Unpinned behavior of the Fermi level and photovoltage on p-(100) GaAs surface facilitated by deposition of cesium
| Autor: | V.I. Tynnyi, A. G. Paulish, A.S. Terekhov, V.L. Alperovich, H. E. Scheibler |
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| Rok vydání: | 1996 |
| Předmět: |
Chemistry
Annealing (metallurgy) Surface photovoltage Fermi level Analytical chemistry General Physics and Astronomy Surfaces and Interfaces General Chemistry Photovoltaic effect Condensed Matter Physics Surfaces Coatings and Films symbols.namesake Band bending Monolayer symbols Spectroscopy Surface states |
| Zdroj: | Applied Surface Science. :228-233 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/s0169-4332(96)00149-3 |
| Popis: | The preparation technique of (100)GaAs surface with unpinned electronic properties is further developed in this work. It was proved that the unpinned behavior of the Fermi level and surface photovoltage on p-(100)GaAs surface was facilitated by the deposition of cesium. The surface preparation technique included removal of oxides in the solution of HCl in isopropanol and transfer to a UHV set-up in nitrogen atmosphere. The variations of band bending and surface photovoltage were measured by means of photoreflectance spectroscopy after anneals at successively increasing temperatures. Without Cs deposition, the band bending varied only by 50–100 meV as the annealing temperature increased from 300 to 600°C. Deposition of a monolayer of Cs, followed by annealing at 400°C, caused a pronounced decrease of band bending. The evolution of surface photovoltage, which depends both on band bending and on the rates of capture and recombination of the photogenerated carriers on the surface, was more diverse and sensitive to the details of surface treatment. Possible mechanisms of cesium influence on the electronic properties of the surface are discussed. |
| Databáze: | OpenAIRE |
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