A Quantitative Approach for the Determination of Light Induced Defects in a-Se₉₀Sb_10-xAg_xThin Films by Using Thermally Stimulated Current Technique

Abstract

Thin films of Se90Sb10−xAgx (x = 0, 2, 4, 6, 8) glasses have been prepared by vacuum evaporation technique. Present study reports the quantitative estimation of light induced defects in aforesaid thin films by using thermally stimulated current technique. Measurements have been made in a vacuum ≈ 10 −3 Torr before and after exposing amorphous films to white light for different exposure times (0 to 6 h). Results indicate that light induced defects are created due to prolonged exposure of light and this is explained by a microscopic model proposed by Shimakawa and co-workers. It is also found that fractional increase in light induced defect density decreases as Ag concentration increases. A discontinuity has, however, been observed at 4 at.% of Ag which is explained in terms of average coordination number.