Temperature and excitation intensity tuned photoluminescence in Ga0.75In0.25Se crystals
► The photoluminescence measurements on Ga 0.75 In 0.25 Se crystals have been carried out. ► Two peaks were observed at E A = 613 nm (2.02 eV) and E B = 623 nm (1.99 eV). ► Temperature and excitation intensity dependence of the PL spectra were analyzed. ► Activation energies of donor and acceptor levels were calculated. Photoluminescence (PL) spectra of Ga 0.75 In 0.25 Se layered single crystals have been studied in the wavelength range of 580–670 nm and temperature range of 7–59 K. Two PL emission bands centered at 613 nm (2.02 eV, A-band) and 623 nm (1.99 eV, B-band) were revealed at T = 7 K. The excitation laser intensity dependence of the emission bands have been studied in the 0.06–1.40 W cm −2 range. Radiative transitions from shallow donor levels located at E A = 0.11 and E B = 0.15 eV below the bottom of conduction band to single shallow acceptor level located at 0.01 eV above the valence band are suggested to be responsible for the observed A- and B-bands. A simple model was proposed to interpret the recombination processes in Ga 0.75 In 0.25 Se single crystals.