UV-VIS-NIR absorber to harvest energy for solar thermophotovoltaics

Abstract

Ideal ultraviolet-visible-infrared (UV-VIS-NIR) absorbers with consistent performance at elevated temperatures and severe climate conditions are crucial to harvest energy for solar-thermophotovoltaic systems (STPVs). As solar energy promises to fulfill the power demands, its efficient utilization through high-performing light-absorbing devices is inevitable. The requirement of high-temperature durability makes conventional plasmonics an infeasible choice, and those highly thermostable refractory metals/their derivatives suitable ones. In this work, a lossy refractory plasmonic material i.e. Zirconium-Nitride-based subwavelength, ultra-broadband, wide-angle, polarization-insensitive, and free-space impedance-matched metasurface absorber in a three-level Pythagorean fractal structure is demonstrated. A comprehensive investigative study is conducted with the successful attainment of more than 90% absorption between ∼ 500–900 nm with a peak of more than 98% at 655 nm. The mean absorption for wideband (200–2500 nm) is 86.01% and it is 91.37% for visible range. The proposed study provides an efficient choice of meta-absorbers for realizing highly efficient STPVs.