Theoretical Investigation of an Ultra-Wideband Tunable Metamaterial Absorber Based on Four Identical Vanadium Dioxide Resonators in the Terahertz Band

• Published in: Journal of electronic materials 2023-04, Vol.52 (4), p.2852-2864
• Main Authors: Zou, Yuke, Lin, Hongyan, Wu, Yangkuan, Zhu, Huaxin, Zhang, Xiangyang, Wang, Ben-Xin
• Format: Article
• Language: English
• Subjects: Absorbers; Absorbers (materials); Absorption; Arrays; Bandwidths; Broadband; Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; Insulation; Materials Science; Metamaterials; Optical and Electronic Materials; Original Research Article; Solid State Physics; Terahertz frequencies; Ultrawideband; Vanadium dioxide; Vanadium oxides
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-023-10250-y

A scheme for a terahertz metamaterial absorber is designed which consists of a periodic array of vanadium dioxide (VO 2 ) placed on a continuous gold film separated by a dielectric layer. Taking full advantage of the phase change property of VO 2 , which can be transformed from a metallic state to an insulating state, the absorber not only has ultra-wideband absorption, but also has adjustable absorption intensity. According to the simulation results, when VO 2 is in the metallic state, a resonance bandwidth with absorption rate greater than 90% can be reached up to 7.26 THz, from 3.52 THz to 10.78 THz. Its relative absorption bandwidth is 101.54%, which is much larger than previously reported broadband absorbers. Physical mechanism of the ultra-wideband absorption is discussed by analyzing near-field distributions of absorption peaks selected on absorption curve. Size variations of the VO 2 array provide the ability to modulate absorption performance, especially the absorption bandwidth. When VO 2 is in the insulating state, the simulation results show that near-perfect reflection (or near-zero absorption) is obtained, the maximum modulation depth of 97.1% is achieved. The extinction ratio of tunable broadband metamaterial absorber is also estimated. The proposed absorption device with ultra-wideband and tunable absorption features could have great potential for applications in terahertz band.