Stimulated Emission of Thin CuSe.sub.2 Films Irradiated by Protons

Spontaneous and stimulated emission (SE) of thin Cu(In,Ga)Se.sub.2 films, deposited on sodium-containing glass substrates and irradiated by protons with an energy of 2.5 keV and doses of 10.sup.14-10.sup.17 cm.sup.-2, were investigated upon excitation by nanosecond laser pulses with the power density from 5 to 100 kW/cm.sup.2. An increase in the intensity and a decrease in the SE appearance threshold were found for the films irradiated by protons with doses of 10.sup.14-10.sup.15 cm.sup.-2, in comparison with nonirradiated films. An increase in the SE threshold and a decrease in the intensity of SE and spontaneous emission were observed at the irradiation dose of 10.sup.16 cm.sup.-2. After a dose of 10.sup.17 cm.sup.-2 the intensity of emission decreased sharply and the SE threshold was not reached. Possible reasons of the observed effects are discussed.