Stimulated Emission of Thin Cu(In, Ga)Se 2 Films Irradiated by Protons

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