Influence of corona discharge on optical properties of Cu–As$_{2}$Se$_{3}$ thin film structures

Effect of corona discharge on holographic recording of diffraction gratings in Cu–As$_{2}$Se$_{3}$ thin film structure was studied. Thin film structures of Cu–As$_{2}$Se$_{3}$ were prepared on glass substrates by sequential deposition of Cu and As$_{2}$Se$_{3}$ layers using vacuum thermal evaporation technique. Applying of negative corona discharge during recording procedure caused an enhancing both of the holographic sensitivity and diffraction efficiency of the grating. Exposure to actinic light illumination resulted in photodarkening effect in Cu–As$_{2}$Se$_{3}$ thin film structure in the spectrum region of strong absorption. At the same time the fotoinduced bleaching of Cu–As$_{2}$Se$_{3}$ film structure in the spectrum region of weak absorption was observed. Negative corona discharge applied during the light exposure enhanced the bleaching, while positive corona discharge caused its weakening. The photoinduced diffusion of Cu$^+$ ions into Cu–As$_{2}$Se$_{3}$ film was considered to explain qualitatively the experimental results.