Enhanced thermoelectric figure of merit in vertical graphene junctions

Abstract

In this work, we investigate thermoelectric properties of junctions consisting of two partially overlapped graphene sheets coupled to each other in the cross-plane direction. It is shown that because of the weak van-der Waals interactions between graphene layers, the phonon conductance in these junctions is strongly reduced, compared to that of single graphene layer structures, while their electrical performance is weakly affected. By exploiting this effect, we demonstrate that the thermoelectric figure of merit can reach values higher than 1 at room temperature in junctions made of gapped graphene materials, for instance, graphene nanoribbons and graphene nanomeshes. The dependence of thermoelectric properties on the junction length is also discussed. This theoretical study hence suggests an efficient way to enhance thermoelectric efficiency of graphene devices.

6 pages, 4 figures, submitted

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Cited by in corpus (5)

• Seebeck Coefficient of a Single van der Waals Junction in Twisted Bilayer Graphene
• Enhanced Seebeck effect in graphene devices by strain and doping engineering
• Spin and charge caloritronics in bilayer graphene flakes with magnetic contacts
• Strain-induced conduction gap in vertical devices made of twisted graphene layers
• Dimensional crossover and enhanced thermoelectric efficiency due to broken symmetry in graphene antidot lattices