Hole transport in arylamine doped polymers

Abstract

Hole mobilities have been measured in a series of arylamine derivatives doped into poly(styrene). The derivatives were selected for differences in oxidation potentials and dipole moments. The results are described by a formalism based on disorder. The formalism is premised on the assumption that transport occurs by hopping through a manifold of localized states that are distributed in energy. The key parameter of the formalism is σ, the energy width of the hopping site manifold. The results show that the widths are strongly dependent on the dipole moments and independent of oxidation potential. The widths are described by a model of dipolar disorder. The model assumes that the total width is comprised of a dipolar component and a van der Waals component. The dipolar components are between 0.032 and 0.083 eV, increasing with increasing dipole moment. The van der Waals components are ∼0.080 eV for all derivatives. There is no obvious relationship between the prefactor mobilities and either the oxidation potentials or dipole moments.