Abstract
Photocarrier generation, transport, and trapping in two-1ayer organic photoconductors consisting of a carrier generation layer (CGL) and a transparent carrier transport layer (CTL) were studied by photoacoustic spectroscopy, time-of-flight (TOF) photoconductivity measurements, xerographic discharge measurements, and thermally stimulated current (TSC) measurements. The injection and trapping processes of holes at the CGL/CTL interface were evaluated from photoacoustic spectroscopy and xerographic discharge measurments. The drift mobility of holes in the CTL and the activation energy for charge transport were obtained from TOF photoconductivity and TSC measurements. The trapping lifetimes of holes in the CGL and the CTL were measured by the delayed-field and the interrupted-field TOF methods, respectively. From experimental results, we systematically discuss the photoconduction dynamics in two-layer organic photoconductors; (1) the photocarrier generation in the CGL and the trapping of holes at the CGL/CTL interface and (2) the mechanism of the buildup and the decay of the residual potential.
