Juang, Z.-Y., Tseng, C.-C., Shi, Y., Hsieh, W.-P., Ryuzaki, S., Saito, N., Hsiung, C.-E., Chang, W.-H., Hernandez, Y., Han, Y., Tamada, K., Li, L.-J.
Nano Energy 38 385 - 391 2017年
© 2017 Elsevier Ltd Monolayer graphene exhibits impressive in-plane thermal conductivity (> 1000 W m–1 K–1). However, the out-of-plane thermal transport is limited due to the weak van der Waals interaction, indicating the possibility of constructing a vertical thermoelectric (TE) device. Here, we propose a cross-plane TE device based on the vertical heterostructures of few-layer graphene and gold nanoparticles (AuNPs) on Si substrates, where the incorporation of AuNPs further inhibits the phonon transport and enhances the electrical conductivity along vertical direction. A measurable Seebeck voltage is produced vertically between top graphene and bottom Si when the device is put on a hot surface and the figure of merit ZT is estimated as 1 at room temperature from the transient Harman method. The polarity of the output voltage is determined by the carrier polarity of the substrate. The device concept is also applicable to a flexible and transparent substrate as demonstrated.