NEAR-FIELD OPTICAL STUDY OF INGAN GAN EPITAXIAL LAYERS AND QUANTUM-WELLS/

We have employed near-field scanning optical microscopy to investigate the influence of specific microstructural defects on the optical prop erties of thin InGaN/GaN epilayers and quantum wells. These defects ar e empty ''pinholes'' with a hexahedron cone morphology that are nuclea ted by threading dislocations from the GaN buffer layer. By correlatin g atomic force microscopy With spatially and spectrally resolved photo luminescence (PL) on a 100 nm spatial scale, we find that the pinholes have no clearly observable effect on the PL efficiency, at least part ly due to the strong carrier localization in the InGaN nonrandom alloy . (C) 1998 American Institute of Physics.