Design of a Penta-Band Graphene-Based Terahertz Metamaterial Absorber with Fine Sensing Performance

Runing Lai; Hao Chen; Zigang Zhou; Zao Yi; Bin Tang; Jing Chen; Yougen Yi; Chaojun Tang; Jianguo Zhang; Tangyou Sun

doi:10.3390/mi14091802

Design of a Penta-Band Graphene-Based Terahertz Metamaterial Absorber with Fine Sensing Performance

Micromachines (Basel). 2023 Sep 21;14(9):1802. doi: 10.3390/mi14091802.

Authors

Runing Lai¹, Hao Chen¹, Zigang Zhou¹, Zao Yi^{1

2}, Bin Tang³, Jing Chen⁴, Yougen Yi⁵, Chaojun Tang⁶, Jianguo Zhang⁷, Tangyou Sun⁸

Affiliations

¹ Joint Laboratory for Extreme Conditions Matter Properties, Tianfu Institute of Research and Innovation, State Key Laboratory of Environmental Friendly Energy Materials, Key Laboratory of Manufacturing Process Testing Technology of Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China.
² School of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China.
³ School of Microelectronics and Control Engineering, Changzhou University, Changzhou 213164, China.
⁴ College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
⁵ College of Physics and Electronics, Central South University, Changsha 410083, China.
⁶ College of Science, Zhejiang University of Technology, Hangzhou 310023, China.
⁷ Department of Physics, Jinzhong University, Jinzhong 030619, China.
⁸ Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, China.

Abstract

This paper presents a new theoretical proposal for a surface plasmon resonance (SPR) terahertz metamaterial absorber with five narrow absorption peaks. The overall structure comprises a sandwich stack consisting of a gold bottom layer, a silica medium, and a single-layer patterned graphene array on top. COMSOL simulation represents that the five absorption peaks under TE polarization are at f_I = 1.99 THz (95.82%), f_Ⅱ = 6.00 THz (98.47%), f_Ⅲ = 7.37 THz (98.72%), f_Ⅳ = 8.47 THz (99.87%), and f_V = 9.38 THz (97.20%), respectively, which is almost consistent with the absorption performance under TM polarization. In contrast to noble metal absorbers, its absorption rates and resonance frequencies can be dynamically regulated by controlling the Fermi level and relaxation time of graphene. In addition, the device can maintain high absorptivity at 0~50° in TE polarization and 0~40° in TM polarization. The maximum refractive index sensitivity can reach S_V = 1.75 THz/RIU, and the maximum figure of merit (FOM) can reach FOM_V = 12.774 RIU^-1. In conclusion, our design has the properties of dynamic tunability, polarization independence, wide-incident-angle absorption, and fine refractive index sensitivity. We believe that the device has potential applications in photodetectors, active optoelectronic devices, sensors, and other related fields.

Keywords: dynamic tunability; graphene; high figure of merit; penta-band absorption; terahertz; wide-angle absorption.

Grants and funding

The authors are grateful to the support by National Natural Science Foundation of China (No. 51606158, 11604311, 61705204, 21506257); the Funded by the Basic Research Program of Shanxi Province (202103021223353); the funded by the Open Fund of the Key Laboratory for Metallurgical Equipment and Control Technology of Ministry of Education in Wuhan University of Science and Technology, China (No. MECOF2022B01); the Funded by the Open Fund of Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering at Wuhan University of Science and Technology (MTMEOF2021B02).