Photoinduced Phenomena in Sulphur Crystals and Films

The irradiation of sulphur crystals and films with ultraviolet light induces the change of transmission in the visible part of spectra. It was found that these phenomena exist only at low temperatures (4.2-50 K). The behaviour of optical transparency as a function of time after switching the rumination off was investigated. These dependences are essentially different for the films and crystals. In order to understand the origin of these phenomena the structural investigation was conducted. Very unusual behaviour of darkening kinetics was obtained.