Semiconductors and Materials Science Research Center

Optical quenching of photocurrent, the dependence of the quenching magnitude on the wavelength of the additional quenching light, and temperature were studied in stoichiometric, nonstoichiometric, and copper-doped CdIn2S4 samples. It was shown that a deficiency of cadmium and indium in CdIn2S4 does not change the energy distance of slow recombination centers from the valence band top ( E_{vr}^0 = 0.73 eV for both undoped samples and those with cadmium and indium deficiency), whereas doping the crystals with copper leads to a slight increase in this energy distance ( E_{vr}^0 = 0.86 eV). https://link.springer.com/article/10.1134/S1063783425601079

Experimental investigations of the photoelectric properties of CdGa2S4 single crystals were carried out. The study examined the temperature dependence of the photocurrent (within the 110–420 K range), as well as the spectral dependence and transient characteristics of optical quenching at T = 300 K. Optical quenching of the photocurrent was observed within a secondary light beam energy range of 0.6 - 2.49 eV. Measurements revealed energy levels at Ec - 0.21 eV, Ec - 0.42 eV, and Ec - 1.06 eV, as well as sensitizing levels at Ev + 0.89 eV. The decrease in photocurrent at temperatures above 300 K is attributed to thermal quenching. Both optical and thermal quenching of photoconductivity in CdGa2S4 crystals are ascribed to changes in the charge state and exchange dynamics of sensitizing and recombination centers.