Optical and Magnetic Resonance Studies of Mg-Doped GaN Homoepitaxial Layers Grown by Molecular Beam Epitaxy
Abstract
Low-temperature photoluminescence (PL) and optically detected magnetic resonance (ODMR) at 24GHz have been performed on a series of MBE-grown Mg-doped (10[expn 17]-10[expn 20]cm[expn -3]) GaN homoepitaxial layers. High-resolution PL at 5K revealed intense bandedge emission with narrow linewidths (0.2-0.4 meV) attributed to annihilation of excitons bound to shallow Mg acceptors. In contrast to many previous reports for GaN heteroepitaxial layers doped with [Mg]> 10(expn 18) cm(expn -3), the only visible PL observed was strong shallow donor?shallow acceptor recombination with zero phonon line at 3.27 eV. Most notably, ODMR on this emission from a sample doped with [Mg] of 1 x 10(expn 17)cm(expn -3) revealed the first evidence for the highly anisotropic g-tensor (g[ sub parallel] ~2.19, g[sub perpendicular]~0) expected for Mg shallow acceptors in wurtzite GaN. This result is attributed to the much reduced dislocation densities (</= 5 x 10[expn 6]cm[expn -3]) and Mg impurity concentrations compared to those characteristic of the more conventional investigated Mg-doped GaN heteroepitaxial layers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2007
- Accession Number
- ADA593753
Entities
People
- D. J. Smith
- David F. Storm
- Evan R. Glaser
- J. A. Freitas Jr.
- Lipu Zhou
- M. Murthy
Organizations
- United States Naval Research Laboratory