Temperature dependent behavior of the SPV for n-type GaN

Joy Dorene McNamara, M. Foussekis, H. Liu, H. Morkoç, M. A. Reshchikov, A. A. Baski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Scopus citations

Abstract

N-type GaN exhibits upward, near-surface band bending that can be decreased by generating a surface photovoltage (SPV). Fitting SPV measurements with a thermionic model based on the emission of charge carriers over the nearsurface barrier provides information about the band bending in dark. We have studied the temperature dependent SPV behavior from a Si-doped, n-type GaN sample grown by hydride vapor phase epitaxy in order to determine how the magnitude of band bending changes at higher temperatures. We have measured the effect of temperature and oxygen on the steady-state SPV behavior, where oxygen is photo-adsorbed on the surface under band-to-band illumination in an air/oxygen ambient more efficiently at higher temperatures. As predicted, the intensity-dependent SPV measurements performed at temperatures between 295 and 500 K exhibit a decrease in the maximum SPV with increasing temperature. When illumination ceases, the band bending then begins to restore to its dark value with a rate proportional to the sample temperature, which also fits a thermionic model.

Original languageEnglish (US)
Title of host publicationGallium Nitride Materials and Devices VII
DOIs
StatePublished - Apr 16 2012
EventGallium Nitride Materials and Devices VII - San Francisco, CA, United States
Duration: Jan 23 2012Jan 26 2012

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8262
ISSN (Print)0277-786X

Other

OtherGallium Nitride Materials and Devices VII
CountryUnited States
CitySan Francisco, CA
Period1/23/121/26/12

Keywords

  • GaN
  • Kelvin probe
  • band bending
  • surface photovoltage

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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