Space charge memory effect in a-Si:H at low temperatures

摘要

Space 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 condatining 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.