Zhang Yanyu, Hou Bin, Song Qianju, Yi Zao, Zeng Qingdong
School of Mathematics and Physics, Southwest University of Science and Technology, Mianyang 621010, China.
School of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China.
Dalton Trans. 2024 Dec 10;53(48):19264-19271. doi: 10.1039/d4dt02475c.
Terahertz (THz) devices are highly desired in modulation, detection, and receiving devices. Recently, active metamaterials have been applied as a novel strategy for the design of terahertz devices. However, their performance and function need to be further developed. Here, an active controllable THz smart switch is designed using vanadium dioxide (VO), a thermally controlled phase transition material. The THz smart switch is simple, consisting of three layers: the top and bottom layers are VO, and the intermediate dielectric layer is SiO. Based on impedance matching theory and an analysis of the electric field distribution, the mechanism by which the device achieves perfect absorption is studied. The results show that the THz smart switch can achieve ultra-wideband and wide-angle absorption and transmission of terahertz waves, and can flexibly switch between these modes. When VO is in the metal state, the THz smart switch can achieve ultra-wideband absorption, and the absorption bandwidth is as high as 5.8 THz ( > 90%). When VO is in the insulating state, the THz smart switch can achieve ultra-wideband transmission, with an average transmission of 86% (Δ = 4.7 THz). As the ambient temperature changes, the THz smart switch can achieve active switching of the absorption from 2% to 99.9% and the transmission from 89% to 0%. It is worth noting that the THz smart switch can also realize the active switching of absorption and transmission over a wide-angle range. This study provides important insights for the design of active controllable devices and also offers a new concept for the design of THz multi-functional devices.
太赫兹（THz）器件在调制、检测和接收设备中具有很高的需求。最近，有源超材料已被用作太赫兹器件设计的一种新策略。然而，它们的性能和功能仍需进一步发展。在此，使用热控相变材料二氧化钒（VO₂）设计了一种有源可控太赫兹智能开关。该太赫兹智能开关结构简单，由三层组成：顶层和底层为VO₂，中间介电层为SiO₂。基于阻抗匹配理论并通过对电场分布的分析，研究了该器件实现完美吸收的机制。结果表明，太赫兹智能开关能够实现太赫兹波的超宽带和广角吸收与透射，并且可以在这些模式之间灵活切换。当VO₂处于金属态时，太赫兹智能开关可实现超宽带吸收，吸收带宽高达5.8 THz（> 90%）。当VO₂处于绝缘态时，太赫兹智能开关可实现超宽带透射，平均透射率为86%（Δ = 4.7 THz）。随着环境温度的变化，太赫兹智能开关能够实现吸收从2%到99.9%以及透射从89%到0%的有源切换。值得注意的是，太赫兹智能开关还能在广角范围内实现吸收和透射的有源切换。本研究为有源可控器件的设计提供了重要见解，也为太赫兹多功能器件的设计提供了新的概念。
