Effective Temperature Models for the Electric Field Dependence of Charge Carrier Mobility in Tris(8-hydroxyquinoline) Aluminum

Abstract

The development of accurate and predictive models of charge carrier mobility is a crucial milestone on the path to the rational design of organic semiconductor devices. In this chapter we review effective temperature models that combine both the temperature and electric field dependence of the charge carriermobility into a single parameter – the effective temperature. Although effective temperature models were originally developed for use in disordered inorganic semiconductors, here we compare various models to data from the archetype small molecular weight organic semiconductor tris(8-hydroxyquinoline) aluminum (AlQ3). We conclude that it may prove impossible to develop a universal effective temperature model that is valid for all electric fields and temperatures. But several effective temperature models are observed to work well within the typical operational environments of electronic devices. Thus, the effective temperature concept promises to be a practical and useful tool for the development of organic semiconductor technology.