Nitrogen-related complexes in gallium arsenide

Citation
Je. Lowther et al., Nitrogen-related complexes in gallium arsenide, APPL PHYS L, 79(2), 2001, pp. 200-202
Citations number
25
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
00036951 → ACNP
Volume
79
Issue
2
Year of publication
2001
Pages
200 - 202
Database
ISI
SICI code
0003-6951(20010709)79:2<200:NCIGA>2.0.ZU;2-Q
Abstract
A first-principles pseudopotential method has been used to study some poten tially important metastable defects in N-doped GaAs. Formation energies hav e been obtained and related to those of As and Ga vacancies in the intrinsi c material. Of the structures considered, two are identified that crucially depend on overall material stoichiometry. These are N on a Ga site (N-Ga) or a NN dimer on an As site (NNAs). N-Ga has a partly shallow energy-level structure with a fully occupied level lying near the valence-band edge, whe reas NNAs has localized character with a midgap deep level. Both defects ma y be responsible for the onset of a reduction in the apparent band gap that has been recently observed in heavily N-doped GaAs prior to alloying. (C) 2001 American Institute of Physics.