Atomic simulations and HRTEM observations of a Σ 18 tilt grain boundary in GaN

✍ Scribed by Kioseoglou, J. ;Béré, A. ;Komninou, Ph. ;Dimitrakopulos, G. P. ;Nouet, G. ;Iliopoulos, E. ;Serra, A. ;Karakostas, Th.

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 318 KB
• Volume: 202
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200461419

✦ Synopsis

Abstract

The crystalline quality of GaN thin films grown on foreign substrates for opto‐ and micro‐electronics applications depends strongly on the growth conditions. Among a variety of microstructural defects that appear in GaN epilayers, grain boundaries (GBs) are extended defects that may be formed during the growth process under certain circumstances. In this work, the atomic structures of a ‘symmetric' and an ‘asymmetric' 70.53° 〈$ 1 \bar 2 10$〉 Σ18 tilt boundaries are investigated by combining large scale energetic calculations, using a modified Stillinger–Weber interatomic potential, with high resolution transmission electron microscopy observations. The energetically favourable short‐period asymmetric interface is matched to the experimental observations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)