Correlation between growth interruption and indium segregation in InGaN MQWs

InGaN/GaN multiple quantum wells (MQWs) with the same indium content and QW widths were grown by metalorganic chemical vapor deposition using metal precursor flow interruptions of different length. The influence of the growth interruption length on photoluminescence (PL) properties was studied by combining temperature-dependent and spatially-resolved PL spectroscopy. The PL band variations are attributed to the transformation of localizing potential: growth interruptions change the density of indium clusters, which modifies the density of localized states. The optimized localizing potential in the structure grown using 9 s-long growth interruptions facilitated an increase in PL intensity by a factor of up to 2.