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Kang H, Oh D, Jeon N, Kim J, Kim H, Badloe T, Rho J. Tailoring high-refractive-index nanocomposites for manufacturing of ultraviolet metasurfaces. Microsyst Nanoeng 2024; 10:53. [PMID: 38654843 PMCID: PMC11035676 DOI: 10.1038/s41378-024-00681-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 02/09/2024] [Accepted: 02/19/2024] [Indexed: 04/26/2024]
Abstract
Nanoimprint lithography (NIL) has been utilized to address the manufacturing challenges of high cost and low throughput for optical metasurfaces. To overcome the limitations inherent in conventional imprint resins characterized by a low refractive index (n), high-n nanocomposites have been introduced to directly serve as meta-atoms. However, comprehensive research on these nanocomposites is notably lacking. In this study, we focus on the composition of high-n zirconium dioxide (ZrO2) nanoparticle (NP) concentration and solvents used to produce ultraviolet (UV) metaholograms and quantify the transfer fidelity by the measured conversion efficiency. The utilization of 80 wt% ZrO2 NPs in MIBK, MEK, and acetone results in conversion efficiencies of 62.3%, 51.4%, and 61.5%, respectively, at a wavelength of 325 nm. The analysis of the solvent composition and NP concentration can further enhance the manufacturing capabilities of high-n nanocomposites in NIL, enabling potential practical use of optical metasurfaces.
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Affiliation(s)
- Hyunjung Kang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Dongkyo Oh
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Nara Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Hongyoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Trevon Badloe
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
- Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang, Republic of Korea
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2
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Latif S, Kim J, Khaliq HS, Mahmood N, Ansari MA, Chen X, Akbar J, Badloe T, Zubair M, Massoud Y, Mehmood MQ, Rho J. Spin-Selective Angular Dispersion Control in Dielectric Metasurfaces for Multichannel Meta-Holographic Displays. Nano Lett 2024; 24:708-714. [PMID: 38165767 DOI: 10.1021/acs.nanolett.3c04064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Angle-dependent next-generation displays have potential applications in 3D stereoscopic and head-mounted displays, image combiners, and encryption for augmented reality (AR) and security. Metasurfaces enable such exceptional functionalities with groundbreaking achievements in efficient displays over the past decades. However, limitations in angular dispersion control make them unfit for numerous nanophotonic applications. Here, we propose a spin-selective angle-dependent all-dielectric metasurface with a unique design strategy to manifest distinct phase information at different incident angles of light. As a proof of concept, the phase masks of two images are encoded into the metasurface and projected at the desired focal plane under different angles of left circularly polarized (LCP) light. Specifically, the proposed multifunctional metasurface generates two distinct holographic images under LCP illumination at angles of +35 and -35°. The presented holographic displays may provide a feasible route toward multifunctional meta-devices for potential AR displays, encrypted imaging, and information storage applications.
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Affiliation(s)
- Sabiha Latif
- MicroNano Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Hafiz Saad Khaliq
- MicroNano Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan
| | - Nasir Mahmood
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Muhammad Afnan Ansari
- Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Xianzhong Chen
- Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Jehan Akbar
- Glasgow College, University of Electronic Science and Technology of China, Chengdu 610056, China
| | - Trevon Badloe
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Muhammad Zubair
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Yehia Massoud
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Muhammad Qasim Mehmood
- MicroNano Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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3
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Ko B, Jeon N, Kim J, Kang H, Seong J, Yun S, Badloe T, Rho J. Hydrogels for active photonics. Microsyst Nanoeng 2024; 10:1. [PMID: 38169527 PMCID: PMC10757998 DOI: 10.1038/s41378-023-00609-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 01/05/2024]
Abstract
Conventional photonic devices exhibit static optical properties that are design-dependent, including the material's refractive index and geometrical parameters. However, they still possess attractive optical responses for applications and are already exploited in devices across various fields. Hydrogel photonics has emerged as a promising solution in the field of active photonics by providing primarily deformable geometric parameters in response to external stimuli. Over the past few years, various studies have been undertaken to attain stimuli-responsive photonic devices with tunable optical properties. Herein, we focus on the recent advancements in hydrogel-based photonics and micro/nanofabrication techniques for hydrogels. In particular, fabrication techniques for hydrogel photonic devices are categorized into film growth, photolithography (PL), electron-beam lithography (EBL), and nanoimprint lithography (NIL). Furthermore, we provide insights into future directions and prospects for deformable hydrogel photonics, along with their potential practical applications.
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Affiliation(s)
- Byoungsu Ko
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Nara Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Jaekyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Hyunjung Kang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Junhwa Seong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Suhyeon Yun
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Trevon Badloe
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673 Republic of Korea
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4
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Yang Y, Badloe T, Song D, Park S, Rho J. Building an optics and photonics research ecosystem in South Korea: Collaborative innovation between academia and industry. Light Sci Appl 2023; 12:289. [PMID: 38044357 PMCID: PMC10694129 DOI: 10.1038/s41377-023-01332-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 11/07/2023] [Indexed: 12/05/2023]
Affiliation(s)
- Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Duheon Song
- Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
- School of System Semiconductor Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seongjin Park
- Pohang Iron and Steel Company (POSCO), Pohang, 37859, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea.
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Abstract
Metalenses have the potential to revolutionize optical devices into the next generation of consumer devices. Through new inventive strategies, metalenses with advanced functionalities have been released to integrate multiple responses into a single flat device. Here, we design metalenses that are sensitive to the incident spin angular momentum to provide three distinct modes based on the handedness of the incident and transmitted light. Propagation phase is employed to encode a hyperbolic lens phase to the metalens, while geometric phase is exploited for additional spin-selective properties. We experimentally demonstrate two different metalenses: the co-polarized channels function as a standard metalens, while the cross-polarized channels (1) deflect and (2) introduce orbital angular momentum to the transmitted light. We experimentally characterize the metalenses and prove their use for spin-selective imaging of visible light. We envision that such trichannel metalenses could be employed in chiral bioimaging, optical computing, and computer vision.
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Affiliation(s)
- Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Junhwa Seong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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6
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Badloe T, Kim Y, Kim J, Park H, Barulin A, Diep YN, Cho H, Kim WS, Kim YK, Kim I, Rho J. Bright-Field and Edge-Enhanced Imaging Using an Electrically Tunable Dual-Mode Metalens. ACS Nano 2023. [PMID: 37490514 DOI: 10.1021/acsnano.3c02471] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
The imaging of microscopic biological samples faces numerous difficulties due to their small feature sizes and low-amplitude contrast. Metalenses have shown great promise in bioimaging as they have access to the complete complex information, which, alongside their extremely small and compact footprint and potential to integrate multiple functionalities into a single device, allow for miniaturized microscopy with exceptional features. Here, we design and experimentally realize a dual-mode metalens integrated with a liquid crystal cell that can be electrically switched between bright-field and edge-enhanced imaging on the millisecond scale. We combine the concepts of geometric and propagation phase to design the dual-mode metalens and physically encode the required phase profiles using hydrogenated amorphous silicon for operation at visible wavelengths. The two distinct metalens phase profiles include (1) a conventional hyperbolic metalens for bright-field imaging and (2) a spiral metalens with a topological charge of +1 for edge-enhanced imaging. We demonstrate the focusing and vortex generation ability of the metalens under different states of circular polarization and prove its use for biological imaging. This work proves a method for in vivo observation and monitoring of the cell response and drug screening within a compact form factor.
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Affiliation(s)
- Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Hyemi Park
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Aleksandr Barulin
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yen N Diep
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hansang Cho
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Won-Sik Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Young-Ki Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Inki Kim
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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7
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So S, Kim J, Badloe T, Lee C, Yang Y, Kang H, Rho J. Multicolor and 3D Holography Generated by Inverse-Designed Single-Cell Metasurfaces. Adv Mater 2023; 35:e2208520. [PMID: 36575136 DOI: 10.1002/adma.202208520] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/17/2022] [Indexed: 05/17/2023]
Abstract
Metasurface-generated holography has emerged as a promising route for fully reproducing vivid scenes by manipulating the optical properties of light using ultra-compact devices. However, achieving multiple holographic images using a single metasurface is still difficult due to the capacity limit of a single meta-atom. In this work, an inverse design method based on gradient-descent optimization is presented to encode multiple pieces of holographic information into a single metasurface. The proposed method allows the inverse design of single-cell metasurfaces without the need for complex meta-atom design strategies, facilitating high-throughput fabrication using broadband low-loss materials. By exploiting the proposed design method, both multiplane red-green-blue (RGB) color and three-dimensional (3D) holograms are designed and experimentally demonstrated. Multiplane RGB color holograms with nine distinct holograms are achieved, which demonstrate the state-of-the-art data capacity of a phase-only metasurface. The first experimental demonstration of metasurface-generated 3D holograms with completely independent and distinct images in each plane is also presented. The current research findings provide a viable route for practical metasurface-generated holography by demonstrating the high-density holography produced by a single metasurface. It is expected to ultimately lead to optical storage, display, and full-color imaging applications.
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Affiliation(s)
- Sunae So
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Electro-Mechanical Systems Engineering, Korea University, Sejong, 30019, Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Chihun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Hyunjung Kang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang, 37673, Republic of Korea
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8
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Kim J, Kim W, Oh DK, Kang H, Kim H, Badloe T, Kim S, Park C, Choi H, Lee H, Rho J. One-step printable platform for high-efficiency metasurfaces down to the deep-ultraviolet region. Light Sci Appl 2023; 12:68. [PMID: 36882418 PMCID: PMC9992517 DOI: 10.1038/s41377-023-01086-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 12/25/2022] [Accepted: 01/31/2023] [Indexed: 05/20/2023]
Abstract
A single-step printable platform for ultraviolet (UV) metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput. By dispersing zirconium dioxide (ZrO2) nanoparticles in a UV-curable resin, ZrO2 nanoparticle-embedded-resin (nano-PER) is developed as a printable material which has a high refractive index and low extinction coefficient from near-UV to deep-UV. In ZrO2 nano-PER, the UV-curable resin enables direct pattern transfer and ZrO2 nanoparticles increase the refractive index of the composite while maintaining a large bandgap. With this concept, UV metasurfaces can be fabricated in a single step by nanoimprint lithography. As a proof of concept, UV metaholograms operating in near-UV and deep-UV are experimentally demonstrated with vivid and clear holographic images. The proposed method enables repeat and rapid manufacturing of UV metasurfaces, and thus will bring UV metasurfaces more close to real life.
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Affiliation(s)
- Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Wonjoong Kim
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Dong Kyo Oh
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Hyunjung Kang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Hongyoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Seokwoo Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Chanwoong Park
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Hojung Choi
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Heon Lee
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea.
- National Institute of Nanomaterials Technology (NINT), Pohang, 37673, Republic of Korea.
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9
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Mahmood N, Kim J, Naveed MA, Kim Y, Seong J, Kim S, Badloe T, Zubair M, Mehmood MQ, Massoud Y, Rho J. Ultraviolet-Visible Multifunctional Vortex Metaplates by Breaking Conventional Rotational Symmetry. Nano Lett 2023; 23:1195-1201. [PMID: 36622968 DOI: 10.1021/acs.nanolett.2c04193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Metasurfaces have shown remarkable potential to manipulate many of light's intrinsic properties, such as phase, amplitude, and polarization. Recent advancements in nanofabrication technologies and persistent efforts from the research community result in the realization of highly efficient, broadband, and multifunctional metasurfaces. Simultaneous control of these characteristics in a single-layered metasurface will be an apparent technological extension. Here, we demonstrate a broadband multifunctional metasurface platform with the unprecedented ability to independently control the phase profile for two orthogonal polarization states of incident light over dual-wavelength spectra (ultraviolet to visible). In this work, multiple single-layered metasurfaces composed of bandgap-engineered silicon nitride nanoantennas are designed, fabricated, and optically characterized to demonstrate broadband multifunctional light manipulation ability, including structured beam generation and meta-interferometer implementation. We envision the presented metasurface platform opening new avenues for broadband multifunctional applications including ultraviolet-visible spectroscopy, spatially modulated illumination microscopy, optical data storage, and information encoding.
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Affiliation(s)
- Nasir Mahmood
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal23995, Saudi Arabia
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
| | - Muhammad Ashar Naveed
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal23995, Saudi Arabia
| | - Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
| | - Junhwa Seong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
| | - Seokwoo Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
| | - Muhammad Zubair
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal23995, Saudi Arabia
| | - Muhammad Qasim Mehmood
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal23995, Saudi Arabia
| | - Yehia Massoud
- Innovative Technologies Laboratories (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal23995, Saudi Arabia
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang37673, Republic of Korea
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10
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Ko B, Kim J, Yang Y, Badloe T, Park J, Ko JH, Jeong M, Kang H, Jung C, Song YM, Rho J. Humidity-Responsive RGB-Pixels via Swelling of 3D Nanoimprinted Polyvinyl Alcohol. Adv Sci (Weinh) 2023; 10:e2204469. [PMID: 36373672 PMCID: PMC9839877 DOI: 10.1002/advs.202204469] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/19/2022] [Indexed: 06/16/2023]
Abstract
Humidity-responsive structural coloration is actively investigated to realize real-time humidity sensors for applications in smart farming, food storage, and healthcare management. Here, humidity-tunable nano pixels are investigated with a 700 nm resolution that demonstrates full standard RGB (sRGB) gamut coverage with a millisecond-response time. The color pixels are designed as Fabry-Pérot (F-P) etalons which consist of an aluminum mirror substrate, humidity-responsive polyvinyl alcohol (PVA) spacer, and a top layer of disordered silver nanoparticles (NPs). The measured volume change of the PVA reaches up to 62.5% when the relative humidity (RH) is manipulated from 20 to 90%. The disordered silver NP layer permits the penetration of water molecules into the PVA layer, enhancing the speed of absorption and swelling down to the millisecond level. Based on the real-time response of the hydrogel-based F-P etalons with a high-throughput 3D nanoimprint technique, a high-resolution multicolored color print that can have potential applications in display technologies and optical encryption, is demonstrated.
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Affiliation(s)
- Byoungsu Ko
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Jaekyung Kim
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Younghwan Yang
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Trevon Badloe
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Jeonghoon Park
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Joo Hwan Ko
- School of Electrical Engineering and Computer ScienceGwangju Institute of Science and Technology (GIST)Gwangju61005Republic of Korea
| | - Minsu Jeong
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Hyunjung Kang
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Chunghwan Jung
- Department of Chemical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Young Min Song
- School of Electrical Engineering and Computer ScienceGwangju Institute of Science and Technology (GIST)Gwangju61005Republic of Korea
| | - Junsuk Rho
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- Department of Chemical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- POSCO‐POSTECH‐RIST Convergence Research Center for Flat Optics and MetaphotonicsPohang37673Republic of Korea
- National Institute of Nanomaterials Technology (NINT)Pohang37673Republic of Korea
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11
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Ko B, Badloe T, Yang Y, Park J, Kim J, Jeong H, Jung C, Rho J. Tunable metasurfaces via the humidity responsive swelling of single-step imprinted polyvinyl alcohol nanostructures. Nat Commun 2022; 13:6256. [PMID: 36270995 PMCID: PMC9587293 DOI: 10.1038/s41467-022-32987-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/26/2022] [Indexed: 11/09/2022] Open
Abstract
The application of hydrogels in nanophotonics has been restricted due to their low fabrication feasibility and refractive index. Nevertheless, their elasticity and strength are attractive properties for use in flexible, wearable-devices, and their swelling characteristics in response to the relative humidity highlight their potential for use in tunable nanophotonics. We investigate the use of nanostructured polyvinyl alcohol (PVA) using a one-step nanoimprinting technique for tunable and erasable optical security metasurfaces with multiplexed structural coloration and metaholography. The resolution of the PVA nanoimprinting reaches sub-100 nm, with aspect ratios approaching 10. In response to changes in the relative humidity, the PVA nanostructures swell by up to ~35.5%, providing precise wavefront manipulation of visible light. Here, we demonstrate various highly-secure multiplexed optical encryption metasurfaces to display, hide, or destroy encrypted information based on the relative humidity both irreversibly and reversibly. PVA is a hydrogel that has attractive swelling properties for use in tunable photonic applications. Here, the authors exploit PVA with nanoimprint lithography to realize multiplexed optical encryption metasurfaces to display, hide, and destroy encrypted information.
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Affiliation(s)
- Byoungsu Ko
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jeonghoon Park
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jaekyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Heonyeong Jeong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Chunghwan Jung
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea. .,Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea. .,POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea. .,National Institute of Nanomaterials Technology (NINT), Pohang, 37673, Republic of Korea.
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12
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Naveed MA, Kim J, Ansari MA, Kim I, Massoud Y, Kim J, Oh DK, Badloe T, Lee J, Kim Y, Jeon D, Choi J, Zubair M, Mehmood MQ, Rho J. Single-Step Fabricable Flexible Metadisplays for Sensitive Chemical/Biomedical Packaging Security and Beyond. ACS Appl Mater Interfaces 2022; 14:31194-31202. [PMID: 35775833 DOI: 10.1021/acsami.2c09628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Secure packaging and transportation of light-sensitive chemical and biomedical test tubes are crucial for environmental protection and public health. Benefiting from the compact form factor and high efficiency of optical metasurfaces, we propose a broad-band polarization-insensitive flexible metasurface for the security of sensitive packages in the transport industry. We employ both the propagation and the geometric phase of novel TiO2 resin-based anisotropic nanoresonators to demonstrate a flexible and broad-band polarization-insensitive metasurface in the visible domain. The ultraviolet nanoimprint lithographic technique (UV-NIL) is used to fabricate high-index TiO2 nanoparticle-embedded-resin (nano-PER) structures that are patterned on a flexible substrate. This novel approach provides swift single-step fabrication without secondary fabrication steps such as deposition and etching. Moreover, replicating and transforming patterns over flexible substrates make the proposed technique highly suitable for large-throughput commercial manufacturing. As the proposed metahologram manifests high transmission efficiency in the visible domain, such flexible metaholographic platforms could find several exciting applications in bendable/curved displays, wearable devices, and holographic labeling for interactive displays.
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Affiliation(s)
- Muhammad Ashar Naveed
- MicroNano Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Lahore 54600, Pakistan
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Muhammad Afnan Ansari
- Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
- Department of Electrical Engineering, Faculty of Engineering and Computer Sciences, National University of Modern Languages (NUML), Islamabad 44000, Pakistan
| | - Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yehia Massoud
- Innovative Technologies Laboratories (ITL), Electrical and Computer Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Jaekyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Dong Kyo Oh
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jihae Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Dongmin Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jonghyun Choi
- The New Zealand Institute for Plant and Food Research Ltd., Hamilton 3230, New Zealand
| | - Muhammad Zubair
- MicroNano Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Lahore 54600, Pakistan
| | - Muhammad Qasim Mehmood
- MicroNano Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Lahore 54600, Pakistan
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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13
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Kim W, Yoon G, Kim J, Jeong H, Kim Y, Choi H, Badloe T, Rho J, Lee H. Thermally-curable nanocomposite printing for the scalable manufacturing of dielectric metasurfaces. Microsyst Nanoeng 2022; 8:73. [PMID: 35800398 PMCID: PMC9253025 DOI: 10.1038/s41378-022-00403-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 04/10/2022] [Accepted: 05/20/2022] [Indexed: 05/29/2023]
Abstract
Metasurfaces consisting of artificially designed meta-atoms have been popularized recently due to their advantages of amplitude and phase of light control. However, the electron beam lithography method for metasurface fabrication has high cost and low throughput, which results in a limitation for the fabrication of metasurfaces. In this study, nanocomposite printing technology is used to fabricate high-efficiency metasurfaces with low cost. To demonstrate the efficiency of the proposed fabrication method, a metahologram is designed and fabricated using a nanocomposite. The metahologram exhibits conversion efficiencies of 48% and 35% at wavelengths of 532 and 635 nm, respectively. The nanocomposite is composed of polymers with nanoparticles, so durability tests are also performed to evaluate the effects of temperature and humidity on the metasurfaces. The test verifies that at temperatures below the glass transition temperature of the base resin, the nanostructures do not collapse, so the efficiency of the metasurfaces remains almost the same. The surrounding humidity does not affect the nanostructures at all. Hence, the durability of the nanocomposite metasurfaces can be further enhanced by replacing the base resin, and this nanocomposite printing method will facilitate practical metasurface use at low cost.
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Affiliation(s)
- Wonjoong Kim
- Department of Materials Science and Engineering, Korea University, Seoul, 02841 Republic of Korea
| | - Gwanho Yoon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- Department of Manufacturing Systems and Design Engineering, Seoul National University of Science and Technology, Seoul, 01811 Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Heonyeong Jeong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Hojung Choi
- Department of Materials Science and Engineering, Korea University, Seoul, 02841 Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673 Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang, 37673 Republic of Korea
| | - Heon Lee
- Department of Materials Science and Engineering, Korea University, Seoul, 02841 Republic of Korea
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14
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Kim WG, Lee JM, Yang Y, Kim H, Devaraj V, Kim M, Jeong H, Choi EJ, Yang J, Jang Y, Badloe T, Lee D, Rho J, Kim JT, Oh JW. Three-Dimensional Plasmonic Nanocluster-Driven Light-Matter Interaction for Photoluminescence Enhancement and Picomolar-Level Biosensing. Nano Lett 2022; 22:4702-4711. [PMID: 35622690 DOI: 10.1021/acs.nanolett.2c00790] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Plasmonic nanoparticle clusters promise to support unique engineered electromagnetic responses at optical frequencies, realizing a new concept of devices for nanophotonic applications. However, the technological challenges associated with the fabrication of three-dimensional nanoparticle clusters with programmed compositions remain unresolved. Here, we present a novel strategy for realizing heterogeneous structures that enable efficient near-field coupling between the plasmonic modes of gold nanoparticles and various other nanomaterials via a simple three-dimensional coassembly process. Quantum dots embedded in the plasmonic structures display ∼56 meV of a blue shift in the emission spectrum. The decay enhancement factor increases as the total contribution of radiative and nonradiative plasmonic modes increases. Furthermore, we demonstrate an ultracompact diagnostic platform to detect M13 viruses and their mutations from femtoliter volume, sub-100 pM analytes. This platform could pave the way toward an effective diagnosis of diverse pathogens, which is in high demand for handling pandemic situations.
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Affiliation(s)
- Won-Geun Kim
- BIT Fusion Technology Center, Pusan National University, Busan 46241, Republic of Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jong-Min Lee
- BIT Fusion Technology Center, Pusan National University, Busan 46241, Republic of Korea
- Center of Nano Convergence Technology and School of Nanoconvergence Technology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Hongyoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Vasanthan Devaraj
- BIT Fusion Technology Center, Pusan National University, Busan 46241, Republic of Korea
| | - Minjun Kim
- Department of Physics, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hyuk Jeong
- BIT Fusion Technology Center, Pusan National University, Busan 46241, Republic of Korea
| | - Eun-Jung Choi
- BIT Fusion Technology Center, Pusan National University, Busan 46241, Republic of Korea
| | - Jihyuk Yang
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Yudong Jang
- Institute of Quantum Systems (IQS), Chungnam National University, Daejeon 34134, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Donghan Lee
- Department of Physics, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
| | - Ji Tae Kim
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Jin-Woo Oh
- BIT Fusion Technology Center, Pusan National University, Busan 46241, Republic of Korea
- Department of Nanoenergy Engineering, Pusan National University, Busan 46241, Republic of Korea
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15
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Abbas MA, Kim J, Rana AS, Kim I, Rehman B, Ahmad Z, Massoud Y, Seong J, Badloe T, Park K, Mehmood MQ, Zubair M, Rho J. Nanostructured chromium-based broadband absorbers and emitters to realize thermally stable solar thermophotovoltaic systems. Nanoscale 2022; 14:6425-6436. [PMID: 35416207 DOI: 10.1039/d1nr08400c] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The efficiency of traditional solar cells is constrained due to the Shockley-Queisser limit, to circumvent this theoretical limit, the concept of solar thermophotovoltaics (STPVs) has been introduced. The typical design of an STPV system consists of a wideband absorber with its front side facing the sun. The back of this absorber is physically attached to the back of a selective emitter facing a low-bandgap photovoltaic (PV) cell. We demonstrate an STPV system consisting of a wideband absorber and emitter pair achieving a high absorptance of solar radiation within the range of 400-1500 nm (covering the visible and infrared regions), whereas the emitter achieves an emittance of >95% at a wavelength of 2.3 μm. This wavelength corresponds to the bandgap energy of InGaAsSb (0.54 eV), which is the targeted PV cell technology for our STPV system design. The material used for both the absorber and the emitter is chromium due to its high melting temperature of 2200 K. An absorber and emitter pair is also fabricated and the measured results are in agreement with the simulated results. The design achieves an overall solar-to-electrical simulated efficiency of 21% at a moderate temperature of 1573 K with a solar concentration of 3000 suns. Furthermore, an efficiency of 15% can be achieved at a low temperature of 873 K with a solar concentration of 500 suns. The designs are also insensitive to polarization and show negligible degradation in solar absorptance and thermal emittance with a change in the angle of incidence.
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Affiliation(s)
- Muhammad Aamir Abbas
- MicroNano Lab, Electrical Engineering Department, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan.
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Ahsan Sarwar Rana
- MicroNano Lab, Electrical Engineering Department, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan.
- Department of Electrical & Computer Engineering, Air University, Islamabad, 44000, Pakistan
| | - Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | | | - Zubair Ahmad
- Qatar University Young Scientists Center (QUYSC), Qatar University, Doha 2713, Qatar
| | - Yehia Massoud
- Innovative Technologies Laboratory (ITL), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Junhwa Seong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Keunhan Park
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Muhammad Qasim Mehmood
- MicroNano Lab, Electrical Engineering Department, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan.
| | - Muhammad Zubair
- MicroNano Lab, Electrical Engineering Department, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore 54600, Pakistan.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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16
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Badloe T, Kim J, Kim I, Kim WS, Kim WS, Kim YK, Rho J. Liquid crystal-powered Mie resonators for electrically tunable photorealistic color gradients and dark blacks. Light Sci Appl 2022; 11:118. [PMID: 35487908 PMCID: PMC9054757 DOI: 10.1038/s41377-022-00806-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 04/11/2022] [Accepted: 04/18/2022] [Indexed: 05/20/2023]
Abstract
Taking inspiration from beautiful colors in nature, structural colors produced from nanostructured metasurfaces have shown great promise as a platform for bright, highly saturated, and high-resolution colors. Both plasmonic and dielectric materials have been employed to produce static colors that fulfil the required criteria for high-performance color printing, however, for practical applications in dynamic situations, a form of tunability is desirable. Combinations of the additive color palette of red, green, and blue enable the expression of further colors beyond the three primary colors, while the simultaneous intensity modulation allows access to the full color gamut. Here, we demonstrate an electrically tunable metasurface that can represent saturated red, green, and blue pixels that can be dynamically and continuously controlled between on and off states using liquid crystals. We use this to experimentally realize ultrahigh-resolution color printing, active multicolor cryptographic applications, and tunable pixels toward high-performance full-color reflective displays.
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Affiliation(s)
- Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Won-Sik Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Wook Sung Kim
- Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Young-Ki Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea.
- National Institute of Nanomaterials Technology (NINT), Pohang, 37673, Republic of Korea.
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17
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Kim G, Kim S, Kim H, Lee J, Badloe T, Rho J. Metasurface-empowered spectral and spatial light modulation for disruptive holographic displays. Nanoscale 2022; 14:4380-4410. [PMID: 35266481 DOI: 10.1039/d1nr07909c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The holographic display, one of the most realistic ways to reconstruct optical images in three-dimensional (3D) space, has gained a lot of attention as a next-generation display platform for providing deeper immersive experiences to users. So far, diffractive optical elements (DOEs) and spatial light modulators (SLMs) have been used to generate holographic images by modulating electromagnetic waves at each pixel. However, such architectures suffer from limitations in terms of having a resolution of only a few microns and the bulkiness of the entire optical system. In this review, we describe novel metasurfaces-based nanophotonic platforms that have shown exceptional control of electromagnetic waves at the subwavelength scale as promising candidates to overcome existing restrictions, while realizing flat optical devices. After introducing the fundamentals of metasurfaces in terms of spatial and spectral wavefront modulation, we present a variety of multiplexing approaches for high-capacity and full-color metaholograms exploiting the multiple properties of light as an information carrier. We then review tunable metaholograms using active materials modulated by several external stimuli. Afterward, we discuss the integration of metasurfaces with other optical elements required for future 3D display platforms in augmented/virtual reality (AR/VR) displays such as lenses, beam splitters, diffusers, and eye-tracking sensors. Finally, we address the challenges of conventional nanofabrication methods and introduce scalable preparation techniques that can be applied to metasurface-based nanophotonic technologies towards commercially and ergonomically viable future holographic displays.
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Affiliation(s)
- Gyeongtae Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Seokwoo Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Hongyoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Jihae Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
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18
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Kim J, Jeon D, Seong J, Badloe T, Jeon N, Kim G, Kim J, Baek S, Lee JL, Rho J. Photonic Encryption Platform via Dual-Band Vectorial Metaholograms in the Ultraviolet and Visible. ACS Nano 2022; 16:3546-3553. [PMID: 35184548 DOI: 10.1021/acsnano.1c10100] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Metasurface-driven optical encryption devices have attracted much attention. Here, we propose a dual-band vectorial metahologram in the visible and ultraviolet (UV) regimes for optical encryption. Nine polarization-encoded vectorial holograms are observed under UV laser illumination, while another independent hologram appears under visible laser illumination. The proposed engineered silicon nitride, which is transparent in UV, is employed to demonstrate the UV hologram. Nine holographic images for different polarization states are encoded using a pixelated metasurface. The dual-band metahologram is experimentally implemented by stacking the individual metasurfaces that operate in the UV and visible. The visible hologram can be decrypted to provide the first key, a polarization state, which is used to decode the password hidden in the UV vectorial hologram through the use of an analyzer. Considering the property of UV to be invisible to the naked eye, the multiple polarization channels of the vectorial hologram, and the dual-band decoupling, the demonstrated dual-band vectorial hologram device could be applied in various high-security and anticounterfeiting applications.
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Affiliation(s)
- Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Dongmin Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Junhwa Seong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Nara Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Gyeongtae Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jaekyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Sangwon Baek
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jong-Lam Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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19
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Kim Y, Kim H, Yang Y, Badloe T, Jeon N, Rho J. Three-dimensional artificial chirality towards low-cost and ultra-sensitive enantioselective sensing. Nanoscale 2022; 14:3720-3730. [PMID: 35230363 DOI: 10.1039/d1nr05805c] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Artificial chiral structures have potential applications in the field of enantioselective signal sensing. Advanced nanofabrication methods enable a large diversity in geometric structures and broad selectivity of materials, which can be exploited to manufacture artificial three-dimensional chiral structures. Various chiroptical phenomena exploiting spin and orbital angular momentum at the nanoscale have been continuously exploited as a way to effectively detect enantiomers. This review introduces precisely controlled bottom-up and large-area top-down metamaterial fabrication methods to solve the limitations of high manufacturing cost and low production speed. Particle synthesis, self-assembly, glanced angled vapor deposition, and three-dimensional plasmonic nanostructure printing are introduced. Furthermore, emerging sensitive chiral sensing methods such as cavity-enhanced chirality, photothermal circular dichroism, and helical dichroism of single particles are discussed. The continuous progress of nanofabrication technology presents the strong potential for developing artificial chiral structures for applications in biomedical, pharmaceutical, nanophotonic systems.
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Affiliation(s)
- Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Hongyoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Nara Jeon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
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20
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Ko B, Chae JY, Badloe T, Kim H, Kim SJ, Hong SH, Paik T, Rho J. Multilevel Absorbers via the Integration of Undoped and Tungsten-Doped Multilayered Vanadium Dioxide Thin Films. ACS Appl Mater Interfaces 2022; 14:1404-1412. [PMID: 34978805 DOI: 10.1021/acsami.1c19223] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Reconfigurable light absorbers have attracted much attention by providing additional optical responses and expanding the number of degrees of freedom in security applications. Fabry-Pèrot absorbers based on phase change materials with tunable properties can be implemented over large scales without the need for additional steps such as lithography, while exhibiting reconfigurable optical responses. However, a fundamental limitation of widely used phase change materials such as vanadium dioxide and germanium-antimony-tellurium-based chalcogenide glasses is that they have only two distinct phases; therefore, only two different states of optical properties are available. Here, we experimentally demonstrate active multilevel absorbers that are tuned by controlling the external temperature. This is produced by creating large-scale lithography-free multilayer structures with both undoped and tungsten-doped solution-processed monoclinic-phase vanadium dioxide thin films. The doping of vanadium dioxide with tungsten allows for the modulation of the phase-transition temperature, which results in an extra degree of freedom and therefore an additional step for the tunable properties. The proposed multilevel absorber is designed and characterized both numerically and experimentally. Such large-scale multilevel tunable absorbers realized with nanoparticle-based solution fabrication techniques are expected to open the way for advanced thermo-optical cryptographic devices based on tunable reflective coloration and near-infrared absorption.
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Affiliation(s)
- Byoungsu Ko
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Ji-Yeon Chae
- School of Integrative Engineering, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Hongyoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Soo-Jung Kim
- Materials and Component Research Division, Electronics and Telecommunications Research Institute (ETRI), Daejeon 34129, Republic of Korea
| | - Sung-Hoon Hong
- Materials and Component Research Division, Electronics and Telecommunications Research Institute (ETRI), Daejeon 34129, Republic of Korea
| | - Taejong Paik
- School of Integrative Engineering, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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21
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Cho H, Jeong H, Yang Y, Badloe T, Rho J. Enhancement of Luminous Intensity Emission from Incoherent LED Light Sources within the Detection Angle of 10° Using Metalenses. Nanomaterials (Basel) 2022; 12:153. [PMID: 35010103 PMCID: PMC8746482 DOI: 10.3390/nano12010153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/27/2022]
Abstract
In this work, we present metalenses (MLs) designed to enhance the luminous intensity of incoherent light-emitting diodes (LEDs) within the detection angles of 0° and 10°. The detection angle of 0° refers to the center of the LED. Because the light emitted from LEDs is incoherent and expressed as a surface light source, they are numerically described as a set of point sources and calculated using incoherent summation. The titanium dioxide (TiO2) and amorphous silicon (a-Si) nanohole meta-atoms are designed; however, the full 2π phase coverage is not reached. Nevertheless, because the phase modulation at the edge of the ML is important, an ML is successfully designed. The typical phase profile of the ML enhances the luminous intensity at the center, and the phase profile is modified to increase the luminous intensity in the target detection angle region. Far field simulations are conducted to calculate the luminous intensity after 25 m of propagation. We demonstrate an enhancement of the luminous intensity at the center by 8551% and 2115% using TiO2 and a-Si MLs, respectively. Meanwhile, the TiO2 and a-Si MLs with the modified phase profiles enhance the luminous intensity within the detection angle of 10° by 263% and 30%, respectively.
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Affiliation(s)
- Hanlyun Cho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (H.C.); (H.J.); (Y.Y.); (T.B.)
| | - Heonyeong Jeong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (H.C.); (H.J.); (Y.Y.); (T.B.)
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (H.C.); (H.J.); (Y.Y.); (T.B.)
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (H.C.); (H.J.); (Y.Y.); (T.B.)
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (H.C.); (H.J.); (Y.Y.); (T.B.)
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Korea
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22
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Abstract
Optically variable devices (OVDs) are in tremendous demand as optical indicators against the increasing threat of counterfeiting. Conventional OVDs are exposed to the danger of fraudulent replication with advances in printing technology and widespread copying methods of security features. Metasurfaces, two-dimensional arrays of subwavelength structures known as meta-atoms, have been nominated as a candidate for a new generation of OVDs as they exhibit exceptional behaviors that can provide a more robust solution for optical anti-counterfeiting. Unlike conventional OVDs, metasurface-driven OVDs (mOVDs) can contain multiple optical responses in a single device, making them difficult to reverse engineered. Well-known examples of mOVDs include ultrahigh-resolution structural color printing, various types of holography, and polarization encoding. In this review, we discuss the new generation of mOVDs. The fundamentals of plasmonic and dielectric metasurfaces are presented to explain how the optical responses of metasurfaces can be manipulated. Then, examples of monofunctional, tunable, and multifunctional mOVDs are discussed. We follow up with a discussion of the fabrication methods needed to realize these mOVDs, classified into prototyping and manufacturing techniques. Finally, we provide an outlook and classification of mOVDs with respect to their capacity and security level. We believe this newly proposed concept of OVDs may bring about a new era of optical anticounterfeit technology leveraging the novel concepts of nano-optics and nanotechnology.
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Affiliation(s)
- Chunghwan Jung
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Gyeongtae Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Minsu Jeong
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Zhaogang Dong
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 138634, Singapore
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Joel K W Yang
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 138634, Singapore.,Engineering Product Development, Singapore University of Technology and Design, 487372, Singapore
| | - Junsuk Rho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.,Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.,POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
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23
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Badloe T, Kim I, Kim Y, Kim J, Rho J. Electrically Tunable Bifocal Metalens with Diffraction-Limited Focusing and Imaging at Visible Wavelengths. Adv Sci (Weinh) 2021; 8:e2102646. [PMID: 34486242 PMCID: PMC8564427 DOI: 10.1002/advs.202102646] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/22/2021] [Indexed: 05/25/2023]
Abstract
Tunable optical devices powered by metasurfaces provide a new path for functional planar optics. In particular, lenses with tunable focal lengths can play a key role in various fields with applications in imaging, displays, and augmented and virtual reality devices. Here, the authors demonstrate an electrically controllable bifocal metalens at visible wavelengths by incorporating a metasurface designed to focus light at two different focal lengths, with liquid crystals to actively manipulate the focal length of the metalens through the application of an external bias. By utilizing hydrogenated amorphous silicon that is optimized to provide an extremely low extinction coefficient in the visible regime, the metalens is highly efficient with measured focusing efficiencies of around 44%. They numerically design and experimentally realize and characterize tunable focusing and demonstrate electrically tunable active imaging at visible wavelengths using the bifocal metalens combined with liquid crystals. Diffraction limited focusing and imaging is verified through the analysis of the measured optical intensities at the focal points and the modulation transfer function. The bifocal metalens is used to demonstrate electrically modulated focus switching between the two designed focal planes, to display images of positive and negative target objects.
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Affiliation(s)
- Trevon Badloe
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Inki Kim
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- Department of BiophysicsInstitute of Quantum BiophysicsSungkyunkwan UniversitySuwon16419Republic of Korea
| | - Yeseul Kim
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Joohoon Kim
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Junsuk Rho
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- Department of Chemical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- POSCO‐POSTECH‐RIST Convergence Research Center for Flat Optics and MetaphotonicsPohang37673Republic of Korea
- National Institute of Nanomaterials Technology (NINT)Pohang37673Republic of Korea
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24
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Abstract
The complex degrees of freedom of light, such as amplitude, phase, polarization, and orbital angular momentum, make it a prime candidate for use in optical security and encryption. By exploiting the unique characteristics of metasurfaces, exciting new optical security platforms have been demonstrated.
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Affiliation(s)
- Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Junsuk Rho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea.
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25
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Kim J, Rana AS, Kim Y, Kim I, Badloe T, Zubair M, Mehmood MQ, Rho J. Chiroptical Metasurfaces: Principles, Classification, and Applications. Sensors (Basel) 2021; 21:4381. [PMID: 34206760 PMCID: PMC8271883 DOI: 10.3390/s21134381] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 02/07/2023]
Abstract
Chiral materials, which show different optical behaviors when illuminated by left or right circularly polarized light due to broken mirror symmetry, have greatly impacted the field of optical sensing over the past decade. To improve the sensitivity of chiral sensing platforms, enhancing the chiroptical response is necessary. Metasurfaces, which are two-dimensional metamaterials consisting of periodic subwavelength artificial structures, have recently attracted significant attention because of their ability to enhance the chiroptical response by manipulating amplitude, phase, and polarization of electromagnetic fields. Here, we reviewed the fundamentals of chiroptical metasurfaces as well as categorized types of chiroptical metasurfaces by their intrinsic or extrinsic chirality. Finally, we introduced applications of chiral metasurfaces such as multiplexing metaholograms, metalenses, and sensors.
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Affiliation(s)
- Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea; (J.K.); (Y.K.); (I.K.); (T.B.)
| | - Ahsan Sarwar Rana
- NanoTech Lab, Department of Electrical Engineering, Information Technology University of the Punjab, Ferozepur Road, Lahore 54600, Pakistan; (A.S.R.); (M.Z.)
| | - Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea; (J.K.); (Y.K.); (I.K.); (T.B.)
| | - Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea; (J.K.); (Y.K.); (I.K.); (T.B.)
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea; (J.K.); (Y.K.); (I.K.); (T.B.)
| | - Muhammad Zubair
- NanoTech Lab, Department of Electrical Engineering, Information Technology University of the Punjab, Ferozepur Road, Lahore 54600, Pakistan; (A.S.R.); (M.Z.)
| | - Muhammad Qasim Mehmood
- NanoTech Lab, Department of Electrical Engineering, Information Technology University of the Punjab, Ferozepur Road, Lahore 54600, Pakistan; (A.S.R.); (M.Z.)
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea; (J.K.); (Y.K.); (I.K.); (T.B.)
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea
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26
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Kim I, Jang J, Kim G, Lee J, Badloe T, Mun J, Rho J. Pixelated bifunctional metasurface-driven dynamic vectorial holographic color prints for photonic security platform. Nat Commun 2021; 12:3614. [PMID: 34127669 PMCID: PMC8203667 DOI: 10.1038/s41467-021-23814-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/19/2021] [Indexed: 02/07/2023] Open
Abstract
Vectorial holography has gained a lot of attention due to the promise of versatile polarization control of structured light for enhanced optical security and multi-channel optical communication. Here, we propose a bifunctional metasurface which combines both structural color printing and vectorial holography with eight polarization channels towards advanced encryption applications. The structural colour prints are observed under white light while the polarization encoded holograms are reconstructed under laser illumination. To encode multiple holographic images for different polarization states, a pixelated metasurface is adopted. As a proof-of-concept, we devise an electrically tunable optical security platform incorporated with liquid crystals. The optical security platform is doubly encrypted: an image under white light is decrypted to provide the first key and the corresponding information is used to fully unlock the encrypted information via projected vectorial holographic images. Such an electrically tunable optical security platform may enable smart labels for security and anticounterfeiting applications. The authors present a bi-functional metasurface, combining structural color printing observed under white light and polarization encoded It is appropriate. vectorial holography. A pixelated design is used encode multiple holographic images, and they demonstrate an electrically tunable optical security platform.
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Affiliation(s)
- Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Gyeongtae Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Jihae Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Jungho Mun
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea. .,Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea. .,National Institute of Nanomaterials Technology (NINT), Pohang, Republic of Korea.
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27
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Lee T, Kim J, Koirala I, Yang Y, Badloe T, Jang J, Rho J. Nearly Perfect Transmissive Subtractive Coloration through the Spectral Amplification of Mie Scattering and Lattice Resonance. ACS Appl Mater Interfaces 2021; 13:26299-26307. [PMID: 34048213 DOI: 10.1021/acsami.1c03427] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Silicon has been utilized in metasurfaces to produce structural color filters due to its compatibility with mature and cost-effective methods for complementary metal oxide semiconductor devices. In this work, we propose and demonstrate efficiency- and scattering-enhanced structural color filters using all-dielectric metasurfaces made up of engineered hydrogenated amorphous silicon (a-Si:H) nanoblocks. Wavelength-dependent filtering is achieved by Mie scattering as each structure individually supports the electric dipole (ED) and magnetic dipole (MD) resonances. The ED and MD resonances are identified by observing the field profiles of the resonance calculated by finite element method (FEM) simulations. To enhance the efficiency and scattering response of the all-dielectric metasurfaces, the proposed structural color filters are designed with consideration of the lattice resonances and scattering directivity. The spectral positions of the transmission dips and peaks are rigorously analyzed in accordance with the Mie theory and multipole expansion. The transmission spectra exhibit 100% transmission where Kerker's first condition is satisfied, while the lattice resonances amplify the ED and MD scattering responses throughout the entire visible regime. Various colors are generated by varying the resonance peak, which is controlled by varying the geometric parameters of a-Si:H nanoblocks. The proposed structural color printing devices are expected to have applications in dynamic color displays, imaging devices, and photorealistic color printing.
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Affiliation(s)
- Taejun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Ishwor Koirala
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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28
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Oh DK, Lee T, Ko B, Badloe T, Ok JG, Rho J. Nanoimprint lithography for high-throughput fabrication of metasurfaces. Front Optoelectron 2021; 14:229-251. [PMID: 36637666 PMCID: PMC9743954 DOI: 10.1007/s12200-021-1121-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/02/2021] [Indexed: 05/27/2023]
Abstract
Metasurfaces are composed of periodic sub-wavelength nanostructures and exhibit optical properties that are not found in nature. They have been widely investigated for optical applications such as holograms, wavefront shaping, and structural color printing, however, electron-beam lithography is not suitable to produce large-area metasurfaces because of the high fabrication cost and low productivity. Although alternative optical technologies, such as holographic lithography and plasmonic lithography, can overcome these drawbacks, such methods are still constrained by the optical diffraction limit. To break through this fundamental problem, mechanical nanopatterning processes have been actively studied in many fields, with nanoimprint lithography (NIL) coming to the forefront. Since NIL replicates the nanopattern of the mold regardless of the diffraction limit, NIL can achieve sufficiently high productivity and patterning resolution, giving rise to an explosive development in the fabrication of metasurfaces. In this review, we focus on various NIL technologies for the manufacturing of metasurfaces. First, we briefly describe conventional NIL and then present various NIL methods for the scalable fabrication of metasurfaces. We also discuss recent applications of NIL in the realization of metasurfaces. Finally, we conclude with an outlook on each method and suggest perspectives for future research on the high-throughput fabrication of active metasurfaces.
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Affiliation(s)
- Dong Kyo Oh
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Taejun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Byoungsu Ko
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jong G Ok
- Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology (SEOULTECH), Seoul, 01811, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
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29
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Kim I, Martins RJ, Jang J, Badloe T, Khadir S, Jung HY, Kim H, Kim J, Genevet P, Rho J. Nanophotonics for light detection and ranging technology. Nat Nanotechnol 2021; 16:508-524. [PMID: 33958762 DOI: 10.1038/s41565-021-00895-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 03/10/2021] [Indexed: 05/21/2023]
Abstract
Light detection and ranging (LiDAR) technology, a laser-based imaging technique for accurate distance measurement, is considered one of the most crucial sensor technologies for autonomous vehicles, artificially intelligent robots and unmanned aerial vehicle reconnaissance. Until recently, LiDAR has relied on light sources and detectors mounted on multiple mechanically rotating optical transmitters and receivers to cover an entire scene. Such an architecture gives rise to limitations in terms of the imaging frame rate and resolution. In this Review, we examine how novel nanophotonic platforms could overcome the hardware restrictions of existing LiDAR technologies. After briefly introducing the basic principles of LiDAR, we present the device specifications required by the industrial sector. We then review a variety of LiDAR-relevant nanophotonic approaches such as integrated photonic circuits, optical phased antenna arrays and flat optical devices based on metasurfaces. The latter have already demonstrated exceptional functional beam manipulation properties, such as active beam deflection, point-cloud generation and device integration using scalable manufacturing methods, and are expected to disrupt modern optical technologies. In the outlook, we address the upcoming physics and engineering challenges that must be overcome from the viewpoint of incorporating nanophotonic technologies into commercially viable, fast, ultrathin and lightweight LiDAR systems.
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Affiliation(s)
- Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Renato Juliano Martins
- Université Côte d'Azur, Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications (CRHEA), CNRS, Valbonne, France
| | - Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Samira Khadir
- Université Côte d'Azur, Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications (CRHEA), CNRS, Valbonne, France
| | - Ho-Youl Jung
- Department of Information and Communication Engineering, Yeungnam University, Gyeongsan, Republic of Korea
| | - Hyeongdo Kim
- Advanced Technology Research Center, SL Corporation, Gyeongsan, Republic of Korea
| | - Jongun Kim
- Advanced Technology Research Center, SL Corporation, Gyeongsan, Republic of Korea
| | - Patrice Genevet
- Université Côte d'Azur, Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications (CRHEA), CNRS, Valbonne, France.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
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Kim I, Kim WS, Kim K, Ansari MA, Mehmood MQ, Badloe T, Kim Y, Gwak J, Lee H, Kim YK, Rho J. Holographic metasurface gas sensors for instantaneous visual alarms. Sci Adv 2021; 7:7/15/eabe9943. [PMID: 33827821 PMCID: PMC8026120 DOI: 10.1126/sciadv.abe9943] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/22/2021] [Indexed: 05/21/2023]
Abstract
The rapid detection of biological and chemical substances in real time is particularly important for public health and environmental monitoring and in the military sector. If the process of substance detection to visual reporting can be implemented into a single miniaturized sensor, there could be a profound impact on practical applications. Here, we propose a compact sensor platform that integrates liquid crystals (LCs) and holographic metasurfaces to autonomously sense the existence of a volatile gas and provide an immediate visual holographic alarm. By combining the advantage of the rapid responses to gases realized by LCs with the compactness of holographic metasurfaces, we develop ultracompact gas sensors without additional complex instruments or machinery to report the visual information of gas detection. To prove the applicability of the compact sensors, we demonstrate a metasurface-integrated gas sensor on safety goggles via a one-step nanocasting process that is attachable to flat, curved, and flexible surfaces.
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Affiliation(s)
- Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Won-Sik Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Kwan Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Muhammad Afnan Ansari
- Department of Electrical Engineering, Information Technology University of the Punjab, Lahore 54600, Pakistan
| | - Muhammad Qasim Mehmood
- Department of Electrical Engineering, Information Technology University of the Punjab, Lahore 54600, Pakistan
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Yeseul Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Junho Gwak
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Heon Lee
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Young-Ki Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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31
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Naveed MA, Ansari MA, Kim I, Badloe T, Kim J, Oh DK, Riaz K, Tauqeer T, Younis U, Saleem M, Anwar MS, Zubair M, Mehmood MQ, Rho J. Optical spin-symmetry breaking for high-efficiency directional helicity-multiplexed metaholograms. Microsyst Nanoeng 2021; 7:5. [PMID: 34567723 PMCID: PMC8433315 DOI: 10.1038/s41378-020-00226-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/24/2020] [Accepted: 10/04/2020] [Indexed: 05/04/2023]
Abstract
Helicity-multiplexed metasurfaces based on symmetric spin-orbit interactions (SOIs) have practical limits because they cannot provide central-symmetric holographic imaging. Asymmetric SOIs can effectively address such limitations, with several exciting applications in various fields ranging from asymmetric data inscription in communications to dual side displays in smart mobile devices. Low-loss dielectric materials provide an excellent platform for realizing such exotic phenomena efficiently. In this paper, we demonstrate an asymmetric SOI-dependent transmission-type metasurface in the visible domain using hydrogenated amorphous silicon (a-Si:H) nanoresonators. The proposed design approach is equipped with an additional degree of freedom in designing bi-directional helicity-multiplexed metasurfaces by breaking the conventional limit imposed by the symmetric SOI in half employment of metasurfaces for one circular handedness. Two on-axis, distinct wavefronts are produced with high transmission efficiencies, demonstrating the concept of asymmetric wavefront generation in two antiparallel directions. Additionally, the CMOS compatibility of a-Si:H makes it a cost-effective alternative to gallium nitride (GaN) and titanium dioxide (TiO2) for visible light. The cost-effective fabrication and simplicity of the proposed design technique provide an excellent candidate for high-efficiency, multifunctional, and chip-integrated demonstration of various phenomena.
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Affiliation(s)
- Muhammad Ashar Naveed
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Muhammad Afnan Ansari
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Joohoon Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Dong Kyo Oh
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
| | - Kashif Riaz
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Tauseef Tauqeer
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Usman Younis
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Murtaza Saleem
- Department of Physics, Lahore University of Management Sciences (LUMS), Lahore, 54792 Pakistan
| | - Muhammad Sabieh Anwar
- Department of Physics, Lahore University of Management Sciences (LUMS), Lahore, 54792 Pakistan
| | - Muhammad Zubair
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Muhammad Qasim Mehmood
- NanoTech Lab, Department of Electrical Engineering, Information Technology University (ITU) of the Punjab, Ferozepur Road, Lahore, 54600 Pakistan
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673 Republic of Korea
- National Institute of Nanomaterials and Technology (NINT), Pohang, 37673 Republic of Korea
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Yang Y, Yoon G, Park S, Namgung SD, Badloe T, Nam KT, Rho J. Revealing Structural Disorder in Hydrogenated Amorphous Silicon for a Low-Loss Photonic Platform at Visible Frequencies. Adv Mater 2021; 33:e2005893. [PMID: 33511758 DOI: 10.1002/adma.202005893] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 12/22/2020] [Indexed: 05/17/2023]
Abstract
The high refractive index of hydrogenated amorphous silicon (a-Si:H) at optical frequencies is an essential property for the efficient modulation of the phase and amplitude of light. However, substantial optical loss represented by its high extinction coefficient prevents it from being utilized widely. Here, the bonding configurations of a-Si:H are investigated, in order to manipulate the extinction coefficient and produce a material that is competitive with conventional transparent materials, such as titanium dioxide and gallium nitride. This is achieved by controlling the hydrogenation and silicon disorder by adjusting the chemical deposition conditions. The extinction coefficient of the low-loss a-Si:H reaches a minimum of 0.082 at the wavelength of 450 nm, which is lower than that of crystalline silicon (0.13). Beam-steering metasurfaces are demonstrated to validate the low-loss optical properties, reaching measured efficiencies of 42%, 62%, and 75% at the wavelengths of 450, 532, and 635 nm, respectively. Considering its compatibility with mature complementary metal-oxide-semiconductor processes, the low-loss a-Si:H will provide a platform for efficient photonic operating in the full visible regime.
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Affiliation(s)
- Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Gwanho Yoon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Sunghak Park
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seok Daniel Namgung
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Ki Tae Nam
- Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang, 37673, Republic of Korea
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Jang J, Badloe T, Yang Y, Lee T, Mun J, Rho J. Spectral Modulation through the Hybridization of Mie-Scatterers and Quasi-Guided Mode Resonances: Realizing Full and Gradients of Structural Color. ACS Nano 2020; 14:15317-15326. [PMID: 33090760 DOI: 10.1021/acsnano.0c05656] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Metasurfaces made up of subwavelength arrays of Mie scatterers can be engineered to control the optical properties of incident light. The hybridization of the fundamental Mie resonances with lattice resonances greatly enhances the scattering cross-section of individual Mie scatterers. Through careful design of the locations of these hybridized modes using two differently engineered hydrogenated amorphous silicon nanorods, we numerically calculate and experimentally fabricate two examples of full color printing; one with spectral colors comparable to the Adobe RGB gamut, and another with gradients of color. We identify and characterize the mechanisms behind each and provide a framework that can be used to design any all-dielectric metasurfaces of subwavelength Mie scatterers for spectral modulation.
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Affiliation(s)
- Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Taejun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jungho Mun
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Junsuk Rho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- National Institute of Nanomaterials Technology (NINT), Pohang, 37673, Republic of Korea
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Jang J, Badloe T, Sim YC, Yang Y, Mun J, Lee T, Cho YH, Rho J. Full and gradient structural colouration by lattice amplified gallium nitride Mie-resonators. Nanoscale 2020; 12:21392-21400. [PMID: 33078822 DOI: 10.1039/d0nr05624c] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The hybridised resonances between Mie-scatterers and lattice resonances, i.e. quasi-guided mode resonances, are investigated. The scattering of the Mie-resonators is improved by the first order of transmitted diffracted light which is coupled to the lattice formed by the Mie-resonators. The conditions of coupling are dependent on the refractive index of the substrate and the effective refractive index of the unit cell of the resonators. Based on the momentum matching conditions, the cut-off wavelength of coupling and the amount of the amplification can be controlled. As a proof-of-concept application of this framework, gallium nitride metasurfaces are designed to produce metasurfaces that display structural colour. Palettes of full spectral colour and gradients are successfully demonstrated. The hue of the colour can be controlled by changing the periodicity of the unit cell at a fixed filling ratio of Mie-scatterer radius to unit cell periodicity, since the increase in periodicity redshifts the cut-off wavelength of the lattice resonance conditions, identified as the Rayleigh anomaly. The brightness of the colour can be tuned by adjusting the filling ratio of the unit cell. Consequently, the proposed framework may provide a fundamental guideline to design spectral filters made up of low-index Mie-scatterers for various applications.
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Affiliation(s)
- Jaehyuck Jang
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Young Chul Sim
- Department of Physics and KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Jungho Mun
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Taejun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Yong-Hoon Cho
- Department of Physics and KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
| | - Junsuk Rho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea. and Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea and National Institute of Nanomaterials Technology (NINT), Pohang 37673, Republic of Korea
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Cho H, So S, Badloe T, Bang S, Rho J. Critical Layer Thickness Analysis of Vertically Stacked Hyperbolic Metamaterials for Effective Negative Refraction Generation. Adv Theory Simul 2020. [DOI: 10.1002/adts.202000138] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hanlyun Cho
- Department of Mechanical Engineering Pohang University of Science and Technology 77 Cheongam‐ro Nam‐gu Pohang 37673 Republic of Korea
| | - Sunae So
- Department of Mechanical Engineering Pohang University of Science and Technology 77 Cheongam‐ro Nam‐gu Pohang 37673 Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering Pohang University of Science and Technology 77 Cheongam‐ro Nam‐gu Pohang 37673 Republic of Korea
| | - Sanghun Bang
- Department of Mechanical Engineering Pohang University of Science and Technology 77 Cheongam‐ro Nam‐gu Pohang 37673 Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering Pohang University of Science and Technology 77 Cheongam‐ro Nam‐gu Pohang 37673 Republic of Korea
- Department of Chemical Engineering Pohang University of Science and Technology 77 Cheongam‐ro Nam‐gu Pohang 37673 Republic of Korea
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Mun J, Kim M, Yang Y, Badloe T, Ni J, Chen Y, Qiu CW, Rho J. Electromagnetic chirality: from fundamentals to nontraditional chiroptical phenomena. Light Sci Appl 2020; 9:139. [PMID: 32922765 PMCID: PMC7463035 DOI: 10.1038/s41377-020-00367-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 06/25/2020] [Accepted: 07/08/2020] [Indexed: 05/05/2023]
Abstract
Chirality arises universally across many different fields. Recent advancements in artificial nanomaterials have demonstrated chiroptical responses that far exceed those found in natural materials. Chiroptical phenomena are complicated processes that involve transitions between states with opposite parities, and solid interpretations of these observations are yet to be clearly provided. In this review, we present a comprehensive overview of the theoretical aspects of chirality in light, nanostructures, and nanosystems and their chiroptical interactions. Descriptions of observed chiroptical phenomena based on these fundamentals are intensively discussed. We start with the strong intrinsic and extrinsic chirality in plasmonic nanoparticle systems, followed by enantioselective sensing and optical manipulation, and then conclude with orbital angular momentum-dependent responses. This review will be helpful for understanding the mechanisms behind chiroptical phenomena based on underlying chiral properties and useful for interpreting chiroptical systems for further studies.
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Affiliation(s)
- Jungho Mun
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Minkyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Jincheng Ni
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
| | - Yang Chen
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
| | - Junsuk Rho
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
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Sajedian I, Badloe T, Lee H, Rho J. Deep Q-network to produce polarization-independent perfect solar absorbers: a statistical report. Nano Converg 2020; 7:26. [PMID: 32748091 PMCID: PMC7399723 DOI: 10.1186/s40580-020-00233-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/23/2020] [Indexed: 05/06/2023]
Abstract
Using reinforcement learning, a deep Q-network was used to design polarization-independent, perfect solar absorbers. The deep Q-network selected the geometrical properties and materials of a symmetric three-layer metamaterial made up of circular rods on top of two films. The combination of all the possible permutations gives around 500 billion possible designs. In around 30,000 steps, the deep Q-network was able to produce 1250 structures that have an integrated absorption of higher than 90% in the visible region, with a maximum of 97.6% and an integrated absorption of less than 10% in the 8-13 µm wavelength region, with a minimum of 1.37%. A statistical analysis of the distribution of materials and geometrical parameters that make up the solar absorbers is presented.
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Affiliation(s)
- Iman Sajedian
- Department of Materials Science and Engineering, Korea University, Seoul, 02842, Republic of Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Heon Lee
- Department of Materials Science and Engineering, Korea University, Seoul, 02842, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
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Lee T, Lee C, Oh DK, Badloe T, Ok JG, Rho J. Scalable and High-Throughput Top-Down Manufacturing of Optical Metasurfaces. Sensors (Basel) 2020; 20:E4108. [PMID: 32718085 PMCID: PMC7435655 DOI: 10.3390/s20154108] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/18/2020] [Accepted: 07/19/2020] [Indexed: 11/18/2022]
Abstract
Metasurfaces have shown promising potential to miniaturize existing bulk optical components thanks to their extraordinary optical properties and ultra-thin, small, and lightweight footprints. However, the absence of proper manufacturing methods has been one of the main obstacles preventing the practical application of metasurfaces and commercialization. Although a variety of fabrication techniques have been used to produce optical metasurfaces, there are still no universal scalable and high-throughput manufacturing methods that meet the criteria for large-scale metasurfaces for device/product-level applications. The fundamentals and recent progress of the large area and high-throughput manufacturing methods are discussed with practical device applications. We systematically classify various top-down scalable patterning techniques for optical metasurfaces: firstly, optical and printing methods are categorized and then their conventional and unconventional (emerging/new) techniques are discussed in detail, respectively. In the end of each section, we also introduce the recent developments of metasurfaces realized by the corresponding fabrication methods.
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Affiliation(s)
- Taejun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (T.L.); (C.L.); (D.K.O.); (T.B.)
| | - Chihun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (T.L.); (C.L.); (D.K.O.); (T.B.)
| | - Dong Kyo Oh
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (T.L.); (C.L.); (D.K.O.); (T.B.)
- Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul 01811, Korea;
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (T.L.); (C.L.); (D.K.O.); (T.B.)
| | - Jong G. Ok
- Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul 01811, Korea;
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (T.L.); (C.L.); (D.K.O.); (T.B.)
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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Lee D, Gwak J, Badloe T, Palomba S, Rho J. Metasurfaces-based imaging and applications: from miniaturized optical components to functional imaging platforms. Nanoscale Adv 2020; 2:605-625. [PMID: 36133253 PMCID: PMC9419029 DOI: 10.1039/c9na00751b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/14/2020] [Indexed: 05/29/2023]
Abstract
This review focuses on the imaging applications of metasurfaces. These optical elements provide a unique platform to control light; not only do they have a reduced size and complexity compared to conventional imaging systems but they also enable novel imaging modalities, such as functional-imaging techniques. This review highlights the development of metalenses, from their basic principles, to the achievement of achromatic and tunable lenses, and metasurfaces implemented in functional optical imaging applications.
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Affiliation(s)
- Dasol Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Junho Gwak
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
| | - Stefano Palomba
- Institute of Photonics and Optical Science, School of Physics, The University of Sydney Sydney NSW 2006 Australia
- The University of Sydney Nano Institute, The University of Sydney Sydney NSW 2006 Australia
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH) Pohang 37673 Republic of Korea
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Abstract
By learning the optimal policy with a double deep Q-learning network (DDQN), we design ultra-broadband, biomimetic, perfect absorbers with various materials, based the structure of a moth's eye. All absorbers achieve over 90% average absorption from 400 to 1600 nm. By training a DDQN with moth-eye structures made up of chromium, we transfer the learned knowledge to other, similar materials to quickly and efficiently find the optimal parameters from the ∼1 billion possible options. The knowledge learned from previous optimisations helps the network to find the best solution for a new material in fewer steps, dramatically increasing the efficiency of finding designs with ultra-broadband absorption.
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Affiliation(s)
- Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Inki Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea. and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
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Sajedian I, Badloe T, Rho J. Optimisation of colour generation from dielectric nanostructures using reinforcement learning. Opt Express 2019; 27:5874-5883. [PMID: 30876182 DOI: 10.1364/oe.27.005874] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recently, a novel machine learning model has emerged in the field of reinforcement learning known as deep Q-learning. This model is capable of finding the best possible solution in systems consisting of millions of choices, without ever experiencing it before, and has been used to beat the best human minds at complex games such as, Go and chess, which both have a huge number of possible decisions and outcomes for each move. With a human-level intelligence, it has solved the problems that no other machine learning model has done before. Here, we show the steps needed for implementing this model to an optical problem. We investigate the colour generation by dielectric nanostructures and show that this model can find geometrical properties that can generate much purer red, green and blue colours compared to previously reported results. The model found these results in 9000 steps from a possible 34.5 million solutions. This technique can easily be extended to predict and optimise the design parameters for other optical structures.
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Mardiansyah D, Badloe T, Triyana K, Mehmood MQ, Raeis-Hosseini N, Lee Y, Sabarman H, Kim K, Rho J. Effect of temperature on the oxidation of Cu nanowires and development of an easy to produce, oxidation-resistant transparent conducting electrode using a PEDOT:PSS coating. Sci Rep 2018; 8:10639. [PMID: 30006611 PMCID: PMC6045652 DOI: 10.1038/s41598-018-28744-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 06/28/2018] [Indexed: 11/30/2022] Open
Abstract
Oxidation can strongly influence the performance of Cu nanowires (CuNWs) by decreasing their conductivity. Here, we identify and investigate a way to prevent the oxidation process of CuNWs to maintain the high conducting performance of CuNWs as transparent electrodes. CuNWs were synthesised using an aqueous method. We prepared several temperature treatments (from 0–300 °C) to represent oxidation of CuNWs in different environments, to study the oxidation process and changes in morphology in detail. Depending on the temperature, smooth and uniform CuNWs exposed to oxidation produced rough Cu2O and CuO nanowires. We then suggest a method of protecting nanowires from oxidation, using the Mayer rod coating method to apply a layer of PEDOT:PSS to a transparent conducting film of CuNWs. The result indicates that this method of protection can protect the film, and maintain a stable, and constant resistance over of time, without effecting the excellent conductivity properties of pure CuNWs.
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Affiliation(s)
- Dedi Mardiansyah
- Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia.,Department of Physics Education, Universitas Pasir Pengaraian, Riau, 28558, Indonesia.,Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kuwat Triyana
- Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia.,Nanomaterials Research Group, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Muhammad Q Mehmood
- Department of Electrical Engineering, Information Technology University of the Punjab, Lahore, 54000, Pakistan
| | - Niloufar Raeis-Hosseini
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Yoonkyung Lee
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Harsojo Sabarman
- Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia.,Nanomaterials Research Group, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
| | - Kyunghoon Kim
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea. .,Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
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