Ultra-broadband perfect solar absorber by an ultra-thin refractory titanium nitride meta-surface

作者:Liu, Zhengqi*; Liu, Guiqiang; Huang, Zhenping; Liu, Xiaoshan; Fu, Guolan
来源:Solar Energy Materials and Solar Cells, 2018, 179: 346-352.
DOI:10.1016/j.solmat.2017.12.033

摘要

Electromagnetic wave absorbers with thinner structural thickness but with broader spectral absorption bandwidth are more desirable for various applications in solar energy and optoelectronics. In this work, a refractory titanium nitride meta-surface with efficient, ultra-broadband solar energy absorption is theoretically designed and numerically demonstrated. The resulting 250-nm-thick meta-surface absorber exhibits an ultra-broadband perfect absorption over the whole ultraviolet-visible-near infrared range. With taking the A > 90% into account, the absorption bandwidth is up to 1110 nm with the wavelength range varied from 0.316 mu m to 1.426 mu m. The titanium nitride nano-resonators array and its coating structure of titanium dioxide array cooperatively provide multiple resonant modes, which therefore introduce strong coupling with the solar radiation and eventually produce an ultra-broadband absorption. The absorption spectrum can be feasibly manipulated via tuning the structural parameters. Most importantly, in sharp contrast to the common absorbers formed with metallic nano-resonators, the titanium nitride based solar absorber is with much stronger thermal stability, illustrating the impressive promise for wide applications such as thermo-photovoltaics and other high-power optoelectronic processes.