Extending the absorption band from infrared to ultraviolet using the ITO transition from reflection to transparence

Abstract

A numerical simulation based on the finite-element method shows that a metamaterial absorber using Tungsten (W) and Indium tin oxide (ITO) plasmonic metals can be ultra-broadband and high-performance. Conventional broadband absorbers usually consist of multiple metal-dielectric layers or multi-resonators and have a bulky shape. The present investigates the possibility to reach optimal characteristics with a simple design by combining two plasmonic materials (W/ITO) within a single resonator. Involving the ITO transition from reflection to transparence dramatically increases the absorption bandwidth, which is extended from infrared to ultraviolet, with up to 99.92% absorption. The design is polarization-insensitive under oblique incidence, up to 75° and 80°, for TE and TM polarization waves, respectively.