CARRIER TRANSPORT IN TITANYL PHTHALOCYANINE PIGMENT DISPERSED IN BINDER POLYMER

The carrier transport mechanism of a single-layered photoreceptor cont aining titanyl phthalocyanine pigment dispersed in an insulating binde r polymer was investigated by the measurement of hole drift mobility, using the conventional time-of-flight technique. The transient wavefor m of the photocurrent exhibited a plateau and kink at higher electric field than 2 x 10(5) V/cm. The drift mobility for a titanyl phthalocya nine-polycarbonate polymer layer varied from 1.2 x 10(-6) to 7 x 10(-5 ) cm(2) V-1 s(-1) as the concentrations changed from 20 to 50 wt% of p igment. The increase of dark conductivity and drift mobility in the ra nge of pigment concentration higher than 20 wt% of pigments depended o n the formation of pigment particle chains in the photoconductive laye r.