2026/03/09 by Kazim Ali, Muhammad Asif, Abida Perveen +4
Materials Science · Engineering · #Metamaterials and Metasurfaces Applications #Transition Metal Oxide Nanomaterials #Thermal Radiation and Cooling Technologies
paper · doi:10.1088/1402-4896/ae4f30
Abstract Terahertz (THz) absorbers have been the subject of extensive research because of their promising applications in advanced technologies. However, their widespread use is limited by an inherently narrow operating bandwidth. We report an innovative absorber that employs metamaterial concepts to achieve high efficiency across a broad terahertz (THz) frequency range, effectively addressing this challenge. The absorber features a three-layer design, consisting of a top vanadium dioxide (V O 2 ) film, a SiO 2 dielectric middle layer, and an Au ground layer. The upper V O 2 layer is precisely patterned into a configuration that includes cross-circular and split square rings, thus improving impedance matching and broadening absorption performance. The simulation results reveal that the proposed structure reaches an absorption rate over 90% under normal incidence in a broad frequency range of 2.82 to 6.79 THz, with a central resonance peak at 4.8 THz. Furthermore, this corresponds to an impressive relative bandwidth of approximately 83%. Moreover, by modulating the conductivity of the V O 2 , the absorption can be dynamically adjusted, achieving peak values between 0.83% and 99.85%. The structure is independent of the polarization angle and shows angular stability for both (TE) and (TM) modes, while maintaining perfect absorption efficiency across various incident angles. The perfect absorption mechanism is comprehensively explained through three key approaches, relative impedance matching with free space, interference theory and validation using the equivalent circuit model(ECM). Owing to its structurally simple design, ease of integration, and superior electromagnetic performance, the proposed absorber holds significant potential for applications in terahertz filtering, electromagnetic cloaking, sensing, communication systems, and optoelectronic switching.