Photoinduced phenomena in thin films of chalcogenide system Ga-Ge-S: a role of oxidation

Thin films of the chalcogenide glassy system 15(Ga2S3) ‐ 85(GeS2) were deposited by ultra violet (UV) laser ablation method. Optical absorption edge and refractive index of the films were studied. It was found that optical properties of the as‐deposited (fresh deposited) films exhibit modification with time (ageing phenomenon). Photoinduced changes of the optical properties of the films were studied after films exposure to sub‐bandgap, and independently super‐bandgap monochromatic radiation. Considerable change of the optical parameters of the films ‐ photobleaching (blue shift of the optical absorption edge position) and decreasing of the refractive index as a result of laser illumination was found in both cases. The reason of photobleaching and ageing phenomena is supposed to be the same. These phenomena can be associated with the films oxidation. (© 2006 by Astro, Ltd. Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)