Wu Guozheng, Li Chao, Wang Dong, Gao Song, Chen Wenya, Guo Shijing, Xiong Jiaran
School of Information Science and Engineering, University of Jinan, 250022, China.
Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China.
Phys Chem Chem Phys. 2024 Mar 13;26(11):8993-9004. doi: 10.1039/d4cp00268g.
This paper proposes a simulated design for a versatile terahertz absorber that can be actively tuned. The absorber utilizes the unique tuning capabilities of graphene and vanadium dioxide, enabling it to alternate between ultra-broadband absorption, broadband absorption, and almost complete reflection. In the metallic phase of vanadium dioxide, coupled with a graphene Fermi level at 0 eV, the absorber achieves ultra-broadband absorption. This spans an extensive frequency range from 3.85 THz to 9.73 THz, exhibiting an absorption rate surpassing 90%. As we shift to the insulating phase of vanadium dioxide and adjust the graphene Fermi level to 1 eV, the absorber operates in a broadband absorption mode. This mode spans 2.98 THz to 4.63 THz, demonstrating an absorption rate exceeding 90%. In the insulating state of vanadium dioxide with a graphene Fermi level at 0 eV, the absorber metamorphoses into a nearly total reflector. Its maximum absorption rate is a mere 0.52%. The unique adjustability of vanadium dioxide and graphene independently enables the fine-tuning of absorption rates for both ultra-broadband and broadband absorption without encountering interference. Additionally, thanks to the central symmetry inherent in the proposed structure, the absorber exhibits insensitivity to alterations in polarization angles and remains stable under a broad range of incident angles. With these benefits, the absorber shows promising potential for applications in electromagnetic stealth, wireless communication, and so on.
本文提出了一种可主动调谐的多功能太赫兹吸收体的模拟设计。该吸收体利用了石墨烯和二氧化钒独特的调谐能力，使其能够在超宽带吸收、宽带吸收和几乎完全反射之间切换。在二氧化钒的金属相中，结合费米能级为0 eV的石墨烯，吸收体实现超宽带吸收。其频率范围从3.85太赫兹到9.73太赫兹，吸收率超过90%。当转变到二氧化钒的绝缘相并将石墨烯费米能级调整到1 eV时，吸收体工作在宽带吸收模式。该模式覆盖2.98太赫兹到4.63太赫兹，吸收率超过90%。在二氧化钒绝缘态且石墨烯费米能级为0 eV时，吸收体转变为几乎全反射体。其最大吸收率仅为0.52%。二氧化钒和石墨烯各自独特的可调性使得能够对超宽带和宽带吸收的吸收率进行微调而互不干扰。此外，得益于所提出结构的中心对称性，吸收体对偏振角的变化不敏感，并且在很宽的入射角范围内都保持稳定。有了这些优点，该吸收体在电磁隐身、无线通信等应用中显示出广阔的潜力。
