Presentation
26 July 2016 Radiative engineering with refractory epsilon-near-zero metamaterials (Conference Presentation)
Pavel N. Dyachenko, Sean Molesky, Alexander Yu. Petrov, Michael Störmer, Tobias Krekeler, Slawa Lang, Martin Ritter, Zubin Jacob, Manfred Eich
Author Affiliations +
Abstract
Improvement in high-temperature stable spectrally selective absorbers and emitters is integral for the further development of thermophotovoltaic (TPV), lighting and solar thermal applications. However, the high operational temperatures (T>1000oC) required for efficient energy conversion, along with application specific criteria such as the operational range of low bandgap semiconductors, greatly restrict what can be accomplished with natural materials. Motivated by this challenge, we demonstrate the first example of high temperature thermal radiation engineering with metamaterials. By employing the naturally selective thermal excitation of radiative modes that occurs near topological transitions, we show that thermally stable highly selective emissivity features are achieved for temperatures up to 1000°C with low angular dependence in a sub-micron thick refractory tungsten/hafnium dioxide epsilon-near-zero (ENZ) metamaterial. We also investigate the main mechanisms of thermal degradation of the fabricated refractory metamaterial both in terms of optical performance and structural stability using spectral analysis and energy-dispersive X-ray spectroscopy (EDS) techniques. Importantly, we observe chemical stability of the constituent materials for temperatures up to 1000°C and structural stability beyond 1100°C. The scalable fabrication, requiring magnetron sputtering, and thermally robust optical properties of this metamaterial approach are ideally suited to high temperature emitter applications such as lighting or TPV. Our findings provide a first concrete proof of radiative engineering with high temperature topological transition in ENZ metamaterials, and establish a clear path for implementation in TPV energy harvesting applications.
Conference Presentation
© (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Pavel N. Dyachenko, Sean Molesky, Alexander Yu. Petrov, Michael Störmer, Tobias Krekeler, Slawa Lang, Martin Ritter, Zubin Jacob, and Manfred Eich "Radiative engineering with refractory epsilon-near-zero metamaterials (Conference Presentation)", Proc. SPIE 9883, Metamaterials X, 98830V (26 July 2016); https://doi.org/10.1117/12.2227829
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KEYWORDS
Metamaterials

Light sources and illumination

Chemical analysis

Fabrication

Solar thermal energy

Thermal engineering

X-rays

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