Thermoelectric properties of a single graphene sheet and its derivatives

Abstract

The thermoelectric properties of pristine graphene and H₂S adsorbed onto bridge, hollow and top sites of a graphene sheet are investigated using the semi-classical Boltzmann transport theory. The average values of electrical conductivity, thermal conductivity, Seebeck coefficient, figure of merit (ZT) and the average value of the power factor (P^av) are reported and discussed in detail. While pristine graphene is a zero band gap semiconductor, adsorption of H₂S onto the bridge site opens up a direct energy gap of about 0.04 eV, adsorption of a H₂S molecule onto the top site opens up a gap of 0.3 eV, and adsorption of H₂S onto the hollow site makes it metallic. The investigation of ZT and power factor values suggests that a top-site configuration could be a potential candidate for thermoelectric applications in the range 300–600 K.