Ultra-broadband and wide-angle perfect solar absorber based on TiN nanodisk and Ti thin film structure

At present, solar energy is widely used as a kind of clean energy. The main solar radiation range under AM 1.5 is about 300 similar to 3000 nm. In this paper, we designed an efficient, ultra-broadband perfect solar absorber to have as long absorption bands in this range as possible to help alleviate the energy problem. The simulation calculations and experiments of the solar absorber show that the absorption bandwidth with absorption greater than 90% is greater than 2100 nm. It is worth noting that the perfect absorption bandwidth with absorption greater than 99% has more than 1600 nm. The absorption rate over the whole wavelength range (300 nm-3000 nm) (weighted directly around the sun by solar AM 1.5) is more than 90%. We can effectively control the absorption spectrum by adjusting the structural parameters. In addition, the proposed solar absorber is polarization independent, both the transverse electrical (TE) mode and the transverse magnetic (TM) mode, Absorption remains above 80% when the wide incidence angle is as high as 50 degrees. Our propose design has high broadband absorption and great potential for solar thermal energy harvesting, thermoelectrics, and thermal emitters applications.