A numerical research of wideband solar absorber based on refractory metal from visible to near infrared

Abstract The range of solar radiation observed on Earth is about 295–2500 nm. Designing the absorber within this range allows it to obtain as long an absorption band as possible to help alleviate energy problems. In this paper, a refractory metal material is theoretically designed to have an efficiency in designing an absorber with broadband solar absorption, and using FDTD method to numerically simulate it. The absorber achieves broadband absorption in the visible-near-infrared range, absorbing an absorption bandwidth of A > 90% up to 1264 nm (0.36 μm - 1624 μm). The absorption spectrum of the absorber can be manipulated by adjusting the structural parameters. More importantly, solar absorbers composed of TiO2 and TiN have higher thermal stability than nano resonators composed of conventional metal materials. Moreover, such an absorber does not reduce the absorption of solar radiation in the case where the angle of incidence changes.