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Cong X, Yin H, Zheng Y, He W. Recent progress of group III-V materials-based nanostructures for photodetection. NANOTECHNOLOGY 2024; 35:382002. [PMID: 38759630 DOI: 10.1088/1361-6528/ad4cf0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 05/17/2024] [Indexed: 05/19/2024]
Abstract
Due to the suitable bandgap structure, efficient conversion rates of photon to electron, adjustable optical bandgap, high electron mobility/aspect ratio, low defects, and outstanding optical and electrical properties for device design, III-V semiconductors have shown excellent properties for optoelectronic applications, including photodiodes, photodetectors, solar cells, photocatalysis, etc. In particular, III-V nanostructures have attracted considerable interest as a promising photodetector platform, where high-performance photodetectors can be achieved based on the geometry-related light absorption and carrier transport properties of III-V materials. However, the detection ranges from Ultraviolet to Terahertz including broadband photodetectors of III-V semiconductors still have not been more broadly development despite significant efforts to obtain the high performance of III-V semiconductors. Therefore, the recent development of III-V photodetectors in a broad detection range from Ultraviolet to Terahertz, and future requirements are highly desired. In this review, the recent development of photodetectors based on III-V semiconductor with different detection range is discussed. First, the bandgap of III-V materials and synthesis methods of III-V nanostructures are explored, subsequently, the detection mechanism and key figures-of-merit for the photodetectors are introduced, and then the device performance and emerging applications of photodetectors are provided. Lastly, the challenges and future research directions of III-V materials for photodetectors are presented.
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Affiliation(s)
- Xiangna Cong
- College of Electronics and Information Engineering, Institute of Microelectronics, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Huabi Yin
- College of Electronics and Information Engineering, Institute of Microelectronics, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Yue Zheng
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Wenlong He
- College of Electronics and Information Engineering, Institute of Microelectronics, Shenzhen University, Shenzhen 518060, People's Republic of China
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Lu G, Wang J, Zhou R, Xie Z, Yuan Y, Huang L, Yeow JTW. Terahertz communication: detection and signal processing. NANOTECHNOLOGY 2024; 35:352002. [PMID: 38768574 DOI: 10.1088/1361-6528/ad4dad] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 05/20/2024] [Indexed: 05/22/2024]
Abstract
The development of 6 G networks has promoted related research based on terahertz communication. As submillimeter radiation, signal transportation via terahertz waves has several superior properties, including non-ionizing and easy penetration of non-metallic materials. This paper provides an overview of different terahertz detectors based on various mechanisms. Additionally, the detailed fabrication process, structural design, and the improvement strategies are summarized. Following that, it is essential and necessary to prevent the practical signal from noise, and methods such as wavelet transform, UM-MIMO and decoding have been introduced. This paper highlights the detection process of the terahertz wave system and signal processing after the collection of signal data.
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Affiliation(s)
- Guanxuan Lu
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Jiaqi Wang
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Rui Zhou
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Zhemiao Xie
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Yifei Yuan
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Lin Huang
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - John T W Yeow
- Advanced Micro-/Nano- Devices Lab, Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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Garriga Francis KJ, Zhang XC. Local measurement of terahertz field-induced second harmonic generation in plasma filaments. FRONTIERS OF OPTOELECTRONICS 2023; 16:44. [PMID: 38091154 PMCID: PMC10719236 DOI: 10.1007/s12200-023-00095-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/29/2023] [Indexed: 12/17/2023]
Abstract
The concept of Terahertz Field-Induced Second Harmonic (TFISH) Generation is revisited to introduce a single-shot detection scheme based on third order nonlinearities. Focused specifically on the further development of THz plasma-based sources, we begin our research by reimagining the TFISH system to serve as a direct plasma diagnostic. In this work, an optical probe beam is used to mix directly with the strong ponderomotive current associated with laser-induced ionization. A four-wave mixing (FWM) process then generates a strong second-harmonic optical wave because of the mixing of the probe beam with the nonlinear current components oscillating at THz frequencies. The observed conversion efficiency is high enough that for the first time, the TFISH signal appears visible to the human eye. We perform spectral, spatial, and temporal analysis on the detected second-harmonic frequency and show its direct relationship to the nonlinear current. Further, a method to detect incoherent and coherent THz inside plasma filaments is devised using spatio-temporal couplings. The single-shot detection configurations are theoretically described using a combination of expanded FWM models with Kostenbauder and Gaussian Q-matrices. We show that the retrieved temporal traces for THz radiation from single- and two-color laser-induced air-plasma sources match theoretical descriptions very well. High temporal resolution is shown with a detection bandwidth limited only by the spatial extent of the probe laser beam. Large detection bandwidth and temporal characterization is shown for THz radiation confined to under-dense plasma filaments induced by < 100 fs lasers below the relativistic intensity limit.
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Affiliation(s)
| | - Xi-Cheng Zhang
- The Institute of Optics, University of Rochester, Rochester, NY, 14627, USA.
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Ding G, Zhou Y, Zhang S, Luo X, Wang S. Design of a Reconfigurable Ultra-Wideband Terahertz Polarization Rotator Based on Graphene Metamaterial. SENSORS (BASEL, SWITZERLAND) 2023; 23:5449. [PMID: 37420616 DOI: 10.3390/s23125449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/09/2023]
Abstract
In this work, a reconfigurable ultra-wideband transmissive terahertz polarization rotator based on graphene metamaterial is proposed that can switch between two states of polarization rotation within a broad terahertz band by changing the Fermi level of graphene. The proposed reconfigurable polarization rotator is based on a two-dimensional periodic array of multilayer graphene metamaterial structure, which is composed of metal grating, graphene grating, silicon dioxide thin film, and a dielectric substrate. The graphene metamaterial can achieve high co-polarized transmission of a linearly polarized incident wave at the off-state of the graphene grating without applying the bias voltage. Once the specially designed bias voltage is applied to change the Fermi level of graphene, the polarization rotation angle of linearly polarized waves is switched to 45° by the graphene metamaterial at the on-state. The working frequency band with 45-degree linear polarized transmission remaining above 0.7 and the polarization conversion ratio (PCR) above 90% is from 0.35 to 1.75 THz, and the relative bandwidth reaches 133.3% of the central working frequency. Furthermore, even with oblique incidence at large angles, the proposed device retains high-efficiency conversion in a broad band. The proposed graphene metamaterial offers a novel approach for the design of a terahertz tunable polarization rotator and is expected to be applied in the applications of terahertz wireless communication, imaging, and sensing.
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Affiliation(s)
- Guowen Ding
- Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China
| | - Yanjun Zhou
- Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Shuyang Zhang
- Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Xinyao Luo
- Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China
- School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China
| | - Shenyun Wang
- Research Center of Applied Electromagnetics, Nanjing University of Information Science and Technology, Nanjing 210044, China
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Zhang K, Hu Z, Zhang L, Chen Y, Wang D, Jiang M, D'Olimpio G, Han L, Yao C, Chen Z, Xing H, Kuo CN, Lue CS, Vobornik I, Wang SW, Politano A, Hu W, Wang L, Chen X, Lu W. Ultrasensitive Self-Driven Terahertz Photodetectors Based on Low-Energy Type-II Dirac Fermions and Related Van der Waals Heterojunctions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2205329. [PMID: 36344449 DOI: 10.1002/smll.202205329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/08/2022] [Indexed: 06/16/2023]
Abstract
The exotic electronic properties of topological semimetals (TSs) have opened new pathways for innovative photonic and optoelectronic devices, especially in the highly pursuit terahertz (THz) band. However, in most cases Dirac fermions lay far above or below the Fermi level, thus hindering their successful exploitation for the low-energy photonics. Here, low-energy type-II Dirac fermions in kitkaite (NiTeSe) for ultrasensitive THz detection through metal-topological semimetal-metal heterostructures are exploited. Furthermore, a heterostructure combining two Dirac materials, namely, graphene and NiTeSe, is implemented for a novel photodetector exhibiting a responsivity as high as 1.22 A W-1 , with a response time of 0.6 µs, a noise-equivalent power of 18 pW Hz-0.5 , with outstanding stability in the ambient conditions. This work brings to fruition of Dirac fermiology in THz technology, enabling self-powered, low-power, room-temperature, and ultrafast THz detection.
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Affiliation(s)
- Kaixuan Zhang
- Department of Optoelectronic Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Zhen Hu
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Libo Zhang
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
- College of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, No. 1, Sub-Lane Xiangshan, Xihu District, Hangzhou, 310024, China
| | - Yulu Chen
- The 50th Research Institute of China Electronics Technology Group Corporation, Shanghai, 200331, China
| | - Dong Wang
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Mengjie Jiang
- Department of Optoelectronic Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Gianluca D'Olimpio
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio, L'Aquila, AQ, 67100, Italy
| | - Li Han
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
- College of Physics and Optoelectronic Engineering, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, No. 1, Sub-Lane Xiangshan, Xihu District, Hangzhou, 310024, China
| | - Chenyu Yao
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Zhiqingzi Chen
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Huaizhong Xing
- Department of Optoelectronic Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Chia-Nung Kuo
- Department of Physics, Cheng Kung University, 1 Ta-Hsueh Road, Taiwan, 70101, China
| | - Chin Shan Lue
- Department of Physics, Cheng Kung University, 1 Ta-Hsueh Road, Taiwan, 70101, China
| | - Ivana Vobornik
- CNR-IOM, Area Science Park, Strada Statale 14 km 163.5, Trieste, I-34149, Italy
| | - Shao-Wei Wang
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Antonio Politano
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio, L'Aquila, AQ, 67100, Italy
- Department of Physics, Cheng Kung University, 1 Ta-Hsueh Road, Taiwan, 70101, China
| | - Weida Hu
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Lin Wang
- Department of Optoelectronic Science and Engineering, Donghua University, Shanghai, 201620, China
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Xiaoshuang Chen
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
| | - Wei Lu
- State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai, 200083, China
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Zhang T, Fan F, Cheng J, Wang X, Chang S. Terahertz polarization sensing for protein concentration and a crystallization process on a reflective metasurface. APPLIED OPTICS 2022; 61:6391-6397. [PMID: 36256255 DOI: 10.1364/ao.463924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/28/2022] [Indexed: 06/16/2023]
Abstract
Terahertz (THz) waves have attracted much attention in the field of biosensing due to advantages including non-destructiveness, being label-free, and high-sensitivity detection. Here we have experimentally demonstrated a THz polarization sensing method based on reflective metasurface sensors for detecting concentrations of protein solutions and their crystallization process. The protein with varying concentrations has been detected by five different polarization parameters, which show different spectral responses and sensing sensitivities. The sensing accuracy can reach the order of ng/mm2. Furthermore, the crystallization process of the protein sample from the dissolved state to the crystalline has been dynamically measured by polarization sensing, of which the highest sensitivity can reach 0.67 °/%. Therefore, this new sensing platform can have broad development prospects in the trace matter detection of the biological sample.
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Aji AP, Satoh H, Apriono C, Rahardjo ET, Inokawa H. Responsivity and NEP Improvement of Terahertz Microbolometer by High-Impedance Antenna. SENSORS 2022; 22:s22145107. [PMID: 35890785 PMCID: PMC9324361 DOI: 10.3390/s22145107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/27/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022]
Abstract
The antenna-coupled microbolometer with suspended titanium heater and thermistor was attractive as a terahertz (THz) detector due to its structural simplicity and low noise levels. In this study, we attempted to improve the responsivity and noise-equivalent power (NEP) of the THz detector by using high-resistance heater stacked on the meander thermistor. A wide range of heater resistances were prepared by changing the heater width and thickness. It was revealed that the electrical responsivity and NEP could be improved by increasing the heater’s resistance. To make the best use of this improvement, a high-impedance folded dipole antenna was introduced, and the optical performance at 1 THz was found to be better than that of the conventional halfwave dipole antenna combined with a low-resistance heater. Both the electrical and optical measurement results indicated that the increase in heater resistance could reduce the thermal conductance in the detector, thus improved the responsivity and NEP even if the thermistor resistance was kept the same.
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Affiliation(s)
- Arie Pangesti Aji
- Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8011, Japan;
- Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia; (C.A.); (E.T.R.)
| | - Hiroaki Satoh
- Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011, Japan;
| | - Catur Apriono
- Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia; (C.A.); (E.T.R.)
| | - Eko Tjipto Rahardjo
- Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia; (C.A.); (E.T.R.)
| | - Hiroshi Inokawa
- Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8011, Japan;
- Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8011, Japan;
- Correspondence:
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Ma W, Gao Y, Shang L, Zhou W, Yao N, Jiang L, Qiu Q, Li J, Shi Y, Hu Z, Huang Z. Ultrabroadband Tellurium Photoelectric Detector from Visible to Millimeter Wave. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103873. [PMID: 34923772 PMCID: PMC8844568 DOI: 10.1002/advs.202103873] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/18/2021] [Indexed: 05/19/2023]
Abstract
Ultrabroadband photodetection is of great significance in numerous cutting-edge technologies including imaging, communications, and medicine. However, since photon detectors are selective in wavelength and thermal detectors are slow in response, developing high performance and ultrabroadband photodetectors is extremely difficult. Herein, one demonstrates an ultrabroadband photoelectric detector covering visible, infrared, terahertz, and millimeter wave simultaneously based on single metal-Te-metal structure. Through the two kinds of photoelectric effect synergy of photoexcited electron-hole pairs and electromagnetic induced well effect, the detector achieves the responsivities of 0.793 A W-1 at 635 nm, 9.38 A W-1 at 1550 nm, 9.83 A W-1 at 0.305 THz, 24.8 A W-1 at 0.250 THz, 87.8 A W-1 at 0.172 THz, and 986 A W-1 at 0.022 THz, respectively. It also exhibits excellent polarization detection with a dichroic ratio of 468. The excellent performance of the detector is further verified by high-resolution imaging experiments. Finally, the high stability of the detector is tested by long-term deposition in air and high-temperature aging. The strategy provides a recipe to achieve ultrabroadband photodetection with high sensitivity and fast response utilizing full photoelectric effect.
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Affiliation(s)
- Wanli Ma
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
- University of Chinese Academy of Sciences19 Yu Quan RoadBeijing100049P. R. China
| | - Yanqing Gao
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
| | - Liyan Shang
- Technical Center for Multifunctional Magneto‐Optical Spectroscopy (Shanghai)Engineering Research Center of Nanophotonics & Advanced Instrument (Ministry of Education)Department of MaterialsSchool of Physics and Electronic ScienceEast China Normal University500 Dongchuan RoadShanghai200241P. R. China
| | - Wei Zhou
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
| | - Niangjuan Yao
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
| | - Lin Jiang
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
| | - Qinxi Qiu
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
- University of Chinese Academy of Sciences19 Yu Quan RoadBeijing100049P. R. China
| | - Jingbo Li
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
- University of Chinese Academy of Sciences19 Yu Quan RoadBeijing100049P. R. China
| | - Yi Shi
- Donghua University2999 North Renmin RoadShanghai201620P. R. China
| | - Zhigao Hu
- Technical Center for Multifunctional Magneto‐Optical Spectroscopy (Shanghai)Engineering Research Center of Nanophotonics & Advanced Instrument (Ministry of Education)Department of MaterialsSchool of Physics and Electronic ScienceEast China Normal University500 Dongchuan RoadShanghai200241P. R. China
| | - Zhiming Huang
- State Key Laboratory of Infrared PhysicsShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
- Key Laboratory of Space Active Opto‐Electronics TechnologyShanghai Institute of Technical PhysicsChinese Academy of Sciences500 Yu Tian RoadShanghai200083P. R. China
- Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences1 Sub‐Lane XiangshanHangzhou310024P. R. China
- Institute of OptoelectronicsFudan University2005 Songhu RoadShanghai200438P. R. China
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Xu C, Cao P, Wang N, Ma H, Lin M. Photo-enhanced electrocatalytic hydrogen evolution reaction coupled semiconductor with plasma in neutral solution. Chem Commun (Camb) 2021; 57:8596-8599. [PMID: 34357363 DOI: 10.1039/d1cc03671h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A gold-ruthenium/zinc oxide nanorod composite was synthesized. The electrochemical catalytic efficiency of the noble metal-semiconductor nanostructure increased by nearly 30% under the irradiation of an external light source. It provides an efficient way of thinking for the design of electrocatalysts with a photoresponse.
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Affiliation(s)
- Congcong Xu
- Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
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Zhang R, You B, Wang S, Han K, Shen X, Wang W. Broadband and switchable terahertz polarization converter based on graphene metasurfaces. OPTICS EXPRESS 2021; 29:24804-24815. [PMID: 34614828 DOI: 10.1364/oe.432601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
In this work, we propose broadband and switchable terahertz (THz) polarization converters based on either graphene patch metasurface (GPMS) or its complementary structure (graphene hole metasurface, GHMS). The patch and hole are simply cross-shaped, composed of two orthogonal arms, along which plasmonic resonances mediated by Fabry-Perot cavity play a key role in polarization conversion (PC). An incidence of linear polarization will be converted to its cross-polarization (LTL) or circular polarization (LTC), as the reflected wave in the direction of two arms owning the same amplitude and π phase difference (LTL), or ±π/2 phase difference (LTC). Such requirements can be met by optimizing the width and length of two arms, thickness of dielectric layer, and Fermi level EF of graphene. By using GPMS, LTL PC of polarization conversion ratio (PCR) over 90% is achieved in the frequency range of 2.92 THz to 6.26 THz, and by using GHMS, LTC PC of ellipticity χ ≤ -0.9 at the frequencies from 4.45 THz to 6.47 THz. By varying the Fermi level, the operating frequency can be actively tuned, and the functionality can be switched without structural modulation; for instance, GPMS supports LTL PC as EF = 0.6 eV and LTC PC of χ ≥ 0.9 as EF = 1.0 eV, in the frequency range of 2.69 THz to 4.19 THz. Moreover, GHMS can be optimized to sustain LTL PC and LTC PC of |χ| ≥ 0.9, in the frequency range of 4.96 THz to 6.52 THz, which indicates that the handedness of circular polarization can be further specified. The proposed polarization converters of broad bandwidth, active tunability, and switchable functionality will essentially make a significant progress in THz technology and device applications, and can be widely utilized in THz communications, sensing and spectroscopy.
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