Persistent photoconductivity in a InP:Fe single layer structure at room temperature

Measurements of current in the dark and under illumination were carried out at room temperature on samples of semi-insulating (SI) InP:Fe, on which a layer of low resistivity InP:Fe was deposited. A voltage of 25 mV was applied. After the illumination was switched off, a remaining current was observed, for at least one hour, higher than the current before the illumination. This phenomenon is known as persistent photoconductivity (PPC) and, according to the suggested models, is due to the barriers separating electrons and holes and preventing their recombination.