First-Principle Based Modeling of Electron and Hole Transfer in Amorphous Polyethylene Terephthalate Oligomer

Abstract

Recently, we have proposed a first-principles based multi-scale modeling method for studying carrier transport properties in polymers with flexible backbones, and have successfully modeled hole transfer in polyethylene (PE). In this study, in order to see if we can model carrier transport in more complex polymers, we have utilized the multi-scale modeling method to simulate the time-of-flight carrier transients in polyethylene terephthalate (PET). When the electrostatic disorder was taken into account, the computed electron and hole mobilities were in reasonable agreement with experimental data, indicating that the multi-scale modeling technique can most likely be applied to other polymer dielectrics as well. Simulated current waveform was dispersive to a certain extent due to the disordered energetic landscape of the hopping site energies. Unlike the case for hole transfer in PE where the energetic disorder is dominated by the conformational disorder of the polymer chain, the energetic disorder for the electron and hole transfer in PET oligomer was dominated by the electrostatic disorder, which is caused by the local dipole of the PET molecule.