Factors affecting the luminescence emission of InGaN multi-quantum wells grown on (0001) sapphire substrates by MOVPE

The luminescence emission of InGaN/GaN multi-quantum wells (MQW) is affected by several factors, i.e. the composition, the QW thickness, the piezoelectric field and the high density of threading dislocations. In the case of heterostructures containing several QWs piled up, one has to consider the homogeneity of each QW and the thickness of the barrier layers between them, which have influence on the strain. We present herein a Cathodoluminescence (CL) study of a series of InGaN QW structures, paying special emphasis to the problem of the lateral distribution of In, and how it influences the emission properties of the QWs