Temperature- and excitation intensity-dependent photoluminescence in Ga4Se3S layered crystals

Determination of trapping parameters in n-Ga4Se3S by thermally stimulated current measurements

“…comparable with those obtained by different heating and curve fitting methods in the previous subsections. At this point, it may be informative to compare present TSC results with the ones obtained from our previous PL studies on Ga 4 Se 3 S, which revealed the existence of two levels at 11 and 150 meV [18]. The results of the present TSC study suggest the presence of one trap level with energy 19 meV.…”

“…As a result of these studies, six trapping levels with activation energies of 50, 60, 120, 630, 710 and 750 meV were revealed for GaS [14], three trapping levels with activation energies of 70, 210 and 357 meV for Ga 4 SeS 3 [15], three trapping levels with activation energies of 72, 100 and 150 meV for Ga 2 SeS [16] and three trapping levels with activation energies of 20, 100 and 260 meV for GaSe [17]. Recently, we have also studied the temperature-and excitation intensity-dependent behaviours of the photoluminescence (PL) spectra of Ga 4 Se 3 S crystals, which revealed the presence of two acceptor levels having activation energies of 11 and 125 meV [18]. The trapping and recombination centres in the crystals were attributed as being due to stacking faults, dislocations or the presence of unintentional impurities.…”

Optoelectronic properties of Ga4Se3S-layered single crystals

“…Due to these potential applications, it is very important to determine the structural, electrical and optical properties of such materials. In addition to the GaSe crystals, most of the physical properties of the GaSe-GaS system crystals are being established as well [8][9][10][11][12][13][14][15][16][17][18][19][20]. In particular, the photoluminescence, Raman scattering, the thermally stimulated conductivity, the carrier-scattering mechanisms and the energy-localized levels in Ga 4 Se 3 S and Ga 4 SeS 3 crystals have been studied.…”