Excitation Spectra and Temperature Dependence of the Luminescence of ZnS Single Crystals

The luminescence of ZnS: Cl and ZnS: Cu: Cl crystals was measured for the temperature region 80-500^∘{}K and for different wavelengths of exciting light. The behavior of the luminescence versus temperature curves differed from similar curves for powders reported in literature.Excitation spectra were also obtained for the green and blue luminescence bands. These were found to consist of a complexity of fine bands. Each of the bands was found not to shift when varying the temperature of the crystal. The relative intensity of the bands near the absorption edge of the crystal, however, changed with temperature in such a way as to cause an apparent shift in the maximum of the excitation spectrum in this region.