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GaAsSb bandgap, surface fermi level, and surface state density studied by photoreflectance modulation spectroscopy.
- Source :
-
Applied Physics Letters . 5/28/2012, Vol. 100 Issue 22, p222104-222104-4. 1p. 1 Chart, 5 Graphs. - Publication Year :
- 2012
-
Abstract
- The bandgap, surface Fermi level, and surface state density of a series of GaAs1-xSbx surface intrinsic-n+ structures with GaAs as substrate are determined for various Sb mole fractions x by the photoreflectance modulation spectroscopy. The dependence of the bandgap on the mole composition x is in good agreement with previous measurements as well as predictions calculated using the dielectric model of Van Vechten and Bergstresser in Phys. Rev. B 1, 3551 (1970). For a particular composition x, the surface Fermi level is always strongly pinned within the bandgap of GaAs1-xSbx and we find its variation with composition x is well described by a function EF = 0.70 - 0.192 x for 0 <= x <= 0.35, a result which is notably different from that reported by Chouaib et al. [Appl. Phys. Lett. 93, 041913 (2008)]. Our results suggest that the surface Fermi level is pinned at the midgap of GaAs and near the valence band of the GaSb. [ABSTRACT FROM AUTHOR]
- Subjects :
- *BAND gaps
*FERMI surfaces
*GALLIUM arsenide
*DIELECTRICS
*MODULATION spectroscopy
Subjects
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 100
- Issue :
- 22
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 76311185
- Full Text :
- https://doi.org/10.1063/1.4724097