Photodielectric processes in ZnS:Cu polycrystalline layers

The frequency dependences of dielectric parameters of zinc sulfide electroluminescent polycrystalline structures doped with copper are studied in the dark and under light excitation in the visible wavelength range. A positive photodielectric effect most pronounced in the low-frequency range was revealed. The experimental results are explained within framework of formation of a space charge in the bulk of a semiconductor. The analysis of data indicates they can be correlated with luminance characteristics of an electroluminescent layer.