Electronic heat capacity and thermal conductivity of armchair graphene nanoribbons

Abstract

Using the Green’s function formalism and tight-binding Hamiltonian model in the band representation, for various widths of armchair graphene nanoribbons, the band structure, density of states, and temperature dependence of the heat capacity and thermal conductivity are considered for the electronic contribution per single width of the ribbons. Observed for various widths are similar peaks of Schottky anomaly, but with a tiny departure toward higher temperatures and a slight decline (rise) before (after) it for wider ribbons. Furthermore, the thermal conductivity decreases as the width of the ribbon gets larger, owing to the overlap between the nonhybridized $p_{z}$ orbitals which provide literal paths across the ribbon to distract a part of the electron’s drift from the axial direction.