“…10 Earlier, we studied the low-temperature photoluminescence (PL) of ternary TlGaSe 2 and TlInS 2 crystals and observed one and two broad emission bands, respectively, which were assigned to donoracceptor pair (DAP) recombination. 13,14 Moreover, recently, we have investigated the low-temperature PL spectra of quaternary Tl 2 InGaSe 4 and Tl 2 InGaS 4 crystals and revealed one and three broad emission bands, respectively, which were attributed to the transitions from moderately deep donor to shallow acceptor levels. 15,16 In the present paper, we report the first results of the intensity variations of the PL spectra with temperature (17-62 K) and laser excitation intensity (0.1-55.7 mW cm À2 ) in TGISS crystals.…”