Properties of the main Mg-related acceptors in GaN from optical and structural studies

Authors

B. Monemar, Linköping University
P. P. Paskov, Linköping University
G. Pozina, Linköping University
C. Hemmingsson, Linköping University
J. P. Bergman, Linköping University
S. Khromov, Linköping University
V. N. Izyumskaya, Virginia Commonwealth UniversityFollow
V. Avrutin, Virginia Commonwealth UniversityFollow
X. Li, Virginia Commonwealth University
H. Morkoç, Virginia Commonwealth UniversityFollow
H. Amano, Nagoya University
M. Iwaya, Meijo University
I. Akasaki, Meijo University

Document Type

Article

Original Publication Date

2014

Journal/Book/Conference Title

Journal of Applied Physics

Volume

115

Issue

5

DOI of Original Publication

10.1063/1.4862928

Comments

Originally published at http://dx.doi.org/10.1063/1.4862928

Date of Submission

October 2015

Abstract

The luminescent properties of Mg-doped GaN have recently received particular attention, e.g., in the light of new theoretical calculations, where the deep 2.9 eV luminescence band was suggested to be the main optical signature of the substitutional Mg Ga acceptor, thus, having a rather large binding energy and a strong phonon coupling in optical transitions. We present new experimental data on homoepitaxial Mg-doped layers, which together with the previous collection of data give an improved experimental picture of the various luminescence features in Mg-doped GaN. In n-type GaN with moderate Mg doping (<10¹⁸ cm⁻³), the 3.466 eV ABE1 acceptor bound exciton and the associated 3.27 eV donor-acceptor pair (DAP) band are the only strong photoluminescence (PL) signals at 2 K, and are identified as related to the substitutional Mg acceptor with a binding energy of 0.225 ± 0.005 eV, and with a moderate phonon coupling strength. Interaction between basal plane stacking faults (BSFs) and Mgacceptors is suggested to give rise to a second deeper Mg acceptor species, with optical signatures ABE2 at 3.455 eV and a corresponding weak and broad DAP peak at about 3.15 eV. The 2.9 eV PL band has been ascribed to many different processes in the literature. It might be correlated with another deep level having a low concentration, only prominent at high Mg doping in material grown by the Metal Organic Chemical Vapor Deposition technique. The origin of the low temperature metastability of the Mg-related luminescence observed by many authors is here reinterpreted and explained as related to a separate non-radiative metastable deep level defect, i.e., not the Mg Ga acceptor.

Rights

Monemar, B., Paskov, P. P., & Pozina, G., et al. Properties of the main Mg-related acceptors in GaN from optical and structural studies. Journal of Applied Physics, 115, 053507 (2014). Copyright © 2014 AIP Publishing LLC.

Is Part Of

VCU Electrical and Computer Engineering Publications