Green Electroluminescence from ZnS-CuGaS2 Heterojunction Diode in DC Operation

Abstract
The dc green electroluminescence (EL) from the ZnS-CuGaS2 heterojunction diode is described in the temperature range of 93-291 K. The EL spectrum at 93 K which consists of the only band peaking at 514 nm resembles the photoluminescence (PL) spectrum. At elevated temperatures, another emission band emerges at the shorter-wavelength side of the main band. The main peak position shifts toward the longer-wavelength direction with increasing temperature and reaches 529 nm at 291 K. The EL intensity, which rises steeply with the current, decreases with increasing temperature.