Realistic simulation of thermoelectric characteristics of organic semiconductors based on electronic structure calculations

Abstract

We report a realistic evaluation of the electrical conductivity and Seebeck coefficient of organic semiconductors using electronic structure calculations based on density functional theory. For this purpose, thermal fluctuation in crystal structures, which dominates the transport phenomena, is explicitly considered by averaging the electronic properties of various deformed structures generated by molecular dynamics simulations. We apply our scheme to pentacene and rubrene and find that a faithful treatment of carrier flow in a disordered lattice yields computational results that agree with the experiments. This agreement allows us to consistently investigate thermoelectric properties, which may pave the way for material exploration.