Hole trapping in molecularly doped polymers

Hole mobilities have been measured in di-p-tolylphenylamine-doped poly(styrene) containing 1-phenyl-3-p-diethylaminostyryl-5-p-diethylamino-phenylpyrazoline (DEASP), an 0.38 eV trap. For molar concentrations of less than a few multiples of 10(-7), DEASP has no effect on the mobility. For concentrations in excess of 10(-6), the mobility decreases with concentration as c(-1.5). A concentration of 10(-3) suppresses the trap-free mobility by approximately 5 orders of magnitude. The results are described within the framework of a formalism due to Hoesterey-Letson and the recent simulations of Wolf et al. and Borsenberger et al. (C) 1999 John Wiley & Sons, Inc.