Photoinduced absorption in Se–Ge glasses

Abstract
Photoinduced absorption (PA) and excitation spectra are reported at 4·2 K for a range ofbulk Ge y Se1–y (y⩽ 0·33) glasses. The temperature dependence of PA has been measured from 4·2 to 150 K and the effects of metallic (In, Cu, Fe) doping and applied electric field studied. A macroscopic model and calculation procedure is developed to determine densities of excited centres and cross-sections for centre creation. Low-temperature absorption edges are reported for doped and undoped samples. The results are compared with those of recent work on photoinduced E.S.R. and PL fatigue.