Thermoelectric model to characterize carrier transport in organic semiconductors

Abstract

A model for the Seebeck coefficient in the regime of hopping transport that includes the effects of Gaussian carrier density of states width and carrier localization allows these parameters to be derived independently of the attempt-to-jump rate, which can subsequently be derived from measured electrical conductivity. This model is applied to prototypical small molecular and polymer organic semiconductors to characterize carrier localization, quantify the role of dopants on the hopping transport parameters, and derive the effective dopant ionization fraction and activation energy.