The effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.122579· OSTI ID:663671

Wright, A F ^[1]; Grossner, U ^[2]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1415 (United States)
2. Institut fuer Festkoerpertheorie und Theoretische Optik, Friedrich-Schiller-Universitaet Jena, D 07743 Jena (Germany)

Density-functional-theory calculations have been performed to study the effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN. Four candidate structures were examined and their formation energies were found to depend strongly on Fermi level and growth stoichiometry. A structure having gallium vacancies at the dislocation core is predicted to be most stable in {ital n}-type material grown under nitrogen-rich conditions, while a structure without vacancies is most stable in {ital p}-type material grown under these conditions. In material grown under gallium-rich conditions, a structure having nitrogen vacancies at the dislocation core is predicted to be most stable in {ital p}-type material, whereas a variety of core structures should be present in {ital n}-type material. Edge dislocations are predicted to behave as electron traps in {ital n}-type material and may act as hole traps in {ital p}-type material depending on the growth conditions. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 663671
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 19 Vol. 73; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL DEFECTS
CRYSTAL DOPING
EDGE DISLOCATIONS
ELECTRON DENSITY
FERMI LEVEL
GALLIUM COMPOUNDS
GALLIUM NITRIDES
STOICHIOMETRY
TRAPS
VACANCIES