Space Charge Memory Effect in a-Si:H at low Temperatures

Abstract

ABSTRACTSpace charges build up near one or both electrodes of a photoconductor unless the thermoionic current balances the photocurrent. Space charges built up also when a voltage U is applied at low T to a semiconductor containing a non-equilibrium distribution of carriers. The presence of a space charge is observed as a relaxation-current transient when the sample is illuminated at zero bias. If one type of carrier is immobile the steady state photocurrent becomes zero.