Charge carrier transport in phenylated poly(naphthoylenebenzimidazole)

Charge carrier transport in pure and phenylated poly(naphthoylenebenzimidaz ole) was compared by measurements of transient radiation-induced conductivi ty. Irradiation with single 100-mus pulses of 55-keV electrons was carried out in vacuum at room temperature. Contrary to expectations, the phenylatio n deteriorated the transport properties of a polymer: the delayed radiation -induced conductivity in phenylated poly(naphthoylenebenzimidazole) was alm ost 50 times lower than in the initial polymer, with the dispersion paramet er decreasing from 0.4-0.25 to less than or equal to0.05. As a result, the drift mobility of charge carriers falls by a few orders of magnitude. The m echanism of such behavior still remains unclear.