Spatial variation of photoluminescence and related defects in InGaN/GaN quantum wells

Abstract
Spatially and spectrally resolved photoluminescence of InGaN/GaN quantum wells grown by metalorganic chemical vapor deposition is studied with near-field scanning optical microscopy (NSOM) and transmission electron microscopy (TEM). High-spatial-resolution NSOM images show bright blue quantum well emission around V defects and yellow emission inside the defects. TEM data suggest that the spatial distribution of blue luminescence is partly due to dislocation gettering by V defects. The yellow emission is attributed to the Ga vacancy-impurity complexes trapped inside V defects.