A Selective Metasurface Absorber with An Amorphous Carbon Interlayer for Solar Thermal Applications

TL;DR

This paper develops a metal-dielectric-metal metasurface with amorphous carbon interlayer optimized for solar thermal applications, demonstrating high absorptance in the visible range and low thermal radiation, with detailed modeling and experimental validation.

Contribution

It introduces a novel gold-based metasurface absorber with optimized patterning for solar thermal efficiency, paving the way for high-temperature refractory metal replacements.

Findings

High absorptance (400-1200nm) achieved

Excellent agreement between measured and modeled results

Potential for high-temperature refractory metal implementation

Abstract

This paper presents fabrication, measurement and modelling results for a metal-dielectric-metal metasurface absorber for solar thermal applications. The structure uses amorphous carbon as an inter-layer between thin gold films with the upper film patterned with a 2D periodic array using focused ion beam etching. The patterned has been optimised to give high absorptance from 400-1200nm and low absorptance above this wavelength range to minimise thermal radiation and hence obtain higher temperature performance. Wide angle absorptance results are shown and detailed modelling of a realistic nanostructured upper layer results in excellent agreement between measured and modelled results. The use of gold in this paper is a first step towards a high temperature metasurface where gold can be replaced by other refractory metals such as tungsten or chrome.