Imaging of High-Angle Annular Dark Field Scanning Transmission Electron Microscopy and Microscopy Studies of GaN-based Light Emitting Diodes and Laser Diodes
Makoto Shiojiri* Author for corresponding; e-mail address: shiojiri@pc4.so-net.ne.jp
Volume: Vol.35 No.3 (SEPTEMBER 2008)
Short Communication
DOI:
Received: 3 April 2008, Revised: -, Accepted: 13 May 2008, Published: -
Citation: Shiojiri M., Imaging of High-Angle Annular Dark Field Scanning Transmission Electron Microscopy and Microscopy Studies of GaN-based Light Emitting Diodes and Laser Diodes, Chiang Mai Journal of Science, 2008; 35(3): 495-520.
Abstract
Atomic-resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) has been used to the structural and compositional analysis of materials. The first part of this paper is a review of our recent HAADF-STEM investigations, which comprise physics to understand its imaging, and illustration of artifacts in images and imaging process. Next, we present our investigations of the multiple InGaN/GaN quantum wells and the strained AlGaN/GaN superlattice cladding in InGaN-based light emitting diodes or laser diodes, which have been performed by HAADF-STEM, high-resolution field-emission scanning electron microscopy, and high-resolution transmission electron microscopy. The observation of ultra-high density InGaN quantum dots is also shown.