ON THE PHOTOCONDUCTIVE PROPERTIES OF THALLIUM-INDIUM-SULFIDE SINGLE-CRYSTALS

TlInS2 is a photosensitive compound, single crystals of which can be grown relatively easily with a direct melting of their constituents. Possible applications in photoconductive and photovoltaic devices require a previous knowledge of the different energy gaps and the distribution of the localized levels in them, which greatly influences the performance of the crystals in this direction. For this reason their electrical conductivity in dark was investigated as a function of the applied voltage; the free carriers concentration p was studied for different wavelengths of the incident light, at 300 and 90 K; further, the dependence of the concentration p on the generation rate G was investigated. The simultaneous illumination of the samples with quenching light proved to influence severely the ln(p) vs. ln(G) characteristics.