Local variation in Bi crystal sites of epitaxial GaAsBi studied by photoelectron spectroscopy and first-principles calculations
| Autor: | Pekka Laukkanen, Jacek Osiecki, A. Lahti, Joonas Hilska, Marko Patrick John Punkkinen, Marjukka Tuominen, Jaakko Mäkelä, Mikhail Kuzmin, Johnny Dahl, Kalevi Kokko, Mircea Guina, Janne Puustinen, Muhammad Yasir, Karina Schulte |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Diffraction Materials science Photoluminescence ta114 Infrared Analytical chemistry General Physics and Astronomy Synchrotron radiation 02 engineering and technology Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Epitaxy 01 natural sciences Spectral line Surfaces Coatings and Films Crystal X-ray photoelectron spectroscopy 0103 physical sciences 0210 nano-technology ta116 |
| Zdroj: | Applied Surface Science. 396:688-694 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2016.11.009 |
| Popis: | Epitaxial Bi-containing III–V crystals (III-V1-xBix) have attracted increasing interest due to their potential in infrared applications. Atomic-scale characterization and engineering of bulk-like III-V1-xBix properties (e.g., Bi incorporation and defect formation) are challenging but relevant to develop applications. Toward that target, we report here that the traditional surface-science measurement of photoelectron spectroscopy (PES) is a potential, non-destructive method to be combined in the studies of bulk-like properties, when surface effects are properly removed. We have investigated epitaxial GaAs1-xBix films, capped by epitaxial AlAs layers, with high-resolution photoelectron spectroscopy. The Bi5d core-level spectra of GaAs1-xBix together with ab-initio calculations give direct evidence of variation of Bi bonding environment in the lattice sites. The result agrees with photoluminescence (PL) measurement which shows that the studied GaAs1-xBix films include local areas with higher Bi content, which contribute to PL but do not readily appear in x-ray diffraction (XRD). The measured and calculated Bi core-level shifts show also that Ga vacancies and Bi clusters are dominant defects. |
| Databáze: | OpenAIRE |
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