An assessment of the role of polaron formation to hole transport in a triarylamine doped polymer Original Research Article

Hole mobilities have been measured in a doped polymer containing a triarylamine compound with multiple donor functionalities. The results are compared to predictions of three-dimensional polaron models which include effects of nuclear tunnelling and disorder. The results show that polaron models cannot account for the field and temperature dependencies of the mobility, particularly at low dopant concentrations and high temperatures. Analytic approximations of the mobility in the presence of polaron formation and disorder show that for a large range of polaron binding energies, polaron formation has a limited effect on the field and temperature dependencies of the mobility.