Observation of ultrahigh density InGaN quantum dots
Journal
Journal of Applied Physics
Journal Volume
102
Journal Issue
1
Date Issued
2007
Author(s)
Abstract
High density InGaN quantum dots (QDs) grown on an underlying GaN layer that was partially masked with SiNx nanocrystals were investigated by cross-sectional high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM), high-resolution transmission electron microscopy, and energy dispersive x-ray spectroscopy. The layer of SiNx masks appeared as a dark line in the HAADF-STEM images, and from the thickness of that dark line, the height of the masks was roughly estimated to be less than 2nm. The InGaN QDs appeared as bright triangles in the HAADF-STEM images. The QDs can be regarded as nanosized island crystals consisting of {101?1} sidewalls, with a height of several nanometers. The lattices in the InGaN crystals were strained as compared to the underlying and the capping GaN lattices and contacted them coherently.
Type
journal article