Optical properties of C-doped bulk GaN wafers grown by halide vapor phase epitaxy

Journal Article · Sun Dec 14 04:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4903819· OSTI ID:22402761

Khromov, S.; Hemmingsson, C.; Monemar, B.; Hultman, L.; Pozina, G. ^[1]

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1. Department of Physics, Chemistry, and Biology (IFM), Linköping University, S-581 83 Linköping (Sweden)

Freestanding bulk C-doped GaN wafers grown by halide vapor phase epitaxy are studied by optical spectroscopy and electron microscopy. Significant changes of the near band gap (NBG) emission as well as an enhancement of yellow luminescence have been found with increasing C doping from 5 × 10{sup 16} cm{sup −3} to 6 × 10{sup 17} cm{sup −3}. Cathodoluminescence mapping reveals hexagonal domain structures (pits) with high oxygen concentrations formed during the growth. NBG emission within the pits even at high C concentration is dominated by a rather broad line at ∼3.47 eV typical for n-type GaN. In the area without pits, quenching of the donor bound exciton (DBE) spectrum at moderate C doping levels of 1–2 × 10{sup 17} cm{sup −3} is observed along with the appearance of two acceptor bound exciton lines typical for Mg-doped GaN. The DBE ionization due to local electric fields in compensated GaN may explain the transformation of the NBG emission.

• OSTI ID: 22402761
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 22 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CATHODOLUMINESCENCE
DOMAIN STRUCTURE
DOPED MATERIALS
ELECTRIC FIELDS
ELECTRON MICROSCOPY
GALLIUM NITRIDES
HALIDES
OPTICAL PROPERTIES
OXYGEN
QUENCHING
SPECTRA
SPECTROSCOPY
VAPOR PHASE EPITAXY