Hole transport in p‐diethylamino‐benzaldehyde‐diphenyl hydrazone

Hole mobilities have been measured in vapour‐deposited films of p ‐diethylamino‐benzaldehyde‐diphenyl hydrazone (DEH). The results are described by a model based on hopping through a manifold of sites broadened by energetic and positional disorder. The application of the model leads to the conclusion that the width of the density of hopping states is influenced by dipolar disorder due to dipole moments of the DEH molecules. In comparing the results with those observed in other molecular solids, the degree of positional disorder is shown to be relatively small.