Blue-light emission from ZnSTe-based EL devices

We have demonstrated blue-light emission from ZnSTe-based electroluminescence (EL) devices. Photoelectroluminescence technique is used to study field-quenching effects on Te isoelectronic centers in undoped ZnSTe alloy. Heavy doping by Al in ZnSTe alloy is found to help reduce field quenching action and gives rise to much higher EL emission in ZnSTe:Al-based Schottky-barrier type structures. I-V characteristics and emission spectra reveal that a tunneling dominated mechanism is responsible for generating the carriers for impact excitation of the localized states associated with Te isoelectronic centers in these structures.