From Monomer Sequence to Charge Mobility in Semiconductor Polymers via Model Reduction

摘要

A model reduction scheme for polymer semiconductors is presented that canbe utilized to compute intra-chain charge-carrier mobility from the monomersequence. The reduced model can be used in conjunction with any quantumdynamics approach, but it is explored here assuming that transport takesplace through incoherent hopping events between states of different degreesof delocalization. The procedure is illustrated by considering 28 realisticpolymers for which a quantitative correlation is established between chargelocalization characteristics and charge mobility. The data set helps inestablishing plausible ranges for all the microscopic parameters of the modeland it can therefore be used to determine the maximum plausibleimprovement in mobility. The reduced model is also used to provide someinsight on the observation that the highest mobility polymers do not have verybroad valence bands: there is indeed a range of the inter-monomer couplingfor which this parameter has little effect on the mobility.