METHODS FOR REDUCING DEEP-LEVEL EMISSIONS FROM ZNSE GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

Methods for reducing deep level emission from ZnSe layers grown by photo-assisted organometallic vapor phase epitaxy were studied using photoluminescence. A number of approaches to achieve reductions in deep level emissions were investigated. One of them was the use of a flow modulation technique. Reduction in the deep level emissions was observed when the layers were annealed under zinc-rich conditions during this growth process. The effect of cadmium as an isoelectronic dopant in ZnSe was also studied. It was observed that ''doping'' levels of cadmium resulted in considerable reduction in deep level emissions from ZnSe layers. Layers were grown under different II/VI ratios, and compared to cadmium doped layers of similar ratios. Reduction in deep level emissions were observed in all cadmium doped layers. Cadmium, therefore, seems to be the most promising isovalent dopant for reducing the deep level emissions in ZnSe.