Screw dislocations in GaN
GaN has received much attention over the past few years because of several new applications, including light emitting diodes, blue laser diodes and high-power microwave transistors. One of the biggest problems is a high density of structural defects, mostly dislocations, due to a lack of a suitable lattice-matched substrate since bulk GaN is difficult to grow in large sizes. Transmission Electron Microscopy (TEM) has been applied to study defects in plan-view and cross-sections on samples prepared by conventional techniques such as mechanical thinning and precision ion milling. The density of dislocations close to the sample surface of a 1 mm-thick HVPE sample was in the range of 3x109 cm-2. All three types of dislocations were present in these samples, and almost 50 percent were screw dislocations. Our studies suggest that the core structure of screw dislocations in the same material might differ when the material is grown by different methods.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director, Office of Science. Office of Basic Energy Studies. Materials Science and Engineering Division (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 806105
- Report Number(s):
- LBNL-49640; R&D Project: 503601; B& R KC0201010; TRN: US200303%%538
- Resource Relation:
- Conference: Microscopy and Microanalysis 2002, Quebec City (CA), 08/04/2002--08/08/2002; Other Information: PBD: 15 Feb 2002
- Country of Publication:
- United States
- Language:
- English
Similar Records
Screw dislocations in GaN grown by different methods
Recombination-related properties of a-screw dislocations in GaN: A combined CL, EBIC, TEM study