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Electronic Structure of a Nitrogen Vacancy in Cubic Gallium Nitride
Author(s) -
Gubanov V. A.,
Wright A. F.,
Nelson J. S.,
Fong C. Y.,
Lu Z. W.,
Klein Barry M.,
Hamann D. R.
Publication year - 1998
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/(sici)1521-3951(199809)209:1<63::aid-pssb63>3.0.co;2-4
Subject(s) - vacancy defect , pseudopotential , gallium , condensed matter physics , atom (system on chip) , band gap , density of states , tight binding , electronic structure , atomic physics , materials science , density functional theory , valence (chemistry) , atomic orbital , chemistry , molecular physics , crystallography , computational chemistry , physics , embedded system , metallurgy , electron , organic chemistry , quantum mechanics , computer science
The electronic structure of a nitrogen vacancy in zinc‐blende GaN has been calculated using two different supercells with the plane‐wave pseudopotential (PWPP) and the tight‐binding linear muffin‐tin orbitals (TB‐LMTO) methods. The Ga 3d states are included in the valence states. Relaxation near a nitrogen vacancy site was examined with the PWPP method using a 31‐atom unit cell. The nearest neighbor Ga atoms were found to move toward the vacancy site by 0.04 Å resulting in a relaxation energy of only 0.04 eV. Given the absence of large relaxations, TB‐LMTO calculations were then performed for 31‐ and 63‐atom unit cells using an ideal (unrelaxed) geometry. Densities of states and charge density maps show that a nitrogen vacancy can induce a partially filled band, which overlaps with the conduction states, resulting in n‐type conductivity. The energy shift of this band under pressure was investigated for volume compressions up to 12% and compared with results from recent high‐pressure measurements for GaN.