Multi-band, tunable, high figure of merit, high sensitivity single-layer patterned graphene—Perfect absorber based on surface plasmon resonance

• Published in: Diamond and related materials Vol. 116; p. 108393
• Main Authors: Chen, Zihao, Chen, Hao, Yin, Jiankang, Zhang, Renyin, Jile, Huge, Xu, Danyang, Yi, Zao, Zhou, Zigang, Cai, Shuangshuang, Yan, Peiguang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2021; Elsevier BV
• Subjects: Absorbers; Energy levels; Figure of merit; Graphene; High figure of merit; High sensitivity; Multi-band perfect absorption; Refractivity; Relaxation time; Resonance absorption; Sensitivity; Silicon dioxide; Surface chemistry; Surface plasmon resonance; Thermal radiation; Tunable; High figure of merit; Tunable; Graphene; Multi-band perfect absorption; High sensitivity
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2021.108393

This paper propose a perfect absorber with multi-band, adjustable, high figure of merit (FOM) and high sensitivity is based on single-layer patterned graphene surface plasmon resonance (SPR). The wave absorber is composed of a patterned graphene structure etched in a circular shape in the middle and a bottom metal film separated by a SiO2 dielectric layer. It has simple structural features and can greatly simplify the manufacturing process. In the mid-infrared band of 3 μm ~ 5 μm, the numerical results of FDTD method show that the absorbers have three perfect absorption peaks, which are λ1 = 3275.31 nm, λ2 = 3706.12 nm and λ3 = 4481.76 nm, respectively. The absorption rates are 99.44%, 98.22% and 99.10%, respectively. The resonant wavelength of the absorber can be tuned by controlling the Fermi energy level and relaxation time of the graphene layer. In addition, the wave absorber is insensitive to polarization and can keep high absorption in a wide range of incident angles from 0° to 50°. At last, we explore the sensitivity and FOM of the absorber by changing the environmental refractive index. The results show that the sensitivity of its three resonance absorption peaks is 666.75 nm/RIU, 760.50 nm/RIU and 907.88 nm/RIU (RIU is the per refractive index unit), and the FOM is 86.82, 53.03 and 56.14, respectively. Therefore, we believe that the absorber can be used in the fields of narrow-band thermal radiation, narrow-band light detection and narrow-band sensor. [Display omitted] •By FDTD simulation, the absorber has three perfect absorption peaks.•The absorption property can be turned by controlling Fermi level or relaxation time.•The proposed ideal plasma absorber has polarization independence.•The proposed wave absorber has good resistance to wide incident angle.•The wave absorber has extremely high refractive index sensitivity and FOM.