Abstract
From a study of the effect of light exposure on photoconductivity and solar cell performance of hydrogenated amorphous silicon alloys for different exposure time and intensity, we show that the light-induced changes do not obey reciprocity. Degradation is larger at high intensity light exposure for a shorter time than at low intensity exposure for a longer time even though the product of the exposure time and light intensity is kept a constant. A model that can explain the failure of reciprocity is discussed.