Program

I.5 -- Invited, IWTCP-3

Date: Monday, 27 July 2015

Time: 16h00 - 16h35

Thermoelectric effects in graphene nanostructures

V. Hung Nguyen (1,2), M. Chung Nguyen (1,2), H. Viet Nguyen (2), J. Saint-Martin (1), P. Dollfus (1)

(1) Institute of Fundamental Electronics, CNRS, Univ. of Paris-Sud, Orsay, France; (2) Center for Computational Physics, Institute of Physics, VAST, Hanoi, Vietnam

The thermoelectric effect enables direct conversion of a temperature difference into an electric voltage and vice versa, and provides a viable route for electrical power generation from waste heat. The thermoelectric properties of graphene and graphene nanostructures have recently attracted significant attention from the physics and engineering communities. First, the analysis of Seebeck and Nernst effects is very useful in elucidating some details of the electronic band structure of graphene that cannot be probed by conductance measurements alone, due in particular to the ambipolar nature of this gapless material. Second, the potential of graphene in thermoelectric devices is also quite intriguing. On the one hand, to be a good thermoelectric channel, graphene has two major disadvantages to overcome. The first disadvantage is its gapless character, which leads to a small Seebeck coefficient due to the opposite contributions of electrons and holes. The second one is the high thermal conductivity of graphene that makes it an excellent thermal conductor but not a thermoelectric material. However, several nanostructuring and bandgap engineering techniques for graphene have been recently explored, which suggests various strategies to concomitantly reduce the lattice thermal conductance and enhance the Seebeck coefficient without dramatically degrading the electronic conductance. Hence, in various graphene nanostructures, the thermoeelectric efficiency has been predicted to be high enough to make them attractive for energy conversion. In this talk, I will review the main studies reported recently on the thermoelectric properties of graphene and its nanostructures, and aslo of other graphene-like materials.

Reference: Philippe Dollfus, Viet Hung Nguyen and Jérôme Saint-Martin, J. Phys.: Condens. Matter 27 133204 (2015)

Presenter: Viet-Hung Nguyen