DOCSLIB.ORG

Design of Absorbers Using Metamaterials Zeinab Fneich

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Design of Absorbers Using Metamaterials Zeinab Fneich Design of absorbers using metamaterials Zeinab Fneich To cite this version: Zeinab Fneich. Design of absorbers using metamaterials. Micro and nanotechnolo- gies/Microelectronics. Normandie Université; Université libanaise, 2020. English. NNT : 2020NORMR095. tel-03192631 HAL Id: tel-03192631 https://tel.archives-ouvertes.fr/tel-03192631 Submitted on 8 Apr 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. INTERNATIONAL COTUTELLE THESIS To obtain the doctorate degree Specialty (Applied Physics) Prepared at the Rouen University and the Lebanese University Design of Absorbers Using Metamaterials Presented by Zeinab FNEISH Thesis defended on (03-02-2020) before the jury composed of : Mr. Fabien NDAGIJIMANA Professor in the Grenoble University Reviewer Master of Conference /HDR Mrs. Sylvie BARANOWSKI Reviewer Lille University Research supervisor in Lebanese National Mr. Ghaleb FAOUR Examiner Center for Scientific Research (CNRS) Mr. Mohammed RAMDANI Professor at ESEO Examiner Instructor-Researcher /HDR Mr. Moncef KADI Supervisor ESIGELEC Professor in the Lebanese University IUT Mr. Mohammad RAMMAL Supervisor Saida Professor in the Lebanese University Mr. Jalal JOMAA Co-supervisor Branch I Associate Professor in the Lebanese Mr. Hussam AYAD Examinor University Branch I Thesis directed by Dr. Kadi MONCEF Rouen University Prof. Mohammad Rammal Lebanese University 1 | P a g e Table of Contents Acknowledgements ....................................................................................................................... 5 List of Publications ....................................................................................................................... 7 Abstract .......................................................................................................................................... 8 List of Figures ................................................................................................................................ 9 List of Tables ............................................................................................................................... 14 List of Abbreviations .................................................................................................................. 15 General introduction .................................................................................................................. 16 1. Chapter 1: State of the Art ..................................................................................................... 18 1.1 Introduction .................................................................................................................... 18 1.2 Categories of Main Industrial Absorber ......................................................................... 18 1.2.1 Dielectric Absorber ................................................................................................. 18 1.2.2 Structural Absorbers ............................................................................................... 19 1.2.3 Resonant Absorber .................................................................................................. 21 1.2.4 Magnetic Absorber.................................................................................................. 22 1.3 Anechoic Chamber ......................................................................................................... 22 1.3.1 Description of its Structure ..................................................................................... 22 1.3.2 Dimension VS Operating frequencies .................................................................... 23 1.3.3 Anechoic Chamber Disadvantages ........................................................................... 24 1.4 Metamaterial Absorber ................................................................................................... 24 1.4.1 Categories of Metamaterial Absorber ................................................................... 25 1.4.2 Broadening Ways ................................................................................................. 30 1.5 Conclusion ...................................................................................................................... 37 1.6 Reference ...................................................................................................................... 38 2. Chapter 2: Pyramidal Design Setup ...................................................................................... 44 2.1 Introduction .................................................................................................................... 44 2 | P a g e 2.2 Plasmonic Resonance Study........................................................................................... 45 2.2.1 Absorption Mechanism ........................................................................................... 45 2.2.2 Simulation Results .................................................................................................. 46 2.2.3 Conclusion .................................................................................................................... 51 2.3 Design of Pyramidal Absorber ....................................................................................... 52 2.4 Parametric Analysis........................................................................................................ 54 2.4.1 Geometrical parameters influence ........................................................................... 55 2.4.2 Material Properties Influence .................................................................................. 60 2.5 Curved Altitude Enhancing Factor .................................................................................. 63 2.7 Conclusion ....................................................................................................................... 66 2.8 Reference ......................................................................................................................... 67 3. Chapter 3: Activating Metamaterial to low frequency ....................................................... 69 3.1 Introduction ..................................................................................................................... 69 3.2 Resonant Frequency Equation ......................................................................................... 69 3.3 Material Properties .......................................................................................................... 70 3.3.1 Insertion of Water Substrate ................................................................................... 72 3.3.2 Encapsulated Water in a FR4 Coating ...................................................................... 74 3.3.3 Conclusion ................................................................................................................ 76 3.5 Minimal Surface Geometry ............................................................................................. 76 3.5.1 Rough Surface Effect .................................................................................................... 76 3.5.1 Helicoid Model ............................................................................................................. 81 3.6 Conclusion ....................................................................................................................... 85 3.7 Reference ......................................................................................................................... 86 4. Chapter 4: Design of Metamaterial Broadband Absorber ................................................. 88 4.1 Introduction ..................................................................................................................... 88 4.2 By Adding Layers ........................................................................................................... 89 4.2.1 Simulation Setup........................................................................................................... 89 4.2.2 Results and Discussion ................................................................................................. 90 4.3 By Combining Complementary Pyramids ...................................................................... 94 3 | P a g e 4.3.1 Simulation Setup........................................................................................................... 94 4.3.2 Results and Discussion ................................................................................................. 96 4.4 Enhanced Combined design ............................................................................................ 97 4.4.1 Simulation Setup........................................................................................................... 97 4.4.1 Results and discussions ................................................................................................ 97 4.5 “Heel and Heads”
Load more

Recommended publications
  • Plasmonic and Metamaterial Structures As Electromagnetic Absorbers
    Plasmonic and Metamaterial Structures as Electromagnetic Absorbers Yanxia Cui 1,2, Yingran He1, Yi Jin1, Fei Ding1, Liu Yang1, Yuqian Ye3, Shoumin Zhong1, Yinyue Lin2, Sailing He1,* 1 State Key Laboratory of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, Zhejiang University, Hangzhou 310058, China 2 Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024, China 3 Department of Physics, Hangzhou Normal University, Hangzhou 310012, China Corresponding author: e-mail [email protected] Abstract: Electromagnetic absorbers have drawn increasing attention in many areas. A series of plasmonic and metamaterial structures can work as efficient narrow band absorbers due to the excitation of plasmonic or photonic resonances, providing a great potential for applications in designing selective thermal emitters, bio-sensing, etc. In other applications such as solar energy harvesting and photonic detection, the bandwidth of light absorbers is required to be quite broad. Under such a background, a variety of mechanisms of broadband/multiband absorption have been proposed, such as mixing multiple resonances together, exciting phase resonances, slowing down light by anisotropic metamaterials, employing high loss materials and so on. 1. Introduction physical phenomena associated with planar or localized SPPs [13,14]. Electromagnetic (EM) wave absorbers are devices in Metamaterials are artificial assemblies of structured which the incident radiation at the operating wavelengths elements of subwavelength size (i.e., much smaller than can be efficiently absorbed, and then transformed into the wavelength of the incident waves) [15]. They are often ohmic heat or other forms of energy.
    [Show full text]
  • All-Metal Terahertz Metamaterial Absorber and Refractive Index Sensing Performance
    hv photonics Communication All-Metal Terahertz Metamaterial Absorber and Refractive Index Sensing Performance Jing Yu, Tingting Lang * and Huateng Chen Institute of Optoelectronic Technology, China Jiliang University, Hangzhou 310018, China; [email protected] (J.Y.); [email protected] (H.C.) * Correspondence: [email protected] Abstract: This paper presents a terahertz (THz) metamaterial absorber made of stainless steel. We found that the absorption rate of electromagnetic waves reached 99.95% at 1.563 THz. Later, we ana- lyzed the effect of structural parameter changes on absorption. Finally, we explored the application of the absorber in refractive index sensing. We numerically demonstrated that when the refractive index (n) is changing from 1 to 1.05, our absorber can yield a sensitivity of 74.18 µm/refractive index unit (RIU), and the quality factor (Q-factor) of this sensor is 36.35. Compared with metal–dielectric–metal sandwiched structure, the absorber designed in this paper is made of stainless steel materials with no sandwiched structure, which greatly simplifies the manufacturing process and reduces costs. Keywords: metamaterial absorber; stainless steel; refractive index sensing; sensitivity 1. Introduction Metamaterials are new artificial materials that are periodically arranged according to certain subwavelength dimensions [1,2]. Owing to their unique properties of perfect absorption, perfect transmission, and stealth, metamaterials show promising applications Citation: Yu, J.; Lang, T.; Chen, H. in sensors [3–11], absorbers [12,13], imaging [14,15], etc. Among them, in biomolecular All-Metal Terahertz Metamaterial sensing, metamaterial devices are spurring unprecedented interest as a diagnostic protocol Absorber and Refractive Index for cancer and infectious diseases [10,11].
    [Show full text]
  • A Metamaterial Frequency-Selective Super-Absorber That Has Absorbing Cross Section Significantly Bigger Than the Geometric Cross Section
    A metamaterial frequency-selective super-absorber that has absorbing cross section significantly bigger than the geometric cross section Jack Ng*, Huanyang Chen*,†, and C. T. Chan Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China Abstract Using the idea of transformation optics, we propose a metamaterial device that serves as a frequency-selective super-absorber, which consists of an absorbing core material coated with a shell of isotropic double negative metamaterial. For a fixed volume, the absorption cross section of the super-absorber can be made arbitrarily large at one frequency. The double negative shell serves to amplify the evanescent tail of the high order incident cylindrical waves, which induces strong scattering and absorption. Our conclusion is supported by both analytical Mie theory and numerical finite element simulation. Interesting applications of such a device are discussed. I. Introduction It is possible for a particle to absorb more than the light incident on it. Bohren gave explicit examples in which a small particle can absorb better than a perfect black body of the same size. Examples of such type include a silver particle excited at its surface plasmon resonance and a silicon carbide particle at its surface phonon polariton resonance.1 However, such mechanism is typically limited to very small particles, and for a fixed particle volume, the absorption cross section cannot increase without bound. We shall show in this article that it is possible to design, within the framework of transformation optics,2,3 a device whose absorption efficiency can be arbitrarily large, at least in principle.
    [Show full text]
  • Tunable Infrared Metamaterial Emitter for Gas Sensing Application
    nanomaterials Article Tunable Infrared Metamaterial Emitter for Gas Sensing Application Ruijia Xu and Yu-Sheng Lin * State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou 510275, China; [email protected] * Correspondence: [email protected] Received: 17 June 2020; Accepted: 22 July 2020; Published: 24 July 2020 Abstract: We present an on-chip tunable infrared (IR) metamaterial emitter for gas sensing applications. The proposed emitter exhibits high electrical-thermal-optical efficiency, which can be realized by the integration of microelectromechanical system (MEMS) microheaters and IR metamaterials. According to the blackbody radiation law, high-efficiency IR radiation can be generated by driving a Direct Current (DC) bias voltage on a microheater. The MEMS microheater has a Peano-shaped microstructure, which exhibits great heating uniformity and high energy conversion efficiency. The implantation of a top metamaterial layer can narrow the bandwidth of the radiation spectrum from the microheater to perform wavelength-selective and narrow-band IR emission. A linear relationship between emission wavelengths and deformation ratios provides an effective approach to meet the requirement at different IR wavelengths by tailoring the suitable metamaterial pattern. The maximum radiated power of the proposed IR emitter is 85.0 µW. Furthermore, a tunable emission is achieved at a wavelength around 2.44 µm with a full-width at half-maximum of 0.38 µm, which is suitable for high-sensitivity gas sensing applications. This work provides a strategy for electro-thermal-optical devices to be used as sensors, emitters, and switches in the IR wavelength range.
    [Show full text]
  • Conceptual-Based Design of an Ultrabroadband Microwave Metamaterial Absorber
    Conceptual-based design of an ultrabroadband microwave metamaterial absorber Sichao Qua,1, Yuxiao Houa,1, and Ping Shenga,2 aDepartment of Physics, Hong Kong University of Science and Technology, Hong Kong, China Edited by David A. Weitz, Harvard University, Cambridge, MA, and approved August 4, 2021 (received for review June 07, 2021) By introducing metallic ring structural dipole resonances in the micro- In this work, the basic building block in our design is just a wave regime, we have designed and realized a metamaterial absorber metallic ring that is fabricated by the printed circuit board (PCB) with hierarchical structures that can display an averaged −19.4 dB technology. The final integrated sample can exhibit near-perfect reflection loss (∼99% absorption) from 3 to 40 GHz. The measured absorption from 3 to 40 GHz, covering the whole high-frequency performance is independent of the polarizations of the incident wave 5G bands (32). Another crucial measure of an absorber is its thick- at normal incidence, while absorption at oblique incidence remains ness. While a thick enough absorber can absorb everything over considerably effective up to 45°. We provide a conceptual basis for all frequency regimes, it is nevertheless impractical in terms of our absorber design based on the capacitive-coupled electrical di- applications. For a passive absorber, there is a common standard pole resonances in the lateral plane, coupled to the standing wave set by the causality-dictated minimum sample thickness that is along the incident wave direction. To realize broadband imped- associated with any given reflection spectrum (33). In our case, ance matching, resistive dissipation of the metallic ring is optimally the overall thickness of the absorber is 14.2 mm, only 5% over tuned by using the approach of dispersion engineering.
    [Show full text]
  • 1 Narrowband Metamaterial Absorber for Terahertz Secure Labeling
    Narrowband Metamaterial Absorber for Terahertz Secure Labeling Magued Nasr *a, Jonathan T. Richard *d, Scott A. Skirlo *b, Martin S. Heimbeck c, John D. Joannopoulos,b Marin Soljacic b, Henry O. Everitt c†, Lawrence Domash a * Equal contributors a Triton Systems Inc., 200 Turnpike Rd #2, Chelmsford, MA 01824 b Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 c U.S. Army Aviation and Missile RD&E Center, Redstone Arsenal, AL 35898 d IERUS Technologies, 2904 Westcorp Blvd Suite 210, Huntsville, AL 35805 † Corresponding author: [email protected] Abstract Flexible metamaterial films, fabricated by photolithography on a thin copper-backed polyimide substrate, are used to mark or barcode objects securely. The films are characterized by continuous wave terahertz spectroscopic ellipsometry and visualized by a scanning confocal imager coupled to a vector network analyzer that constructed a terahertz spectral hypercube. These films exhibit a strong, narrowband, polarization- and angle-insensitive absorption at wavelengths near one millimeter. Consequently, the films are nearly indistinguishable at visible or infrared wavelengths and may be easily observed by terahertz imaging only at the resonance frequency of the film. 1 Introduction Terahertz radiation in the long wavelength 1 - 3 mm band penetrates dry dielectrics such as plastics, concrete, and fabric while being strongly absorbed by water and water vapor. This combination of characteristics may be exploited for numerous applications including short-range communications and radar, collision avoidance radar, non-destructive testing of materials and structures, security imaging, medical diagnosis, and spectroscopy.[1,2,3] Materials with interesting terahertz properties also play a role in numerous security applications due to their limited range and high bandwidth.
    [Show full text]
  • Wide-Angle Metamaterial Absorber with Highly Insensitive Absorption
    www.nature.com/scientificreports OPEN Wide‑angle metamaterial absorber with highly insensitive absorption for TE and TM modes Majid Amiri*, Farzad Tofgh, Negin Shariati, Justin Lipman & Mehran Abolhasan Being incident and polarization angle insensitive are crucial characteristics of metamaterial perfect absorbers due to the variety of incident signals. In the case of incident angles insensitivity, facing transverse electric (TE) and transverse magnetic (TM) waves afect the absorption ratio signifcantly. In this scientifc report, a crescent shape resonator has been introduced that provides over 99% absorption ratio for all polarization angles, as well as 70% and 93% efciencies for diferent incident angles up to θ = 80◦ for TE and TM polarized waves, respectively. Moreover, the insensitivity for TE and TM modes can be adjusted due to the semi-symmetric structure. By adjusting the structure parameters, the absorption ratio for TE and TM waves at θ = 80◦ has been increased to 83% and 97%, respectively. This structure has been designed to operate at 5 GHz spectrum to absorb undesired signals generated due to the growing adoption of Wi-Fi networks. Finally, the proposed absorber has been fabricated in a 20 × 20 array structure on FR-4 substrate. Strong correlation between measurement and simulation results validates the design procedure. Veslago investigated double negative (DNG) materials in 1968, since then new approaches have been found in the microwave regime1. DNG materials are well-known as metamaterials (MTMs) due to their superior characteristics. MTMs are 2D or 3D medium with a specifc structure. 3D MTMs can be a lactic or regular 3D structure that are built using several components or printed by 3D printers.
    [Show full text]
  • A Review Paper on Metamaterial Absorber
    1 International Journal of Scientific & Engineering ResearchVolume 6, Issue 10, October-2015 ISSN 2229-5518 A Review paper on Metamaterial Absorber Purvi Soni , Santosh Meena Abstract :In this paper a brief review of various structures designed from Metamaterial Absorbers is given. Compared with conventional materials, Metamaterials exhibit some specific features that are not found in conventional material. Absorbers from metamater ials are used for the various applications such as Antennas, Clocking Devices, Super Lenses etc. Keywords:MetamaterialAbsorber, Triple-Band, Circular Split Ring, Four-band absorption, Perfect absorber. ———————————————————— 1. INTRODUCTION: overlapping of four resonance frequencies, and the mechanism of absorption is investigated by the distribution of ith the emergence of a new field of electromagnetic, w electric field . The frequency of each absorption peak can be metamaterials was brought about by the demand of materials flexibly controlled by varying the size of the corresponding with exotic properties unattainable in nature.Metamaterials metallic ring. The proposed is applicable to other types of have been demonstrated to have different optical properties absorber structure and can be readily scaled up to the relying on the shapes and arrangements of the constituent structures that are working in microwave frequency range. elements. Different applications such as super lens, clocking, The proposed structure has applications in detection, sensing and perfect absorption have been studied based on imaging, and stealth technology. the optical resonance in metamaterials. One such property to enhance the use of metamaterial is a negative refractive index that requires both effective dielectric permittivity and magnetic permeabitlity to be negative. Some applications of negative index metamaterial(NIMs) include “perfect” lenses, sub-wavelength transmission lines and resonators, miniature antennas.
    [Show full text]
  • Metamaterials and Their Applications Towards Novel Imaging Technologies
    Metamaterials and their applications towards novel imaging technologies Author: Claire Watts Persistent link: http://hdl.handle.net/2345/bc-ir:104631 This work is posted on eScholarship@BC, Boston College University Libraries. Boston College Electronic Thesis or Dissertation, 2015 Copyright is held by the author, with all rights reserved, unless otherwise noted. Boston College The Graduate School of Arts and Sciences Department of Physics METAMATERIALS AND THEIR APPLICATIONS TOWARDS NOVEL IMAGING TECHNOLOGIES a dissertation by CLAIRE M. WATTS submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 2015 © copyright by CLAIRE M WATTS 2015 Metamaterials and Their Applications Towards Novel Imaging Technologies Claire M. Watts Boston College, Graduate School of Arts and Sciences, Spring 2015 Graduate Advisor: Willie J. Padilla Abstract This thesis will describe the implementation of novel imaging applications with electromagnetic metamaterials. Metamaterials have proven to be host to a multitude of interesting physical phenomena and give rich insight electromagnetic theory. This thesis will explore not only the physical theory that give them their interesting electromagnetic properties, but also the many applications of metamaterials. There is a strong need for efficient, low cost imaging solutions, specifically in the longer wavelength regime. While this technology has often been at a standstill due to the lack of natural materials that can effectively operate at these wavelengths, metamaterials have revolutionized the creation of devices to fit these needs. Their scalability has allowed them to access regimes of the electromagnetic spectrum previously unobtainable with natural materials. Along with metamaterials, mathematical techniques can be utilized to make these imaging systems streamlined and effective.
    [Show full text]
  • A Concept on Metamaterial Absorbers for Various Applications
    International Journal of Scientific & Engineering Research Volume 11, Issue 9, September-2020 ISSN 2229-5518 92 A CONCEPT ON METAMATERIAL ABSORBERS FOR VARIOUS APPLICATIONS Lakshmi Mishra, Meha Shrivastava, Rajesh Sharama ABSTRACT Conventional wideband absorbers used for different applications suffer from narrow bandwidth and their fabrication is also complicated because they are fragile and hard. To overcome the limitation faced by conventional absorber metamaterial absorbers are proposed. Metamaterial are artificial material whose properties are not similar as compare to nature occurring material. The metamaterial absorber proposed by different researchers are thin and easy to fabricated. In this article a review of different metamaterial absorbers for various frequencies is analysed and summarized. Index Terms— Metamaterial, Wideband absorber, Bandwidth, Electromagnetic wave, fragile, fabrication, frequencies. —————————— ◆ —————————— 2 2 1. INTRODUCTION 퐴푏푠표푟푝푡푖푣푖푡푦 = 1 − |푆11| − |푆21| (1) Metamaterial are manmade artificial materials Where 푆11 and 푆21 represent the reflected and whose electromagnetic properties are not similar transmitted power respectively. In equation 1 to the natural occurring materials [1]. Due to parameter is zero because the ground plane of these unique electromagnetic properties’ metamaterial absorber is fully covered with metamaterial finds applications in different field copper due to this no wave can transmitted such as superlense [2], cloaking [3], antennas [4], through the structure and absorptivity fully
    [Show full text]
  • A Multi-Band Metamaterial Absorber Design for Solar Cell Applications
    A MULTI-BAND METAMATERIAL ABSORBER DESIGN FOR SOLAR CELL APPLICATIONS A THESIS SUBMITTED TO THE BOARD OF GRADUATE PROGRAMS OF MIDDLE EAST TECHNICAL UNIVERSITY, NORTHERN CYPRUS CAMPUS BY BATUHAN MULLA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN SUSTAINABLE ENVIRONMENT AND ENERGY SYSTEMS AUGUST 2016 Approval of the Board of Graduate Programs _______________________ Prof. Dr. Tanju Mehmetoğlu Chair person I certify that this thesis satisfies all the requirements as a thesis for the degree of Master of Science. ______________________ Assoc. Prof. Dr. Ali Muhtaroğlu Program Coordinator This is to certify that we have read this thesis and that in our opinion it is fully adequate, in scope and quality, as a thesis for the degree of Master of Science. _______________________ Assoc. Prof. Dr. Cumali Sabah Supervisor Examining Committee Members Assoc. Prof. Dr. Cumali Sabah Electrical and Electronics ____________ Engineering Dept. METU NCC Assoc. Prof. Dr. Murat Fahrioğlu Electrical and Electronics ____________ Engineering Dept. METU NCC Assoc. Prof. Dr. Hüseyin Ademgil Computer Engineering Dept. _________ European University of Lefke I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last name: Batuhan Mulla Signature : iii ABSTRACT A MULTIBAND METAMATERIAL ABSORBER DESIGN FOR SOLAR CELL APPLICATIONS Mulla, Batuhan M.Sc. Sustainable Environment and Energy Systems Program Supervisor: Assoc. Prof. Dr. Cumali Sabah Solar energy is one of the most abundant energy in nature.
    [Show full text]
  • Ultra-Broadband Refractory All-Metal Metamaterial Selective Absorber for Solar Thermal Energy Conversion
    nanomaterials Article Ultra-Broadband Refractory All-Metal Metamaterial Selective Absorber for Solar Thermal Energy Conversion Buxiong Qi , Wenqiong Chen, Tiaoming Niu and Zhonglei Mei * School of Information Science and Engineering, Lanzhou University, Tianshui South Road, Lanzhou 730000, China; [email protected] (B.Q.); [email protected] (W.C.); [email protected] (T.N.) * Correspondence: [email protected] Abstract: A full-spectrum near-unity solar absorber has attracted substantial attention in recent years, and exhibited broad application prospects in solar thermal energy conversion. In this paper, an all-metal titanium (Ti) pyramid structured metamaterial absorber (MMA) is proposed to achieve broadband absorption from the near-infrared to ultraviolet, exhibiting efficient solar-selective ab- sorption. The simulation results show that the average absorption rate in the wavelength range of 200–2620 nm reached more than 98.68%, and the solar irradiation absorption efficiency in the entire solar spectrum reached 98.27%. The photothermal conversion efficiency (PTCE) reached 95.88% in the entire solar spectrum at a temperature of 700 ◦C. In addition, the strong and broadband absorption of the MMA are due to the strong absorption of local surface plasmon polariton (LSPP), coupled results of multiple plasmons and the strong loss of the refractory titanium material itself. Addi- tionally, the analysis of the results show that the MMA has wide-angle incidence and polarization insensitivity, and has a great processing accuracy tolerance. This broadband MMA paves the way for selective high-temperature photothermal conversion devices for solar energy harvesting and seawater desalination applications. Citation: Qi, B.; Chen, W.; Niu, T.; Mei, Z.
    [Show full text]