A unified description of thermal transport performance in disordered organic semiconductors

Abstract

Thermal transport in disordered organic semiconductors fundamentally differs from that in inorganic materials and is determined by the charge carriers and phonons in localized states. Understanding thermal transport performance of organic semiconductors is important for a fundamental description of energy flow and then a better design of organic thermoelectric devices. We present a unified theoretical model to describe the thermal transport performance of the disordered organic semiconductors based on hopping transport theory. The proposed model predicts that the contribution from phonon to the thermal conductivity is larger than that from charge carrier in the disordered organic semiconductors. Moreover, the proposed model can well interpret the thermal transport feature of the organic semiconductors by combining the disorder, temperature, and carrier concentration. Simulation results imply that thermal conductivity in the disordered organic semiconductors could be strongly affected under large electric field, high carrier and dopant concentration.