Effect of Laser Irradiation on Low-Temperature Photoconductivity and Photoluminescence Spectra of Gallium Selenide

Features of photoluminescence (PL) and photoconductivity (PC) spectra, taken at 4.2 to 60 K, of GaSe crystals of stoichiometric composition and grown with an excess and with a lack of Ga atoms are analyzed. It is shown that the presence of excessive Se atoms in the matrix of GaSe crystals results in the formation of centres where triplet excitons are bound. Excessive Ga atoms formed in a crystal both, in the process of its growth and under the effect of laser irradiation give rise to regions with another polytype composition (γ‐modification). The presence of such (γ‐polytype) regions is shown to produce packing defects whre localization of excited electron states (n > 1) occurs. An effect of PC signal increase with increasing exposure dose is found, which is attributed to the formation of acceptor centres. [Russian Text Ignored].