The concentration dependence of the hole mobility of 1,1-bis(di-4-tolylaminophenyl)cyclohexane doped bisphenol-A-polycarbonate

Hole mobilities of 1,1,-bis(di-4-tolylaminophenyl)cyclohexane (TAPC) doped bisphenol-A- polycarbonate have been measured over a range of concentrations. The mobilities are strongly concentration dependent, increasing with increasing TAPC concentration. The results are described within the framework of the disorder formalism, due to Bässler and co-workers. The formalism is based on the assumption that charge propagation occurs by hopping through a manifold of states subject to concurrent energetic and positional disorder. The results show that both energetic and positional disorder increase with decreasing TAPC concentration. The increase in energy disorder is attributed to dipole moments of the carbonyl groups associated with the polycarbonate while the increase in positional disorder is suggested as due to packing constraints induced by the polymer host.