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On the validity of the amphoteric-defect model in gallium arsenide and a criterion for Fermi-level pinning by defects

Publication ,  Journal Article
Chen, CH; Tan, TY
Published in: Appl. Phys. A, Mater. Sci. Process. (Germany)
1995

Using the theoretically calculated point-defect total-energy values of Baraff and Schlueter in GaAs, an amphoteric-defect model has been proposed by Walukiewicz to explain a large number of experimental results. The suggested amphoteric-defect system consists of two point-defect species capable of transforming into each other: the doubly negatively charged Ga vacancy V2-Ga and the triply positively charged defect complex (ASGa+VAs)3+, with AsGa being the antisite defect of an As atom occupying a Ga site and VAs being an As vacancy. When present in sufficiently high concentrations, the amphoteric defect system V2-Ga/(AsGa+VAs)3+ is supposed to be able to pin the GaAs Fermi level at approximately the Ev+0.6 eV level position, which requires that the net free energy of the VGa/(AsGa+VAs) defect system to be minimum at the same Fermi-level position. We have carried out a quantitative study of the net energy of this defect system in accordance with the individual point-defect total-energy results of Baraff and Schlueter, and found that the minimum net defect-system-energy position is located at about the Ev+1.2 eV level position instead of the needed Ev+0.6 eV position. Therefore, the validity of the amphoteric-defect model is in doubt. We have proposed a simple criterion for determining the Fermi-level pinning position in the deeper part of the GaAs band gap due to two oppositely charged point-defect species, which should be useful in the future

Duke Scholars

Published In

Appl. Phys. A, Mater. Sci. Process. (Germany)

DOI

Publication Date

1995

Volume

A61

Issue

4

Start / End Page

397 / 405

Related Subject Headings

  • Applied Physics
  • 5104 Condensed matter physics
  • 5102 Atomic, molecular and optical physics
  • 4016 Materials engineering
  • 0912 Materials Engineering
  • 0205 Optical Physics
  • 0204 Condensed Matter Physics
 

Citation

APA
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ICMJE
MLA
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Chen, C. H., & Tan, T. Y. (1995). On the validity of the amphoteric-defect model in gallium arsenide and a criterion for Fermi-level pinning by defects. Appl. Phys. A, Mater. Sci. Process. (Germany), A61(4), 397–405. https://doi.org/10.1007/s003390050219
Chen, C. H., and T. Y. Tan. “On the validity of the amphoteric-defect model in gallium arsenide and a criterion for Fermi-level pinning by defects.” Appl. Phys. A, Mater. Sci. Process. (Germany) A61, no. 4 (1995): 397–405. https://doi.org/10.1007/s003390050219.
Chen CH, Tan TY. On the validity of the amphoteric-defect model in gallium arsenide and a criterion for Fermi-level pinning by defects. Appl Phys A, Mater Sci Process (Germany). 1995;A61(4):397–405.
Chen, C. H., and T. Y. Tan. “On the validity of the amphoteric-defect model in gallium arsenide and a criterion for Fermi-level pinning by defects.” Appl. Phys. A, Mater. Sci. Process. (Germany), vol. A61, no. 4, 1995, pp. 397–405. Manual, doi:10.1007/s003390050219.
Chen CH, Tan TY. On the validity of the amphoteric-defect model in gallium arsenide and a criterion for Fermi-level pinning by defects. Appl Phys A, Mater Sci Process (Germany). 1995;A61(4):397–405.

Published In

Appl. Phys. A, Mater. Sci. Process. (Germany)

DOI

Publication Date

1995

Volume

A61

Issue

4

Start / End Page

397 / 405

Related Subject Headings

  • Applied Physics
  • 5104 Condensed matter physics
  • 5102 Atomic, molecular and optical physics
  • 4016 Materials engineering
  • 0912 Materials Engineering
  • 0205 Optical Physics
  • 0204 Condensed Matter Physics