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Photoemission study of chemisorption and Fermi-level pinning at K/GaAs(100) interface with synchrotron radiation
- Source :
- Applied Surface Science. 249:340-345
- Publication Year :
- 2005
- Publisher :
- Elsevier BV, 2005.
-
Abstract
- The adsorption of K on the n-GaAs(I 0 0) surface was investigated by X-ray photoelectron spectroscopy (XPS) and synchrotron radiation photoemission spectroscopy (SR-PES). The Ga3d and As3d core level was measured for clean and K adsorbed GaAs(I 0 0) surface. The adsorption of K induced chemical reaction between K and As, and the K-As reactant formed when the K coverage theta > I ML. The chemical reaction between K and Ga did not occur, but Ga atoms were exchanged by K atoms. From the data of band bending, the Schottky barrier is 0.70 eV. The Fermi-level pinning was not caused by defect levels. The probable reason is that the dangling bonds of surface Ga atoms were filled by the outer-shell electrons of K atoms, forming a half-filled surface state. The Fermi-level pinning was caused by this half-filled surface state. (c) 2004 Elsevier B.V. All rights reserved.
- Subjects :
- Chemistry
Photoemission spectroscopy
Schottky barrier
Fermi level
Dangling bond
General Physics and Astronomy
Surfaces and Interfaces
General Chemistry
Condensed Matter Physics
Molecular physics
Surfaces, Coatings and Films
symbols.namesake
Band bending
X-ray photoelectron spectroscopy
Chemisorption
symbols
Atomic physics
Surface states
Subjects
Details
- ISSN :
- 01694332
- Volume :
- 249
- Database :
- OpenAIRE
- Journal :
- Applied Surface Science
- Accession number :
- edsair.doi...........7ffe329a7f6053c9fd4257fe6d01dc5b