Effect of Corona Discharge on the Optical Properties of Thin-Film Cu–As2Se3 Structures

The effect that corona discharge has on holographic recording of diffraction gratings in a thin-film Cu−As2Se3 structure deposited on glass by thermal vacuum evaporation is studied. The use of negative corona discharge during holographic recording enhances the holographic sensitivity of the Cu−As2Se3 structure and the diffraction efficiency of inscribed gratings. Irradiation of the Cu−As2Se3 structure with actinic light results in photodarkening in the spectral region in which the structure exhibits a strongly absorption, while the region characterized by a weaker absorption becomes more transparent. The effect of photoinduced transparency is enhanced if samples are treated using positive corona discharge and with negative corona discharge the effect is weakened. The experimental results are explained qualitatively, assuming the diffusion of Cu+ ions into the As2Se3 layer.