First-principles study of electron and hole transfer properties in various polymers

Abstract

Recently, we have shown that hole conduction in polyethylene (PE) can be simulated with the aid of quantum chemical calculations without adopting any ad hoc parameters. In this contribution, we examine the applicability of the established theories of carrier conduction in conductors and semiconductors to electronic carrier conduction in various polymeric insulators by evaluating the Marcus parameters. As expected, it turns out that the electron and hole transfer in most polymers occur in the nonadiabatic hopping regime with the exception of electron transfer in PE. Thus the modeling approach developed in our studies to evaluate the hole transfer property in crystalline and amorphous PE can be utilized to investigate the electron and hole transfer characteristics in various polymers. In line with experimental findings, computed electron and hole hopping rates indicate that (1) the electron and hole mobility in polystyrene (PS) are comparable, (2) electrons are less mobile than holes in polytetrafluoroethylene (PTFE), and (3) the electron and hole mobilities in PS is larger than those in PE and PTFE. In addition, the results imply that the minor differences in the polymer structure can result in the large variation of carrier mobilities.