Atomic nature of the Schottky barrier height formation of the Ag/GaAs(001)-2 × 4 interface: An in-situ synchrotron radiation photoemission study
| Autor: | Yi-Ting Cheng, Minghwei Hong, Raymond T. Tung, Guo-Jhen Wei, Yen-Hsun Lin, Keng-Yung Lin, Wan-Sin Chen, J. Kwo, Hsien-Wen Wan, Chiu-Ping Cheng, Tun-Wen Pi |
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| Rok vydání: | 2017 |
| Předmět: |
Passivation
Chemistry Schottky barrier General Physics and Astronomy Synchrotron radiation 02 engineering and technology Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Molecular physics Surfaces Coatings and Films Dipole Band bending Transition metal Secondary emission 0103 physical sciences Atomic physics 010306 general physics 0210 nano-technology Deposition (law) |
| Zdroj: | Applied Surface Science. 393:294-298 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2016.10.027 |
| Popis: | The Interface of Ag with p -type α2 GaAs(001)-2 × 4 has been studied to further understand the formation mechanism of the Schottky barrier height (SBH). In the initial phase of Ag deposition, high-resolution core-level data show that Ag adatoms effectively passivate the surface As-As dimers without breaking them apart. The Ag(+)-As(−) dipoles are thus generated with a maximal potential energy of 0.26 eV; a SBH of 0.38 eV was measured. Greater Ag coverage causes elemental segregation of As/Ga atoms, reversing the direction of the net dipole. The band bending effect near the interface shows a downward shift of 0.08 eV, and the final SBH is similar to the value as measured at the initial Ag deposition. Both parameters are secured at 0.25 A of Ag thickness prior to the observation of metallic behavior of Ag. Inadequacy of the metal-induced gap-state model for explaining SBH is evident. |
| Databáze: | OpenAIRE |
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