Polaron effect dependence of thermopower in organic semiconductors

A unified physical model for thermopower was presented in organic semiconductors, based on the Marcus theory and variable-range hopping theory. According to the proposed model, the characteristic of charge carrier thermoelectric transport in organic semiconductors has been investigated. In particular, polaron effects, energetic disorder, and carrier density dependence of the thermopower have been discussed in detailed. The calculation also shows a good agreement with the experimental data in organic semiconductors. - Highlights: • Polaron dependence of thermopower model in organic semiconductors was presented. • Thermopower decreases with the increase of polaron effect. • Thermopower increases with the increase of energetic disorder. • The model well explains the carrier density dependence of thermopower