite Cobalt Oxide Sr4Co3O9
Hao-Bo Li, Shunsuke Kobayashi, Weitao Yan, Binjie Chen, Tong Zhu, Morito Namba, Yoshinori Kotani, Hiroshi Takatsu, Takahito Terashima, Kei Nakayama, Akihide Kuwabara, AzusaNakamoto Hattori, Wei-Hua Wang, Hiromichi Ohta, Hidekazu Tanaka, Hiroshi Kageyama
Inorganic Chemistry, 64, 6589, 6596, American Chemical Society (ACS), 24 Mar. 2025, [Peer-reviewed]
English, Scientific journal - Systematic investigation of charge transport and thermoelectric properties in semicrystalline polymers: electrochemical doping effects on doping level and temperature dependence using one sample
Shun-Ichiro Ito, Hisaaki Tanaka, Yugo Oshima, Kaito Kanahashi, Hiroshi Ito, Binjie Chen, Hiromichi Ohta, Taishi Takenobu
Applied Physics Express, 01 Feb. 2025, [Peer-reviewed]
English, Scientific journal - High-performance solid-state electrochemical thermal switches with earth-abundant cerium oxide
Ahrong Jeong, Mitsuki Yoshimura, Hyeonjun Kong, Zhiping Bian, Jason Tam, Bin Feng, Yuichi Ikuhara, Takashi Endo, Yasutaka Matsuo, Hiromichi Ohta
Science Advances, 11, eads6137, 01 Jan. 2025, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 41337912 - Water-soluble CaO sacrificial layer heteroepitaxially grown on yttria-stabilized zirconia substrate for large ferroelectric BaTiO3 sheets
Weikun Zhou, Lizhikun Gong, Ren Mitsuya, Diwen Chen, Hiromichi Ohta, Tsukasa Katayama
Journal of Materials Chemistry C, 19 Dec. 2024, [Peer-reviewed]
English, Scientific journal - Thermopower modulation analyses of effective channel thickness for Zn-incorporated In2O3-based thin-film transistors
Yuzhang Wu, Prashant R. Ghediya, Yuqiao Zhang, Yasutaka Matsuo, Hiromichi Ohta, Yusaku Magari
Japanese Journal of Applied Physics, 02 Dec. 2024, [Corresponding author]
English, Scientific journal - High-Mobility Indium Oxide Thin Film Transistors with High Reliability
Prashant Ghediya, Yusaku Magari, Hikaru Sadahira, Takashi Endo, Mamoru Furuta, Yuqiao Zhang, Yasutaka Matsuo, Hiromichi Ohta
ECS Meeting Abstracts, 22 Nov. 2024, [Invited], [Last author, Corresponding author]
English, Scientific journal - Ferroelectric BaTiO3 Freestanding Sheets for an Ultra-High-Speed Light-Driven Actuator
Lizhikun Gong, Atsushi Taguchi, Weikun Zhou, Ren Mitsuya, Hiromichi Ohta, Tsukasa Katayama
ACS Applied Materials & Interfaces, 09 Oct. 2024
English, Scientific journal - Unusual Crystal Orientation in Hexagonal HoFeO3 Multiferroic Films and the Effect on Magnetism
Binjie Chen, Jinghuang Lin, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta, Tsukasa Katayama
Crystal Growth & Design, 03 Oct. 2024
English, Scientific journal - Reliable Operation in High‐Mobility Indium Oxide Thin Film Transistors
Prashant R. Ghediya, Yusaku Magari, Hikaru Sadahira, Takashi Endo, Mamoru Furuta, Yuqiao Zhang, Yasutaka Matsuo, Hiromichi Ohta
Small Methods, Wiley, 03 Aug. 2024, [Last author, Corresponding author]
English, Scientific journal, Abstract
Transparent oxide semiconductors (TOSs) based thin‐film transistors (TFTs) that exhibit higher field effect mobility (µFE) are highly required toward the realization of next‐generation displays. Among numerous types of TOS‐TFTs, In2O3‐based TFTs are the front‐running candidate because they exhibit the highest µFE ≈100 cm2 V−1 s−1. However, the device operation of In2O3 TFTs is unreliable; a large voltage shift occurs especially when negative gate bias is applied due to adsorption/desorption of gas molecules. Although passivation of the TFTs is used to overcome such instability, previously proposed passivation materials do not improve the reliability. Here, it is shown that the In2O3 TFTs passivated with Y2O3 and Er2O3 films are highly reliable and do not show threshold voltage shifts when applying gate bias. Positive and negative gate bias is applied to the In2O3 TFTs passivated with various insulating oxides and found that only the In2O3 TFTs passivated with Y2O3 and Er2O3 films do not exhibit threshold voltage shifts. It is observed that only the Y2O3 grew heteroepitaxially on the In2O3 crystal. This is the origin of the high reliability of the In2O3 TFTs passivated with Y2O3 and Er2O3 films. This finding accelerates the development of next‐generation displays using high‐mobility In2O3 TFTs. - High-mobility and high-reliability Zn-incorporated amorphous In2O3-based thin-film transistors
Yuzhang Wu, Yusaku Magari, Prashant R. Ghediya, Yuqiao Zhang, Yasutaka Matsuo, Hiromichi Ohta
Japanese Journal of Applied Physics, 63, 7, 076504, 076504, IOP Publishing, 01 Jul. 2024, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Abstract
Polycrystalline indium oxide-based thin film transistors (In2O3 TFTs) have attracted considerable attention because of high field effect mobility (μ FE ∼ 100 cm2 V−1 s−1). However, In2O3 TFTs exhibit poor reliability owing to the adsorption and/or desorption of gas molecules at the grain boundaries. The incorporation of Zn suppresses the crystallization of In2O3. Herein, we systematically studied the effect of Zn incorporation into In2O3 TFTs. The crystallization of In2O3 was suppressed when the Zn concentration ranged from 25% to 68%. Amorphous InZnO (IZO) TFTs with 25% Zn exhibited the highest μ FE of 41 cm2 V−1 s−1 and excellent reliability. In contrast, polycrystalline IZO TFTs showed a low μ FE <12 cm2 V−1 s−1 due to the formation of grain boundaries, and poor reliability after positive gate bias, mostly due to electron trapping at the polycrystalline/insulator interface. These results render an approach to realize In2O3 TFTs that show reasonably high μ FE and excellent reliability. - Solid-State Electrochemical Thermal Switches with Large Thermal Conductivity Switching Widths
Zhiping Bian, Mitsuki Yoshimura, Ahrong Jeong, Haobo Li, Takashi Endo, Yasutaka Matsuo, Yusaku Magari, Hidekazu Tanaka, Hiromichi Ohta
Advanced Science, 2401331, Wiley, 25 Jun. 2024, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Abstract
Thermal switches that switch the thermal conductivity (κ) of the active layers are attracting increasing attention as thermal management devices. For electrochemical thermal switches, several transition metal oxides (TMOs) are proposed as active layers. After electrochemical redox treatment, the crystal structure of the TMO is modulated, which results in the κ switching. However, the κ switching width is still small (<4 W m−1 K−1). In this study, it demonstrates that LaNiOx‐based solid‐state electrochemical thermal switches have a κ switching width of 4.3 W m−1 K−1. Fully oxidized LaNiO3 (on state) has a κ of 6.0 W m−1 K−1 due to the large contribution of electron thermal conductivity (κele, 3.1 W m−1 K−1). In contrast, reduced LaNiO2.72 (off state) has a κ of 1.7 W m−1 K−1 because the phonons are scattered by the oxygen vacancies. The LaNiOx‐based electrochemical thermal switch is cyclable of κ and the crystalline lattice of LaNiOx. This electrochemical thermal switch may be a promising platform for next‐generation devices such as thermal displays., 41337912 - Wide-range thermal conductivity modulation based on protonated nickelate perovskite oxides
Hao-Bo Li, Zhiping Bian, Mitsuki Yoshimura, Kohei Shimoyama, Chengchao Zhong, Keiji Shimoda, Azusa N. Hattori, Kunihiko Yamauchi, Ikutaro Hamada, Hiromichi Ohta, Hidekazu Tanaka
Applied Physics Letters, 124, 191901, 06 May 2024, [Peer-reviewed], [Corresponding author]
English, Scientific journal, 41337912 - High-concentration doping effects of aliovalent Al and Ga on ferroelectric properties of BaTiO3 Films
Ko Marunouchi, Lizhikun Gong, Hiromichi Ohta, Tsukasa Katayama
Thin Solid Films, 796, 140339, 140339, Elsevier BV, May 2024, [Peer-reviewed]
English, Scientific journal - Large tensile-strained BaTiO3 films grown on lattice-mismatched La-doped BaSnO3 bottom electrode
Lizhikun Gong, Ko Marunouchi, Akira Chikamatsu, Hiromichi Ohta, Tsukasa Katayama
CrystEngComm, Royal Society of Chemistry (RSC), 24 Apr. 2024, [Peer-reviewed]
English, Scientific journal, Perovskite BaTiO3 has been widely studied and utilized in various applications owing to its high permittivity, ferroelectricity, non-toxicity, and stability. However, its low ferroelectric-paraelectric phase transition temperature (TC, 120 °C)... - Magnetic Phase Transition-Induced Modulation of Ferroelectric Properties in Hexagonal RFeO3 (R = Tb and Ho)
Yaoming Liu, Binjie Chen, Yosuke Hamasaki, Lizhikun Gong, Hiromichi Ohta, Tsukasa Katayama
ACS Applied Materials & Interfaces, 16, 14, 17832, 17837, American Chemical Society (ACS), 01 Apr. 2024, [Peer-reviewed]
English, Scientific journal, 44581815 - Pure Fluorine Intercalation into Brownmillerite Oxide Thin Films by Using Ionic Liquid Gating
Morito Namba, Hiroshi Takatsu, Hao-Bo Li, Kantaro Murayama, Ryo Terada, Qian Yang, Takahito Terashima, Hiromichi Ohta, Hiroshi Kageyama
Chemistry of Materials, 36, 4, 2076, 2084, American Chemical Society (ACS), 07 Feb. 2024, [Peer-reviewed]
English, Scientific journal - Fabrication and Thermoelectric Properties of Freestanding Ba1/3CoO2 Single-Crystalline Films
Kungwan Kang, Fumiaki Kato, Akitoshi Nakano, Ichiro Terasaki, Takashi Endo, Yasutaka Matsuo, Hyoungjeen Jeen, Hiromichi Ohta
ACS Applied Electronic Materials, 5, 5749, 5754, American Chemical Society (ACS), 16 Oct. 2023, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 44581815 - High-mobility rutile SnO2 epitaxial films grown on (1−100) α-Al2O3
Binjie Chen, Jinghuang Lin, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta
Journal of the Ceramic Society of Japan, 131, 10, 640, 644, Ceramic Society of Japan, 01 Oct. 2023, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 44581815 - Ferroelectricity, High Permittivity, and Tunability in Millimeter-Size Crack-Free Ba1–xSrxTiO3 Flexible Epitaxial Sheets
Rui Yu, Lizhikun Gong, Hiromichi Ohta, Tsukasa Katayama
ACS Applied Electronic Materials, 5, 5234, 5239, 26 Sep. 2023, [Peer-reviewed]
English, Scientific journal, 44581815 - Significant Reduction in the Switching Time of Solid-State Electrochemical Thermal Transistors
Mitsuki Yoshimura, Qian Yang, Zhiping Bian, Hiromichi Ohta
ACS Applied Electronic Materials, 5, 8, 4233, 4239, 24 Jul. 2023, [Last author, Corresponding author]
English, Scientific journal, 41337912 - Solid-State Electrochemical Thermal Transistors with Strontium Cobaltite–Strontium Ferrite Solid Solutions as the Active Layers
Zhiping Bian, Qian Yang, Mitsuki Yoshimura, Hai Jun Cho, Joonhyuk Lee, Hyoungjeen Jeen, Takashi Endo, Yasutaka Matsuo, Hiromichi Ohta
ACS Applied Materials & Interfaces, 15, 19, 23512, 23517, American Chemical Society (ACS), 03 May 2023, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 41337912 - Synthesis and transparent conductivity of crack-free La:BaSnO3 epitaxial flexible sheets
Lizhikun Gong, Rui Yu, Hiromichi Ohta, Tsukasa Katayama
Dalton Transactions, Royal Society of Chemistry (RSC), 17 Apr. 2023, [Peer-reviewed]
English, Scientific journal, La-doped BaSnO3 (LBSO), which exhibits both high electron mobility and visible-light transparency, is a promising transparent electrode/transistor material that does not require expensive elements such as indium., 24741427 - Suppression of Strain Relaxation in VO2/TiO2 Multilayered Films
Binjie Chen, Chuchu Yang, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta
ACS Applied Electronic Materials, 5, 4, 2433, 2438, American Chemical Society (ACS), 04 Apr. 2023, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Direct Imaging of Ion Migration in Amorphous Oxide Electronic Synapses with Intrinsic Analog Switching Characteristics
Atsushi Tsurumaki-Fukuchi, Takayoshi Katase, Hiromichi Ohta, Masashi Arita, Yasuo Takahashi
ACS Applied Materials & Interfaces, 15, 13, 16842, 16852, American Chemical Society (ACS), 23 Mar. 2023, [Peer-reviewed]
English, Scientific journal, 24741427 - Solid‐State Electrochemical Thermal Transistors
Qian Yang, Hai Jun Cho, Zhiping Bian, Mitsuki Yoshimura, Joonhyuk Lee, Hyoungjeen Jeen, Jinghuang Lin, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta
Advanced Functional Materials, 33, 19, 2214939, Wiley, 21 Feb. 2023, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 41337912 - Contamination of rare earth oxide surfaces stored in vacuum environment
Jason Tam, Peter M. Brodersen, Hiromichi Ohta, Uwe Erb
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 659, 130829, 130829, Elsevier BV, Feb. 2023, [Peer-reviewed]
English, Scientific journal, 24741427 - Improved Electron Transport Properties of Zn-Rich In-Ga-Zn-O Thin-Film Transistors
Hiromichi Ohta
The Journal of Physical Chemistry C, 25 Jan. 2023, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Efficient electrocatalytic H2O2 evolution utilizing electron-conducting molecular wires spatially separated by rotaxane encapsulation
Sheng-Ying Chou, Hiroshi Masai, Masaya Otani, Hiromichi V. Miyagishi, Gentaro Sakamoto, Yusuke Yamada, Yusuke Kinoshita, Hitoshi Tamiaki, Takayoshi Katase, Hiromichi Ohta, Tomoki Kondo, Akinobu Nakada, Ryu Abe, Takahisa Tanaka, Ken Uchida, Jun Terao
Applied Catalysis B: Environmental, 327, 122373, Elsevier BV, Jan. 2023, [Peer-reviewed]
English, Scientific journal - Significant Suppression of Cracks in Freestanding Perovskite Oxide Flexible Sheets Using a Capping Oxide Layer
Hiromichi Ohta
ACS Nano, 16, 21013, 21019, 27 Dec. 2022, [Peer-reviewed]
English, Scientific journal, 24741427 - Orthorhombic distortion-induced anatase-like optoelectronic properties of rutile TiO2
Hiromichi Ohta
Journal of Applied Physics, 132, 18, 185301, 185301, 14 Nov. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - 1D Atomic Defect Tunnel Structure of Oxygen‐Deficient Tungsten Oxide Epitaxial Films and Its Redox Device Applications
Gowoon Kim, Hiromichi Ohta
physica status solidi (a), 219, 21, 2200058, 2200058, Wiley, Nov. 2022, [Peer-reviewed], [Invited], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Thermopower Modulation Analyses of High-Mobility Transparent Amorphous Oxide Semiconductor Thin-Film Transistors
Hui Yang, Yuqiao Zhang, Yasutaka Matsuo, Yusaku Magari, Hiromichi Ohta
ACS Applied Electronic Materials, 4, 10, 5081, 5086, American Chemical Society (ACS), 25 Oct. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Modulation of electrical and thermal transports through lattice distortion in BaTi1–x Nb x O3 solid solutions
Yuqiao Zhang, Hai Jun Cho, Feng Jiang, Chengliang Xia, Yue Chen, Weishu Liu, Hiromichi Ohta
Nanotechnology, 33, 40, 405702, 405702, IOP Publishing, 01 Oct. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Abstract
The electron and heat transports in solids are through the movement of carrier electrons and quantized lattice vibrations (phonons), which are sensitive to the lattice distortion and ionized impurities, and are essential aspects for the development of novel thermoelectric materials. In this study, we systematically investigated the modulations of electrical and thermal conductivities of BaTi1–xNbxO3 solid solution (BTNO, 0 ≤ x ≤ 1) epitaxial films. At room temperature, BaTiO3 belongs to tetragonal perovskite and exhibits electron conduction through doubly degenerated Ti 3d-t2g orbitals upon doping, while BaNbO3 belongs to cubic perovskite and exhibits metallic electron conduction through partially filled triply degenerate Nb 4d-t2g orbitals. By controlling the Ti/Nb ratio, we found a dual modulation effect on both the lattice structures and conduction band, which affects the electrical and thermal conductivities. Similar to the SrTi1–xNbxO3 solid solution (STNO, 0 ≤ x ≤ 1) system, a phase transition was detected at x ∼ 0.5, at which both the electron and heat transports exhibit abrupt changes. Unlike the transition in STNO, which was attributed to a polaronic phase transition, the transition in BTNO was due to contributions from both the lattice distortion and polaron effect. By controlling the lattice distortion, conduction band, and polaronic phase transitions, the electrical and thermal conductivity of BTNO epitaxial films are modulated within a much greater range than those of the STNO epitaxial films. Due to the double contribution of electron carriers and phonon to thermal conductivity (κ), the maximum κ modulation ratio of BTNO epitaxial films was ∼6.9. Our research provides an effective route to design electrical/thermal management materials., 24741427 - Ferroelectric and Magnetic Properties of Hexagonal ErFeO3 Epitaxial Films
Binjie Chen, Hiromichi Ohta, Tsukasa Katayama
ACS Applied Electronic Materials, 4, 4547, 4552, American Chemical Society (ACS), 23 Aug. 2022, [Peer-reviewed]
English, Scientific journal, 24741427 - Ceramic science of crystal defect cores
Katsuyuki Matsunaga, Masato Yoshiya, Naoya Shibata, Hiromichi Ohta, Teruyasu Mizoguchi
Journal of the Ceramic Society of Japan, 130, 8, 648, 667, Ceramic Society of Japan, 01 Aug. 2022, [Peer-reviewed]
English, Scientific journal, 24741427 - Ba1/3CoO2: A Thermoelectric Oxide Showing a Reliable ZT of ∼0.55 at 600 °C in Air
Xi Zhang, Yuqiao Zhang, Liao Wu, Akihiro Tsuruta, Masashi Mikami, Hai Jun Cho, Hiromichi Ohta
ACS Applied Materials & Interfaces, 14, 29, 33355, 33360, 27 Jul. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Thin film growth and thermoelectric properties of electron conducting oxides
Hiromichi Ohta
Journal of the Ceramic Society of Japan, 130, 7, 471, 476, Ceramic Society of Japan, 01 Jul. 2022, [Peer-reviewed], [Invited], [Lead author, Last author, Corresponding author]
English, Scientific journal, 24741427 - Observation of topological Hall torque exerted on a domain wall in the ferromagnetic oxide SrRuO 3
Michihiko Yamanouchi, Yasufumi Araki, Takaki Sakai, Tetsuya Uemura, Hiromichi Ohta, Jun’ichi Ieda
Science Advances, 8, 15, American Association for the Advancement of Science (AAAS), 15 Apr. 2022
Scientific journal, In a ferromagnetic Weyl metal SrRuO 3 , a large effective magnetic field Heff exerted on a magnetic domain wall (DW) by current has been reported. We show that the ratio of Heff to current density exhibits nonmonotonic temperature dependence and surpasses those of conventional spin-transfer torques and spin-orbit torques. This enhancement is described well by topological Hall torque (THT), which is exerted on a DW by Weyl electrons emerging around Weyl points when an electric field is applied across the DW. The ratio of the Heff arising from the THT to current density is over one order of magnitude higher than that originating from spin-transfer torques and spin-orbit torques reported in metallic systems, showing that the THT may provide a better way for energy-efficient manipulation of magnetization in spintronics devices. - Optoelectronic properties of transparent oxide semiconductor ASnO3 (A = Ba, Sr, and Ca) epitaxial films and thin film transistors
Anup V. Sanchela, Mian Wei, Hai Jun Cho, Hiromichi Ohta
Journal of Vacuum Science & Technology A, 40, 2, 020803, 020803, American Vacuum Society, Mar. 2022, [Peer-reviewed], [Invited], [Last author, Corresponding author]
English, 24741427 - Effect of annealing on grain growth and Y segregation behavior in tetragonal ZrO 2 thin film
Hiroaki Nakade, Eita Tochigi, Bin Feng, Ryo Ishikawa, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara
Journal of the American Ceramic Society, 105, 3, 2300, 2308, Wiley, Mar. 2022
Scientific journal - Transport properties of LaInO3/BaSnO3 interface analyzed by Poisson-Schrödinger equation
Youjung Kim, Seonghyeon Kim, Hyeongmin Cho, Young Mo Kim, Hiromichi Ohta, Kookrin Char
Physical Review Applied, 17, 1, American Physical Society (APS), 25 Jan. 2022, [Peer-reviewed]
English, Scientific journal - Specular Acoustic Vibrational Wave Transmissions with the Presence of Phononic Bandgaps
Hai Jun Cho, Yuzhang Wu, Jiajun Qi, Yuna Kim, Hiromichi Ohta, Osamu Matsuda
Journal of the Physical Society of Japan, 91, 1, Physical Society of Japan, 15 Jan. 2022
Scientific journal - Antiferroelectric-to-ferroelectric phase transition in hexagonal rare-earth iron oxides
Binjie Chen, Tetsuya Hasegawa, Hiromichi Ohta, Tsukasa Katayama
Journal of Materials Chemistry C, 10, 14, 5621, 5626, Royal Society of Chemistry ({RSC}), 2022
Scientific journal - Breaking of Thermopower-Conductivity Trade-Off in LaTiO3 Film around Mott Insulator to Metal Transition
Takayoshi Katase, Xinyi He, Terumasa Tadano, Jan M. Tomczak, Takaki Onozato, Keisuke Ide, Bin Feng, Tetsuya Tohei, Hidenori Hiramatsu, Hiromichi Ohta, Yuichi Ikuhara, Hideo Hosono, Toshio Kamiya
ADVANCED SCIENCE, 8, 23, Dec. 2021
English, Scientific journal - Solid-State Electrochemical Switch of Superconductor-Metal-Insulators
Xi Zhang, Gowoon Kim, Qian Yang, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta
ACS Applied Materials and Interfaces, 13, 45, 54204, 54209, American Chemical Society, 17 Nov. 2021
English, Scientific journal - Unveiling the electronic structure of grain boundaries in anatase with electron microscopy and first-principles modeling
James A. Quirk, Bin Miao, Bin Feng, Gowoon Kim, Hiromichi Ohta, Yuichi Ikuhara, Keith P. McKenna
Nano Letters, 21, 21, 9217, 9223, American Chemical Society, 10 Nov. 2021
English, Scientific journal - Structure and thermoelectric properties of electrochemically doped polythiophene thin films: Effect of side chain density
Shun-ichiro Ito, Kaito Kanahashi, Hiromichi Ohta, Hiroshi Ito, Taishi Takenobu, Hisaaki Tanaka
APPLIED PHYSICS LETTERS, 119, 18, Nov. 2021
English, Scientific journal - (Invited) Nanoscale Probing of Field-Driven Ion Migration in TaOx for Neuromorphic Memristor Applications
Atsushi Tsurumaki-Fukuchi, Takayoshi Katase, Hiromichi Ohta, Masashi Arita, Yasuo Takahashi
ECS Transactions, 104, 4, 93, 101, The Electrochemical Society, 01 Oct. 2021
Scientific journal - Overlayer deposition-induced control of oxide ion concentration in SrFe0.5Co0.5O2.5 oxygen sponges
Joonhyuk Lee, Younghak Kim, Jinhyung Cho, Hiromichi Ohta, Hyoungjeen Jeen
RSC Advances, 11, 51, 32210, 32215, Royal Society of Chemistry (RSC), 29 Sep. 2021, [Peer-reviewed], [Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, We form flat oxide-interfaces,i.e. manganite- and titanate-oxygen sponges, and observe peculiar oxygen transport behaviors relying on chemical potential difference at the interfaces. Oxygen transport into oxygen-sponge leads weak ferromagnetism. - Reversible Redox Control of Optoelectronic Properties of Hexagonal Tungsten Oxide Epitaxial Films Grown on YSZ Solid Electrolyte
Gowoon Kim, Hai Jun Cho, Hiromichi Ohta
ACS Applied Electronic Materials, 3, 8, 3619, 3624, American Chemical Society (ACS), 06 Aug. 2021, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Atomistic Origin of Li-Ion Conductivity Reduction at (Li3xLa2/3–x)TiO3 Grain Boundary
Shun Sasano, Ryo Ishikawa, Gabriel Sánchez-Santolino, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara
Nano Letters, 21, 14, 6282, 6288, 19 Jul. 2021, [Peer-reviewed]
English, Scientific journal, 24741427 - Solid-State Electrochemical Protonation of SrCoO2.5 into HxSrCoO2.5 (x = 1, 1.5, and 2)
Qian Yang, Joonhyuk Lee, Hyoungjeen Jeen, Hai Jun Cho, Hiromichi Ohta
ACS Applied Electronic Materials, 3, 7, 3296, 3300, American Chemical Society (ACS), 14 Jul. 2021, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741427 - Single-Dislocation Schottky Diodes
Ang Tao, Tingting Yao, Yixiao Jiang, Lixin Yang, Xuexi Yan, Hiromichi Ohta, Yuichi Ikuhara, Chunlin Chen, Hengqiang Ye, Xiuliang Ma
Nano Letters, 21, 13, 5586, 5592, American Chemical Society (ACS), 14 Jul. 2021, [Peer-reviewed], ［Internationally co-authored］
English, Scientific journal - Pressure-tunable thermal conductivity observed for bisamide functionalized diacetylene crystals
Jiajun Qi, Yuzhang Wu, Hai Jun Cho, Yuna Kim, Hiromichi Ohta, Nobuyuki Tamaoki
Journal of Materials Science, 56, 27, 15481, 15490, 22 Jun. 2021, [Peer-reviewed]
English, Scientific journal - Solid-state electrochemical redox control of the optoelectronic properties for SrFeOx thin films
Qian Yang, Hai Jun Cho, Hyoungjeen Jeen, Hiromichi Ohta
Journal of Applied Physics, 129, 21, 215303, 215303, AIP Publishing, 02 Jun. 2021, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741427 - Thermal Diffusivity of the Mott Insulator Ca2RuO4 in a Non-equilibrium Steady State
Shuji Kawasaki, Akitoshi Nakano, Hiroki Taniguchi, Hai Jun Cho, Hiromichi Ohta, Fumihiko Nakamura, Ichiro Terasaki
Journal of the Physical Society of Japan, 90, 6, 063601, 063601, 19 May 2021, [Peer-reviewed]
English, Scientific journal, 24741427 - Low thermal conductivity of SrTiO3−LaTiO3 and SrTiO3−SrNbO3 thermoelectric oxide solid solutions
Yuqiao Zhang, Hai Jun Cho, Kenyu Sugo, Masashi Mikami, Sungmin Woo, Myung‐Chul Jung, Yao‐Hua Zhuang, Bin Feng, Yu‐Miin Sheu, Woosuck Shin, Woo Seok Choi, Myung Joon Han, Yuichi Ikuhara, Hiromichi Ohta
Journal of the American Ceramic Society, 104, 8, 4075, 4085, 26 Mar. 2021, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Insulator-to-metal transition and Ru3+ state in Ru-substituted Cr2O3 thin films
Fujiwara Kohei, Kitamura Miho, Shiga Daisuke, Niwa Yasuhiro, Horiba Koji, Nojima Tsutomu, Ohta Hiromichi, Kumigashira Hiroshi, Tsukazaki Atsushi
JSAP Annual Meetings Extended Abstracts, 2021.1, 1272, 1272, The Japan Society of Applied Physics, 26 Feb. 2021
Japanese - Anomalously Low Heat Conduction in Single‐Crystal Superlattice Ceramics Lower Than Randomly Oriented Polycrystals
Hai Jun Cho, Yuzhang Wu, Yu‐Qiao Zhang, Bin Feng, Masashi Mikami, Woosuck Shin, Yuichi Ikuhara, Yu‐Miin Sheu, Keiji Saito, Hiromichi Ohta
Advanced Materials Interfaces, 8, 7, 2001932, 2001932, 15 Feb. 2021, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Anisotropic Electrical Conductivity of Oxygen-Deficient Tungsten Oxide Films with Epitaxially Stabilized 1D Atomic Defect Tunnels
Gowoon Kim, Bin Feng, Sangkyun Ryu, Hai Jun Cho, Hyoungjeen Jeen, Yuichi Ikuhara, Hiromichi Ohta
ACS Applied Materials & Interfaces, 13, 5, 6864, 6869, American Chemical Society (ACS), 10 Feb. 2021, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Hot-carrier Separation Induced by the Electric Field of a p-n Junction between Titanium Dioxide and Nickel Oxide
Keisuke Nakamura, Tomoya Oshikiri, Kosei Ueno, Hiromichi Ohta, Hiroaki Misawa
Chemistry Letters, 50, 2, 374, 377, The Chemical Society of Japan, 05 Feb. 2021, [Peer-reviewed]
English, Scientific journal - Room Temperature Insulator-to-Metal Transition of VO2/TiO2 Epitaxial Bilayer Films Grown on M-plane Sapphire Substrates
Binjie Chen, Gowoon Kim, Hai Jun Cho, Hiromichi Ohta
Advanced Electronic Materials, John Wiley and Sons Inc, 2021
English, Scientific journal - Optimization of Two-Dimensional Channel Thickness in Nanometer-Thick SnO2-Based Top-Gated Thin-Film Transistors Using Electric Field Thermopower Modulation: Implications for Flat-Panel Displays
Doudou Liang, Bin-jie Chen, Bin Feng, Yuichi Ikuhara, Hai Jun Cho, Hiromichi Ohta
ACS Applied Nano Materials, 3, 12, 12427, 12432, American Chemical Society (ACS), 24 Dec. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Tuning of the Optoelectronic Properties for Transparent Oxide Semiconductor ASnO3 by Modulating the Size of A-Ions
Mian Wei, Hai Jun Cho, Hiromichi Ohta
ACS Applied Electronic Materials, 2, 12, 3971, 3976, American Chemical Society (ACS), 22 Dec. 2020, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, 24741427 - Substrate-Independent Energy-Level Pinning of an Organic Semiconductor Providing Versatile Hole-Injection Electrodes
Tianshu Zhai, Rongbin Wang, Takayoshi Katase, Frances Quigley, Hiromichi Ohta, Patrick Amsalem, Norbert Koch, Steffen Duhm
ACS Applied Electronic Materials, 2, 12, 3994, 4001, American Chemical Society (ACS), 22 Dec. 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Charge and thermoelectric transport mechanism in donor-acceptor copolymer films
Kaito Kanahashi, Yong-Young Noh, Won-Tae Park, Hoichang Yang, Hiromichi Ohta, Hisaaki Tanaka, Taishi Takenobu
Physical Review Research, 2, 4, 043330, 07 Dec. 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - High Electron and Low Heat Transports of 1D Atomic Defect Tunnels Stabilized in Tungsten Oxide Epitaxial Films
Gowoon Kim, Bin Feng, Yu-Miin Sheu, Hai Jun Cho, Yuichi Ikuhara, Hiromichi Ohta
ECS Meeting Abstracts, 23 Nov. 2020
Scientific journal - Electrochemical Manipulation of the Electron Transports of SrCoO x Epitaxial Films
Qian Yang, Hai Jun Cho, Hyoungjeen Jeen, Hiromichi Ohta
ECS Meeting Abstracts, 23 Nov. 2020
Scientific journal - Fabrication and characterization of tetragonal yttria‐stabilized zirconia single‐crystalline thin film
Hiroaki Nakade, Eita Tochigi, Bin Feng, Yukio Nezu, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara
Journal of the American Ceramic Society, Wiley, 05 Nov. 2020, [Peer-reviewed]
English, Scientific journal, 24741424 - Thickness Optimization toward High-Performance Bottom-Gated Transparent Tin Dioxide Thin-Film Transistors
Dou-Dou Liang, Binjie Chen, Hai Jun Cho, Hiromichi Ohta
ACS Applied Electronic Materials, 2, 10, 3454, 3458, American Chemical Society (ACS), 27 Oct. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Layered cobalt oxide epitaxial films exhibiting thermoelectric ZT = 0.11 at room temperature
Yugo Takashima, Yu-qiao Zhang, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hai Jun Cho, Hiromichi Ohta
Journal of Materials Chemistry A, 9, 1, 274, 280, Royal Society of Chemistry (RSC), Oct. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal,A high
, 24741424ZT of 0.11 at room temperature was realized in layered cobalt oxide by substitution of heavy atomic mass Ba. - Non-equilibrium Steady State in the Mott Insulator Ca2RuO4
Ichiro Terasaki, Isuzu Sano, Kosuke Toda, Shuji Kawasaki, Akitoshi Nakano, Hiroki Taniguchi, Hai Jun Cho, Hiromichi Ohta, Fumihiko Nakamura
Journal of the Physical Society of Japan, 89, 9, 093707, 093707, 15 Sep. 2020, [Peer-reviewed]
English, Scientific journal, 24741427 - Spontaneous Generation of Carrier Electrons at the Interface between Polycrystalline ZnO and Amorphous InGaZnO4
Fabian Krahl, Yuzhang Wu, Hai Jun Cho, Maarit Karppinen, Hiromichi Ohta
Advanced Electronic Materials, 6, 2000404, 2000404, Wiley, 11 Sep. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Fabrication and Characterization of Ba1/3CoO2Epitaxial Films Exhibiting Thermoelectric ZT = 0.12 at Room Temperature
Yugo Takashima, Yu-Qiao Zhang, Jiake Wei, Bin Feng, Yuichi Ikuhara, Hai Jun Cho, Hiromichi Ohta
Proceedings of AM-FPD 2020 - 27th International Workshop on Active-Matrix Flatpanel Displays and Devices: TFT Technologies and FPD Materials, 123, 126, Institute of Electrical and Electronics Engineers Inc., 01 Sep. 2020
English, International conference proceedings - Coexistence of High Electron Conduction and Low Heat Conduction in Tungsten Oxide Epitaxial Films with 1D Atomic Defect Tunnels
Gowoon Kim, Bin Feng, Yu-Miin Sheu, Hai Jun Cho, Yuichi Ikuhara, Hiromichi Ohta
ACS Applied Electronic Materials, 2, 8, 2507, 2513, American Chemical Society (ACS), 25 Aug. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Unusually Large Thermopower Change from +330 to −185 μV K–1 of Brownmillerite SrCoO2.5
Qian Yang, Joonhyuk Lee, Bin Feng, Yuichi Ikuhara, Gowoon Kim, Hai Jun Cho, Hyoungjeen Jeen, Hiromichi Ohta
ACS Applied Electronic Materials, 2, 7, 2250, 2256, American Chemical Society (ACS), 28 Jul. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Fabrication and Operating Mechanism of Deep‐UV Transparent Semiconducting SrSnO3‐Based Thin Film Transistor
Mian Wei, Lizhikun Gong, Dou‐dou Liang, Hai Jun Cho, Hiromichi Ohta
Advanced Electronic Materials, 6, 7, 2000100, 2000100, Wiley, Jul. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Insulator-to-Metal Transition of Cr2O3 Thin Films via Isovalent Ru3+ Substitution
Kohei Fujiwara, Miho Kitamura, Daisuke Shiga, Yasuhiro Niwa, Koji Horiba, Tsutomu Nojima, Hiromichi Ohta, Hiroshi Kumigashira, Atsushi Tsukazaki
Chemistry of Materials, 32, 12, 5272, 5279, American Chemical Society (ACS), 23 Jun. 2020, [Peer-reviewed]
English, Scientific journal, 24741427 - Oligothiophene-based Phosphonates for Interfacial Engineering of Ultraflat Transparent Conductive Oxides
M. Timpel, M. V. Nardi, B. Wegner, G. Ligorio, L. Pasquali, M. Pätzel, S. Hecht, H. Ohta, N. Koch
Adv. Mater. Interfaces, 1902114, 04 May 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Electric field thermopower modulation analyses of the operation mechanism of transparent amorphous SnO2 thin-film transistor
Dou-dou Liang, Yu-qiao Zhang, Hai Jun Cho, Hiromichi Ohta
Appl. Phys. Lett., 116, 143503, 08 Apr. 2020, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal, 24741424 - Effect of lattice distortions on the electron and thermal transport properties of transparent oxide semiconductor Ba1-xSrxSnO3 solid solution films
Hai Jun Cho, Koichi Sato, Mian Wei, Gowoon Kim, Hiromichi Ohta
J. Appl. Phys., 127, 115701, Mar. 2020, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Erratum: Thermoelectric phase diagram of the SrTiO3-LaTiO3 solid-solution system through a metal to Mott insulator transition (Journal of Applied Physics (2019) 126 (075104) DOI: 10.1063/1.5100993)
Yuqiao Zhang, Kenyu Sugo, Hai Jun Cho, Hiromichi Ohta
Journal of Applied Physics, 127, 8, American Institute of Physics Inc., 24 Feb. 2020
English, Scientific journal - Thermoelectric properties of a semicrystalline polymer doped beyond the insulator-to-metal transition by electrolyte gating
Hisaaki Tanaka, Kaito Kanahashi, Naoya Takekoshi, Hiroaki Mada, Hiroshi Ito, Yukihiro Shimoi, Hiromichi Ohta, Taishi Takenobu
Science Adv., 6, 7, eaay8065, 14 Feb. 2020, [Peer-reviewed]
English, Scientific journal - Arbitrary control of the diffusion potential between a plasmonic metal and a semiconductor by an angstrom-thick interface dipole layer
Tomoya Oshikiri, Hiroki Sawayanagi, Keisuke Nakamura, Kosei Ueno, Takayoshi Katase, Hiromichi Ohta, Hiroaki Misawa
J. Chem. Phys., 152, 934705, 17 Jan. 2020, [Peer-reviewed]
English, Scientific journal - An oxide-based flexible electrochromic transistor under mechanical stress
Takaki Onozato, Hai Jun Cho, Hiromichi Ohta
Japanese Journal of Applied Physics, 59, 024002, 16 Jan. 2020, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Current-induced effective magnetic field in La0.67Sr0.33MnO3/LaAlO3/SrTiO3 structures
Michihiko Yamanouchi, Tatsuro Oyamada, Hiromichi Ohta
AIP Advances, 10, 015129, 14 Jan. 2020, [Peer-reviewed], [Last author]
English, Scientific journal - High electrical conducting deep-ultraviolet-transparent oxide semiconductor La-doped SrSnO3 exceeding ∼3000 S cm−1
Mian Wei, Anup V. Sanchela, Bin Feng, Yuichi Ikuhara, Hai Jun Cho, Hiromichi Ohta
Applied Physics Letters, 116, 022103, 13 Jan. 2020, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Phase Instability amid Dimensional Crossover in Artificial Oxide Crystal
Seung Gyo Jeong, Taewon Min, Sungmin Woo, Jiwoong Kim, Yu-Qiao Zhang, Seong Won Cho, Jaeseok Son, Young-Min Kim, Jung Hoon Han, Sungkyun Park, Hu Young Jeong, Hiromichi Ohta, Suyoun Lee, Tae Won Noh, Jaekwang Lee, Woo Seok Choi
Phys. Rev. Lett., 124, 026401, 13 Jan. 2020, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Anisotropic Heat Conduction in Ion‐Substituted Layered Cobalt Oxides
Hai Jun Cho, Yugo Takashima, Yukio Nezu, Takaki Onozato, Hiromichi Ohta
Advanced Materials Interfaces, 7, 1901816, 01 Jan. 2020, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Ferroelectric oxide thin film with an out-of-plane electrical conductivity
Tingting Yao, Yixiao Jiang, Chunlin Chen, Xuexi Yan, Ang Tao, Lixin Yang, Chuihong Li, Kenyu Sugo, Hiromichi Ohta, Hengqiang Ye, Yuichi Ikuhara, Xiuliang Ma
Nano Lett., 26 Dec. 2019, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Macroscopic Visualization of Fast Electrochemical Reaction of SrCoOx Oxygen Sponge
Qian Yang, Hai Jun Cho, Hyoungjeen Jeen, Hiromichi Ohta
Advanced Materials Interfaces, 6, 1901260, 1901260, Wiley, 22 Dec. 2019, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Surface charge accumulation and electrochemical protonation of transition metal oxides using water-infiltrated nanoporous glass
Takayoshi Katase, Hiromichi Ohta
Semiconductor Science and Technology, 34, 123001, 15 Nov. 2019, [Peer-reviewed], [Invited], [Last author, Corresponding author]
English, Scientific journal - Giant power factors in p- and n-type large-area graphene films on a flexible plastic substrate
Kaito Kanahashi, Masatou Ishihara, Masataka Hasegawa, Hiromichi Ohta, Taishi Takenobu
npj 2D Mater. Appl., 3, 44, 08 Nov. 2019, [Peer-reviewed]
English, Scientific journal - Investigation of electrical and thermal transport property reductions in La-doped BaSnO3 films
Hai Jun Cho, Bin Feng, Takaki Onozato, Mian Wei, Anup V. Sanchela, Yuichi Ikuhara, Hiromichi Ohta
Physical Review Materials, 3, 9, 03 Sep. 2019
Scientific journal - High electron and thermal transport properties of La-doped BaSnO3 films fabricated under ozone atmosphere
Hai Jun Cho, Bin Feng, Takaki Onozato, Mian Wei, Anup Sanchela, Yuichi Ikuhara, Hiromichi Ohta
Phys. Rev. Materials, 3, 094601, Sep. 2019, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Thermoelectric phase diagram of the SrTiO3-LaTiO3 solid-solution system through a metal to Mott insulator transition
Yuqiao Zhang, Kenyu Sugo, Hai Jun Cho, Hiromichi Ohta
Journal of Applied Physics, 126, 075104, 21 Aug. 2019, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Electrical, optical and thermal transport properties of oxygen deficient amorphous WOx (2.5 < x < 3) films
Gowoon Kim, Hai Jun Cho, Yu-Miin Sheu, Hiromichi Ohta
The Journal of Physical Chemistry C, 123, 15419, May 2019, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Oxide-based optical, electrical and magnetic properties switching devices with water-incorporated gate insulator
Takayoshi Katase, Hiromichi Ohta
Japanese Journal of Applied Physics, 58, 090501, 11 Apr. 2019, [Peer-reviewed], [Invited], [Last author, Corresponding author]
English, Scientific journal - Room-temperature ferroelectric ferromagnet in 1D tetrahedral chain network
Kyeong Tae Kang, Chang Jae Roh, Jinyoung Lim, Taewon Min, Jun Han Lee, Kyoungjun Lee, Tae Yoon Lee, Seunghun Kang, Daehee Seol, Jiwoong Kim, Hiromichi Ohta, Amit Khare, Sungkyun Park, Yunseok Kim, Seung Chul Chae, Yoon Seok Oh, Jaekwang Lee, Jaejun Yu, Jong Seok Lee, Woo Seok Choi
Adv. Mater., 31, 1808104, Apr. 2019, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Thermal conductivity tensor of NbO2
Hai Jun Cho, Gowoon Kim, Takaki Onozato, Hyoungjeen Jeen, Hiromichi Ohta
International Journal of Heat and Mass Transfer, 137, 263, Mar. 2019, [Peer-reviewed], [Last author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Peculiar magnetotransport properties in La0.67Sr0.33MnO3/LaAlO3/SrTiO3
Michihiko Yamanouchi, Tatsuro Oyamada, Hiromichi Ohta
AIP Advances, 9, 035129, Mar. 2019, [Peer-reviewed], [Last author]
English, Scientific journal - Sign reversal of current-induced effective magnetic field in La0.67Sr0.33MnO3 heterostructures
Yamanouchi Michihiko, Oyamada Tatsuro, Ohta Hiromichi
JSAP Annual Meetings Extended Abstracts, 2019.1, 1900, 1900, The Japan Society of Applied Physics, 25 Feb. 2019
English - Current-induced modulation of coercive field in the ferromagnetic oxide SrRuO3
Michihiko Yamanouchi, Tatsuro Oyamada, Koichi Sato, Hiromichi Ohta, Jun’ichi Ieda
IEEE Transactions on Magnetics, 1400604, Feb. 2019, [Peer-reviewed]
English, Scientific journal - Fast operation of a WO3-based solid-state electrochromic transistor
Takaki Onozato, Yukio Nezu, Hai Jun Cho, Hiromichi Ohta
AIP Advances, 9, 025122, Feb. 2019, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Formation of environmentally stable hole-doped graphene films: Instantaneous and high-density carrier doping by a boron-based oxidant
Kaito Kanahashi, Naoki Tanaka, Yoshiaki Shoji, Mina Maruyama, Il Jeon, Kenji Kawahara, Masatou Ishihara, Masataka Hasegawa, Hiromichi Ohta, Hiroki Ago, Yutaka Matsuo, Susumu Okada, Takanori Fukushima, Taishi Takenobu
npj 2D Materials and Applications, 3, 7, Feb. 2019, [Peer-reviewed]
English, Scientific journal - 2D thermoelectrics
Yu-Qiao Zhang, Hiromichi Ohta
2D Nanomaterials for Energy Applications: Graphene and Beyond, 209, 225, Elsevier, 01 Jan. 2019
English, In book - Buffer layer-less fabrication of a high-mobility transparent oxide semiconductor, La-doped BaSnO3
Anup Sanchela, Mian Wei, Joonhyuk Lee, Gowoon Kim, Hyoungjeen Jeen, Bin Feng, Yuichi Ikuhara, Hai Jun Cho, Hiromichi Ohta
Journal of Materials Chemistry C, 7, 5797, 5802, 2019, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal,Hall mobility of La-doped BaSnO3 films was improved without any buffer layers if the films are grown under O3 atmospheres.
- Thermopower modulation clarification of the operating mechanism in wide bandgap BaSnO3−SrSnO3 solid-solution based thin film transistors
Anup V. Sanchela, Mian Wei, Hai Jun Cho, Hiromichi Ohta
Small, 15, 1805394, Jan. 2019, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Effects of vacuum annealing on the electron mobility of epitaxial La-doped BaSnO3 films
Hai Jun Cho, Takaki Onozato, Mian Wei, Anup Sanchela, Hiromichi Ohta
APL Mater., 7, 022507, Dec. 2018, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Extremely light carrier effective mass in a distorted simple metal oxide
Gowoon Kim, Yu-Qiao Zhang, Taewon Min, Hoyoung Suh, Jae Hyuck Jang, Hyeonjun Kong, Joonhyuk Lee, Jaekwang Lee, Tae-Yeol Jeon, Inwon Lee, Jinhyung Cho, Hiromichi Ohta, Hyoungjeen Jeen
Adv. Electron. Mater., 5, 1800504, Dec. 2018, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Oxygen vacancies allow tuning the work function of vanadium dioxide
Rongbin Wang, Takayoshi Katase, Ke-Ke Fu, Tianshu Zhai, Jiacheng Yang, Qiankun Wang, Hiromichi Ohta, Norbert Koch, Steffen Duhm
Adv. Mater. Interfaces, Oct. 2018, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Anomalous magneto-transports of La0.67Sr0.33MnO3/2DES-LaAlO3/SrTiO3
Oyamada Tatsuro, Ohta Hiromichi, Yamanouchi Michihiko
JSAP Annual Meetings Extended Abstracts, 2018.2, 2021, 2021, The Japan Society of Applied Physics, 05 Sep. 2018
Japanese - Crystallographic orientation – surface energy – wetting property relationships of rare earth oxides
Jason Tam, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta, Uwe Erb
J. Mater. Chem. A, 6, 38, 18384, 18388, Sep. 2018, [Peer-reviewed], [Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Double thermoelectric power factor of a 2D electron system
Yuqiao Zhang, Bin Feng, Hiroyuki Hayashi, Cheng-Ping Chang, Yu-Miin Sheu, Isao Tanaka, Yuichi Ikuhara, Hiromichi Ohta
Nature Communications, 9, 2224, Jul. 2018, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Large thickness dependence of the carrier mobility in a transparent oxide semiconductor, La-doped BaSnO3
Anup V. Sanchela, Mian Wei, Haruki Zensyo, Bin Feng, Joonhyuk Lee, Gowoon Kim, Hyoungjeen Jeen, Yuichi Ikuhara, Hiromichi Ohta
Applied Physics Letters, 112, 23, 232102, American Institute of Physics Inc., 04 Jun. 2018, [Peer-reviewed], [Last author, Corresponding author], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Plasmon-Assisted Polarity Switching of a Photoelectric Conversion Device by UV and Visible Light Irradiation
Keisuke Nakamura, Tomoya Oshikiri, Kosei Ueno, Takayoshi Katase, Hiromichi Ohta, Hiroaki Misawa
J. Phys. Chem. C, 122, 25, 14064, 14071, Apr. 2018, [Peer-reviewed]
English, Scientific journal - Stoichiometric and Oxygen-Deficient VO2 as Versatile Hole Injection Electrode for Organic Semiconductors
Keke Fu, Rongbin Wang, Takayoshi Katase, Hiromichi Ohta, Norbert Koch, Steffen Duhm
ACS Applied Materials and Interfaces, 10, 12, 10552, 10559, American Chemical Society, 28 Mar. 2018, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
English, Scientific journal - Chemical hole doping into large-area transition metal dichalcogenide monolayers using boron-based oxidant
Hirofumi Matsuoka, Kaito Kanahashi, Naoki Tanaka, Yoshiaki Shoji, Lain-Jong Li, Jiang Pu, Hiroshi Ito, Hiromichi Ohta, Takanori Fukushima, Taishi Takenobu
Japanese Journal of Applied Physics, 57, 2, 02CCB15, Japan Society of Applied Physics, 01 Feb. 2018, [Peer-reviewed]
English, International conference proceedings - High Thermoelectric Power Factor of High-Mobility 2D Electron Gas
Ohta, Hiromichi, Kim, Sung Wng, Kaneki, Shota, Yamamoto, Atsushi, Hashizume, Tamotsu
Advanced Science, 5, 1, 2018
Scientific journal - Directing Oxygen Vacancy Channels in SrFeO2.5 Epitaxial Thin Films
Amit Khare, Jaekwang Lee, Jaeseoung Park, Gi-Yeop Kim, Si-Young Choi, Takayoshi Katase, Seulki Roh, Tae Sup Yoo, Jungseek Hwang, Hiromichi Ohta, Junwoo Son, Woo Seok Choi
ACS Applied Materials and Interfaces, 10, 5, 4831, 4837, American Chemical Society, 2018, [Peer-reviewed]
English, Scientific journal - High thermoelectric power factor of high-mobility two-dimensional electron gas
Hiromichi Ohta, Sung Wng Kim, Shota Kaneki, Atsushi Yamamoto, Tamotsu Hashizume
Adv. Sci., 4, 1700696-1, 1700696-6, Nov. 2017, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal - Solid-phase epitaxial film growth and optical properties of a ferroelectric oxide, Sr2Nb2O7
Yukio Nezu, Yu-Qiao Zhang, Chunlin Chen, Yuichi Ikuhara, Hiromichi Ohta
JOURNAL OF APPLIED PHYSICS, 122, 13, 135305, Oct. 2017, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Highly conducting leakage-free electrolyte for SrCoOx-based non-volatile memory device
Takayoshi Katase, Yuki Suzuki, Hiromichi Ohta
JOURNAL OF APPLIED PHYSICS, 122, 13, 135303, Oct. 2017, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Te Monolayer-Driven Spontaneous van der Waals Epitaxy of Two-dimensional Pnictogen Chalcogenide Film on Sapphire
Jae-Yeol Hwang, Young-Min Kim, Kyu Hyoung Lee, Hiromichi Ohta, Sung Wng Kim
NANO LETTERS, 17, 10, 6140, 6145, Oct. 2017, [Peer-reviewed], [Corresponding author]
English, Scientific journal - Topotactic Metal-Insulator Transition in Epitaxial SrFeOx Thin Films
Amit Khare, Dongwon Shin, Tae Sup Yoo, Minu Kim, Tae Dong Kang, Jaekwang Lee, Seulki Roh, In-Ho Jung, Jungseek Hwang, Sung Wng Kim, Tae Won Noh, Hiromichi Ohta, Woo Seok Choi
ADVANCED MATERIALS, 29, 37, 1606566, Oct. 2017, [Peer-reviewed]
English, Scientific journal - Gate tunable spin-orbit coupling and weak antilocalization effect in an epitaxial La2/3Sr1/3MnO3 thin film
Shao-Pin Chiu, Michihiko Yamanouchi, Tatsuro Oyamada, Hiromichi Ohta, Juhn-Jong Lin
PHYSICAL REVIEW B, 96, 8, 085143, Aug. 2017, [Peer-reviewed]
English, Scientific journal - Thermopower modulation clarification of the intrinsic effective mass in transparent oxide semiconductor BaSnO3
Anup V. Sanchela, Takaki Onozato, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta
PHYSICAL REVIEW MATERIALS, 1, 3, 034603, Aug. 2017, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Thermoelectric phase diagram of the SrTiO3-SrNbO3 solid solution system
Yuqiao Zhang, Bin Feng, Hiroyuki Hayashi, Tetsuya Tohei, Isao Tanaka, Yuichi Ikuhara, Hiromichi Ohta
JOURNAL OF APPLIED PHYSICS, 121, 18, 185102-1, 185102-7, May 2017, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Infrared-transmittance tunable metal-insulator conversion device with thin-film-transistor-type structure on a glass substrate
Takayoshi Katase, Kenji Endo, Hiromichi Ohta
APL MATERIALS, 5, 5, 056105, May 2017, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Reactive Solid-Phase Epitaxy and Electrical Conductivity of Layered Sodium Manganese Oxide Films
Shota Katayama, Takayoshi Katase, Tetsuya Tohei, Bin Feng, Yuichi Ikuhara, Hiromichi Ohta
CRYSTAL GROWTH & DESIGN, 17, 4, 1849, 1853, Apr. 2017, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Thickness Dependence of Current-Induced Effective Magnetic Field in La0.67Sr0.33MnO3/SrTiO3 heterostructure
Oyamada Tatsuro, Katase Takayoshi, Ohta Hiromichi, Yamanouchi Michihiko
JSAP Annual Meetings Extended Abstracts, 2017.1, 2047, 2047, The Japan Society of Applied Physics, 01 Mar. 2017
Japanese - Highly air- and moisture-stable hole-doped carbon nanotube films achieved using boron-based oxidant
Kazuma Funahashi, Naoki Tanaka, Yoshiaki Shoji, Naoki Imazu, Ko Nakayama, Kaito Kanahashi, Hiroyuki Shirae, Suguru Noda, Hiromichi Ohta, Takanori Fukushima, Taishi Takenobu
APPLIED PHYSICS EXPRESS, 10, 3, Mar. 2017, [Peer-reviewed]
English, Scientific journal - Graphene Substrate for van der Waals Epitaxy of Layer-Structured Bismuth Antimony Telluride Thermoelectric Film
Eun Sung Kim, Jae-Yeol Hwang, Kyu Hyoung Lee, Hiromichi Ohta, Young Hee Lee, Sung Wng Kim
ADVANCED MATERIALS, 29, 8, 1604899, Feb. 2017, [Peer-reviewed]
English, Scientific journal - Solid-liquid phase epitaxial growth of Li4Ti5O12 thin film
Ning Li, Takayoshi Katase, Yanbei Zhu, Takao Matsumoto, Tomonari Umemura, Yuichi Ikuhara, Hiromichi Ohta
APPLIED PHYSICS EXPRESS, 9, 12, 125501, Dec. 2016, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Current-induced effects on switching magnetic field in La0.67Sr0.33MnO3/SrTiO3
Yamanouchi Michihiko, Oyamada Tatsuro, Katase Takayoshi, Ohta Hiromichi
JSAP Annual Meetings Extended Abstracts, 2016.2, 1933, 1933, The Japan Society of Applied Physics, 01 Sep. 2016
Japanese - Enhanced thermoelectric power in two-dimensional transition metal dichalcogenide monolayers
Jiang Pu, Kaito Kanahashi, Nguyen Thanh Cuong, Chang-Hsiao Chen, Lain-Jong Li, Susumu Okada, Hiromichi Ohta, Taishi Takenobu
PHYSICAL REVIEW B, 94, 1, 014312, Jul. 2016, [Peer-reviewed]
English, Scientific journal - Optoelectronic properties of valence-state-controlled amorphous niobium oxide
Takaki Onozato, Takayoshi Katase, Akira Yamamoto, Shota Katayama, Koichi Matsushima, Naho Itagaki, Hisao Yoshida, Hiromichi Ohta
JOURNAL OF PHYSICS-CONDENSED MATTER, 28, 25, 25501, Jun. 2016, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Reversibly Switchable Electromagnetic Device with Leakage-Free Electrolyte
Takayoshi Katase, Yuki Suzuki, Hiromichi Ohta
ADVANCED ELECTRONIC MATERIALS, 2, 6, Jun. 2016, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - A transparent electrochromic metal-insulator switching device with three-terminal transistor geometry
Takayoshi Katase, Takaki Onozato, Misako Hirono, Taku Mizuno, Hiromichi Ohta
SCIENTIFIC REPORTS, 6, 25819, May 2016, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Atomic structures and oxygen dynamics of CeO2 grain boundaries
Bin Feng, Issei Sugiyama, Hajime Hojo, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara
SCIENTIFIC REPORTS, 6, 20288, Feb. 2016, [Peer-reviewed]
English, Scientific journal - Efficiency and long-term durability of a nitrogen-doped single-walled carbon nanotube electrocatalyst synthesized by defluorination-assisted nanotube-substitution for oxygen reduction reaction
Koji Yokoyama, Shun Yokoyama, Yoshinori Sato, Kazutaka Hirano, Shinji Hashiguchi, Kenichi Motomiya, Hiromichi Ohta, Hideyuki Takahashi, Kazuyuki Tohji, Yoshinori Sato
JOURNAL OF MATERIALS CHEMISTRY A, 4, 23, 9184, 9195, 2016, [Peer-reviewed]
English, Scientific journal - Search for non-equilibrium thermoelectrics
Ichiro Terasaki, Ryuji Okazaki, Hiromichi Ohta
SCRIPTA MATERIALIA, 111, 23, 28, Jan. 2016, [Peer-reviewed]
English, Scientific journal - Solid-Phase Epitaxial Growth of A-Site-Ordered Perovskite Sr4-xErxCo4O12-delta: A Room Temperature Ferrimagnetic p-Type Semiconductor
Takayoshi Katase, Hidefumi Takahashi, Tetsuya Tohei, Yuki Suzuki, Michihiko Yamanouchi, Yuichi Ikuhara, Ichiro Terasaki, Hiromichi Ohta
ADVANCED ELECTRONIC MATERIALS, 1, 12, 1500199, Dec. 2015, [Peer-reviewed]
English, Scientific journal - Defluorination-assisted nanotube-substitution reaction with ammonia gas for synthesis of nitrogen-doped single-walled carbon nanotubes
Koji Yokoyama, Yoshinori Sato, Kazutaka Hirano, Hiromichi Ohta, Kenichi Motomiya, Kazuyuki Tohji, Yoshinori Sato
CARBON, 94, 1052, 1060, Nov. 2015, [Peer-reviewed]
English, Scientific journal - Thermopower analysis of metal-insulator transition temperature modulations in vanadium dioxide thin films with lattice distortion
Takayoshi Katase, Kenji Endo, Hiromichi Ohta
PHYSICAL REVIEW B, 92, 3, 035302, Jul. 2015, [Peer-reviewed]
English, Scientific journal - Room-Temperature-Protonation-Driven On-Demand Metal-Insulator Conversion of a Transition Metal Oxide
Takayoshi Katase, Kenji Endo, Tetsuya Tohei, Yuichi Ikuhara, Hiromichi Ohta
ADVANCED ELECTRONIC MATERIALS, 1, 7, 1500063, Jul. 2015, [Peer-reviewed]
English, Scientific journal - Characterization of electronic structure around metal-insulator transition in V1-x WxO2 thin films by thermopower measurement
Takayoshi Katase, Kenji Endo, Hiromichi Ohta
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 123, 1437, 307, 311, May 2015, [Peer-reviewed]
English, Scientific journal - Polaron Transport and Thermoelectric Behavior in La-Doped SrTiO3 Thin Films with Elemental Vacancies
Woo Seok Choi, Hyang Keun Yoo, Hiromichi Ohta
ADVANCED FUNCTIONAL MATERIALS, 25, 5, 799, 804, Feb. 2015, [Peer-reviewed]
English, Scientific journal - Thermopower Enhancement by Fractional Layer Control in 2D Oxide Superlattices
Woo Seok Choi, Hiromichi Ohta, Ho Nyung Lee
ADVANCED MATERIALS, 26, 39, 6701, 6705, Oct. 2014, [Peer-reviewed]
English, Scientific journal - Thermopower analysis of the electronic structure around the metal-insulator transition in V1-xWxO2
Takayoshi Katase, Kenji Endo, Hiromichi Ohta
PHYSICAL REVIEW B, 90, 16, 161105(R), Oct. 2014, [Peer-reviewed]
English, Scientific journal - Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen sponge
Hyoungjeen Jeen, Woo Seok Choi, Michael D. Biegalski, Chad M. Folkman, I-Cheng Tung, Dillon D. Fong, John W. Freeland, Dongwon Shin, Hiromichi Ohta, Matthew F. Chisholm, Ho Nyung Lee
NATURE MATERIALS, 12, 11, 1057, 1063, Nov. 2013, [Peer-reviewed]
English, Scientific journal - Topotactic Phase Transformation of the Brownmillerite SrCoO2.5 to the Perovskite SrCoO3-delta
H. Jeen, W. S. Choi, J. W. Freeland, H. Ohta, C. U. Jung, H. N. Lee
ADVANCED MATERIALS, 25, 27, 3651, 3656, Jul. 2013, [Peer-reviewed]
English, Scientific journal - Lithium-ion conducting La2/3-xLi3xTiO3 solid electrolyte thin films with stepped and terraced surfaces (vol 100, 173107, 2012)
Hiromichi Ohta, Teruyasu Mizoguchi, Noriyuki Aoki, Takashi Yamamoto, Akhmad Sabarudin, Tomonari Umemura
APPLIED PHYSICS LETTERS, 102, 8, Feb. 2013, [Peer-reviewed]
English - Domain formation in anatase TiO2 thin films on LaAlO3 substrates
Shijian Zheng, Craig A. J. Fisher, Takeharu Kato, Yuki Nagao, Hiromichi Ohta, Yuichi Ikuhara
APPLIED PHYSICS LETTERS, 101, 19, 191602, Nov. 2012, [Peer-reviewed]
English, Scientific journal - Lithium-ion conducting La2/3-xLi3xTiO3 solid electrolyte thin films with stepped and terraced surfaces
Hiromichi Ohta, Teruyasu Mizoguchi, Noriyuki Aoki, Takashi Yamamoto, Akhmad Sabarudin, Tomonari Umemura
APPLIED PHYSICS LETTERS, 100, 17, 173107, Apr. 2012, [Peer-reviewed]
English, Scientific journal - Unusually Large Enhancement of Thermopower in an Electric Field Induced Two-Dimensional Electron Gas
Hiromichi Ohta, Taku Mizuno, Shijian Zheng, Takeharu Kato, Yuichi Ikuhara, Katsumi Abe, Hideya Kumomi, Kenji Nomura, Hideo Hosono
ADVANCED MATERIALS, 24, 6, 740, +, Feb. 2012, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal - Atomic structure of a Sigma 3 [110]/(111) grain boundary in CeO2
B. Feng, H. Hojo, T. Mizoguchi, H. Ohta, S. D. Findlay, Y. Sato, N. Shibata, T. Yamamoto, Y. Ikuhara
APPLIED PHYSICS LETTERS, 100, 7, 073109, Feb. 2012, [Peer-reviewed]
English, Scientific journal - Epitaxial thin films of p-type spinel ferrite grown by pulsed laser deposition
Munetoshi Seki, Hitoshi Tabata, Hiromichi Ohta, Katsuhiko Inaba, Shintaro Kobayashi
APPLIED PHYSICS LETTERS, 99, 24, 242504, Dec. 2011, [Peer-reviewed]
English, Scientific journal - Electric field thermopower modulation analysis of an interfacial conducting layer formed between Y2O3 and rutile TiO2
Taku Mizuno, Yuki Nagao, Akira Yoshikawa, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta
JOURNAL OF APPLIED PHYSICS, 110, 6, 063719, Sep. 2011, [Peer-reviewed]
English, Scientific journal - Controlling Interface Intermixing and Properties of SrTiO3-Based Superlattices
Teruyasu Mizoguchi, Hiromichi Ohta, Hak-Sung Lee, Nobuaki Takahashi, Yuichi Ikuhara
ADVANCED FUNCTIONAL MATERIALS, 21, 12, 2258, 2263, Jun. 2011, [Peer-reviewed]
English, Scientific journal - Atomic structure and strain field of threading dislocations in CeO2 thin films on yttria-stabilized ZrO2
Hajime Hojo, Eita Tochigi, Teruyasu Mizoguchi, Hiromichi Ohta, Naoya Shibata, Bin Feng, Yuichi Ikuhara
APPLIED PHYSICS LETTERS, 98, 15, 153104, Apr. 2011, [Peer-reviewed]
English, Scientific journal - Atomic structure of a CeO2 grain boundary: The role of oxygen vacancies
Hajime Hojo, Teruyasu Mizoguchi, Hiromichi Ohta, Scott D. Findlay, Naoya Shibata, Takahisa Yamamoto, Yuichi Ikuhara
Nano Letters, 10, 11, 4668, 4672, 10 Nov. 2010, [Peer-reviewed]
English, Scientific journal - Field-induced water electrolysis switches an oxide semiconductor from an insulator to a metal
Hiromichi Ohta, Yukio Sato, Takeharu Kato, SungWng Kim, Kenji Nomura, Yuichi Ikuhara, Hideo Hosono
NATURE COMMUNICATIONS, 1, 118, Nov. 2010, [Lead author, Corresponding author]
English, Scientific journal - Electric field modulation of thermopower for transparent amorphous oxide thin film transistors
Hirotaka Koide, Yuki Nagao, Kunihito Koumoto, Yuka Takasaki, Tomonari Umemura, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta
APPLIED PHYSICS LETTERS, 97, 18, 182105, Nov. 2010
English, Scientific journal - Enhancing the electron mobility via delta-doping in SrTiO3
Y. Kozuka, M. Kim, H. Ohta, Y. Hikita, C. Bell, H. Y. Hwang
APPLIED PHYSICS LETTERS, 97, 22, 222115, Nov. 2010, [Peer-reviewed]
English, Scientific journal - Experimental characterization of the electronic structure of anatase TiO2: Thermopower modulation
Yuki Nagao, Akira Yoshikawa, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta
APPLIED PHYSICS LETTERS, 97, 17, 172112, Oct. 2010
English, Scientific journal - Metal-nonmetal transition in LixCoO2 thin films and thermopower enhancement at high Li concentration
Y. Ishida, A. Mizutani, K. Sugiura, H. Ohta, K. Koumoto
PHYSICAL REVIEW B, 82, 7, 075325, Aug. 2010
English, Scientific journal - Dimensional crossover of polaron dynamics in Nb:SrTiO3/SrTiO3 superlattices: Possible mechanism of thermopower enhancement
Woo Seok Choi, Hiromichi Ohta, Soon Jae Moon, Yun Sang Lee, Tae Won Noh
PHYSICAL REVIEW B, 82, 2, 024301, Jul. 2010
English, Scientific journal - A single crystalline strontium titanate thin film transistor
Kosuke Uchida, Akira Yoshikawa, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta
JOURNAL OF APPLIED PHYSICS, 107, 9, 096103, May 2010
English, Scientific journal - Enhancement of thermoelectric performance in rare earth-doped Sr3Ti2O7 by symmetry restoration of TiO6 octahedra
Yifeng Wang, Kyu Hyoung Lee, Hideki Hyuga, Hideki Kita, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF ELECTROCERAMICS, 24, 2, 76, 82, Apr. 2010, [Peer-reviewed]
English, Scientific journal - Fabrication of Atomically Flat ScAlMgO4 Epitaxial Buffer Layer and Low-Temperature Growth of High-Mobility ZnO Films
Takayoshi Katase, Kenji Nomura, Hiromichi Ohta, Hiroshi Yanagi, Toshio Kamiya, Masahiro Hirano, Hideo Hosono
CRYSTAL GROWTH & DESIGN, 10, 3, 1084, 1089, Mar. 2010
English, Scientific journal - Ca-DOPING AND THERMOELECTRIC PROPERTIES OF CaxCoO2 EPITAXIAL FILMS
Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Hideo Hosono, Kunihito Koumoto
ADVANCES IN ELECTRONIC CERAMICS II, 30, 9, 95, +, 2010, [Peer-reviewed]
English, International conference proceedings - Electric-Field Modulation of Thermopower for the KTaO3 Field-Effect Transistors
Akira Yoshikawa, Kosuke Uchida, Kunihito Koumoto, Takeharu Kato, Yuichi Ikuhara, Hiromichi Ohta
APPLIED PHYSICS EXPRESS, 2, 12, 121103, Dec. 2009
English, Scientific journal - Field-modulated thermopower in SrTiO3-based field-effect transistors with amorphous 12CaO center dot 7Al(2)O(3) glass gate insulator
Hiromichi Ohta, Yumi Masuoka, Ryoji Asahi, Takeharu Kato, Yuichi Ikuhara, Kenji Nomura, Hideo Hosono
APPLIED PHYSICS LETTERS, 95, 11, 113505, Sep. 2009
English, Scientific journal - Thermal conductivity and Seebeck coefficient of 12CaO center dot 7Al(2)O(3) electride with a cage structure
Sung Wng Kim, Ryuichi Tarumi, Hideo Iwasaki, Hiromichi Ohta, Masahiro Hirano, Hideo Hosono
PHYSICAL REVIEW B, 80, 7, 075201, Aug. 2009
English, Scientific journal - Enhanced effective mass in doped SrTiO3 and related perovskites
Wilfried Wunderlich, Hiromichi Ohta, Kunihito Koumoto
PHYSICA B-CONDENSED MATTER, 404, 16, 2202, 2212, Aug. 2009, [Peer-reviewed]
English, Scientific journal - Thermoelectric properties of electron doped SrO(SrTiO3)(n) (n=1,2) ceramics
Yifeng Wang, Kyu Hyoung Lee, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF APPLIED PHYSICS, 105, 10, 103701, May 2009
English, Scientific journal - Large domain growth of GaN epitaxial films on lattice-matched buffer layer ScAlMgO4
Takayoshi Katase, Kenji Nomura, Hiromichi Ohta, Hiroshi Yanagi, Toshio Kamiya, Masahiro Hirano, Hideo Hosono
MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS, 161, 1-3, 66, 70, Apr. 2009
English, Scientific journal - Anisotropic carrier transport properties in layered cobaltate epitaxial films grown by reactive solid-phase epitaxy
Kenji Sugiura, Hiromichi Ohta, Shin-ichi Nakagawa, Rong Huang, Yuichi Ikuhara, Kenji Nomura, Hideo Hosono, Kunihito Koumoto
APPLIED PHYSICS LETTERS, 94, 15, 142105, Apr. 2009
English, Scientific journal - Structural Transformation of Ca-Arrangements and Carrier Transport Properties in Ca0.33CoO2 Epitaxial Films
Kenji Sugiura, Hiromichi Ohta, Yukiaki Ishida, Rong Huang, Tomohiro Saito, Yuichi Ikuhara, Kenji Nomura, Hideo Hosono, Kunihito Koumoto
APPLIED PHYSICS EXPRESS, 2, 3, 035503, Mar. 2009
English, Scientific journal - Microstructure evolution of Ca0.33CoO2 thin films investigated by high-angle annular dark-field scanning transmission electron microscopy
Rong Huang, Teruyasu Mizoguchi, Kenji Sugiura, Shin-ichi Nakagawa, Hiromichi Ohta, Tomohiro Saito, Kunihito Koumoto, Tsukasa Hirayama, Yuichi Ikuhara
JOURNAL OF MATERIALS RESEARCH, 24, 1, 279, 287, Jan. 2009
English, Scientific journal - Defect passivation and homogenization of amorphous oxide thin-film transistor by wet O(2) annealing
Kenji Nomura, Toshio Kamiya, Hiromichi Ohta, Masahiro Hirano, Hideo Hosono
APPLIED PHYSICS LETTERS, 93, 19, 192107, Nov. 2008
English, Scientific journal - Direct observations of Ca ordering in Ca0.33CoO2 thin films with different superstructures
Rong Huang, Teruyasu Mizoguchi, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto, Tsukasa Hirayama, Yuichi Ikuhara
APPLIED PHYSICS LETTERS, 93, 18, 181907, Nov. 2008
English, Scientific journal - Recent progress in oxide thermoelectric materials: p-type Ca3CO4O9 and n-type SrTiO3-
Hiromichi Ohta, Kenji Sugiura, Kunihito Koumoto
INORGANIC CHEMISTRY, 47, 19, 8429, 8436, Oct. 2008
English, Scientific journal - Relationship between non-localized tail states and carrier transport in amorphous oxide semiconductor, In-Ga-Zn-O
K. Nomura, T. Kamiya, H. Ohta, K. Shimizu, M. Hirano, H. Hosono
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 205, 8, 1910, 1914, Aug. 2008
English, Scientific journal - Fabrication of ScAlMgO4 epitaxial thin films using ScGaO3(ZnO)(m) buffer layers and its application to lattice-matched buffer layer for ZnO epitaxial growth
Takayoshi Katase, Kenji Noinura, Hirornichi Ohta, Hiroshi Yanagi, Toshio Kamiya, Masahiro Hirano, Hideo Hosono
THIN SOLID FILMS, 516, 17, 5842, 5846, Jul. 2008
English, Scientific journal - Critical thickness for giant thermoelectric Seebeck coefficient of 2DEG confined in SrTiO3/SrTi0.8Nb0.2O3 superlattices
Hiromichi Ohta, Yoriko Mune, Kunihito Koumoto, Teruyasu Mizoguchi, Yuichi Ikuhara
THIN SOLID FILMS, 516, 17, 5916, 5920, Jul. 2008
English, Scientific journal - Fabrication and thermoelectric properties of heavily rare-earth metal-doped SrO(SrTiO3)(n) (n=1, 2) ceramics
Yi Feng Wang, Kyu Hyoung Lee, Hiromichi Ohta, Kunihito Kournoto
CERAMICS INTERNATIONAL, 34, 4, 849, 852, May 2008
English, Scientific journal - Epitaxial film growth of LixCoO2 (0.6 <= x <= 0.9) via topotactic ion exchange of Na0.8CoO2
Atsushi Mizutani, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto
CRYSTAL GROWTH & DESIGN, 8, 3, 755, 758, Mar. 2008
English, Scientific journal - Coherent and incoherent excitations of electron-doped SrTiO(3)
Yukiaki Ishida, Ritsuko Eguchi, Masaharu Matsunami, Koji Horiba, Munetaka Taguchi, Ashish Chainani, Yasunori Senba, Haruhiko Ohashi, Hiromichi Ohta, Shik Shin
PHYSICAL REVIEW LETTERS, 100, 5, 056401, Feb. 2008
English, Scientific journal - Large enhancement of the thermoelectric Seebeck coefficient for amorphous oxide semiconductor superlattices with extremely thin conductive layers
Hiromichi Ohta, Rong Huang, Yuichi Ikuhara
Physica Status Solidi - Rapid Research Letters, 2, 3, 105, 107, 2008
English, Scientific journal - Thermal stability of giant thermoelectric seebeck coefficient for SrTiO3/SrTi0.8Nb0.2O3 superlattices at 900 K
Kyu Hyoung Lee, Yoriko Mune, Hiromichi Ohta, Kunihito Koumoto
APPLIED PHYSICS EXPRESS, 1, 1, 015007, Jan. 2008
English, Scientific journal - Two-dimensional thermoelectric Seebeck coefficient of the SrTiO3 based superlattices
phys. stat. sol. (b), 245, 2363, 2008 - THERMOELECTRIC PERFORMANCE OF DOPED SrO(SrTiO3)(n) (n=1, 2) RUDDLESDEN-POPPER PHASES
Kyu Hyoung Lee, Yi Feng Wang, Hiromichi Ohta, Kunihito Koumoto
ADVANCES IN ELECTRONIC CERAMICS, 28, 8, 193, +, 2008, [Peer-reviewed]
English, International conference proceedings - The effect of Eu substitution on thermoelectric properties of SrTi0.8Nb0.2O3
Keisuke Kato, Masahiro Yamamoto, Shingo Ohta, Hiroaki Muta, Ken Kurosaki, Shinsuke Yamanaka, Hideo Iwasaki, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF APPLIED PHYSICS, 102, 11, 116107, Dec. 2007
English, Scientific journal - Enhancement of Seebeck coefficient for SrO(SrTiO3)(2) by Sm substitution: Crystal symmetry restoration of distorted TiO6 octahedra
Yifeng Wang, Kyu Hyoung Lee, Hideki Hyuga, Hideki Kita, Katsuhiko Inaba, Hiromichi Ohta, Kunihito Koumoto
APPLIED PHYSICS LETTERS, 91, 24, Dec. 2007, [Peer-reviewed]
English, Scientific journal - Enhanced Seebeck coefficient of quantum-confined electrons in SrTiO3/SrTi0.8Nb0.2O3 superlattices
Yoriko Mune, Hiromichi Ohta, Kunihito Koumoto, Teruyasu Mizoguchi, Yuichi Ikuhara
APPLIED PHYSICS LETTERS, 91, 19, 192105, Nov. 2007
English, Scientific journal - Temperature dependence of the chemical potential in NaxCoO2: Implications for the large thermoelectric power
Yukiaki Ishida, Hiromichi Ohta, Atsushi Fujimori, Hideo Hosono
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 76, 10, 103709, Oct. 2007
English, Scientific journal - Thermoelectric properties of the layered cobaltite Ca3Co4O9 epitaxial films fabricated by topotactic ion-exchange method
Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Tomohiro Saito, Yuichi Ikuhara, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto
MATERIALS TRANSACTIONS, 48, 8, 2104, 2107, Aug. 2007
English, Scientific journal - Thermoelectric performance of epitaxial thin films of layered cobalt oxides grown by reactive solid-phase epitaxy with topotactic ion-exchange methods
Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto
International Journal of Applied Ceramic Technology, 4, 4, 308, 317, Aug. 2007
English - Thermoelectric properties of Ruddlesden-Popper phase n-type semiconducting oxides: La-, Nd-, and Nb-doped Sr3 Ti2O7
Kyu Hyoung Lee, Yi Feng Wang, Sung Wng Kim, Hiromichi Ohta, Kunihito Koumoto
International Journal of Applied Ceramic Technology, 4, 4, 326, 331, Aug. 2007
English, Scientific journal - Preparation and thermoelectric properties of heavily Nb-doped SrO(SrTiO3)(1) epitaxial films
Kyu Hyoung Lee, Akihiro Ishizaki, Sung Wng Kim, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF APPLIED PHYSICS, 102, 3, 033702, Aug. 2007
English, Scientific journal - Heavy hole doping of epitaxial thin films of a wide gap p-type semiconductor, LaCuOSe, and analysis of the effective mass
Hidenori Hiramatsu, Kazushige Ueda, Hiromichi Ohta, Masahiro Hirano, Maiko Kikuchi, Hiroshi Yanagi, Toshio Kamiya, Hideo Hosono
APPLIED PHYSICS LETTERS, 91, 1, 012104, Jul. 2007
English, Scientific journal - Thermoelectric properties of layered perovskite-type (Sr1-xCax)(3)(Ti1-yNby)(2)O-7
Kyu Hyoung Lee, Sung Wng Kim, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF APPLIED PHYSICS, 101, 8, 083707, Apr. 2007
English, Scientific journal - Giant thermoelectric Seebeck coefficient of two-dimensional electron gas in SrTiO3
Hiromichi Ohta, Sungwng Kim, Yorika Mune, Teruyasu Mizoguchi, Kenji Nomura, Shingo Ohta, Takashi Nomura, Yuki Nakanishi, Yuichi Ikuhara, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto
NATURE MATERIALS, 6, 2, 129, 134, Feb. 2007, [Lead author, Corresponding author]
English, Scientific journal - Thermoelectric phase diagram in a CaTiO3-SrTiO3-BaTiO3 system
Masahiro Yamamoto, Hiromichi Ohta, Kunihito Koumoto
APPLIED PHYSICS LETTERS, 90, 7, 072101, Feb. 2007
English, Scientific journal - Thermoelectric performance of epitaxial thin films of layered cobalt oxides grown by reactive solid-phase epitaxy with topotactic ion-exchange methods
Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, 4, 4, 308, 317, 2007
English, Scientific journal - Local coordination structure and electronic structure of the large electron mobility amorphous oxide semiconductor In-Ga-Zn-O: Experiment and ab initio calculations
Kenji Nomura, Toshio Kamiya, Hiromichi Ohta, Tomoya Uruga, Masahiro Hirano, Hideo Hosono
PHYSICAL REVIEW B, 75, 3, 035212, Jan. 2007
English, Scientific journal - Self-adjusted, three-dimensional lattice-matched buffer layer for growing ZnO epitaxial film: Homologous series layered oxide, InGaO3(ZnO)(5)
Toshio Kamiya, Yujiro Takeda, Kenji Nomura, Hiromichi Ohta, Hiroshi Yanagi, Masahiro Hirano, Hideo Hosono
CRYSTAL GROWTH & DESIGN, 6, 11, 2451, 2456, Nov. 2006
English, Scientific journal - Carrier generation and transport properties of heavily Nb-doped anatase TiO2 epitaxial films at high temperatures
Daisuke Kurita, Shingo Ohta, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF APPLIED PHYSICS, 100, 9, 096105, Nov. 2006
English, Scientific journal - Thermoelectrical properties of A-site substituted Ca1-xRexMnO3 system
D. Flahaut, T. Mihara, R. Funahashi, N. Nabeshima, K. Lee, H. Ohta, K. Koumoto
JOURNAL OF APPLIED PHYSICS, 100, 8, 084911, Oct. 2006
English, Scientific journal - Potential profiling of the nanometer-scale charge-depletion layer in n-ZnO/p-NiO junction using photoemission spectroscopy
Yukiaki Ishida, Atsushi Fujimori, Hiromichi Ohta, Masahiro Hirano, Hideo Hosono
APPLIED PHYSICS LETTERS, 89, 15, 153502, Oct. 2006
English, Scientific journal - Ruddlesden-Popper phases as thermoelectric oxides: Nb-doped SrO(SrTiO3)(n) (n=1,2)
Kyu Hyoung Lee, Sung Wng Kim, Hiromichi Ohta, Kunihito Koumoto
JOURNAL OF APPLIED PHYSICS, 100, 6, 063717, Sep. 2006
English, Scientific journal - Opto-electronic properties and light-emitting device application of widegap layered oxychalcogenides: LaCuOCh (Ch = chalcogen) and La2CdO2Se2
Hidenori Hiramatsu, Hayato Kamioka, Kazushige Ueda, Hiromichi Ohta, Toshio Kamiya, Masahiro Hirano, Hideo Hosono
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 203, 11, 2800, 2811, Sep. 2006
English, Scientific journal - High electrical conductivity of layered cobalt oxide Ca3Co4O9 epitaxial films grown by topotactic ion-exchange method
Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto
APPLIED PHYSICS LETTERS, 89, 3, 032111, Jul. 2006
English, Scientific journal - Surface modification of glass substrates for oxide heteroepitaxy: Pasteable three-dimensionally oriented layered oxide thin films
Hiromichi Ohta, Atsushi Mizutani, Kenji Sugiura, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto
ADVANCED MATERIALS, 18, 13, 1649, +, Jul. 2006
English, Scientific journal - Amorphous oxide semiconductors for high-performance flexible thin-film transistors
K Nomura, A Takagi, T Kamiya, H Ohta, M Hirano, H Hosono
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 45, 5B, 4303, 4308, May 2006
English, Scientific journal - Epitaxial film growth and superconducting behavior of sodium-cobalt oxyhydrate, NaxCoO2 center dot yH(2)O (x similar to 0.3, y similar to 1.3)
K Sugiura, H Ohta, K Nomura, H Yanagi, M Hirano, H Hosono, K Koumoto
INORGANIC CHEMISTRY, 45, 5, 1894, 1896, Mar. 2006
English, Scientific journal - Growth and structure of heteroepitaxial thin films of homologous compounds RAO(3)(MO)(m) by reactive solid-phase epitaxy: Applicability to a variety of materials and epitaxial template layers
Y Ogo, K Nomura, H Yanagi, H Ohta, T Kamiya, M Hirano, H Hosono
THIN SOLID FILMS, 496, 1, 64, 69, Feb. 2006
English, Scientific journal - Fabrication and thermoelectric properties of layered cobaltite, gamma-Sr0.32Na0.21CoO2 epitaxial films
K Sugiura, H Ohta, K Nomura, M Hirano, H Hosono, K Koumoto
APPLIED PHYSICS LETTERS, 88, 8, 082109, Feb. 2006
English, Scientific journal - Reactive Solid-Phase Epitaxy : A Powerful Method for Epitaxial Film Growth of Complex Layered Oxides(
The 59th CerSJ Progress Awards for Young Scientists)
OHTA Hiromichi
Journal of the Ceramic Society of Japan, 114, 1326, 147, 154, The Ceramic Society of Japan, 01 Feb. 2006
English, High-quality epitaxial film growth for several complex oxides having layered structure by "Reactive Solid-Phase-Epitaxy (R-SPE)" is reviewed. Materials focused are InGaO_3(ZnO)_m (m=integer), LaCuOS and Na_xCoO_2(x〜0.8). For the epitaxial film growths of the complex systems with a complicated layered crystal structure, it is necessary to form an epitaxial template layer before the film deposition, followed by the thermal annealing of the bilayer films. The layers subsequently deposited on the template layer may be amorphous, polycrystalline or powder, which allows control of the epitaxially grown films in the R-SPE method. - Grain size dependence of thermoelectric performance of Nb-doped SrTiO 3 polycrystals
Shingo Ohta, Hiromichi Ohta, Kunihito Koumoto
Journal of the Ceramic Society of Japan, 114, 1325, 102, 105, Ceramic Society of Japan, 2006
English, Scientific journal - Investigating Ruddlesden-Popper phase as thermoelectric materials: Nb-doped SrO(SrTiO3)n (n=1, 2) （共著）
J. Appl. Phys., 100, 063717, 2006 - High-temperature thermoelectric performance of strontium titanate degenerate semiconductors
Hiromichi Ohta, S. Ohta, K. Koumoto
Ceramic Transactions, 196, 343, 348, 2006
English, International conference proceedings - High-quality epitaxial film growth of superconducting sodium-cobalt oxyhydrate, Na0.3CoO2 · 1.3H2O
Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Hiroshi Yanagi, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto
Ceramic Transactions, 196, 303, 309, 2006
English, International conference proceedings - Excitonic blue luminescence from p-LaCuOSe/n-InGaZn5O8 light-emitting diode at room temperature
H Hiramatsu, K Ueda, H Ohta, T Kamiya, M Hirano, H Hosono
APPLIED PHYSICS LETTERS, 87, 21, 211107, Nov. 2005
English, Scientific journal - Growth of epitaxial ZnO thin films on lattice-matched buffer layer: Application of InGaO3(ZnO)(6) single-crystalline thin film
Y Takeda, K Nomura, H Ohta, H Yanagi, T Kamiya, M Hirano, H Hosono
THIN SOLID FILMS, 486, 1-2, 28, 32, Aug. 2005
English, Scientific journal - Carrier transport and electronic structure in amorphous oxide semiconductor, a-InGaZnO4
A Takagi, K Nomura, H Ohta, H Yanagi, T Kamiya, M Hirano, H Hosono
THIN SOLID FILMS, 486, 1-2, 38, 41, Aug. 2005
English, Scientific journal - Two-dimensional electronic structure and multiple excitonic states in layered oxychalcogenide semiconductors, LaCuOCh (Ch=S, Se, Te): Optical properties and relativistic ab initio study
T Kamiya, K Ueda, H Hiramatsu, H Kamioka, H Ohta, M Hirano, H Hosono
THIN SOLID FILMS, 486, 1-2, 98, 103, Aug. 2005
English, Scientific journal - Large thermoelectric performance of heavily Nb-doped SrTiO3 epitaxial film at high temperature
S Ohta, T Nomura, H Ohta, M Hirano, H Hosono, K Koumoto
APPLIED PHYSICS LETTERS, 87, 9, 092108, Aug. 2005
English, Scientific journal - Preparation and thermoelectric properties of Na xCoO 2/Co 3O 4 layered nano-composite
Peixin Zhu, Takahiro Takeuchi, Hiromichi Ohta, Won-Seon Seo, Kunihito Koumoto
Materials Transactions, 46, 7, 1453, 1455, Jul. 2005
English, Scientific journal - Electrical properties and structure of p-type amorphous oxide semiconductor xZnO center dot Rh2O3
T Kamiya, S Narushima, H Mizoguchi, K Shimizu, K Ueda, H Ohta, M Hirano, H Hosono
ADVANCED FUNCTIONAL MATERIALS, 15, 6, 968, 974, Jun. 2005
English, Scientific journal - High-temperature carrier transport and thermoelectric properties of heavily La- or Nb-doped SrTiO3 single crystals
S Ohta, T Nomura, H Ohta, K Koumoto
JOURNAL OF APPLIED PHYSICS, 97, 3, 034106, Feb. 2005
English, Scientific journal - Effect of boundary plane on the atomic structure of [0001] S7 tilt grain boundaries in ZnO （共著）
J. Mater. Sci., 40, 3067, 2005 - Epitaxial growth of a copper-phthalocyanine on a transparent conductive substrate with an atomically flat surface （共著）
Cryst. Growth Des., 5, 143, 2005 - Reactive solid-phase epitaxial growth of NaxCoO2 (x similar to 0.83) via lateral diffusion of Na into a cobalt oxide epitaxial layer
H Ohta, SW Kim, S Ohta, K Koumoto, M Hirano, H Hosono
CRYSTAL GROWTH & DESIGN, 5, 1, 25, 28, Jan. 2005
English - Epitaxial growth and application of transparent oxide semiconductors
Hiromichi Ohta, Kenji Nomura, Hidenori Hiramatsu, Toshio Kamuya, Masahiro Hirano, Hideo Hosono
Proceedings - Electrochemical Society, PV 2003-29, 64, 78, 2005
English, International conference proceedings - Atomic Structure of Tilt Grain Boundaries in ZnO
OBA Fumiyasu, OHTA Hiromichi, HOSONO Hideo, SATO Yukio, YAMAMOTO Takahisa, IKUHARA Yuichi
Materia Japan, 43, 12, 985, 985, The Japan Institute of Metals and Materials, 20 Dec. 2004
Japanese - Room-temperature fabrication of transparent flexible thin-film transistors using amorphous oxide semiconductors
K Nomura, H Ohta, A Takagi, T Kamiya, M Hirano, H Hosono
NATURE, 432, 7016, 488, 492, Nov. 2004
English, Scientific journal - Optical properties and two-dimensional electronic structure in wide-gap layered oxychalcogenide: La2CdO2Se2
H Hiramatsu, K Ueda, T Kamiya, H Ohta, M Hirano, H Hosono
JOURNAL OF PHYSICAL CHEMISTRY B, 108, 45, 17344, 17351, Nov. 2004, [Peer-reviewed]
English, Scientific journal - Heteroepitaxial growth of wide gap p-type semiconductors: LnCuOCh (Lr=La, Pr and Nd; Ch=S or Se) by reactive solid-phase epitaxy
H Hiramatsu, K Ueda, K Takafuji, H Ohta, M Hirano, T Kamiya, H Hosono
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 79, 4-6, 1517, 1520, Sep. 2004
English, Scientific journal - Degenerate electrical conductive and excitonic photoluminescence properties of epitaxial films of wide gap p-type layered oxychalcogenides, LnCuOCh (Ln=La, Pr and Nd; Ch=S or Se)
H Hiramatsu, K Ueda, K Takafuji, H Ohta, M Hirano, T Kamiya, H Hosono
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 79, 4-6, 1521, 1523, Sep. 2004
English, Scientific journal - Carrier transport in transparent oxide semiconductor with intrinsic structural randomness probed using single-crystalline InGaO3(ZnO)(5) films
K Nomura, T Kamiya, H Ohta, K Ueda, M Hirano, H Hosono
APPLIED PHYSICS LETTERS, 85, 11, 1993, 1995, Sep. 2004
English, Scientific journal - Atomic structure of [0001]-tilt grain boundaries in ZnO: A high-resolution TEM study of fiber-textured thin films
F Oba, H Ohta, Y Sato, H Hosono, T Yamamoto, Y Ikuhara
PHYSICAL REVIEW B, 70, 12, 125415, Sep. 2004
English, Scientific journal - Fabrication of heteroepitaxial thin films of layered oxychalcogenides LnCuOCh (Ln = La-Nd; Ch = S-Te) by reactive solid-phase epitaxy
H Hiramatsu, K Ueda, K Takafuji, H Ohta, M Hirano, T Kamiya, H Hosono
JOURNAL OF MATERIALS RESEARCH, 19, 7, 2137, 2143, Jul. 2004
English, Scientific journal - Natural nanostructures in ionic semiconductors
T Kamiya, H Ohta, H Hiramatsu, K Hayashi, K Nomura, S Matsuishi, K Ueda, M Hirano, H Hosono
MICROELECTRONIC ENGINEERING, 73-4, 620, 626, Jun. 2004
English, Scientific journal - Growth mechanism for single-crystalline thin film of InGaO3(ZnO)(5) by reactive solid-phase epitaxy
K Nomura, H Ohta, K Ueda, T Kamiya, M Orita, M Hirano, T Suzuki, C Honjyo, Y Ikuhara, H Hosono
JOURNAL OF APPLIED PHYSICS, 95, 10, 5532, 5539, May 2004
English, Scientific journal - Single-atomic-layered quantum wells built in wide-gap semiconductors LnCuOCh (Ln=lanthanide, Ch=chalcogen)
K Ueda, H Hiramatsu, H Ohta, M Hirano, T Kamiya, H Hosono
PHYSICAL REVIEW B, 69, 15, 155305, Apr. 2004
English, Scientific journal - All oxide transparent MISFET using high-k dielectrics gates
K Nomura, H Ohta, HA Masahiro, K Ueda, T Kamiya, M Hirano, H Hosono
MICROELECTRONIC ENGINEERING, 72, 1-4, 294, 298, Apr. 2004
English, Scientific journal - Li-doped NiO epitaxial thin film with atomically flat surface
T Kamiya, H Ohta, M Kamiya, K Nomura, K Ueda, M Hirano, H Hosono
JOURNAL OF MATERIALS RESEARCH, 19, 3, 913, 920, Mar. 2004
English, Scientific journal - Mechanism for heteroepitaxial growth of transparent P-type semiconductor: LaCuOS by reactive solid-phase epitaxy
H Hiramatsu, H Ohta, T Suzuki, C Honjo, Y Ikuhara, K Ueda, T Kamiya, M Hirano, H Hosono
CRYSTAL GROWTH & DESIGN, 4, 2, 301, 307, Mar. 2004
English, Scientific journal - Third-order optical nonlinearity originating from room-temperature exciton in layered compounds LaCuOS and LaCuOSe
H Kamioka, H Hiramatsu, H Ohta, M Hirano, K Ueda, T Kamiya, H Hosono
APPLIED PHYSICS LETTERS, 84, 6, 879, 881, Feb. 2004
English, Scientific journal - Transparent organic thin-film transistor with a laterally grown non-planar phthalocyanine channel
H Ohta, T Kambayashi, K Nomura, M Hirano, K Ishikawa, H Takezoe, H Hosono
ADVANCED MATERIALS, 16, 4, 312, +, Feb. 2004
English, Scientific journal - Atomic and electronic structures of Ni/YSZ(111) interface
Takeo Sasaki, Katsuyuki Matsunaga, Hiromichi Ohta, Hideo Hosono, Takahisa Yamamoto, Yuichi Ikuhara
Materials Transactions, 45, 7, 2137, 2143, Japan Institute of Metals (JIM), 2004
English, International conference proceedings - Synthesis of single-phase layered oxychalcogenide La2CdO2Se2: crystal structure, optical and electrical properties
H Hiramatsu, K Ueda, T Kamiya, H Ohta, M Hirano, H Hosono
JOURNAL OF MATERIALS CHEMISTRY, 14, 19, 2946, 2950, 2004, [Peer-reviewed]
English, Scientific journal - Two-dimensional electronic structures in layered oxychalcogenide semiconductors, LaCuOCh (Ch=S, Se, Te) and La2CdO2Se2
T Kamiya, K Ueda, H Hiramatsu, H Ohta, M Hirano, H Hosono
INTEGRATION OF ADVANCED MICRO-AND NANOELECTRONIC DEVICES-CRITICAL ISSUES AND SOLUTIONS, 811, 457, 462, 2004, [Peer-reviewed]
English, International conference proceedings - UV-detector based on pn-heteroj unction diode composed of transparent oxide semiconductors, p-NiO/n-ZnO
H Ohta, M Kamiya, T Kamaiya, M Hirano, H Hosono
THIN SOLID FILMS, 445, 2, 317, 321, Dec. 2003
English, Scientific journal - Electron transport in InGaO3(ZnO)(m) (m = integer) studied using single-crystalline thin films and transparent MISFETs
K Nomura, H Ohta, K Ueda, T Kamiya, M Hirano, H Hosono
THIN SOLID FILMS, 445, 2, 322, 326, Dec. 2003
English, Scientific journal - Wide gap p-type degenerate semiconductor: Mg-doped LaCuOSe
H Hiramatsu, K Ueda, H Ohta, M Hirano, T Kamiya, H Hosono
THIN SOLID FILMS, 445, 2, 304, 308, Dec. 2003
English, Scientific journal - Intrinsic excitonic photoluminescence and band-gap engineering of wide-gap p-type oxychalcogenide epitaxial films of LnCuOCh (Ln=La, Pr, and Nd; Ch=S or Se) semiconductor alloys
H Hiramatsu, K Ueda, K Takafuji, H Ohta, M Hirano, T Kamiya, H Hosono
JOURNAL OF APPLIED PHYSICS, 94, 9, 5805, 5808, Nov. 2003
English, Scientific journal - Electrical and optical properties and electronic structures of LnCuOS (Ln = La similar to Nd)
K Ueda, K Takafuji, H Hiramatsu, H Ohta, T Kamiya, M Hirano, H Hosono
CHEMISTRY OF MATERIALS, 15, 19, 3692, 3695, Sep. 2003
English, Scientific journal - A p-type amorphous oxide semiconductor and room temperature fabrication of amorphous oxide p-n heterojunction diodes
S Narushima, H Mizoguchi, K Shimizu, K Ueda, H Ohta, M Hirano, T Kamiya, H Hosono
ADVANCED MATERIALS, 15, 17, 1409, 1413, Sep. 2003
English, Scientific journal - Fabrication and photoresponse of a pn-heterojunction diode composed of transparent oxide semiconductors, p-NiO and n-ZnO
H Ohta, M Hirano, K Nakahara, H Maruta, T Tanabe, M Kamiya, T Kamiya, H Hosono
APPLIED PHYSICS LETTERS, 83, 5, 1029, 1031, Aug. 2003
English, Scientific journal - Application of a transparent conductive substrate with an atomically flat and stepped surface to lateral growth of an organic molecule: Vanadyl phthalocyanine
H Ohta, T Kambayashi, M Hirano, H Hoshi, K Ishikawa, H Takezoe, H Hosono
ADVANCED MATERIALS, 15, 15, 1258, +, Aug. 2003
English, Scientific journal - Thin-film transistor fabricated in single-crystalline transparent oxide semiconductor
K Nomura, H Ohta, K Ueda, T Kamiya, M Hirano, H Hosono
SCIENCE, 300, 5623, 1269, 1272, May 2003
English, Scientific journal - Degenerate p-type conductivity in wide-gap LaCuOS1-xSex (x=0-1) epitaxial films
H Hiramatsu, K Ueda, H Ohta, M Hirano, T Kamiya, H Hosono
APPLIED PHYSICS LETTERS, 82, 7, 1048, 1050, Feb. 2003
English, Scientific journal - Fabrication and characterization of heteroepitaxial p-n junction diode composed of wide-gap oxide semiconductors p-ZnRh2O4/n-ZnO
H Ohta, H Mizoguchi, M Hirano, S Narushima, T Kamiya, H Hosono
APPLIED PHYSICS LETTERS, 82, 5, 823, 825, Feb. 2003
English, Scientific journal - Single-crystalline films of the homologous series InGaO3(ZnO)(m) grown by reactive solid-phase epitaxy
H Ohta, K Nomura, M Orita, M Hirano, K Ueda, T Suzuki, Y Ikuhara, H Hosono
ADVANCED FUNCTIONAL MATERIALS, 13, 2, 139, 144, Feb. 2003
English, Scientific journal - Atomic and electronic structures of Cu/alpha-Al2O3 interfaces prepared by pulsed-laser deposition
Takeo Sasaki, Katsuyuki Matsunaga, Hiromichi Ohta, Hideo Hosono, Takahisa Yamamoto, Yuichi Ikuhara
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, 4, 6, 575, 584, 2003
English, Scientific journal - UV-detector based on pn-heteroj unction diode composed of transparent oxide semiconductors, p-NiO/n-ZnO
Thin Solid Films, 445, 317, 2003 - Frontier of transparent conductive oxide thin films
H Hosono, H Ohta, M Orita, K Ueda, M Hirano
VACUUM, 66, 3-4, 419, 425, Aug. 2002
English, Scientific journal - Heteroepitaxial growth of a wide-gap p-type semiconductor, LaCuOS
H Hiramatsu, K Ueda, H Ohta, M Orita, M Hirano, H Hosono
APPLIED PHYSICS LETTERS, 81, 4, 598, 600, Jul. 2002
English, Scientific journal - Preparation of transparent p-type (La1-xSrxO)CuS thin films by r.f. sputtering technique
H Hiramatsu, K Ueda, H Ohta, M Orita, M Hirano, H Hosono
THIN SOLID FILMS, 411, 1, 125, 128, May 2002
English, Scientific journal - Novel film growth technique of single crystalline In2O3(ZnO)(m) (m = integer) homologous compound
K Nomura, H Ohta, K Ueda, M Orita, M Hirano, H Hosono
THIN SOLID FILMS, 411, 1, 147, 151, May 2002
English, Scientific journal - Preparation of highly conductive, deep ultraviolet transparent beta-Ga2O3 thin film at low deposition temperatures
M Orita, H Hiramatsu, H Ohta, M Hirano, H Hosono
THIN SOLID FILMS, 411, 1, 134, 139, May 2002
English, Scientific journal - Near-UV emitting diodes based on a transparent p-n Junction composed of heteroepitaxially grown p-SrCu2O2 and n-Zno
H Hosono, H Ohta, K Hayashi, M Orita, M Hirano
JOURNAL OF CRYSTAL GROWTH, 237, 496, 502, Apr. 2002
English, Scientific journal - Surface morphology and crystal quality of low resistive indium tin oxide grown on yittria-stabilized zirconia
H Ohta, M Orita, M Hirano, H Hosono
JOURNAL OF APPLIED PHYSICS, 91, 6, 3547, 3550, Mar. 2002
English, Scientific journal - Electronic structure and optical properties of SrCu2O2
Hiromichi Ohta, Masahiro Orita, Masahiro Hirano, Iwao Yagi, Kazushige Ueda, Hideo Hosono
Journal of Applied Physics, 91, 5, 3074, 3078, 15 Feb. 2002
English, Scientific journal - Carrier doping into MgIn2O4 epitaxial thin films by proton implantation
M Miyakawa, R Noshiro, T Ogawa, K Ueda, H Kawazoe, H Ohta, M Orita, M Hirano, H Hosono
JOURNAL OF APPLIED PHYSICS, 91, 4, 2112, 2117, Feb. 2002, [Peer-reviewed]
English, Scientific journal - Heteroepitaxial growth of single-phase zinc blende ZnS films on transparent substrates by pulsed laser deposition under H2S atmosphere
H Hiramatsu, H Ohta, M Hirano, H Hosono
SOLID STATE COMMUNICATIONS, 124, 10-11, 411, 415, 2002
English, Scientific journal - Fabrication of all oxide transparent p-n homojunction using bipolar CuInO2 semiconducting oxide with delafossite structure
H Yanagi, K Ueda, H Ohta, M Orita, M Hirano, H Hosono
SOLID STATE COMMUNICATIONS, 121, 1, 15, 17, 2002
English, Scientific journal - Pulsed laser deposition system for producing oxide thin films at high temperature
M. Orita, H. Ohta, H. Hiramatsu, M. Hirano, S. Den, M. Sasaki, T. Katagiri, H. Mimura, H. Hosono
Review of Scientific Instruments, 72, 8, 3340, 3343, Aug. 2001
English, Scientific journal - Fabrication and Near-UV Emission of p-SrCu_2O_2/n-ZnO Heterojunction LED
OHTA Hiromichi, ORITA Masahiro, HIRANO Masahiro, HOSONO Hideo
J. Surf. Sci. Soc. Jpn., 22, 7, 419, 424, The Surface Science Society of Japan, 10 Jul. 2001
Japanese, Near-UV emitting diodes composed of wide band gap oxide semiconductors, p-SrCu2O2 and n-ZnO heterojunctions, were fabricated and their emission properties were investigated. Single crystal ITO thin films with very flat surfaces were grown using PLD on YSZ substrates, and ZnO films were heteroepitaxially grown on the ITO surfaces. p-SrCu2O2(112) was preferentially grown on ZnO(0001) at 350oC, while the preferential plane was changed into the (100) when the temperature was increased to 600oC. This device exhibited rectifying I-V characteristics inherent to p-n junction whose turn-on voltage was about 3 V. A relatively sharp electro-luminescence band centered at 382 nm was generated by applying the forward bias voltage larger than the turn-on voltage of 3 V. The red shift in the EL peak was noticed from that of photo-luminescence (377 nm), which was most likely due to the difference in the excited state density between the emission processes. The EL band is attributed to transition in ZnO, probably to that associated with electron-hole plasma. UV-LED performance characteristics such as threshold current and conversion efficiency was improved with higher SrCu2O2 deposition temperatures. - Amorphous transparent conductive oxide InGaO3(ZnO)(m) (m <= 4): a Zn 4s conductor
M Orita, H Ohta, M Hirano, S Narushima, H Hosono
PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES, 81, 5, 501, 515, May 2001
English, Scientific journal - Fabrication and characterization of ultraviolet-emitting diodes composed of transparent p-n heterojunction, p-SrCu2O2 and n-ZnO
H Ohta, M Orita, M Hirano, H Hosono
JOURNAL OF APPLIED PHYSICS, 89, 10, 5720, 5725, May 2001
English, Scientific journal - Epitaxial growth of transparent p-type conducting CuGaO2 thin films on sapphire (001) substrates by pulsed laser deposition
K Ueda, T Hase, H Yanagi, H Kawazoe, H Hosono, H Ohta, M Orita, M Hirano
JOURNAL OF APPLIED PHYSICS, 89, 3, 1790, 1793, Feb. 2001
English, Scientific journal - Transparent conducting indium-tin-oxide thin film with extremely flatted surface
Hiromichi Ohta, Masahiro Orita, Masahiro Hirano, Hideo Hosono
Materials Research Society Symposium - Proceedings, 666, F3151, F3156, Materials Research Society, 2001
English, International conference proceedings - Deep-UV transparent conductive β-Ga2O3 film
Masahiro Orita, Hiromichi Ohta, Masahiro Hirano, Hideo Hosono
Materials Research Society Symposium - Proceedings, 666, F291, F296, Materials Research Society, 2001
English, International conference proceedings - Bipolar electrical conductive transparent oxide, CuInO2
Hiroshi Yanagi, Kazushige Ueda, Hiromichi Ohta, Masahiro Hirano, Hideo Hosono
Materials Research Society Symposium - Proceedings, 666, F3141, F3146, Materials Research Society, 2001
English, International conference proceedings - Deep-ultraviolet transparent conductive beta-Ga2O3 thin films
M Orita, H Ohta, M Hirano, H Hosono
APPLIED PHYSICS LETTERS, 77, 25, 4166, 4168, Dec. 2000
English, Scientific journal - Current injection emission from a transparent p-n junction composed of p-SrCu2O2/n-ZnO
Hiromichi Ohta, Ken-Ichi Kawamura, Masahiro Orita, Masahiro Hirano, Nobuhiko Sarukura, Hideo Hosono
Applied Physics Letters, 77, 4, 475, 477, American Institute of Physics Inc., 24 Jul. 2000
English, Scientific journal - Highly electrically conductive indium-tin-oxide thin films epitaxially grown on yttria-stabilized zirconia (100) by pulsed-laser deposition
H Ohta, M Orita, M Hirano, H Tanji, H Kawazoe, H Hosono
APPLIED PHYSICS LETTERS, 76, 19, 2740, 2742, May 2000, [Lead author]
English, Scientific journal - UV-emitting diode composed of transparent oxide semiconductors: p-SrCu2O2/n-ZnO
H Ohta, K Kawamura, M Orita, N Sarukura, M Hirano, H Hosono
ELECTRONICS LETTERS, 36, 11, 984, 985, May 2000, [Lead author]
English, Scientific journal - Thermoelectric properties of (ZnO)5In2O3 thin films prepared by r.f. sputtering method
Hidenori Hiramatsu, Hiromichi Ohta, Won-Seon Seo, Kunihito Koumoto
Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy, 44, 1, 44, 49, Funtai Funamtsu Yakin Kyokai/Japan Soc. of Powder Metallurgy, 1997
Japanese, Scientific journal - Thermoelectric properties of homologous compounds in the ZnO-In2O3 system
H Ohta, WS Seo, K Koumoto
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 79, 8, 2193, 2196, Aug. 1996, [Lead author]
English, Scientific journal
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Japanese, Introduction scientific journal, 24741427 - 機能コアを活用した新機能薄膜の創成
太田裕道, 寺崎一郎, 齊藤圭司, まてりあ, 61, 10, 661, 665, Oct. 2022, [Invited], [Lead author, Corresponding author]
Japanese, Introduction scientific journal - 安心・安全な熱電変換材料を目指して－優れた変換性能をもつ層状酸化物Ba1/3CoO2
太田裕道, 化学, 76, 6, 68, 69, 01 Jun. 2021, [Invited], [Lead author, Corresponding author]
Japanese, Introduction scientific journal - 過去最高の室温熱電変換性能を示す酸化物の実現
太田裕道, クリーンエネルギー, 30, 3, 46, 49, 10 Mar. 2021, [Invited], [Lead author, Corresponding author]
Japanese, 24741427 - エレクトロクロミック素子の開発最前線－遷移金属酸化物の多彩な物性変化を利用してー
太田裕道, 學士會会報, 947, 81, 85, 01 Mar. 2021, [Invited], [Lead author, Corresponding author]
Japanese - Electron sandwich doubles the thermoelectric power factor of SrTiO3
Yuqiao Zhang, Hiromichi Ohta, Phys. Status Solidi A, 1800832, Mar. 2019, [Peer-reviewed], [Invited]
English, Introduction scientific journal - 薄い電子層を絶縁体でサンドイッチ：熱電変換特性を高める方法
太田裕道, 張 雨橋, 車載テクノロジー, 6, 5, 38, Feb. 2019, [Invited]
Japanese - Fabrication, characterization, and modulation of functional nanolayers
Hiromichi Ohta, Hidenori Hiramatsu, Nanoinformatics, 207, 235, 15 Jan. 2018, [Invited]
Springer Singapore, English - 特別記事・注目をあびるエレクトロクロミック材料とその可能性－窓ガラスがメモリーとして利用可能に－
太田 裕道, 工業材料, 65, 1, 78, 82, Feb. 2017, [Invited]
Japanese - Transition-metal-oxide based functional thin-film device using leakage-free electrolyte
Takayoshi Katase, Hiromichi Ohta, JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 125, 8, 608, 615, 2017, [Invited]
English, Book review - 薄膜プラズモン太陽電池の高性能化に向けた酸化チタンの電気特性の評価
中村圭佑, 片瀬貴義, 押切友也, 上野貢生, 太田裕道, 三澤弘明, 日本化学会春季年会講演予稿集(CD-ROM), 96th, 2016 - Electrolysis-induced protonation of VO2 thin film transistor for the metal-insulator phase modulation
Takayoshi Katase, Kenji Endo, Hiromichi Ohta, OXIDE-BASED MATERIALS AND DEVICES VII, 9749, 974916, 2016, [Peer-reviewed]
English - パルスレーザー堆積法による薄膜プラズモン太陽電池の光電変換特性
中村圭佑, 片瀬貴義, 押切友也, 上野貢生, 太田裕道, 三澤弘明, 日本化学会講演予稿集, 95th, 2, 2015 - ナノ構造熱電材料の開発動向
太田 裕道, 高分子, 63, 11, 785, Nov. 2014, [Invited]
Japanese - 7pAH-12 Field-effect modulated Seebeck coefficient in transition metal dichalcogenide monolayers
Ho,Kou, Kanahashi,K, Nguyen,Thanh Cuong, Li,Lain-Jong, Okada,S, Ohta,H, Takenobu,T, Meeting abstracts of the Physical Society of Japan, 69, 2, 470, Aug. 2014
The Physical Society of Japan (JPS), Japanese - Thermoelectric Seebeck effect of strontium titanate
太田 裕道, 応用物理, 81, 9, 740, 745, Sep. 2012
応用物理学会, Japanese - Thermoelectric oxides: Films and heterostructures
Hiromichi Ohta, Kunihito Koumoto, Multifunctional Oxide Heterostructures, 9780199584123, 30 Aug. 2012, [Peer-reviewed]
Oxford University Press, English - Unusually Large Thermopower Modulation of Electric Field Induced Two-dimensional Electron Gas
OHTA Hiromichi, Ceramics Japan : Bulletin of the Ceramic Society of Japan, 47, 7, 520, 523, 01 Jul. 2012
日本セラミックス協会, Japanese - アモルファス酸化物薄膜トランジスタの熱電能電界変調
小出 浩貴, 長尾 有記, 河本 邦仁, 高崎 裕加, 梅村 知也, 加藤 丈晴, 幾原 雄一, 太田 裕道, 応用物理学会学術講演会講演予稿集, 2011.1, 1500, 1500, 09 Mar. 2011
公益社団法人 応用物理学会, Japanese - Thermoelectric properties of SrTiO3: Bulks, superlattices, and transistors
Hiromichi Ohta, Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy, 57, 4, 232, 236, Apr. 2010
Japanese - Two-dimensional electron layers in SrTiO3: giant thermopower enhancement due to quantum size effect
太田 裕道, Materials science & technology, 79, 3, 219, 222, Mar. 2009
アグネ技術センター, Japanese - Microstructure and electron states of the dielectric TiO2/SrTiO3 heterointerface
太田 裕道, 溝口 照康, 幾原 雄一, Materials integration, 22, 9, 10,38-42, 42, 2009
ティー・アイ・シィー, Japanese - Strontium titanate: possibility as an oxide thermoelectric material
太田 裕道, 化学工業, 60, 1, 47, 50, Jan. 2009
化学工業社, Japanese - Fabrication and thermoelectric properties of heavily rare-earth metal doped SrO(SrTiO3)(n) (n = 1, 2) ceramics (vol 34, pg 849, 2008)
Yi Feng Wang, Kyu Hyoung Lee, Hiromichi Ohta, Kunihito Koumoto, CERAMICS INTERNATIONAL, 35, 1, 537, 537, Jan. 2009
English, Others - Direct observation of carrier entropy of thermoelectric cobaltate by photoemission spectroscopy
石田 行章, 藤森 淳, 太田 裕道, Solid state physics, 43, 6, 343, 349, 2008
アグネ技術センタ-, Japanese - 反応性固相エピタキシャル成長法
機能材料, 28, 27, 2008 - Oxide Superlattices
OHTA Hiromichi, IEEJ Transactions on Sensors and Micromachines, 128, 5, 290, 292, 2008
This article has no abstract., The Institute of Electrical Engineers of Japan, Japanese - 酸化物熱電変換材料の開発動向
セラミックス, 43, 966, 2008 - Thermoelectric properties of CaMnO3 system
R. Funahashi, A. Kosuga, N. Miyasou, E. Takeuchi, S. Urata, K. Lee, H. Ohta, K. Koumoto, PROCEEDINGS ICT 07: TWENTY-SIXTH INTERNATIONAL CONFERENCE ON THERMOELECTRICS, 124, 128, 2008, [Peer-reviewed]
English - Nonlinear thermoelectric properties of layered cobalt oxides
Tomohito Nakano, Wataru Kobayashi, Ryoji Funahashi, Kenji Sugiura, Hiromichi Ohta, Kunihito Koumoto, Ichiro Terasaki, PROCEEDINGS ICT 07: TWENTY-SIXTH INTERNATIONAL CONFERENCE ON THERMOELECTRICS, 121, 123, 2008, [Peer-reviewed]
English - 酸化物半導体の薄膜トランジスタへの応用
野村研二, 神谷利夫, 太田裕道, 平野正浩, 細野秀雄, 機能材料, 28, 3月号, 42, 53, 2008 - Enhanced Seebeck coefficient of amorphous oxide semiconductor superlattices
Hiromichi Ohta, Rong Huang, Yuichi Ikuhara, THERMOELECTRIC POWER GENERATION, 1044, 395, +, 2008, [Peer-reviewed]
English - Quantum size effect of 2DEG confined within BaTiO3/SrTiO3 : Nb superlattices
Yuki Nakanishi, Hiromichi Ohta, Teruyasu Mizoguchi, Yuichi Ikuhara, Kunihito Koumoto, THERMOELECTRIC POWER GENERATION, 1044, 375, +, 2008, [Peer-reviewed]
English - Origin of giant Seebeck coefficient for high density 2DEGs confined in the SrTiO3/SrTi0.8Nb0.2O3 superlattices
Yoriko Mune, Hiromichi Ohta, Teruyasu Mizoguchi, Yuichi Ikuhara, Kunihito Koumoto, THERMOELECTRIC POWER GENERATION, 1044, 369, +, 2008, [Peer-reviewed]
English - 19pWG-5 Electronic structure study of Nb-doped rTiO_3 thin film using resonant photoemission spectroscopy
Ishida Y., Eguchi R., Matsunami M., Horiba K., Taguchi M., Chainani Ashish, Senba Y., Ohashi H., Ohta H., Shin S., Meeting abstracts of the Physical Society of Japan, 62, 1, 592, 592, 28 Feb. 2007
The Physical Society of Japan (JPS), Japanese - Thermoelectrics based on Srtontium Titanate
Materials Today, 10, 44, 2007 - 毒性物質を使わない高性能酸化物熱電材料の開発
熱電学会誌, 3, 2, 2007 - 酸化物熱電変換材料-誘電体中に閉じ込められた二次元電子の巨大熱起電力-
セラミックス, 42, 592, 2007 - R&D: Giant thermopower of two-dimensionally confines electrons in dielectric SrTiO3 crystal
太田 裕道, Function & materials, 27, 69, 69, 74, 2007
シーエムシー出版, Japanese - 脱・重金属！！ありふれた金属酸化物で廃熱を電気に変える
化学, 62, 31, 2007 - 熱電現象の新発見-2DEGが発生する巨大熱起電力
セラミックデータブック2007（工業製品技術協会）, 35, 84, 2007 - SrTiO3:Nb薄膜の軟x線共鳴光電子分光
石田行章, 江口律子, 松波雅治, 堀場弘司, 田口宗孝, CHAINANI Ashish, 仙波泰徳, 大橋治彦, 太田裕道, SHIN S., SHIN S., 応用物理学関係連合講演会講演予稿集, 54th, 1, 2007 - 層状コバルト酸化物エピタキシャル薄膜成長 (特集/最近のセラミックス薄膜)
杉浦 健二, 太田 裕道, 河本 邦仁, Fine ceramics report, 25, 1, 23, 28, 2007
日本ファインセラミックス協会, Japanese - Thermoelectric properties of Nb-doped SrO(SrTiQ3)1 epitaxial films
K. H. Lee, A. Ishizaki, H. Ohta, K. Koumoto, International Conference on Thermoelectrics, ICT, Proceedings, 136, 139, 2007, [Peer-reviewed]
English - Thermoelectric properties and their relation to crystal structure of rare earth (RE = La, Nd, Sm and Gd)-doped SrO(SrTiO3)2 Ruddelsden-Popper phase
Y. F. Wang, K. H. Lee, H. Ohta, K. Koumoto, International Conference on Thermoelectrics, ICT, Proceedings, 157, 160, 2007, [Peer-reviewed]
English - Large thermoelectric response of Ti-containing perovskite oxides
Hiromichi Ohta, Shingo Ohta, Kunihito Koumoto, HIGH-PERFORMANCE CERAMICS IV, PTS 1-3, 336-338, 809, +, 2007, [Peer-reviewed]
English - 20aWG-2 Giant nonlinear conductivity on layered cobalt oxide
Nakano Tomohito, Kobayashi Wataru, Funahashi Ryoji, Sugiura Kenji, Ohta Hiromichi, Koumoto Kunihito, Terasaki Ichiro, Meeting Abstracts of the Physical Society of Japan, 62, 0, 607, 607, 2007
The Physical Society of Japan, Japanese - Reactive solid-phase epitaxy: A powerful method for epitaxial film growth of complex layered oxides
H Ohta, JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 114, 1326, 147, 154, Feb. 2006
English - Thermoelectric properties of layered perovskite-type Nb-doped SrO(SrTiO3)n (n = 1, 2) Ruddlesden-Popper phases
K. H. Lee, H. Ohta, K. Koumoto, International Conference on Thermoelectrics, ICT, Proceedings, 81, 84, 2006, [Peer-reviewed]
English - Effect of the Yb substitutions on the thermoelectric properties of CaMnO3
D. Flahaut, R. Funahashi, K. Lee, H. Ohta, K. Koumoto, ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 103, +, 2006, [Peer-reviewed]
English - Photoemission study of a Na0.8CoO2 epitaxial thin film with large thermoelectric power
Y. Ishida, H. Ohta, A. Fujimori, H. Hosono, LOW TEMPERATURE PHYSICS, PTS A AND B, 850, 1215, +, 2006, [Peer-reviewed]
English - Thermoelectric properties of epitaxial films of layered cobalt oxides fabricated by topotactic ion-exchange methods
Kenji Sugiura, Hiromichi Ohta, Kenji Nomura, Tomohiro Saito, Yuichi Ikuhara, Masahiro Hirano, Hideo Hosono, Kunihito Koumoto, ICT'06: XXV INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS, 99, +, 2006, [Peer-reviewed]
English - 電子デバイスの開発に向けたTOSの高品質エピタキシャル薄膜成長 (特集 最新セラミックス技術--高度化への材料・製法開発への挑戦)
太田 裕道, 工業材料, 53, 8, 70, 73, Aug. 2005
日刊工業新聞社, Japanese - New Research Cluster, What's happening!
OHTA Hiromichi, セラミックス, 40, 4, 321, 322, 01 Apr. 2005
Japanese - 25pWF-12 Photoemission study of Na_<0.8>CoO_2 epitaxial thin film
Ishida Y., Hashimoto M., Fujimori A., Sugiura K., Ohta H., Hirano M., Hosono H., Meeting abstracts of the Physical Society of Japan, 60, 1, 560, 560, 04 Mar. 2005
The Physical Society of Japan (JPS), Japanese - 透明酸化物半導体の高品質薄膜成長
機能材料, 25, 22, 2005 - 特集 世界の熱電変換研究 「n型酸化物熱電変換材料の設計指針～ﾍﾟﾛﾌﾞｽｶｲﾄ型SrTiO3～」
Chen Gang, Yang Ronggui, マテリアルインテグレーション, 18, 9, 31, 36, 2005
ティ-・アイ・シ-, English - Effective mass and thermoelectric properties of SrTiO3-based natural superlattices evaluated by ab-initio calculations
W Wunderlich, S Ohta, H Ohta, K Koumoto, ICT: 2005 24TH INTERNATIONAL CONFERENCE ON THERMOELECTRICS, 237, 240, 2005, [Peer-reviewed]
English - Electron transport and thermoelectric response of Nb- or La-doped SrTiO3 epitaxial film at high-temperature
S Ohta, T Nomura, H Ohta, M Hirano, H Hosono, K Koumoto, ICT: 2005 24TH INTERNATIONAL CONFERENCE ON THERMOELECTRICS, 168, 171, 2005, [Peer-reviewed]
English - 透明酸化物半導体を用いた透明電界効果トランジスタ
野村研二, 太田裕道, 神谷利夫, 平野正浩, 細野秀雄, マテリアルインテグレーション, 18, 2, 3, 9, 2005
ティ-・アイ・シ-, Japanese - 27pXS-5 Excitonic optical absorption in layered oxychalcogenides with natural MQW structure
Ueda K., Hiramatsu H., Ohta, Hirano M., Kamiya T., Hosono H., Meeting abstracts of the Physical Society of Japan, 59, 1, 726, 726, 03 Mar. 2004
The Physical Society of Japan (JPS), Japanese - 27aWP-7 Photoemission study of pn-junction formation in ZnO/NiO
Ishida Y., Fujimori A., Ohta H., Hirano M., Hosono H., Meeting abstracts of the Physical Society of Japan, 59, 1, 881, 881, 03 Mar. 2004
The Physical Society of Japan (JPS), Japanese - High-quality epitaxial film growth of transparent oxide semiconductors
J. Ceram. Soc. Jpn. Suppl., 112, S602-S609, 2004 - Transparent Oxide Optoelectronics
Materials Today, 7, 42, 2004 - 透明酸化物半導体とデバイスへの展開（分担）
オプトロニクス, 10, 2004 - Carrier transport of extended and localized states to InGaO3(ZnO)(5)
K Nomura, H Ohta, K Ueda, T Kamiya, M Hirano, F Hosono, INTEGRATION OF ADVANCED MICRO-AND NANOELECTRONIC DEVICES-CRITICAL ISSUES AND SOLUTIONS, 811, 391, 396, 2004
English - Frontier of transparent oxide semiconductors
H Ohta, K Nomura, H Hiramatsu, K Ueda, T Kamiya, M Hirano, H Hosono, SOLID-STATE ELECTRONICS, 47, 12, 2261, 2267, Dec. 2003
English - Third-order optical nonlinearity of transparent oxide semiconductors La CuOS-Se in UV region
Kamioka H., Hiramatsu H., Ohta H., Ueda K., Kamiya T., Hirano M., Hosono H., Meeting abstracts of the Physical Society of Japan, 58, 2, 616, 616, 15 Aug. 2003
The Physical Society of Japan (JPS), Japanese - 自然超格子構造を有する透明半導体―エピタキシャル成長と光・電子物性―（共著）
平松 秀典, 太田 裕道, 植田 和茂, 月刊ディスプレイ, 9, 5, 78, 83, 2003
テクノタイムズ社, Japanese - Wide-gap p-type conductive properties in layered oxychalcogenides
K Ueda, K Takafuji, H Hiramatsu, H Ohta, M Hirano, H Hosono, H Kawazoe, CRYSTALLINE OXIDE-SILICON HETEROSTRUCTURES AND OXIDE OPTOELECTRONICS, 747, 223, 233, 2003, [Peer-reviewed]
English - X-ray amorphous p-type conductive oxide; ZnRh2O4
S Narushima, H Mizoguchi, H Ohta, M Hirano, K Shimizu, K Ueda, T Kamiya, H Hosono, CRYSTALLINE OXIDE-SILICON HETEROSTRUCTURES AND OXIDE OPTOELECTRONICS, 747, 235, 240, 2003, [Peer-reviewed]
English - Heteroepitaxial growth of a wide gap p-type oxysulfide, LaCuOS
H Hiramatsu, K Ueda, H Ohta, M Hirano, H Hosono, CRYSTALLINE OXIDE-SILICON HETEROSTRUCTURES AND OXIDE OPTOELECTRONICS, 747, 359, 364, 2003, [Peer-reviewed]
English - Fabrication of transparent MISFET using InGaO3(ZnO)5 single crystalline thin film with normally insulating nature
Kenji Nomura, Hiromichi Ohta, Kazushige Ueda, Toshio Kamiya, Masahiro Hirano, Hideo Hosono, Mater. Res. Soc. Symp. Proc., 747, 267, 2003 - 上部電極にITO薄膜を用いたニオブ酸イットリウム薄膜のEL特性
山口誉滋, 掛本博文, 和田智志, 鶴見敬章, 太田裕道, 細野秀雄, 日本セラミックス協会2003年年会、3/22/03-3/24/03、東京, 2003 - Reactive Solid-Phase Epitaxy - A novel growth method for single-crystalline thin films of complex oxides with superlattice structure
H Ohta, K Nomura, H Hiramatsu, T Suzuki, K Ueda, M Orita, M Hirano, Y Ikuhara, H Hosono, CRYSTALLINE OXIDE-SILICON HETEROSTRUCTURES AND OXIDE OPTOELECTRONICS, 747, 257, 265, 2003
English - Fabrication of MISFET exhibiting normally-off characteristics using a single-crystalline InGaO3(ZnO)(5) thin film
K Nomura, H Ohta, K Ueda, T Kamiya, M Hirano, H Hosono, CRYSTALLINE OXIDE-SILICON HETEROSTRUCTURES AND OXIDE OPTOELECTRONICS, 747, 267, 272, 2003
English - HRTEM characterization of atomic structures in Cu/α-Al2O3 (0001) interface
Takeo Sasaki, Katsuyuki Matsunaga, Hiromichi Ohta, Hideo Hosono, Takahisa Yamamoto, Yuichi Ikuhara, Zairyo/Journal of the Society of Materials Science, Japan, 52, 6, 555, 559, 2003
Society of Materials Science Japan, Japanese - Epitaxial growth of transparent conductive oxides
H Ohta, M Orita, M Hirano, K Ueda, H Hosono, INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 16, 1-2, 173, 180, Jan. 2002
English - Fabrication and current injection UV-light emission from a transparent p-n heterojunction composed of p-SrCu2O2 and n-ZnO
H Ohta, M Orita, M Hirano, H Hosono, ASIAN CERAMIC SCIENCE FOR ELECTRONICS I, 214-2, 75, 80, 2002, [Peer-reviewed]
English - HRTEM and Orientation Relationship of Cu/Al2O3 Interface
T. Sasaki, K. Matsunaga, T. Yamamoto, H. Ohta, H. Hosono, Y. Ikuhara, Proc. of the International Conference on Designing of Interfacial Structures in Advanced Materials and their Joints, 237, 2002
English, Summary national conference - 透明導電膜の新展開II「第３章 p型透明酸化物半導体とpnヘテロ接合発光ダイオード」
太田裕道, 細野秀雄, エレクトロニクス材料・技術シリーズ, シーエムシー出版, 41, 2002 - P型アモルファス酸化物の発見とアモルファス酸化物PN接合の形成
鳴島暁, 溝口拓, 折田政寛, 太田裕道, 平野正浩, 神谷利夫, 清水健一, 細野秀雄, 第３５回アモルファス物質に関するセミナーテキスト, 63, 2002 - UV-LED composed of p-SrCu2O2 / n-ZnO heterojunction realized for the first time
J. Sur. Sci. Jpn., 22, 419, 2001 - 透明酸化物半導体を用いた近紫外発光ダイオードの開発
セラミックス, 36, 4, 285, 2001 - p‐SrCu2O2/n‐ZnOワイドバンドギャップp‐n接合ダイオードの試作とEL発光
太田裕道, 折田政寛, 河村賢一, 猿倉信彦, 平野正浩, 細野秀雄, 応用物理学関係連合講演会講演予稿集, 47th, 2, 578, 28 Mar. 2000
Japanese - 透明酸化物半導体の新しい展開
表面, 38, 7, 28, 2000 - Properties of a novel amorphous transparent conductive oxide, InGaO3(ZnO)(m)
M Orita, H Ohta, M Hirano, H Hosono, K Morita, H Tanji, H Kawazoe, MATERIALS SCIENCE OF NOVEL OXIDE-BASED ELECTRONICS, 623, 291, 296, 2000, [Peer-reviewed]
English - Low electrically resistive transparent indium-tin-oxide epitaxial film on (001) surface of YSZ by pulsed laser deposition
H Ohta, M Orita, M Hirano, H Hosono, H Kawazoe, H Tanji, MATERIALS SCIENCE OF NOVEL OXIDE-BASED ELECTRONICS, 623, 253, 258, 2000, [Peer-reviewed]
English - Room temperature operation of UV-LED composed of TCO hetero p-n junction, p-SrCu2O2/n-ZnO
H Ohta, K Kawamura, M Orita, N Sarukura, M Hirano, H Hosono, MATERIALS SCIENCE OF NOVEL OXIDE-BASED ELECTRONICS, 623, 283, 288, 2000
English - 初めて実現した酸化物紫外発光ダイオード：p-SrCu_2_O_2_/n-ZmO
太田裕道, 折田政寛, 平野正浩, 細野秀雄, 第２８５回蛍光体同学会講演資料集, 17, 22, 2000 - Heteroepitaxial growth of In2O3 on YSZ (100) single crystal surface
M Orita, H Ohta, H Tanji, H Hosono, H Kawazoe, FLAT-PANEL DISPLAYS AND SENSORS: PRINCIPLES, MATERIALS AND PROCESSES, 558, 399, 402, 2000
English - Heteroepitaxial growth of zinc oxide single crystal thin films on (111)plane YSZ by pulsed laser deposition
H Ohta, H Tanji, M Orita, H Hosono, H Kawazoe, EPITAXIAL GROWTH-PRINCIPLES AND APPLICATIONS, 570, 309, 313, 1999, [Peer-reviewed]
English - Thermoelectric characteristics of homologous compounds with Layer structures in the ZnO-In2O3 system
K Koumoto, H Ohta, WS Seo, PROCEEDINGS ICT '96 - FIFTEENTH INTERNATIONAL CONFERENCE ON THERMOELECTRICS, 172, 175, 1996, [Peer-reviewed]
English
Books and other publications
- 2D Nanomaterials for Energy Applications (1st Edition)
Yu-qiao Zhang, Hiromichi Ohta, 2D thermoelectrics
Elsevier, 01 Nov. 2019, [Contributor] - Thermoelectric Thin Films: Materials and Devices, Ed. Paolo Mele, Dario Narducci, Michihiro Ohta, Kaniskha Biswas, Juan Morante, Shrikant Saini, Tamio Endo
Hiromichi Ohta, Electric Field Thermopower Modulation of 2D Electron Systems
Springer, 18 Jul. 2019, 9783030200428, xv, 211 p., English, [Contributor] - エレクトロクロミックデバイスの開発最前線
太田裕道, 小野里尚記, 第2編 エレクトロクロミック材料の応用 酸化物エレクトロクロミック材料を用いたメモリデバイスの開発
シーエムシー出版, Jul. 2019, [Joint work] - 10.Fabrication, characterization, and modulation of functional nanolayers, Nanoinformatics
Hiromichi Ohta, Hidenori Hiramatsu, 10.Fabrication, characterization, and modulation of functional nanolayers
Springer, Feb. 2018, [Joint work] - Metal Oxide-Based Thin Film Structures (1st Edition) Formation, Characterization and Application of Interface-based Phenomena
OHTA Hiromichi, Chapter 4.3 Thermoelectrics
ELSEVIER, Sep. 2017, [Joint work] - 透明導電膜の技術 改訂3版
太田 裕道, 6・5 パルスレーザ堆積法
オーム社, Apr. 2014, [Joint work] - Multifunctional Oxide Heterostructures(Eds.) E. Y. Tsymbal, E. R. A. Dagotto, C-B. Eom, and R. Ramesh
H. Ohta, K. Koumoto, Chapter 10 Thermoelectric oxides: films and heterostructures
Oxford, 2012, [Joint work] - セラミック機能化ハンドブック
太田 裕道, 第3章 電子・磁性材料 第2節 熱電材料
エヌ・ティー・エス, 2011, [Joint work] - Handbook of Transparent Conductors (Editors: David Ginley, Hideo Hosono, and David Paine)
Hiromichi Ohta, Chapter 14 Junctions
Springer, 2010, [Joint work] - Handbook of Transparent Conductors (Editors: David Ginley, Hideo Hosono, and David Paine), Chapter 14 Junctions
Springer, 2010 - 無機材料必須300-原理・物性・応用（守吉佑介 編）
太田裕道, 核生成、結晶成長、スピノーダル分解、エピタキシャル成長、導電性材料、固体撮像材料
三共出版, 2008, [Joint work] - 熱電変換技術ハンドブック（梶川武信 監修 ）
太田裕道, 第2章第4節3 酸化物超格子
エヌ・ティ・エス, 2008, [Joint work] - 透明導電膜の技術（改訂2版）
太田裕道, 6章5節 「パルスレーザー堆積法」
オーム社, 2007, [Joint work] - 名古屋大学21世紀COE「自然に学ぶ材料プロセッシング」
太田裕道, 2.3.1 核生成・成長
三共出版, 2007, [Joint work] - 透明酸化物機能材料とその応用
太田裕道, 第2章 「透明p型導電性酸化物とpn接合デバイス」
シーエムシー出版, 2006, [Joint work] - 環境調和型新材料シリーズ「熱電変換材料の技術戦略」
太田裕道, 3章3節 構造・形態制御 「エピタキシャル薄膜」
日本セラミックス協会・日本熱電学会編, 2005, [Joint work] - 新訂版・薄膜作製応用ハンドブック
太田裕道, 細野秀雄, 「透明導電膜～ITOを中心に～」
エヌ・ティ・エス, 2002, [Joint work] - エレクトロニクス材料・技術シリーズ「透明導電膜の新展開II」
太田裕道, 細野秀雄, 第３章 p型透明酸化物半導体とpnヘテロ接合発光ダイオード
シーエムシー出版, 2002, [Joint work]
Lectures, oral presentations, etc.
- 全固体電気化学熱スイッチ
太田裕道
第9回フォノンエンジニアリング研究会, 18 May 2025, English, Invited oral presentation
18 May 2025 - 19 May 2025, 41337912, [Invited] - Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
Japan Meets India: Two Day Summit, IIT Gandhinagar (IITGN), India, 21 Mar. 2025, English, Public discourse
21 Mar. 2025 - 22 Mar. 2025, 41337912, [Invited] - Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
Seminar at Department of Physics, School of Energy Technology, Pandit Deendayal Energy University (PDEU), India, 19 Mar. 2025, English, Public discourse
19 Mar. 2025 - 19 Mar. 2025, 41337912, [Invited] - Solid-state electrochemical thermal transistors
Hiromichi Ohta
2nd RPI-HU Joint Seminar on Advanced Semisonductor and Related Technologies for Future Communication and Computing, 14 Feb. 2025, English, Public discourse
14 Feb. 2025 - 14 Feb. 2025, 41337912, [Invited] - Improvement in the Reliability for Polycrystalline Indium Oxide based Thin-Film Transistors by Epitaxial Passivation Layers
Prashant R. Ghediya, Yusaku Magari, Hikaru Sadahira, Takashi Endo, Mamoru Furuta, Yuqiao Zhang, Yasutaka Matsuo, Hiromichi Ohta
The 31st International Display Workshops (IDW ’24), 04 Dec. 2024, English, Invited oral presentation
04 Dec. 2024 - 06 Dec. 2024, 41337912, [Invited] - Development of Oxide-based Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
The 8th International Conference on Electronic Materials and Nanotechnology for Green Environment (ENGE 2024), 26 Nov. 2024, English, Invited oral presentation
24 Nov. 2024 - 27 Nov. 2024, 41337912, [Invited] - Oxide-based solid-state electrochemical thermal transistors
Hiromichi Ohta
Mini crossover seminar on functional materials 2024 ‘Haobo II’ -2024 Joint seminar of Tanaka-Lab, 26 Sep. 2024, English, Invited oral presentation
41337912, [Invited] - 全固体電気化学熱トランジスタの開発
太田裕道
金属学会 2024年秋期(第175回)講演大会, Japanese, Invited oral presentation
17 Sep. 2024 - 20 Sep. 2024, 41337912, [Invited] - 機能性酸化物の「機能」を引き出す薄膜成長とデバイス応用の可能性
太田裕道
応用物理学会 2024年(令和6年)秋季学術講演会, 16 Sep. 2024, Japanese, Invited oral presentation
16 Sep. 2024 - 20 Sep. 2024, 41337912, [Invited] - Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
Sakura Science Program, 09 Sep. 2024, English, Invited oral presentation
41337912, [Invited] - Oxide-based Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
NANO KOREA 2024, 05 Jul. 2024, English, Invited oral presentation
03 Jul. 2024 - 05 Jul. 2024, 41337912, [Invited] - Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
UNIST Special Seminar: Future Materials, 28 Jun. 2024, English, Public discourse
[Invited] - Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
Department Colloquium at Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 11 Jun. 2024, English, Public discourse
[Invited] - Solid-State Electrochemical Thermal Transistor based on Oxygen Sponge SrCoOx (2 < x < 3)
Hiromichi Ohta
2024 MRS Spring Meeting, 24 Apr. 2024, English, Invited oral presentation
[Invited] - CeO2薄膜の電気化学酸化・還元－熱トランジスタの高性能化に向けて－
ジョンアロン, 卞 志平, 吉村充生, フウビン, 幾原雄一, 曲 勇作, 太田裕道
2024年 第71回 応用物理学会春季学術講演会, 23 Mar. 2024, Japanese, Oral presentation - Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta
MRM2023/IUMRS-ICA2023 (Symposium A-4), 15 Dec. 2023, English, Invited oral presentation
[Invited] - 全固体電気化学熱トランジスタの開発
太田裕道, 楊 倩, Hai Jun Cho, Zhiping Bian, 吉村充生, Joonhyuk Lee, Hyoungjeen Jeen, Jinghuang Lin, Jiake Wei, Bin Feng, 幾原雄一
第49回固体イオニクス討論会, 15 Nov. 2023, Japanese, Oral presentation - A thermoelectric oxide, Ba1/3CoO2
Hiromichi Ohta
14th ISAJ Annual Symposium (Integrated Science for a Sustainable Society), 14 Nov. 2023, English, Keynote oral presentation
[Invited] - Functional oxide thin film growth and application – An introduction –
Hiromichi Ohta
Global Scholar Seminar for Emerging Semiconductor, Emerging Display, Automobile, and Energy, Hanyang University, 19 Oct. 2023, English, Public discourse
[Invited] - SrCoOx/YSZ-based Solid-State Electrochemical Thermal Transistors
Hiromichi Ohta, Qian Yang, Hai Jun Cho, Zhiping Bian, Mitsuki Yoshimura, Joonhyuk Lee, Hyoungjeen Jeen, Jinghuang Lin, Jiake Wei, Bin Feng, Yuichi Ikuhara
29th International Workshop on Oxide Electronics (iWOE29), 16 Oct. 2023, English, Oral presentation - SrCoOx-based solid-state electrochemical thermal transistors
Hiromichi Ohta
International Conference on Condensed Matter and Device Physics (ICCMDP-2023), 27 Sep. 2023, English, Invited oral presentation
[Invited] - 全固体電気化学熱トランジスタ：遷移金属酸化物の熱伝導率を電気的に切替える固体スイッチ
太田裕道
第84回 応用物理学会秋季学術講演会, 20 Sep. 2023, Japanese, Invited oral presentation
19 Sep. 2023 - 23 Sep. 2023, [Invited] - Film Growth of Functional Oxide Thin Films and Their Applications towards Optoelectronics and Thermoelectrics
Hiromichi Ohta
Lecture at Jiangsu University, 30 May 2023, English, Public discourse
[Invited] - 全固体電気化学熱トランジスタ
楊 倩, ジョヘジュン, 卞 志平, 吉村充生, イジュンヤク, ジンヒョンジン, 林 景煌, 魏 家科, 馮 斌, 幾原雄一, 太田裕道
第70回 応用物理学会 春季学術講演会, 17 Mar. 2023, Japanese, Oral presentation - Ba1/3CoO2: A Thermoelectric Oxide Showing a Reliable ZT of ∼0.55 at 600 °C in Air
Xi Zhang, Yuqiao Zhang, Liao Wu, Akihiro Tsuruta, Masashi Mikami, Hai Jun Cho, Hiromichi Ohta
7th International Conference on Advances in Functional Materials (AFM 2023), 12 Jan. 2023, English, Oral presentation - Thermoelectric Oxide Thin Films
Hiromichi Ohta
2022 Asian Conference on Nanoscience & Nanotechnology (AsiaNANO 2022), 09 Nov. 2022, English, Invited oral presentation
09 Nov. 2022 - 11 Nov. 2022, [Invited] - Ba1/3CoO2: 空気中，600 °Cで信頼できるZT ~0.55を示す熱電酸化物
張 習, 張 雨橋, 呉 礼奥, 鶴田彰宏, 三上祐史, ジョヘジュン, 太田裕道
2022年 第83回 応用物理学会秋季学術講演会, 20 Sep. 2022, Japanese, Oral presentation
20 Sep. 2022 - 23 Sep. 2022 - Ba1/3CoO2: 空気中，600 °Cで信頼できるZT ~0.55を示す熱電酸化物
張 習, 張 雨橋, 呉 礼奥, 鶴田彰宏, 三上祐史, ジョヘジュン, 太田裕道
第19回 日本熱電学会学術講演会, 08 Aug. 2022, Japanese, Oral presentation
08 Aug. 2022 - 10 Aug. 2022 - Thermoelectric Properties of Conducting Oxide Thin Films
Hiromichi Ohta
Physics Seminar in Pusan National University, 27 May 2022, English, Invited oral presentation
27 May 2022 - 27 May 2022, [Invited] - Solid-State Electrochemical Control of Oxygen Contents in Transition Metal Oxide Thin Films with Perovskite-Related Crystal Structure
Hiromichi Ohta, Qian Yang, Gowoon Kim, Xi Zhang
2022 MRS Spring Meeting & Exhibit, 08 May 2022, English, Oral presentation
08 May 2022 - 13 May 2022 - 全固体熱トランジスタ
楊 倩, イジュンヤク, ジンヒョンジン, 魏 家科, 馮 斌, 幾原雄一, ジョヘジュン, 太田裕道
2022年 第69回 応用物理学会 春季学術講演会, 22 Mar. 2022, Japanese, Oral presentation
22 Mar. 2022 - 26 Mar. 2022 - (学術賞受賞講演) 電子伝導性酸化物の薄膜化と熱電特性に関する研究
太田裕道
日本セラミックス協会 2022年 年会, 22 Mar. 2022, Japanese, Invited oral presentation
22 Mar. 2022 - 26 Mar. 2022, [Invited] - Solid-State Electrochemical Control of Physical Properties for Transition Metal Oxide Epitaxial Films with Perovskite-Related Crystal Structures
Hiromichi Ohta, Qian Yang, Hyoungjeen Jeen
The American Ceramic Society 2022 Conference on Electronic Materials and Applications (EMA 2022), 19 Jan. 2022, English, Invited oral presentation
19 Jan. 2022 - 21 Jan. 2022, [Invited] - Thermoelectric Energy Conversion using Metal Oxide Thin Films
Hiromichi Ohta
The 22nd RIES-HOKUDAI International Symposium, 05 Dec. 2021, English, Invited oral presentation
05 Dec. 2021 - 07 Dec. 2021, [Invited] - 反応性固相エピタキシャル成長法＋イオン交換法 ―層状酸化物エピタキシャル薄膜を作る方法―
太田裕道
第82回 応用物理学会秋季学術講演会, 11 Sep. 2021, Japanese, Invited oral presentation
24741427, [Invited] - 導電性酸化物薄膜の熱電変換特性
太田裕道
日本学術振興会 R025委員会 ８月研究会「エナジーハーベスティングデバイスの新材料・新構造・新プロセス（熱電変換，太陽電池）」, 23 Aug. 2021, Japanese, Invited oral presentation
24741427, [Invited] - 金属酸化物薄膜の熱電能・熱伝導
太田裕道
2021年 第68回 応用物理学会春季学術講演会, 16 Mar. 2021, Japanese, Invited oral presentation
24741427, [Invited] - Suppression of Anisotropic Heat Conduction in Ion-substituted Layered Cobalt Oxides
Hiromichi Ohta, Hai Jun Cho, Yugo Takashima, Takaki Onozato
Pacific Rim Meeting on Electrochemical and Solid State Science (PRiME 2020), 04 Oct. 2020, English, Oral presentation
24741427 - イオン置換を施した層状コバルト酸化物AxCoO2の異方的熱伝導率
太田裕道, 高嶋佑伍, 小野里尚記, ジョ ヘジュン
日本セラミックス協会 第33回秋季シンポジウム, 02 Sep. 2020, Japanese, Oral presentation
24741427 - Electron transport properties of wide bandgap transparent oxide semiconductor, BaSnO3-SrSnO3
Hiromichi Ohta
The 12th International Workshop on Oxide Surfaces: IWOX-XII, 06 Jan. 2020, English, Invited oral presentation
05 Jan. 2020 - 10 Jan. 2020, [Invited] - Single Crystalline Film Growth of Layer Structured Oxides and Their Phonon Transports
Hiromichi Ohta, Hai Jun Cho, Yuzhang Wu, Bin Feng, Masashi Mikami, Woosuck Shin, Yuichi Ikuhara, and Keiji Saito
2019 MRS Fall Meeting, 03 Dec. 2019, English, Invited oral presentation
01 Dec. 2019 - 06 Dec. 2019, [Invited] - 酸化物を使った電界（電解）効果トランジスタの開発
太田裕道
日本セラミックス協会東北北海道支部 第27回北海道地区セミナー2019, 25 Nov. 2019, Japanese, Invited oral presentation
[Invited] - 透明酸化物半導体BaSnO3–SrSnO3の電子輸送―エピタキシャル薄膜と薄膜トランジスタ―
太田裕道
日本金属学会 2019年秋期(第165回)講演大会, 13 Sep. 2019, Japanese, Invited oral presentation
11 Sep. 2019 - 13 Sep. 2019, [Invited] - Double enhancement of thermoelectric power factor in SrTiO3 based electron sandwitch
Hiromichi Ohta, Yuqiao Zhang
4th Functional Oxide Thin Films for Advanced Energy and Information Technology Conference, 17 Jul. 2019, English, Invited oral presentation
[Invited], [International presentation] - Thermoelectric properties of two-dimensional electron system -superlattices and TFT channel-
OHTA Hiromichi
2019 Asia-Pacific Workshop on Fundamentals and Applications of Advanced Semiconductor Devices (AWAD 2019), 01 Jul. 2019, English, Invited oral presentation
[Invited], [International presentation] - Electron transport properties of transparent oxide semiconductor, BaSnO3-SrSnO3: Epitaxial films and thin film transistors
Hiromichi Ohta, Anup V. Sanchela
EM-NANO 2019, 19 Jun. 2019, English, Invited oral presentation
[Invited], [International presentation] - 熱電変換材料としての金属酸化物の可能性
太田 裕道
第5回大型実験施設とスーパーコンピュータとの連携利用シンポジウム, 15 Mar. 2019, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - 熱電材料の二次元薄膜化と特性向上
太田 裕道
日本学術振興会161委員会 研究会, 24 Jan. 2019, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Electric field thermopower modulation measurements of two-dimensional electron gas
OHTA Hiromichi
International mini-workshop on Nonequlibrium transport and phase transition in novel materials, 26 Nov. 2018, English, Invited oral presentation
[Invited], [International presentation] - Double thermoelectric powerfactor of a 2D electron system
OHTA Hiromichi
the International Conference on Electronic Materials and Nanotechnology for Green Environment (ENGE 2018), 11 Nov. 2018, English, Invited oral presentation
[Invited], [International presentation] - Development of three-terminal electrochromic device using water electrolysis
OHTA Hiromichi
IUMRS-ICEM 2018, 19 Aug. 2018, English, Invited oral presentation
[Invited], [International presentation] - Thermopower of 2D electron systems
OHTA Hiromichi
The 2018 International Symposium for Advanced Materials Research (ISAMR 2018), 16 Aug. 2018, English, Invited oral presentation
[Invited], [International presentation] - 捨てられている熱を電気に変える熱電変換材料
太田 裕道
国立大学共同利用・共同研究拠点協議会 知の拠点セミナー, 20 Jul. 2018, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Double enhancement of thermoelectric power factor in two-dimensional electron system
OHTA Hiromichi
the 16th International Nanotech Symposium & Nano-Convergence Exhibition, NANO KOREA 2018, 10 Jul. 2018, English, Invited oral presentation
[Invited], [International presentation] - Electric field thermopower modulation of two-dimensional electron gas
OHTA Hiromichi
The 25th International Workshop on Active-Matrix Flatpanel Displays and Devices – TFT Technologies and FPD Materials – (AM-FPD 18), 03 Jul. 2018, English, Invited oral presentation
[Invited], [International presentation] - 二次元電子層のSeebeck効果－人工超格子と電界誘起二次元電子ガス－
太田 裕道
物性談話会, 14 Jun. 2018, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Thermoelectric Seebeck effect of 2D electron systems
OHTA Hiromichi
The first International Joint Symposium of CEFMS-NCTU, RCAS-AS (Taiwan) and 5-Star Alliance (Japan), 18 May 2018, English, Invited oral presentation
[Invited], [International presentation] - Thermopower of two-dimensional electron system
OHTA Hiromichi
Physics Seminar in Pusan National University, 30 Apr. 2018, English, Invited oral presentation
[Invited], [International presentation] - 二次元電子系の熱電ゼーベック効果
太田 裕道
第65回 応用物理学会春季学術講演会, 17 Mar. 2018, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - 水を使った機能性酸化物の光・電気・磁気特性切替え
太田 裕道
平成29年度日本表面科学会東北・北海道支部講演会, 08 Mar. 2018, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - 半導体薄膜の熱電特性
太田 裕道
電子情報通信学会シリコン材料デバイス・電子デバイス合同研究会, 08 Mar. 2018, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Thermopower of oxide heterostructure
H. Ohta, A. Sanchela
ICAMD2017 (The 11th International Conference on Advanced Materials and Devices), 05 Dec. 2017, English, Invited oral presentation
[Invited], [International presentation] - Double enhancement of thermoelectric power factor in oxide two-dimensional electron system via precise dimensionality control
Hiromichi Ohta, Yu-Qiao Zhang
2017 Fall Korean Physical Society (KPS) Meeting, 25 Oct. 2017, English, Invited oral presentation
[Invited], [International presentation] - 薄膜トランジスタ構造を用いた熱電能の計測
太田 裕道
第14回 薄膜材料デバイス研究会, 20 Oct. 2017, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Electric field thermopower modulation measurement
OHTA Hiromichi
Seoul National University, 13 Oct. 2017, English, Public discourse
[Invited], [International presentation] - Epitaxial film growth and some applications of functional oxides
OHTA Hiromichi
Distinguished Lecture Series at Materials Science & Engineering, 03 Oct. 2017, English, Public discourse
[Invited], [International presentation] - Electrochemical modulation of functional oxides using three-terminal thin film transistor structure with water infiltrated gate dielectrics
OHTA Hiromichi
Seminar at Tshinghua University (hosted by Prof. Yu Pu), 26 Sep. 2017, English, Public discourse
[Invited], [International presentation] - 水を使った機能性酸化物薄膜の光・電気・磁気物性切替え手法
太田 裕道
産業技術総合研究所 中部センター 講演会, 15 Sep. 2017, Japanese, Public discourse
[Invited], [Domestic Conference] - 固相エピタキシャル成長法を駆使した機能性酸化物ナノ層の創製
太田 裕道
06 Sep. 2017, Japanese, Keynote oral presentation
[Invited], [Domestic Conference] - Electric field modulation of thermopower in two-dimensional electron gas
H. Ohta
IUMRS-ICAM (The 15th International Conference on Advanced Materials), 27 Aug. 2017, English, Invited oral presentation
[Invited], [International presentation] - Electrochemical function modulation of oxides using three-terminal thin film transistor structure with water infiltrated insulator
OHTA Hiromichi
The 3rd Functional Oxide Thin Films for Advanced Energy and Information Technology, 05 Jul. 2017, English, Invited oral presentation
[Invited], [International presentation] - 導電性酸化物薄膜の物性改質方法
太田 裕道
第64回応用物理学会春季学術講演会（合同セッションK, シンポジウム「金属酸化物の結晶物性に迫る」）, 14 Mar. 2017, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Thermoelectric Seebeck effect of two dimensional electron gas in SrTiO3
OHTA Hiromichi
International conference on Advances in Functional Materials (ICAFM2017), 06 Jan. 2017, English, Invited oral presentation
[Invited], [International presentation] - Unusually large thermopower of nanostructured oxides
OHTA Hiromichi
ENGE 2016 (International Conference on Electronic Materials and Nanotechnology for Green Environment), 06 Nov. 2016, English, Invited oral presentation
[Invited], [International presentation] - 熱電能電界変調法：AlGaN/GaN-MOSHEMT
太田裕道, 金木奨太, 橋詰 保
2016年 第77回応用物理学会秋季学術講演会, 13 Sep. 2016, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Electro-chemical redox switching of functional oxide thin films using water-infiltrated nanoporous glass
H. Ohta, T. Katase
International Workshop on Oxide Surfaces (IWOX-X), 10 Jan. 2016, English, Invited oral presentation
[Invited], [International presentation] - Water electrolysis induced modification of functional oxides−Thermoelectric properties−
H. Ohta, T. Katase
IUMRS-ICAM 2015, 25 Oct. 2015, English, Invited oral presentation
[Invited], [International presentation] - 熱電変換材料って何？
太田 裕道
日本化学会秋季事業 第5回CSJ化学フェスタ2015, 13 Oct. 2015, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - 水の電気分解を利用した機能性酸化物ナノ層創製
太田 裕道
日本金属学会 2015年秋期講演大会, 16 Sep. 2015, Japanese, Keynote oral presentation
[Invited], [Domestic Conference] - Development of oxide-based nanostructured thermoelectric materials
H. Ohta
4th International Symposium on Energy Challenges and Mechanics -working on small scales, 11 Aug. 2015, English, Keynote oral presentation
[Invited], [International presentation] - Two-dimensional giant thermopower –SrTiO3-based superlattices and transistors-
H. Ohta
The American Ceramic Society’s 11th International Conference on Ceramic Materials and Components for Energy and Environmental Applications (CMCEE-11), 14 Jun. 2015, English, Invited oral presentation
[Invited], [International presentation] - Thermoelectric effect of extremely thin electron doped SrTiO3
H. Ohta
The 1st IOP-RIES Joint Workshop, 23 Mar. 2015, English, Invited oral presentation
[Invited], [International presentation] - Thermopower enhancement of two-dimensional electron gas in oxide semiconductors
H. Ohta
The American Ceramic Society’s Electronic Materials and Applications 2015 (EMA2015), 21 Jan. 2015, English, Invited oral presentation
[Invited], [International presentation] - 酸化物薄膜作製におけるパルスレーザー堆積法とその応用
太田 裕道
3次元造形＆薄膜実践セミナー, 26 Sep. 2014, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - 水電気分解を利用した酸化物の熱電能変調
太田 裕道
第75回 応用物理学会秋季学術講演会（シンポジウム：固液界面を使った新しい酸化物エレクトロニクス：化学とデバイスの融合）, 17 Sep. 2014, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Epitaxial Film Growth and Application of Functional Oxides
OHTA Hiromichi
HOKUDAI-NCTU Joint Symposium on Nano, Photo and Bio Sciences, RIES, 10 Sep. 2014, English, Invited oral presentation
[Invited], [International presentation] - 酸化物半導体に蓄積された二次元電子ガスー熱電能を中心にー
太田 裕道
統合物質創製化学推進事業 第５回若手研究会, 23 Jun. 2014, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Electric Field Modulation of a Thermoelectric Material
OHTA Hiromichi
Thermec 2013, 04 Dec. 2013, English, Invited oral presentation
[Invited], [International presentation] - 酸化物半導体のエピタキシャル薄膜成長
太田 裕道
酸化物アライアンス第11回研究会(第5回公開講演会)「透明導電膜のサイエンス」, 24 May 2013, Japanese, Public discourse
[Invited], [Domestic Conference] - Two dimensional thermoelectric effect
OHTA Hiromichi
Distinguished Lecture Series for 2012 fall semester in Sungkyunkwan University, 12 Dec. 2012, English, Public discourse
[Invited], [International presentation] - Electric field thermopower modulation of 2DEG in oxide semiconductor based field effect transistors
太田 裕道
MRS 2012 Fall Meeting, 26 Nov. 2012, English, Invited oral presentation
[International presentation] - Unusually large thermopower enhancement in an electric field induced two-dimensional electron gas
太田 裕道
E-MRS 2012 Spring Meeting, 14 May 2012, English, Invited oral presentation
[Invited], [International presentation] - Electric-Field Thermopower Modulation Method
太田 裕道
Japan-Finland March Meeting for the future in thermoelectrics, 13 Mar. 2012, English, Invited oral presentation
[Invited], [International presentation] - 高分解能X線回折法による金属酸化物薄膜の分析
太田裕道
第240回Ｘ線分析研究懇談会, Dec. 2011
名古屋大学 - ナノ孔に閉じ込められた水を利用した二次元電子ガス生成と巨大熱電能変調
太田裕道, 水野 拓, S. Zheng, 加藤丈晴, 幾原雄一, 安部勝美, 雲見日出也, 野村研二, 細野秀雄
日本金属学会2011年秋期大会, Nov. 2011
沖縄コンベンションセンターおよびカルチャーリゾートフェストーネ（沖縄） - 電界誘起二次元電子ガスの巨大熱電能変調
太田裕道, 水野 拓, Shijian Zheng, 加藤丈晴, 幾原雄一, 安部勝美, 雲見日出也, 野村研二, 細野秀雄
第72回応用物理学会学術講演会, Aug. 2011
山形大学小石川キャンパス（山形） - 温度差で発電する熱電材料-酸化物の挑戦
太田裕道
超精密加工専門委員会第62回研究会（高度エネルギー変換材料）, Jul. 2011
大阪ガーデンパレス（大阪） - チタン酸ストロンチウムの熱電現象
太田裕道
新化学発展協会 電子情報技術部会講演会, Mar. 2011
新化学発展協会会議室（東京） - 水の電気分解を利用したSrTiO3の金属化と熱電能
太田裕道
第55回固体イオニクス研究会「遷移金属複合酸化物：新しい合成法、物質、物性」, Jan. 2011
京都国際会館（京都）
Works
- 科学研究費補助金 新学術領域研究（研究領域提案型）領域番号6103 「機能コアの材料科学」（領域代表者：松永克志 教授・名古屋大学）19H05791 界面制御による高機能薄膜材料創製（研究代表者）
2019 - 2023 - 科学研究費補助金 基盤研究(A) 17H01314 熱電材料の高ZT化に向けたナノ周期平行平板構造の熱伝導率解明（研究代表者）
太田 裕道, Apr. 2017 - 科学研究費補助金 基盤研究（A) 25246023 酸化物半導体一次元電子ガスの電界誘起と超巨大熱電能変調（研究代表者）
太田 裕道, Apr. 2013 - 科学研究費補助金 新学術領域研究（研究領域提案型）領域番号2505 「ナノ構造情報のフロンティア開拓－材料科学の新展開」（領域代表者：田中 功 教授・京都大学）25106007 原子層制御による新しい材料機能探索（研究代表者）
太田 裕道, 2013 - 科研費基盤研究（Ｂ）「酸化物薄膜トランジスタにおける巨大熱電能の電界変調と赤外線センサー応用」
2010 - 2012 - 科研費特定領域「電界誘起二次元電子層の可視化」
2010 - 2011 - 科学技術振興機構さきがけ「電界誘起二次元伝導層の熱起電力と制御」
2008 - 2011 - 科研費特定領域「誘電体へテロ界面に蓄積された二次元電子ガスの電子状態と量子サイズ効果の起源」
2008 - 2010 - 科研費若手研究(A)「二次元電子ガスを有する酸化物超格子の作製と熱電変換物性」
2006 - 2008 - NEDO産業技術研究助成事業「局在化した二次元電子ガスを有する誘電体人工超格子の作製と熱電変換材料への応用」
2005 - 2008
Research Themes
- Creation of Solid-State Thermal Transistor
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
Apr. 2022 - Mar. 2026
Hiromichi Ohta
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, Principal investigator, 22H00253 - 機能コアの材料科学
科学研究費助成事業
28 Jun. 2019 - 31 Mar. 2024
松永 克志, 阿部 真之, 遊佐 斉, 柴田 直哉, 平山 雅章, 溝口 照康, 太田 裕道, 北岡 諭
本領域研究では、世界最高水準の電子状態計算、モデル実験、ナノ計測を三本柱とし、機能材料、エネルギー材料、構造材料分野で高い研究業績を上げている研究者らと一体になって、機能コアの概念に立脚した新しい材料科学の学理を構築する。総括班ではこの領域の目的を達成するため、以下のような活動を行った。
1) 2021年9月28日および2022年3月30日に総括班会議を開催し、本領域の研究進捗状況について議論した。また、今後の領域運営や計画班運営について、各計画班研究代表者に助言・指導を与えた。さらに、2021年9月28日に領域全体会議をオンライン開催し、領域内研究者との意見交換を通じて今後の研究連携を検討した。2)連携研究および設備有効利用の促進のため設置している、計算解析センター、ナノ計測センター、モデル試料センターについて運営状況の確認や今後の方針策定を行った。3)若手育成支援としてオンラインでの若手の会（若手コラボツアー）を計3回実施した。4)成果公表活動として、2022年3月30日に2021年度公開シンポジウムをオンライン開催した。また国内学会での公募シンポジウムを1件、国際会議でのシンポジウムを1件主催し、機能コアのコンセプトを国内外に広く公表・周知した。5)アウトリーチ活動として、名古屋大学で開催された「テクノフェア名大」で本領域のオンラインブース展示を行い、一般も含む参加者に広く本領域のコンセプトを周知した。またSNS等を活用した本領域の情報発信にも取り組んだ。
日本学術振興会, 新学術領域研究(研究領域提案型), 名古屋大学, 19H05785 - Fabrication of highly functional thin film materials by controlling the interface
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Jun. 2019 - Mar. 2024
太田 裕道, 寺崎 一郎, 齊藤 圭司
物質の原子スケールにおける熱伝導や電子伝導を可視化することができれば、新しい材料やデバイス開発に繋がる。本研究では、目に見える大きさのものとは全く異なる熱輸送特性や電子輸送特性を示す原子スケールの特殊な界面を「機能コア」と位置づけ、超精密な薄膜・デバイス作製技術を駆使して機能コアを導入したモデル材料を作製し、相界面における熱輸送特性や電子輸送特性を調査し、巨大機能の発現とその制御を目指している。太田Gr.では、遷移金属酸化物エピタキシャル薄膜の熱伝導率を計測した。各種薄膜およびデバイスの機能コアの可視化については、A01(ア)(イ)班、A02(ウ)(エ)班、必要時に随時海外共同研究者に分析・解析を依頼した。寺崎Gr.では、機能性熱伝導物質を設計し、単結晶育成を行った。齊藤Gr.では、太田Gr.で得られた熱伝導率の結果を踏まえて機能コアの界面熱抵抗のモデル化を行った。また、太田Gr.では下記の研究成果に関してプレス発表を行った（2020年11月2日）。層状コバルト酸化物Na3/4CoO2薄膜のナトリウムイオンを様々な金属イオン（Ca1/3, Sr1/3, Ba1/3）に置き換えた結果、金属イオン層が重くなるにつれて、電気的な特性は変化せず、熱伝導率だけが減少することを突き止め、最終的に重いバリウムイオンに置き換えたとき、室温で熱電変換性能指数ZTが0.11に達することを発見した。一般に、性能指数ZTは高温になるほど上昇することから、真に安定で実用的な熱電変換材料の実現が期待される。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Hokkaido University, 19H05791 - Phonon transport properties of thermoelectric oxide thin films and superlattices
Grants-in-Aid for Scientific Research
25 Apr. 2019 - 31 Mar. 2021
太田 裕道, ZHANG YUQIAO
外国人特別研究員・張 雨橋 博士との共同研究では、酸化物熱電材料の高性能化をターゲットとして、層状構造を有する酸化物の熱伝導率の精密計測や、固溶体形成に起因する格子歪と熱伝導率の関係の調査などを行った。張博士は酸化物薄膜試料の作製、熱電特性の計測、熱伝導率の計測の実験を担当した。受入研究者である太田は研究計画作成を行った。
本研究の特筆すべき成果は、層状コバルト酸化物Ba1/3CoO2薄膜が、室温における熱電変換性能指数ZT = 0.11を示すことを見出したことである。この値は公表されている酸化物（信頼性のある値として）の室温におけるZTの中では最大である。
また、自然超格子InGaO3(ZnO)m（mは自然数）単結晶薄膜の超格子に対して直交方向の熱伝導率が、多結晶InGaO3(ZnO)mよりも低いことを発見した。単結晶なのに多結晶よりも熱を通さないという、この驚くべき結果は、熱電材料の低熱伝導率化に向けた材料設計指針を与えるだけでなく、超低熱伝導セラミックス実現のための重要な知見となる。
さらに、これまで熱伝導率に及ぼす電子の寄与が大きいとされてきたSrTiO3－SrNbO3－LaTiO3系固溶体を薄膜化し、熱伝導率を精密計測した結果、固溶体形成による格子熱伝導率の減少が顕著に起こるため、キャリア電子濃度が極めて高いにもかかわらず、熱伝導率は低いことが分かった。
以上のように、本共同研究では、酸化物熱電材料の高性能化の鍵となる低熱伝導率化に関する重要な知見を得ることができた。
Japan Society for the Promotion of Science, Grant-in-Aid for JSPS Fellows, Hokkaido University, 19F19049 - Thermal conductivity clarification of parallel plate structured material with nanometer sized period - Toward realization of high ZT thermoelectric materials -
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
Apr. 2017 - Mar. 2021
Ohta Hiromichi
In thermoelectric conversion technology that converts heat into electricity, metal oxides (thermally and chemically stable, harmless) are attractive thermoelectric material candidates, but because of their high thermal conductivity, there is a problem that their efficiency is lower than the conventional thermoelectric materials. In this study, in order to experimentally elucidate the effect of the nanoperiodic parallel plate structure on the thermal conductivity, single crystal thin films of metal oxides having a layered structure were prepared, and the thermal conductivity in the directions orthogonal to and parallel to the layer was precisely measured. 1) InGaO3(ZnO)m: It was found that the thermal conductivity of the nanoperiodic parallel plate structure in the plane perpendicular direction is lower than the thermal conductivity of polycrystals. 2) Layered cobalt oxide thin film: It was found that Ba1/3CoO2 thin film shows the highest room temperature figure of merit (ZT = 0.11).
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 17H01314 - エネルギー応用に向けた層状遷移金属酸化物の機能化
二国間交流事業（韓国との共同研究）
Apr. 2018 - Mar. 2020
太田 裕道
日本学術振興会, Principal investigator, Competitive research funding - 半導体界面に蓄積された二次元電子ガスの熱電能電界変調
2017年度 ステップアップ助成
Apr. 2017 - Mar. 2020
太田 裕道
旭硝子財団, Principal investigator, Competitive research funding - 色・導電率を切替え可能な三端子型WO3薄膜トランジスタの低電圧・高速動作に向けた材料改質
平成29年度 自然科学部門 助成金
Oct. 2017 - Sep. 2018
太田 裕道
三菱財団, Principal investigator, Competitive research funding - Exploration of nanostructure-property relationships for materials innovation
Grants-in-Aid for Scientific Research
06 Nov. 2015 - 31 Mar. 2018
TANAKA Isao, MATSUNAGA Katsuyuki, MUTO Shunsuke, TANIGUCHI Takashi, KITAOKA Satoshi, KANNO Ryoji, TAKAKUSAKI Satoru, TSUDA Koji
This group encouraged many international activities of project members. This group supported publishing an open-access international book of our research summary, publishing a special issue in an international journal and providing a series of lectures on our studies. This group also supported young researches to collaborate with foreign researchers.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Kyoto University, 15K21748 - Exploration of nanostructure - property relationships for materials innovation
Grants-in-Aid for Scientific Research
28 Jun. 2013 - 31 Mar. 2018
TANAKA Isao, MATSUNAGA Katsuyuki, SHIBATA Naoya, MUTO Shunsuke, TANIGUCHI Takashi, OHTA Hiromichi, KITAOKA Satoshi, KANNO Ryoji, TAKAKUSAKI Satoru, TSUDA Koji, ADACHI Hirohiko, SAKUMA Taketo, TAKANO Mikio, MORI Hirotaro, HIGUCHI Tomoyuki
This group mainly encouraged the collaboration between project members. This group organized international symposiums for publishing our studies, organized many small workshops for accelerating the communication between researchers with different backgrounds, published an international book of our research summary, and encouraged may activities of young researchers. In addition, this group supported the building of a web site and publication of a booklet.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Kyoto University, 25106001 - Charge transport in photo-doped conductors
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
Apr. 2014 - Mar. 2018
Terasaki Ichiro, KOHNO Hiroshi, OKAZAKI Ryuji, TANABE Kenji, FUJITA Masaru, SHIRAISHI Yuuka, MAIGNAN Antoine
The purpose of this research is to create conductors by irradiating light to oxide insulators, to precisely measure their transport parameters, and to clarify the transport properties and microscopic mechanism of the photo-doped carrier.
Various insulators such as ZnS, ZnO, SrTiO3, CuO, La2CuO4, CuFeS2 were irradiated with light from visible to ultraviolet region. Then we quantitatively measured the photoconductivity, the photo-Hall coefficient, and the photo-Seebeck coefficient, and have clarified the transport characteristics of the photo-doped carrier. In particular, we have revealed that the thermopower is screened by quantum paraelectricity in SrTiO3. We have also found that thin films, single crystals and polycrystaline samples of ZnO show nearly the same saturated photo-Seebeck coefficient.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Nagoya University, 26287064 - Searching for new materials functions by atomic layer control
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Jun. 2013 - Mar. 2018
Ohta Hiromichi, KATASE TAKAYOSHI, YAMANOUCHI MICHIHIKO
In this study, we fabricated “Nano-layers”, which are thin films controlled in the thickness at the atomic level. We searched for new materials functions, and worked on the development of Nanostructure information by providing the nano-layers to other groups. The major results are listed below. [1] We successfully enhanced the thermoelectric power factor of oxide-based superlattices double compared with the bulk. [2] We clarified the origin of carrier mobility suppression of a transparent oxide semiconductor and successfully realized high carrier mobility. [3] We found that two-dimensional electron gas in semiconductor shows high thermoelectric power factor. [4] We realized thin-film devices, which can switch their optical transmission, electrical resistivity, and magnetic properties simultaneously. [5] We realized iron-based superconducting films on the metallic tapes, which showed high critical current density suitable as practical applications.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Hokkaido University, 25106007 - Electric field accumulation and giant thermopower modulation of one dimensional electron gas in oxide semiconductors
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
Apr. 2013 - Mar. 2017
Ohta Hiromichi, KATASE TAKAYOSHI
In this study, I targeted electric field accumulation and observation of giant thermopower of one dimensional electron gas (1DEG) by AFM lithography technique utilizing an electrochemical redox reaction between H+/OH- ions in the nanoporous glass and oxide semiconductors. Although I succeeded AFM lithography of SrTiO3-1DEG since the resultant shape suggested 1DEG formation, the thermopower could not be measured due to the low stability of the resultant 1DEG. Therefore, I searched more appropriate materials, which show stable redox reaction. As a result, I observed several stable reversible redox reactions such as insulating VO2 - metal HxVO2, insulating SrCoO2.5 - metal SrCoO3, and insulating WO3 - metal HWO3 by using H+/OH- ions in the nanoporous glass. These results appeared on Journal papers, newspapers, and TV. Unfortunately 1DEG has not been realized in this study duration, I think that 1DEG can be realized by AFM lithography of the above materials near future.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 25246023 - 超微細熱電材料用汎用熱電能計測装置の開発
平成26年度研究助成金
Apr. 2014 - Mar. 2016
太田 裕道
旭硝子財団, Principal investigator, Competitive research funding - 二次元電子層の電界制御と熱起電力に関する研究
さきがけ
Oct. 2008 - Mar. 2012
太田裕道
科学技術振興機構, Principal investigator, Competitive research funding - Electric Field Modulation of Giant Thermopower in Oxide Thin FilmTransistors and its Application for IR Sensor
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
2010 - 2012
OHTA Hiromichi
Top-gate type thin film transistor structure was fabricated on an oxide semiconductor, SrTiO3 single crystal plate. The electron transport and the thermopower S for the extremely thin two-dimensional electron gas, which can be formed on the SrTiO3 crystal by a gate voltage application, were precisely measured / analyzed. As a result of this study, followings were clarified. 1) Water incorporated nano-porous glass [CAN: H. Ohta et al., Nature Commun. 1: 118 (2010); Adv. Mater. 24, 740 (2012)] is very useful as a gate insulator. 2) Extremely thin 2DEG can be generated on the oxide semiconductor surface when ECBM of the oxide semiconductor is greater than EH2. 3) Extremely thin 2DEG (n3D >4×1021 cm-3) exhibited unusually large S-value, which is five times larger than that of bulk (Figure of merit, ZT~2). This clearly demonstrates that the transistor approach works well as the thermoelectric infrared sensor.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), 22360271 - 電界誘起二次元電子層の可視化
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas
2010 - 2011
太田 裕道
SrTiO_3人工超格子中に閉じ込められた極薄二次元電子層はバルクの数倍の巨大熱電能を示す[H.Ohta et al., Nature Mater, 6,129(2007)]ことから、高効率熱電材料の設計指針を与えるモデルとして有望である。本研究では、srTiO_3単結晶電界効果トランジスタへのゲート電圧印加によりゲート絶縁体/SrTiO_3単結晶界面に高密度で蓄積される二次元電子層を可視化し、極薄二次元電子層の巨大熱電能の起源を明らかにすることを目的とした。具体的には高分解能電子顕微鏡観察ならびにデバイスシミュレーションにより、ゲート絶縁体/SrTiO_3界面に蓄積された電界誘起二次元電子層を可視化し、熱電能との関係を調査した。本特定領域内AO1ナノ計測(ア)班との連携研究により,(1)ゲート絶縁体薄膜が水で満たされた直径約10nmのナノボアを30体積パーセント含み[H.Ohta et al., Nature Communications 1:118(2010).]、(2)ゲート電圧印加によってSrTiO_3表面に押し付けられたナノボア中のH_3O^+イオンが、(3)SrTiO_3中の残留キャリア電子を強力に引き寄せることで、バルクの5倍の巨大熱電能を示す極薄二次元電子層(究極の機能元素)が生成することが明らかになった[H.Ohta et al., Adv. Mater. 24,740-744(2012).]。以上の研究から、機能元素「極薄二次元電子層」を熱電材料の表面に誘起し、巨大熱電能という有用な機能を発現させるための「水電気分解による二次元電子層の電界誘起の学理」を構築することに成功した。また、本研究で得られた水電気分解による二次元電子層の作製手法を応用し、一次元AFMリソグラフィーを行うことで更に大きな熱電能を示す材料が創製できると考えられる。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Priority Areas, Nagoya University, 22015009 - 誘電体ヘテロ界面に蓄積された二次元電子ガスの電子状態と量子サイズ効果の起源
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas
2008 - 2009
太田 裕道
本公募研究の目的は、(1)誘電体人工超格子やヘテロ酸化物界面近傍に誘起される二次元電子ガスの電子状態と量子サイズ効果の相関を明らかにすること、(2)誘電体中の二次元電子ガスを積極的に活用した機能材料設計指針を提案することである。二次元電子ガス近傍の原子・電子状態を高いエネルギー分解能で捉えることにより、巨大Seebeck係数のオリジンを解き明かし、誘電体中の二次元電子ガスを積極的に活用した材料設計指針を提案することが可能と考えている。SrTiO_3/SrTi_<0.8>Nb_<0.2>O_3人工超格子やTiO_2/SrTiO_3などの誘電体ヘテロ界面のSrTiO_31単位格子層(0.3905nm)に局在化した高濃度の電子ガスは、バルクの5倍に相当する巨大熱起電力(Seebeck係数)を示すことから、未だ実現していない酸化物熱電変換材料のひとつの開発指針として注目されている。Seebeck係数の大きさは、フェルミエネルギーにおける伝導帯状態密度(DOS(E))のエネルギー微分(∂DOS(E)/∂E)に依存するため、量子サイズ効果によるDOS(E)の増大が巨大熱起電力の起源と考えられている。また、Seebeck係数は伝導電子濃度の関数であるため、伝導電子濃度を連続的に変化させながらSeebeck係数を計測することでDOS(E)の情報を得ることができる。平成21年度は、誘電体ヘテロ界面の電子濃度を連続的に変化させるため誘電体をチャネルとした電界効果トランジスタを作製し、絶縁体/SrTiO_3および絶縁体/KTaO_3ヘテロ界面のSeebeck係数の電界変調に成功した。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research on Priority Areas, Nagoya University, 20047007 - 局在化した二次元電子ガスを有する誘電体人工超格子の作製と熱電変換材料への応用
産業技術研究助成事業費助成金
Jan. 2006 - Dec. 2008
太田 裕道
NEDO, Principal investigator, Competitive research funding - Fabrication and Thermoelectric Properties of Oxide Superlattices with Two-dimensional Electron Gas
Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)
2006 - 2008
OHTA Hiromichi
人工宝石として知られ、毒性がなく、融点が高いSrTiO_3を用いた熱電変換材料を創製した。精密な超薄膜技術により、電子を生成させた厚さ0.4nmの金属SrTiO_3:Nb層と、絶縁性SrTiO_3からなるサンドイッチ構造を作製することで、二次元平面に高濃度の伝導電子(1021cm^<-3>)を溜め込んだ結果、熱起電力が同濃度の電子を生成させたバルクSrTiO_3の約5倍と大きく、熱電変換性能指数ZT(=[熱起電力]×[熱起電力]×[導電率]×[温度]÷[熱伝導率])が既存重金属材料の約2倍になることを見出した。
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (A), Nagoya University, 18686054
Industrial Property Rights
- 水素化酸化インジウム膜形成用のセラミックターゲットとその製造方法、およびセラミックターゲットを用いた薄膜トランジスタの製造方法
Patent right, 太田裕道, 曲 勇作, ゲディア プラシャント, ラマニクラル, 定平 光, コン ヒョンジュン, 北海道大学
特願2024-150613, 02 Sep. 2024 - 熱トランジスタ
Patent right, 太田裕道, 曲 勇作, ジョンアロン, 卞 志平, 吉村充生, 北海道大学
特願2024-018066, 08 Feb. 2024 - 熱トランジスタ
Patent right, 太田裕道, 楊 倩, チョ ヘジュン, 国立大学法人北海道大学
特願2021-164181, 05 Oct. 2021
特開2023-55209, 17 Apr. 2023
41337912 - エレクトロクロミックトランジスタ、電子カーテン、情報表示記憶装置および防眩ミラー
Patent right, 太田裕道, 小野里尚記
特願2018-243861, 27 Dec. 2018
特開2020-106626, 09 Jul. 2020
12354017 - スイッチング装置
Patent right, 太田裕道, 片瀬貴義, 鈴木雄喜
特願2015-2769, 09 Jan. 2015
特許6629241, 13 Dec. 2019
15 Jan. 2020, 国立大学法人北海道大学 - 固体電解質、固体電解質の製造方法および電気化学デバイス
Patent right, 太田裕道, 青木則之
特願2011-282589, 26 Dec. 2011
特許5910072, 08 Apr. 2016
27 Apr. 2016, ソニー株式会社 - 電界効果トランジスタ及び電界効果トランジスタの製造方法
Patent right, 太田裕道, 小出浩貴, 高木利哉, 藤本隆史
特願2010-206380, 15 Sep. 2010
特許5680916, 16 Jan. 2015
04 Mar. 2015, 国立大学法人名古屋大学, 東京応化工業株式会社 - 電磁気素子用絶縁膜の製造方法
Patent right, 旭 良司, 佐伯優美, 太田裕道
特願2009-181886, 04 Aug. 2009
特許5429661, 13 Dec. 2013
26 Feb. 2014, 株式会社豊田中央研究所, 国立大学法人名古屋大学 - 熱電変換材料及びその製造方法
Patent right, 太田裕道, 河本邦仁, 宗 頼子
特願2006-133179, 12 May 2006
特許4998897, 25 May 2012
15 Aug. 2012, 国立大学法人名古屋大学
24741406 - 熱電素子
Patent right, 旭 良司, 増岡優美, 太田裕道, 栗田大佑
特願2007-285631, 02 Nov. 2007
特許4872050, 02 Dec. 2011
08 Feb. 2012, 株式会社豊田中央研究所, 国立大学法人名古屋大学
特開2009-117430 - 熱電変換材料及び熱電変換材料の製造方法
Patent right, 細野秀雄, 平野正浩, 太田裕道, 河本邦仁
特願2004-331756, 16 Nov. 2004
特許4762911, 17 Jun. 2011
31 Aug. 2011, 独立行政法人科学技術振興機構, 国立大学法人名古屋大学 - 基板回転・加熱装置並びにこれを用いた成膜装置及び分析装置
Patent right, 折田政寛, 太田裕道, 平野正浩, 細野秀雄, 田 昭治, 片桐俊郎, 三村 宗
特願2001-81454, 21 Mar. 2001
特許4755770, 03 Jun. 2011
24 Aug. 2011, 独立行政法人科学技術振興機構
特開２００２－２８０３０６ - 薄膜トランジスタ及びその製造方法
Patent right, 細野秀雄, 平野正浩, 太田裕道, 神谷利夫, 野村研二
特願2004-325938, 10 Nov. 2004
特許4620046, 05 Nov. 2010
科学技術振興機構 - アモルファス酸化物薄膜
Patent right, 細野秀雄, 平野正浩, 太田裕道, 神谷利夫, 野村研二
特願2004-325938, 10 Nov. 2004
特許4568828, 20 Aug. 2010
27 Oct. 2010, 独立行政法人科学技術振興機構
特開2010-219538 - アモルファス酸化物薄膜の気相成膜方法
Patent right, 細野秀雄, 平野正浩, 太田裕道, 神谷利夫, 野村研二
特願2004-325938, 10 Nov. 2004
特許4568827, 20 Aug. 2010
27 Oct. 2010, 独立行政法人科学技術振興機構
特開2010-212696 - 酸化インジウム薄膜及びその製造方法
Patent right, 太田裕道, 折田政寛
特願平11-90248, 30 Mar. 1999
特許4480809, 26 Mar. 2010
16 Jun. 2010, ＨＯＹＡ株式会社
特許4480809 - 低抵抗ＩＴＯ薄膜及びその製造方法
Patent right, 太田裕道, 折田政寛
特願平11-203976, 16 Jul. 1999
特許4397511, 30 Oct. 2009
13 Jan. 2010, ＨＯＹＡ株式会社
特許4397511 - 透明導電性薄膜及びその製造方法
Patent right, 折田政寛, 太田裕道
特願平11-90233, 30 Mar. 1999
特許4397451, 30 Oct. 2009
13 Jan. 2010, ＨＯＹＡ株式会社
特許4397451 - 自然超格子ホモロガス単結晶薄膜とその製造方法
Patent right, 細野秀雄, 植田和茂, 折田政寛, 太田裕道, 平野正浩
特願2001-340066, 05 Nov. 2001
特許4298194, 24 Apr. 2009
15 Jul. 2009, 独立行政法人科学技術振興機構, ＨＯＹＡ株式会社
特許4298194 - 高単結晶性酸化亜鉛薄膜及び製造方法
Patent right, 太田裕道, 折田政寛, 細野秀雄, 川副博司
特願平11-88231, 30 Mar. 1999
特許4237861, 26 Dec. 2008
11 Mar. 2009, ＨＯＹＡ株式会社
特許4237861 - 透明導電性酸化物薄膜を有する物品及びその製造方法
Patent right, 森田 清, 太田裕道, 細野秀雄, 川副博司
特願平10-208948, 24 Jul. 1998
特許4170454, 15 Aug. 2008
22 Oct. 2008, ＨＯＹＡ株式会社
特許4170454 - 酸化物半導体ＰＮ接合デバイス及びその製造方法
Patent right, 太田裕道, 細野秀雄, 神谷利夫, 平野正浩
特願2002-278214, 16 Nov. 2004
特許4164563, 08 Aug. 2008
15 Oct. 2008, 独立行政法人科学技術振興機構, ＨＯＹＡ株式会社
特許４１６４５６３ - ホモロガス薄膜を活性層として用いる透明薄膜電界効果型トランジスタ
Patent right, 太田裕道, 細野秀雄, 神谷利夫, 平野正浩
特願2002-266012, 11 Sep. 2002
特許4164562, 08 Aug. 2008
15 Oct. 2008, 独立行政法人科学技術振興機構, ＨＯＹＡ株式会社
特許４１６４５６２ - ＬｎＣｕＯ（Ｓ，Ｓｅ，Ｔｅ）単結晶薄膜とその製造方法、及び該単結晶薄膜を用いた光デバイス又は電子デバイス
Patent right, 細野秀雄, 平野正浩, 折田政寛, 太田裕道, 平松秀典, 植田和茂
特願2002-45417, 21 Feb. 2002
特許4083486, 22 Feb. 2008
30 Apr. 2008, 独立行政法人科学技術振興機構, 太田 裕道, 折田 政寛
特許４０８３４８６ - 紫外透明導電膜とその製造方法
Patent right, 折田政寛, 太田裕道, 平野正浩, 細野秀雄
特願2000-209139, 10 Jul. 2000
特許4083396, 22 Feb. 2008
30 Apr. 2008, 独立行政法人科学技術振興機構, 太田 裕道, 折田 政寛
特許４０８３３９６ - 超平坦ｐ型酸化物半導体ＮｉＯ単結晶薄膜
Patent right, 細野秀雄, 太田裕道, 神谷利夫, 平野正浩
特願2002-254050, 30 Aug. 2002
特許4014473, 21 Sep. 2007
28 Nov. 2007, 独立行政法人科学技術振興機構, 太田 裕道
特許４０１４４７３ - 透明酸化物積層膜及び透明酸化物ｐ－ｎ接合ダイオードの作製方法
Patent right, 細野秀雄, 植田和茂, 太田裕道, 平野正浩
特願2001-54382, 28 Feb. 2001
特許3969959, 15 Jun. 2007
05 Sep. 2007, 独立行政法人科学技術振興機構, 太田 裕道
特許３９６９９５９ - 透明導電性薄膜
Patent right, 折田政寛, 太田裕道
特願平10-258586, 11 Sep. 1998
特許3824289, 07 Jul. 2006
20 Sep. 2006, ＨＯＹＡ株式会社
特許３８２４２８９ - 電池の製造方法
Patent right, 藤井孝則, 前田紫織, 太田裕道, 中川 弘, 児玉康伸, 西本好宏, 園崎 勉, 中根育朗, 寺司和生, 生川 訓
特願平9-119443, 09 May 1997
特許3717632, 09 Sep. 2005
16 Nov. 2005, 三洋電機株式会社
特許３７１７６３２ - 薄型密閉電池
Patent right, 西本好宏, 太田裕道, 前田紫織, 中川 弘, 児玉康伸, 山崎幹也, 園崎 勉, 藤井孝則, 中根育朗, 寺司和生, 生川 訓
特許3588225, 20 Aug. 2004
10 Nov. 2004, 三洋電機株式会社
特許３５８８２２５ - 超平坦透明導電膜およびその製造方法
Patent right, 太田裕道, 折田政寛, 平野正浩, 細野秀雄
特願2000-205941, 06 Jul. 2000
特許3531865, 12 Mar. 2004
31 May 2004, 独立行政法人 科学技術振興機構, 太田 裕道, 折田 政寛
特許３５３１８６５ - 発光ダイオードおよび半導体レーザー
Patent right, 細野秀雄, 太田裕道, 折田政寛, 河村賢一, 猿倉信彦, 平野正浩
特願2000-24843, 28 Jan. 2000
特許3398638, 14 Feb. 2003
21 Apr. 2003, 科学技術振興事業団, 太田 裕道, 折田 政寛
特許３３９８６３８ - ポリマー電解質電池
Patent right, 山崎幹也, 前田紫織, 太田裕道, 中川 弘, 児玉康伸, 西本好宏, 園崎 勉, 藤井孝則, 中根育朗, 寺司和生, 生川 訓
特願平9-92146, 10 Apr. 1997
特許3378761, 06 Dec. 2002
17 Feb. 2003, 三洋電機株式会社
特許３３７８７６１ - 固体電解質電池及びその製造方法
Patent right, 中川 弘, 太田裕道, 前田紫織, 児玉康伸, 山崎幹也, 西本好宏, 園崎 勉, 藤井孝則, 中根育朗, 寺司和生, 生川 訓
特願平9-92147, 10 Apr. 1997
特許3354430, 27 Sep. 2002
09 Dec. 2002, 三洋電機株式会社
特許３３５４４３０
