On the luminescence of GaS(Cu) single crystals

The photoluminescence and electroluminescence spectra of undoped and Cu-doped (by means of thermal diffusion) GaS single crystals, at temperatures varying from 293 to 78 K are examined. Some correlations between photoluminescence and absorption spectra of the respective crystals have been established. Cu atoms form up p-photoluminescence recombination levels, positioned at 1.23 and 1.48 eV in the forbidden band of GaS, which produce the photoluminescence band by 1.82 eV. The intensity of electroluminescence for GaS(Cu) single crystals exponentially depends on the applied voltage. The electroluminescence spectrum contains impurity bands located at 2.58, 2.13 and 1.63 eV.