Vanadium dioxide-based tunable broadband metamaterial absorber in the terahertz

This study presents a three-layer broadband absorber comprising a vanadium dioxide (VO2) layer at the top, a polytetrafluoroethylene layer in the middle, and a gold film at the bottom. Absorption curves were calculated using the multiple-reflection principle and impedance matching theory, and the obtained results were consistent with the simulation results. According to simulation results, within the range of controllable conductivity of VO2, the absorption rate of the as-developed structure varied from 1.5% to 99.8%, with the bandwidth extending from 0 THz to 5.19 THz. The metamaterial maintained > 75% absorption across the frequency band for incident angles up to 45 degrees, with the absorption rate varying for different polarization angles. The as-developed metamaterial exhibited the characteristics of wide-angle incidence and polarization sensitivity and has excellent application prospects in the domains of medicine, military, and communication.