Silicon nanowire optical Raman line shapes at cryogenic and elevated temperatures
| Autor: | Mirco Cantoro, Christian Thomsen, Sevak Khachadorian, H. Scheel, Andrea C. Ferrari, Alan Colli |
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| Rok vydání: | 2008 |
| Předmět: |
Silicon
Analytical chemistry Nanowire chemistry.chemical_element Atmospheric temperature range Condensed Matter Physics Laser Molecular physics Electronic Optical and Magnetic Materials law.invention symbols.namesake chemistry law Perfect thermal contact symbols Physics::Atomic Physics Raman spectroscopy Excitation Superfluid helium-4 |
| Zdroj: | physica status solidi (b). 245:2090-2093 |
| ISSN: | 0370-1972 |
| DOI: | 10.1002/pssb.200879554 |
| Popis: | We report the Raman spectra of silicon nanowires (SiNWs) in a wide temperature range, between 2 K and 850 K. At room temperature we find a strong influence on the spectrum from applied laser excitation powers. These effects can be attributed a laser heated sample, leading to an inhomogeneous temperature distribution within the laser-spot. If the laser excitation power is small (below 100 jlW) such effects are negligible, and we find a temperature dependence governed by three-phonon decay processes. The results from temperature-dependent measurements indicate a change of sample morphology due to heating. Raman measurements on' SiNWs immersed in superfluid helium at ≈ 2 K show very strong red-shifts, even though they still have the perfect thermal contact via the superfluid helium. Considering anharmonic effects we find massively increased Si core temperatures. |
| Databáze: | OpenAIRE |
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