Improved internal quantum efficiency of green emitting InGaN/GaN multiple quantum wells by in preflow for InGaN well growth

A series of green emitting In1-xGaxN/GaN multi-quantum wells (MQWs) has been grown by using low pressure metal organic chemical vapor deposition. Effects of In flow prior to InGaN well growth for a short duration on structural and optical properties of the MQWs have been studied. In pre-flow does not affect the structural properties such as In composition and interface abruptness of the InGaN/GaN MQW structure. But, it red shifts the photoluminescence (PL) emission peak of MQWs with increase of In pre-flow duration. For specific emission energy, the surface pit density of MQWs grown with In pre-flow is significantly lower than that of MQWs grown without In pre-flow. In pre-flow samples show about 30% enhancement of PL internal quantum efficiency in deep green region (>530nm) compared to MQWs grown without In pre-flow.