Experimental investigation of light induced defects in amorphous thin films of Se90X10 (X = Sb, In, Ag)

Abstract

An attempt is made to observe light induced defects (LID) in amorphous chalcogenides Se90X10 (X=Sb, In, Ag) thin films prepared by vacuum evaporation technique. For the determination of light induced defects quantitatively, space charge limited current (SCLC) measurements have been made in a vacuum ∼10−3Torr before and after exposing amorphous films to white light for different exposure times (0 to 6h). Results indicate that light induced metastable defects are created due to prolonged exposure of light which is explained by a microscopic model for light induced metastable defects creation proposed by Shimakawa and co-workers. Fractional increase in density of defects due to light exposure is found to be least in case of Se90Ag10 indicating that this alloy may be used for optoelectronic applications as degradation upon light soaking is small in this case.