HOLE TRANSPORT IN STYRYL)-5-(P-(DIETHYLAMINO)PHENYL)PYRAZOLINE-DOPED POLYMERS

Hole mobilities have been measured in amino)styryl)-5-(p-(diethylamino )phenyl)pyrazoline (DEASP)-doped polycarbonate (PC) and polystyrene (P S) over a wide range of fields, temperatures, and DEASP concentrations . At low concentrations mobilities of DEASP-doped PS are significantly higher than for DEASP-doped PC. At high concentrations, the mobilitie s are largely independent of the polymer. A key result is that the act ivation energies of the mobilities are independent of both the DEASP c oncentration and the polymer. The results have been compared to predic tions of the disorder formalism, due to Bassler and co-workers, and mo dels based on polaron formation. Describing the results by the disorde r formalism leads to the conclusion that the width of the hopping site manifold is determined by dipole moments associated with the DEASP mo lecule. Agreement with experiment requires that the dipole effect be p urely intramolecular. Interpretation of the results by models based on polaron formation requires that the polaron be intramolecular with a binding energy of approximately 1.2 eV