CHARGE TRAPPING IN MOLECULARLY DOPED POLYMERS

Hole mobilities have been measured in di-p-tolylphenylamine doped poly (styrene) containing p-diethylaminobenzaldehyde diphenylhydrazone (DEH ), an 0.32 eV trap. A DEH molar concentration of 10(-5) decreases the mobility by a factor of two. For concentrations in excess of 10(-5), t he mobilities decrease with increasing concentration as approximately sigma(-1.1), the field and temperature dependencies remaining essentia lly unchanged. For concentrations in excess of 10(-1), transport is do minated by trap-to-trap hopping and the mobility increases with increa sing rnp concentration. The results are discussed within the framework of the Hoesterey-Letson formalism and the recent simulations of Wolf et al. and Borsenberger et al.