Design of Ultra-Narrow Band Graphene Refractive Index Sensor

Qianyi Shangguan; Zihao Chen; Hua Yang; Shubo Cheng; Wenxing Yang; Zao Yi; Xianwen Wu; Shifa Wang; Yougen Yi; Pinghui Wu

doi:10.3390/s22176483

Sensors (Aug 2022)

Design of Ultra-Narrow Band Graphene Refractive Index Sensor

Qianyi Shangguan,
Zihao Chen,
Hua Yang,
Shubo Cheng,
Wenxing Yang,
Zao Yi,
Xianwen Wu,
Shifa Wang,
Yougen Yi,
Pinghui Wu

Affiliations

Qianyi Shangguan: School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China
Zihao Chen: State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 610054, China
Hua Yang: State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China
Shubo Cheng: School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China
Wenxing Yang: School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434023, China
Zao Yi: Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010, China
Xianwen Wu: School of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
Shifa Wang: School of Electronic and Information Engineering, Chongqing Three Gorges University, Chongqing 404000, China
Yougen Yi: College of Physics and Electronics, Central South University, Changsha 410083, China
Pinghui Wu: Fujian Provincial Key Laboratory for Advanced Micro-Nano Photonics Technology and Devices, Quanzhou Normal University, Quanzhou 362000, China

DOI: https://doi.org/10.3390/s22176483
Journal volume & issue: Vol. 22, no. 17
p. 6483

Abstract

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The paper proposes an ultra-narrow band graphene refractive index sensor, consisting of a patterned graphene layer on the top, a dielectric layer of SiO2 in the middle, and a bottom Au layer. The absorption sensor achieves the absorption efficiency of 99.41% and 99.22% at 5.664 THz and 8.062 THz, with the absorption bandwidths 0.0171 THz and 0.0152 THz, respectively. Compared with noble metal absorbers, our graphene absorber can achieve tunability by adjusting the Fermi level and relaxation time of the graphene layer with the geometry of the absorber unchanged, which greatly saves the manufacturing cost. The results show that the sensor has the properties of polarization-independence and large-angle insensitivity due to the symmetric structure. In addition, the practical application of testing the content of hemoglobin biomolecules was conducted, the frequency of first resonance mode shows a shift of 0.017 THz, and the second resonance mode has a shift of 0.016 THz, demonstrating the good frequency sensitivity of our sensor. The S (sensitivities) of the sensor were calculated at 875 GHz/RIU and 775 GHz/RIU, and quality factors FOM (Figure of Merit) are 26.51 and 18.90, respectively; and the minimum limit of detection is 0.04. By comparing with previous similar sensors, our sensor has better sensing performance, which can be applied to photon detection in the terahertz band, biochemical sensing, and other fields.

Published in Sensors

ISSN: 1424-8220 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Chemical technology
Website: http://www.mdpi.com/journal/sensors

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