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Infrared Absorption Study of Zn–S Hybrid and ZnS Ultrathin Films Deposited on Porous AAO Ceramic Support. COATINGS 2020. [DOI: 10.3390/coatings10050459] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Infrared (IR) spectroscopy is a powerful technique to characterize the chemical structure and dynamics of various types of samples. However, the signal-to-noise-ratio drops rapidly when the sample thickness gets much smaller than penetration depth, which is proportional to wavelength. This poses serious problems in analysis of thin films. In this work, an approach is demonstrated to overcome these problems. It is shown that a standard IR spectroscopy can be successfully employed to study the structure and composition of films as thin as 20 nm, when the layers were grown on porous substrates with a well-developed surface area. In contrast to IR spectra of the films deposited on flat Si substrates, the IR spectra of the same films but deposited on porous ceramic support show distinct bands that enabled reliable chemical analysis. The analysis of Zn-S ultrathin films synthesized by atomic layer deposition (ALD) from diethylzinc (DEZ) and 1,5-pentanedithiol (PDT) as precursors of Zn and S, respectively, served as proof of concept. However, the approach presented in this study can be applied to analysis of any ultrathin film deposited on target substrate and simultaneously on porous support, where the latter sample would be a reference sample dedicated for IR analysis of this film.
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Ji Y, Yan Z, Tang C, Chen J, Gu P, Liu B, Liu Z. Efficient Optical Reflection Modulation by Coupling Interband Transition of Graphene to Magnetic Resonance in Metamaterials. NANOSCALE RESEARCH LETTERS 2019; 14:391. [PMID: 31873823 PMCID: PMC6928171 DOI: 10.1186/s11671-019-3233-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Designing powerful electromagnetic wave modulators is required for the advancement of optical communication technology. In this work, we study how to efficiently modulate the amplitude of electromagnetic waves in near-infrared region, by the interactions between the interband transition of graphene and the magnetic dipole resonance in metamaterials. The reflection spectra of metamaterials could be significantly reduced in the wavelength range below the interband transition, because the enhanced electromagnetic fields from the magnetic dipole resonance greatly increase the light absorption in graphene. The maximum modulation depth of reflection spectra can reach to about 40% near the resonance wavelength of magnetic dipole, for the interband transition to approach the magnetic dipole resonance, when an external voltage is applied to change the Fermi energy of graphene.
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Affiliation(s)
- Yiqun Ji
- School of Optoelectronic Science and Engineering, Soochow University, Suzhou, 215006, China
| | - Zhendong Yan
- College of Science, Nanjing Forestry University, Nanjing, 210037, China
| | - Chaojun Tang
- Center for Optics and Optoelectronics Research, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Jing Chen
- College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing, 210096, China.
| | - Ping Gu
- College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
| | - Bo Liu
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001, China
| | - Zhengqi Liu
- College of Physics Communication and Electronics, Jiangxi Normal University, Nanchang, 330022, China
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Liu B, Tang C, Chen J, Xie N, Tang H, Zhu X, Park GS. Multiband and Broadband Absorption Enhancement of Monolayer Graphene at Optical Frequencies from Multiple Magnetic Dipole Resonances in Metamaterials. NANOSCALE RESEARCH LETTERS 2018; 13:153. [PMID: 29767294 PMCID: PMC5955873 DOI: 10.1186/s11671-018-2569-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/08/2018] [Indexed: 05/20/2023]
Abstract
It is well known that a suspended monolayer graphene has a weak light absorption efficiency of about 2.3% at normal incidence, which is disadvantageous to some applications in optoelectronic devices. In this work, we will numerically study multiband and broadband absorption enhancement of monolayer graphene over the whole visible spectrum, due to multiple magnetic dipole resonances in metamaterials. The unit cell of the metamaterials is composed of a graphene monolayer sandwiched between four Ag nanodisks with different diameters and a SiO2 spacer on an Ag substrate. The near-field plasmon hybridizations between individual Ag nanodisks and the Ag substrate form four independent magnetic dipole modes, which result into multiband absorption enhancement of monolayer graphene at optical frequencies. When the resonance wavelengths of the magnetic dipole modes are tuned to approach one another by changing the diameters of the Ag nanodisks, a broadband absorption enhancement can be achieved. The position of the absorption band in monolayer graphene can be also controlled by varying the thickness of the SiO2 spacer or the distance between the Ag nanodisks. Our designed graphene light absorber may find some potential applications in optoelectronic devices, such as photodetectors.
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Affiliation(s)
- Bo Liu
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001 China
| | - Chaojun Tang
- Center for Optics and Optoelectronics Research, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou, 310023 China
| | - Jing Chen
- College of Electronic and Optical Engineering and College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, 210023 China
- Center for THz-driven Biological Systems, Department of Physics and Astronomy, Seoul National University, Seoul, 151-747 South Korea
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing, 210096 China
| | - Ningyan Xie
- College of Electronic and Optical Engineering and College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, 210023 China
| | - Huang Tang
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001 China
| | - Xiaoqin Zhu
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001 China
| | - Gun-sik Park
- Center for THz-driven Biological Systems, Department of Physics and Astronomy, Seoul National University, Seoul, 151-747 South Korea
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Electrically Tunable Fano Resonance from the Coupling between Interband Transition in Monolayer Graphene and Magnetic Dipole in Metamaterials. Sci Rep 2017; 7:17117. [PMID: 29215032 PMCID: PMC5719391 DOI: 10.1038/s41598-017-17394-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/19/2017] [Indexed: 11/08/2022] Open
Abstract
Fano resonance modulated effectively by external perturbations can find more flexible and important applications in practice. We theoretically study electrically tunable Fano resonance with asymmetric line shape over an extremely narrow frequency range in the reflection spectra of metamaterials. The metamaterials are composed of a metal nanodisk array on graphene, a dielectric spacer, and a metal substrate. The near-field plasmon hybridization between individual metal nanodisks and the metal substrate results into the excitation of a broad magnetic dipole. There exists a narrow interband transition dependent of Fermi energy Ef, which manifests itself as a sharp spectral feature in the effective permittivity εg of graphene. The coupling of the narrow interband transition to the broad magnetic dipole leads to the appearance of Fano resonance, which can be electrically tuned by applying a bias voltage to graphene to change Ef. The Fano resonance will shift obviously and its asymmetric line shape will become more pronounced, when Ef is changed for the narrow interband transition to progressively approach the broad magnetic dipole.
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Wang P, Chen N, Tang C, Chen J, Liu F, Sheng S, Yan B, Sui C. Engineering the Complex-Valued Constitutive Parameters of Metamaterials for Perfect Absorption. NANOSCALE RESEARCH LETTERS 2017; 12:276. [PMID: 28420225 PMCID: PMC5394092 DOI: 10.1186/s11671-017-2048-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/05/2017] [Indexed: 05/03/2023]
Abstract
We theoretically studied how to directly engineer the constitutive parameters of metamaterials for perfect absorbers of electromagnetic waves. As an example, we numerically investigated the necessary refractive index n and extinction coefficient k and the relative permittivity ε and permeability μ of a metamaterial anti-reflection layer, which could cancel the reflection from a hydrogenated amorphous silicon (α-Si:H) thin film on a metal substrate, within the visible wavelength range from 300 to 800 nm. We found that the metamaterial anti-reflection layer should have a negative refractive index (n < 0) for short-wavelength visible light but have a positive refractive index (n > 0) for long-wavelength visible light. The relative permittivity ε and permeability μ could be fitted by the Lorentz model, which exhibited electric and magnetic resonances, respectively.
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Affiliation(s)
- Pengwei Wang
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Naibo Chen
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Chaojun Tang
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Jing Chen
- College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China.
| | - Fanxin Liu
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China
| | - Saiqian Sheng
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Bo Yan
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Chenghua Sui
- Center for Optics & Optoelectronics Research, Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
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Liu B, Tang C, Chen J, Yan Z, Zhu M, Sui Y, Tang H. The Coupling Effects of Surface Plasmon Polaritons and Magnetic Dipole Resonances in Metamaterials. NANOSCALE RESEARCH LETTERS 2017; 12:586. [PMID: 29124431 PMCID: PMC5680391 DOI: 10.1186/s11671-017-2350-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 10/24/2017] [Indexed: 05/29/2023]
Abstract
We numerically investigate the coupling effects of surface plasmon polaritons (SPPs) and magnetic dipole (MD) resonances in metamaterials, which are composed of an Ag nanodisk array and a SiO2 spacer on an Ag substrate. The periodicity of the Ag nanodisk array leads to the excitation of SPPs at the surface of the Ag substrate. The near-field plasmon interactions between individual Ag nanodisks and the Ag substrate form MD resonances. When the excitation wavelengths of SPPs are tuned to approach the position of MD resonances by changing the array period of Ag nanodisks, SPPs and MD resonances are coupled together into two hybridized modes, whose positions can be well predicted by a coupling model of two oscillators. In the strong coupling regime of SPPs and MD resonances, the hybridized modes exhibit an obvious anti-crossing, resulting into an interesting phenomenon of Rabi splitting. Moreover, the magnetic fields under the Ag nanodisks are greatly enhanced, which may find some potential applications, such as magnetic nonlinearity.
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Affiliation(s)
- Bo Liu
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001, China
| | - Chaojun Tang
- Center for Optics and Optoelectronics Research, Collaborative Innovation Center for Information Technology in Biological and Medical Physics, College of Science, Zhejiang University of Technology, Hangzhou, 310023, China.
| | - Jing Chen
- College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing, 210096, China.
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing, 210093, China.
| | - Zhendong Yan
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Mingwei Zhu
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yongxing Sui
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001, China
| | - Huang Tang
- School of Mathematics and Physics, Jiangsu University of Technology, Changzhou, 213001, China
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Cheng YZ, Cheng ZZ, Mao XS, Gong RZ. Ultra-Thin Multi-Band Polarization-Insensitive Microwave Metamaterial Absorber Based on Multiple-Order Responses Using a Single Resonator Structure. MATERIALS 2017; 10:ma10111241. [PMID: 29077036 PMCID: PMC5706188 DOI: 10.3390/ma10111241] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 10/19/2017] [Accepted: 10/26/2017] [Indexed: 11/16/2022]
Abstract
We design an ultra-thin multi-band polarization-insensitive metamaterial absorber (MMA) using a single circular sector resonator (CSR) structure in the microwave region. Simulated results show that the proposed MMA has three distinctive absorption peaks at 3.35 GHz, 8.65 GHz, and 12.44 GHz, with absorbance of 98.8%, 99.7%, and 98.3%, respectively, which agree well with an experiment. Simulated surface current distributions of the unit-cell structure reveal that the triple-band absorption mainly originates from multiple-harmonic magnetic resonance. The proposed triple-band MMA can remain at a high absorption level for all polarization of both transverse-electric (TE) and transverse-magnetic (TM) modes under normal incidence. Moreover, by further optimizing the geometric parameters of the CSRs, four-band and five-band MMAs can also be obtained. Thus, our design will have potential application in detection, sensing, and stealth technology.
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Affiliation(s)
- Yong Zhi Cheng
- School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Zheng Ze Cheng
- School of Electronic and Information Engineering, Hubei University of Science and Technology, Xianning 437100, China.
| | - Xue Song Mao
- School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Rong Zhou Gong
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
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Tang C, Yan B, Wang Q, Chen J, Yan Z, Liu F, Chen N, Sui C. Toroidal Dipolar Excitation in Metamaterials Consisting of Metal nanodisks and a Dielectrc Spacer on Metal Substrate. Sci Rep 2017; 7:582. [PMID: 28373721 PMCID: PMC5429647 DOI: 10.1038/s41598-017-00708-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/08/2017] [Indexed: 11/21/2022] Open
Abstract
We have investigated numerically toroidal dipolar excitation at optical frequency in metamaterials whose unit cell consists of three identical Ag nanodisks and a SiO2 spacer on Ag substrate. The near-field plasmon hybridization between individual Ag nanodisks and substrate forms three magnetic dipolar resonances, at normal incidence of plane electromagnetic waves. The strong coupling among three magnetic dipolar resonances leads to the toroidal dipolar excitation, when space-inversion symmetry is broke along the polarization direction of incident light. The influences of some geometrical parameters on the resonance frequency and the excitation strength of toroidal dipolar mode are studied in detail. The radiated power from toroidal dipole is also compared with that from conventional electric and magnetic multipoles.
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Affiliation(s)
- Chaojun Tang
- Center for Optics & Optoelectronics Research and Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Bo Yan
- Center for Optics & Optoelectronics Research and Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Qiugu Wang
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa, 50011, USA
| | - Jing Chen
- College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China. .,National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China.
| | - Zhendong Yan
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China
| | - Fanxin Liu
- Center for Optics & Optoelectronics Research and Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China. .,National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China.
| | - Naibo Chen
- Center for Optics & Optoelectronics Research and Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
| | - Chenghua Sui
- Center for Optics & Optoelectronics Research and Department of Applied Physics, Zhejiang University of Technology, Hangzhou, 310023, China
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Marvi Z, Xu S, Foroutan G, Ostrikov K, Levchenko I. Plasma-deposited hydrogenated amorphous silicon films: multiscale modelling reveals key processes. RSC Adv 2017. [DOI: 10.1039/c7ra00478h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Physical and chemical mechanisms and role of plasma in the synthesis of hydrogenated amorphous silicon were studied numerically to reveal the key growth processes and, hence, to ensure a higher level of control over the film structure and properties.
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Affiliation(s)
- Z. Marvi
- Plasma Sources and Applications Centre
- NIE
- Nanyang Technological University
- 637616 Singapore
- Physics Department
| | - S. Xu
- Plasma Sources and Applications Centre
- NIE
- Nanyang Technological University
- 637616 Singapore
| | - G. Foroutan
- Physics Department
- Faculty of Science
- Sahand University of Technology
- Tabriz
- Iran
| | - K. Ostrikov
- CSIRO-QUT Joint Sustainable Materials and Devices Laboratory
- CSIRO
- Lindfield
- Australia
- School of Chemistry
| | - I. Levchenko
- Plasma Sources and Applications Centre
- NIE
- Nanyang Technological University
- 637616 Singapore
- School of Chemistry
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Poursafar J, Kolahdouz M, Asl-Soleimani E, Golmohammadi S. Ultrathin tandem-plasmonic photovoltaic structures for synergistically enhanced light absorption. RSC Adv 2016. [DOI: 10.1039/c6ra06586d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have proposed and simulated a tandem ultra-thin silicon solar cell, in which each layer is integrated with metal nanostructures, using the FDTD method.
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Affiliation(s)
- Jafar Poursafar
- School of Electrical and Computer Engineering
- University of Tehran
- Tehran
- Iran
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