CONCENTRATION-DEPENDENCE OF THE HOLE MOBILITY OF 1,1-BIS((DI-4-TOLYLAMINO)PHENYL)CYCLOHEXANE (TAPC) DOPED POLY(STYRENE) (PS)

Hole mobilities have been measured in TAPC doped PS over a range of fields, temperatures, and TAPC concentrations. The results are compared to predictions of the disorder formalism, due to Bassler and co-workers. According to the formalism, charge transport occurs by hopping through a manifold of localized states with superimposed positional disorder. A key parameter of the formalism is sigma, the energy width of the hopping site distribution. Results of this study, in conjunction with published data for TAPC doped poly(carbonate), show that sigma is dependent on both the TAPC concentration and the polymer host. These effects are attributed to dipolar disorder due to the dipole moments of the polymer repeat units.