Experimental study and configurational-coordinate model for photo-induced effects in amorphous As2Se3 films

The optical absorption of As2Se3 thin films is studied in the W-VIS spectra l range and the value of the optical energy gap is determined. The effect o f photo-irradiation on the optical absorption and transmission of thin film samples is also investigated. The optical energy gap was found to decrease with photo-irradiation time. The results of photo-irradiation are discusse d in correlation with the structural aspects of As2Se3. A model is proposed to account for the structural changes, resulting from photo-irradiation, c ausing the decrease of the energy gap. The effect of gamma -radiation on th e optical absorption of As2Se3 thin films was studied also and no detectabl e effect on the value of the optical energy gap was observed. (C) 2001 Else vier Science Ltd. All rights reserved.