Structural Anisotropy of Amorphous Silicon Films Modified by Femtosecond Laser Pulses
| Autor: | S. V. Zabotnov, Denis E. Presnov, I. A. Romanov, A. V. Zoteev, Irina N. Parkhomenko, D. V. Shuleiko, Fedor Potemkin, F. V. Kashaev |
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| Rok vydání: | 2018 |
| Předmět: |
Amorphous silicon
Materials science Silicon Physics::Optics chemistry.chemical_element 02 engineering and technology 01 natural sciences law.invention chemistry.chemical_compound symbols.namesake law 0103 physical sciences Anisotropy 010302 applied physics business.industry 021001 nanoscience & nanotechnology Laser Atomic and Molecular Physics and Optics Nanocrystalline material Electronic Optical and Magnetic Materials chemistry Femtosecond symbols Optoelectronics 0210 nano-technology business Raman spectroscopy Excitation |
| Zdroj: | Optics and Spectroscopy. 124:801-807 |
| ISSN: | 1562-6911 0030-400X |
| DOI: | 10.1134/s0030400x18060218 |
| Popis: | It is demonstrated that the surface-relief orientation in the form of one-dimensional gratings with a period of 1.20 ± 0.02 μm formed under processing of hydrogenated-silicon films by femtosecond laser pulses (1.25 μm) with an energy density of 0.15 J/cm2 is determined by the direction of the polarization vector of the radiation and total laser exposure. Based on the results of the analysis of Raman spectra, the presence of a nanocrystalline phase of silicon with a volume fraction between 15 and 67% (depending on processing conditions) is detected. The observed processes of micro- and nanostructuring are caused by excitation of the surface plasmon–polaritons and nanocrystallization in the near-surface region in the field of high-power femtosecond laser pulses, respectively. In addition, formation of polymorph modifications of silicon Si-III and Si-XII under femtosecond laser processing with a number of pulses exceeding 500 is discovered. Anisotropy of the Raman signal for the above polymorph modifications is revealed. |
| Databáze: | OpenAIRE |
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