Highly efficient Vanadium Nitride based metasurface absorber/emitter for solar-thermophotovoltaic system

Perfect ultraviolet-visible (UV-Vis) absorbers with a stable performance at high temperatures and hostile environments are highly required for energy harvesting through solar-thermophotovoltaic (STPV) systems. Here we propose a novel lossy refractory and thermally stable (melting point 2050 °C) metal Vanadium Nitride (VN) for broadband absorber and thermally stable emitter specifically for STPV applications. Proposed design consists of a metal-dielectric-metal arrangement, displaying an average absorption of > 98% for 300–800 nm with unity peak absorption at 340 nm. Owing to design symmetry, the proposed absorber exhibits polarization insensitivity and a highly robust response to oblique incidences. Moreover, the proposed emitter is designed for Copper Indium Gallium Diselenide (CIGS) PV cell exhibiting an emittance of > 99% for bandgap energy of 1.14 eV (1089 nm). The proposed VN platform's high broadband absorption, narrowband emittance, and high-temperature endurability make it a potential contender for solar energy harvesting systems.