Electro- and photoluminescence in ZnS crystals

Comperative study of spectral characteristics of electroluminescence (EL), induced by alternative electrical field (frequency-10kHz, average field intencity-102-5x103 V/cm), and photoluminescence (PL) of ZnS-Cu microtwin crystals is carried out. It is shown, that PL and EL spectra differ within the hole temperature range of 77-300 K. Difference in the process of EL and PL temperature dependences is revealed. The EL minimum at Tmin ∼ 170-180K. The EL intensity at Tmin is by order lower than at 77 and 300 K. The PL dependence at the same time monotonically decreases by T increase. EL mechanism, explaining the experimental data obtained is proposed