Which factor determines the optical losses in refractory tungsten thin films at high temperatures?
| Autor: | Mahima Arya, Ankita Ganguly, Gnanavel V. Krishnamurthy, Surya S. Rout, Leonid Gurevich, Tobias Krekeler, Martin Ritter, Kjeld Pedersen, Michael Störmer, Alexander Yu Petrov, Manfred Eich, Manohar Chirumamilla |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Thin films
General Physics and Astronomy Physics::Optics Surfaces and Interfaces General Chemistry Condensed Matter Physics Tungsten Surfaces Coatings and Films Thermophotovoltaics Electron–phonon interaction High temperature stability Surface scattering ddc:600 Technik [600] Grain boundary scattering |
| Zdroj: | Arya, M.; Ganguly, A.; Krishnamurthy, G.V.; Rout, S.S.; Gurevich, L.; Krekeler, T.; Ritter, M.; Pedersen, K.; Störmer, M.; Yu Petrov, A.; Eich, M.; Chirumamilla, M.: Which factor determines the optical losses in refractory tungsten thin films at high temperatures?. In: Applied Surface Science. Vol. 588 (2022) 152927. (DOI: /10.1016/j.apsusc.2022.152927) Arya, M, Ganguly, A, Krishnamurthy, G V, Rout, S S, Gurevich, L, Krekeler, T, Ritter, M, Pedersen, K, Störmer, M, Yu Petrov, A, Eich, M & Chirumamilla, M 2022, ' Which factor determines the optical losses in refractory tungsten thin films at high temperatures? ', Applied Surface Science, vol. 588, 152927 . https://doi.org/10.1016/j.apsusc.2022.152927 Applied Surface Science 588: 152927 (2022-06-30) |
| ISSN: | 0169-4332 |
| Popis: | Refractory tungsten (W) plays an important role in high temperature photonic/plasmonic applications. Previously room temperature bulk single/poly-crystalline optical constants were extensively used to calculate the optical properties of W nanostructures at high temperatures. This might lead to a significant deviation between the predicted and measured optical properties due to the exclusion of electron–phonon interaction, as well as grain-boundary and surface-scattering. Herein, we show experimentally, how film thickness and temperature affects the optical losses in W. A drastic increase in the effective electron collision frequency is observed with decreasing the film thickness down to 5 nm, due to the grain-boundary and surface-scattering mechanisms. At sufficiently high temperatures (greater than 200 °C for W), the electron–phonon interaction eventually becomes the dominant mechanism, linearly increasing collision frequency with temperature, and it is independent of the geometry of the thin film structure. The impact of thickness and temperature-dependent optical properties of W is showcased with a hyperbolic 1D metamaterial structure acting as a thermophotovoltaic emitter. This work opens new directions in accurate prediction of the optical properties of nanostructures and design of efficient devices in various applications, such as aerospace, energy-efficient lighting, radiative cooling and energy harvesting, by incorporating thickness and temperature-dependent optical constants. Deutsche Forschungsgemeinschaft (DFG) |
| Databáze: | OpenAIRE |
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