Microphotoluminescence Intensity Images of InGaN Single Quantum Wells

Photoluminescence spectra and microphotoluminescence images were measured at room temperature for an In 0.06 Ga 0.94 N single quantum well (SQW) and an In 0.14 Ga 0.86 N SQW grown by atmospheric-pressure metalorganic chemical vapor deposition. The spatial homogeneity of their optical properties was studied by means of a photoluminescence intensity imaging technique of typical spatial resolution 150 nm It is found that the microphotoluminescence images taken at different wavelengths show very little difference for the In 0.06 Ga 0.94 N SQW, while some parts are complementary for the In 0.14 Ga 0.86 N SQW. This result strongly suggests that the additional intensity fluctuation which appears with increasing indium composition is due to phase separation in the InGaN layers.