Microphotoluminescence Intensity Images of InGaN Single Quantum Wells

Abstract
Photoluminescence spectra and microphotoluminescence images were measured at room temperature for an In0.06Ga0.94N single quantum well (SQW) and an In0.14Ga0.86N 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 In0.06Ga0.94N SQW, while some parts are complementary for the In0.14Ga0.86N 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.