Wafer-scale ultra-broadband perfect absorber based on ultrathin Al-SiO2 stack metasurfaces

Broadband absorbers with high absorption, ultrathin thickness, and lithography-free planar structure have a wide range of potential applications, such as clocking and solar energy harvesting. For plasmonic metal materials, achieving perfect ultra-broadband absorption remains a challenge owing to the intrinsically narrow bandwidth. In this study, wafer-scale Al-SiO2 stack metasurfaces were experimentally fabricated to realize perfect ultra-broadband absorption. The experimental results show that the absorption for Al-SiO2 stack metasurfaces can reach up to 98% for the wavelength range from the ultraviolet to the near-infrared (350-1400 nm). It was experimentally verified that the absorption performance of Ai-SiO2 stack metasurfaces is dependent on the layer number and is superior to that of other metal-based stack metasurfaces. This study will pave the way for development of plasmonic metal-based ultra-broadband absorbers as in low cost and high performance robust solar energy devices. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

In this study, wafer-scale Al-SiO2 stack metasurfaces were experimentally fabricated to achieve perfect ultra-broadband absorption. The absorption for Al-SiO2 stack metasurfaces reached up to 98% for the wavelength range from ultraviolet to near-infrared. The results demonstrated that the absorption performance of Al-SiO2 stack metasurfaces is superior to other metal-based stack metasurfaces.