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Author Christenson, Sayre G. ♦ Xie, Weiyu ♦ Sun, Y. Y. ♦ Zhang, S. B.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ BINDING ENERGY ♦ CARBON ♦ DENSITY FUNCTIONAL METHOD ♦ GALLIUM NITRIDES ♦ PEAKS ♦ PHONONS ♦ PHOTOLUMINESCENCE ♦ THERMAL EQUILIBRIUM
Abstract We study three carbon defects in GaN, isolated C{sub N} and its two complexes with donors C{sub N}–O{sub N}, and C{sub N}–Si{sub Ga}, as a cause of the yellow luminescence using accurate hybrid density functional calculation, which includes the semi-core Ga 3d electrons as valence electrons and uses a larger 300-atom supercell. We show that the isolated C{sub N} defect yields good agreement with experiment on the photoluminescence (PL) peak position, zero-phonon line, and thermodynamic defect transition level. We find that the defect state of the complexes that is involved in the PL process is the same as that of the C{sub N} defect. The role of the positively charged donors (O{sub N} or Si{sub Ga}) next to C{sub N} is to blue-shift the PL peak. Therefore, the complexes cannot be responsible for the same PL peak as isolated C{sub N}. Our detailed balance analysis further suggests that under thermal equilibrium at typical growth temperature, the concentration of isolated C{sub N} defect is orders of magnitude higher than the defect complexes, which is a result of the small binding energy in these complexes.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-10-07
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 118
Issue Number 13


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