Disorder enhances thermoelectric figure of merit in armchair graphane nanoribbons

Abstract

We study the thermoelectric property of graphane strips by using density functional theory calculations combined with the nonequilibrium Green's function method. It is found that figure of merit (ZT) can be remarkably enhanced five times by randomly introducing hydrogen vacancies to the graphene nanoribon derivatives-armchair graphane nanoribbons. For 5 nm wide ribbons under certain conditions, ZT can be as high as 5.8 and depends on temperature linearly. The high ZT, low cost, and rapid advances in the synthesis of nanoscale graphene derivatives make carbon-based materials a viable choice for thermoelectric applications. © 2009 American Institute of Physics.