Electron transport in N,N′-bis(2-phenethyl)-perylene-3,4: 9,10-bis(dicarboximide)

By time-of-flight techniques, electron mobilities have been measured in vapor deposited films of the title compound. The results were compared to predictions of the disorder formalism, due to Bässler and co-workers, and models based on polaron formation. The results lead to the conclusion that fluctuations in hopping site energies are the major contribution to the activation energy. For consistency between experiment and predictions of the formalism, however, an additional source of activation is required. The source of this activation is believed due to either polaron formation or trapping. The width of the hopping site manifold, σ, is determined as 0.080 eV and the positional disorder parameter, Σ, as 1.0. The interpretation of these results by a model in which transport occurs only by polaron displacement leads to inconsistencies with both the temperature and field dependencies of the mobility.