Refractory Brewster metasurfaces control the frequency and angular spectrum of light absorption

Abstract

Ways to achieve highly efficient electromagnetic absorption over a broad bandwidth and broad angular spectrum have been discussed extensively in the past decades for various applications, such as low reflection devices and energy harvesting. To satisfy the efficiency requirements, metamaterial approaches have been explored in recent years. In this context, most studies have suggested the use of frequency selective surfaces or arrays of plasmonic resonators, which limit bandwidth and angular spectrum of performance. Here, we explore the application of refractory Brewster metasurfaces for photovoltaic applications. By matching the surface impedance of metasurfaces and free space at the Brewster angle, we show that metasurfaces can lead to efficient light absorption, and their response can be controlled accurately both in the angular and in the frequency spectrum to match the requirements of energy harvesting systems and facilitate large efficiency, high-temperature energy harvesting.