Correlation of cathodoluminescence inhomogeneity with microstructural defects in epitaxial GaN grown by metalorganic chemical-vapor deposition
- 27 January 1997
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 70 (4) , 420-422
- https://doi.org/10.1063/1.118322
Abstract
We discuss the relationship between microstructure and luminescence efficiency for heteroepitaxial films of GaN grown on c-axis sapphire substrates by metalorganic chemical-vapor deposition. We directly characterize the correlation between threading dislocations as observed by transmission electron microscopy, surface morphology as observed by atomic force microscopy, and wavelength-resolved cathodoluminescence imaging. We show that the inhomogeneity in the luminescence intensity of these films near band edge can be accounted for by a simple model where nonradiative recombination at threading dislocations causes a deficiency of minority carriers and results in dark regions of the epilayer. An upper bound for average diffusion length is estimated to be 250 nm.Keywords
This publication has 15 references indexed in Scilit:
- Characteristics of InGaN multi-quantum-well-structure laser diodesApplied Physics Letters, 1996
- Scanning tunneling microscopy and tunneling luminescence of the surface of GaN films grown by vapor phase epitaxyApplied Physics Letters, 1996
- Characteristics of light-emitting diodes based on GaN p-n junctions grown by plasma-assisted molecular beam epitaxyJournal of Applied Physics, 1996
- Spatially resolved photoluminescence and Raman scattering experiments on the GaN/substrate interfaceApplied Physics Letters, 1996
- Spatial distribution of the luminescence in GaN thin filmsApplied Physics Letters, 1996
- Stimulated Emission by Current Injection from an AlGaN/GaN/GaInN Quantum Well DeviceJapanese Journal of Applied Physics, 1995
- Open-core screw dislocations in GaN epilayers observed by scanning force microscopy and high-resolution transmission electron microscopyApplied Physics Letters, 1995
- Superbright Green InGaN Single-Quantum-Well-Structure Light-Emitting DiodesJapanese Journal of Applied Physics, 1995
- Structural evolution in epitaxial metalorganic chemical vapor deposition grown GaN films on sapphireApplied Physics Letters, 1995
- High dislocation densities in high efficiency GaN-based light-emitting diodesApplied Physics Letters, 1995