Characterization of Lag Signal in Amorphous Selenium Detectors

The photocurrent and the lag signals in amorphous selenium (a-Se) detectors have been characterized by measuring the optical and residual currents under varying light intensity, applied electric field, and temperature. A mathematical model for the transient photocurrent and residual current in a-Se detectors has also been developed. The photocurrent and the lag signal increase rapidly with the applied field because of enhancement of the quantum yield. The residual current increases with increasing the field, ambient temperature, and light intensity. The lag signal gets saturated with increasing the intensity. The percentage lag signal decreases with increasing the field and light intensity.