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Park D, Kim W, Park C, Choi J, Ghorai A, Lee G, Choi S, Moon W, Jeong U. Interactive Deformable Colored Sound Display Achieved with Electrostrictive Fluoropolymer and Halide Perovskite. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402281. [PMID: 39031625 DOI: 10.1002/smll.202402281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/26/2024] [Indexed: 07/22/2024]
Abstract
The association of color and sound helps human cognition through a synergetic effect like intersensory facilitation. Although soft human-machine interfaces (HMIs) providing unisensory expression have been widely developed, achieving synchronized optic and acoustic expression in one device system has been relatively less explored. It is because their operating principles are different in terms of materials, and implementation has mainly been attempted through structural approaches. Here, a deformable sound display is developed that generates multiple colored lights with large sound at low input voltage. The device is based on alternating-current electroluminescence (ACEL) covered with perovskite composite films. A sound wave is created by a polymer matrix of the ACEL, while simultaneously, various colors are produced by the perovskite films and the blue electroluminescence (EL) emitted from the phosphors in the ACEL. By patterning different colored perovskite films onto the ACELs, associating the color and the sound is successfully demonstrated by a piano keyboard and a wearable interactive device.
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Affiliation(s)
- Doowon Park
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Woongji Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Chaeyong Park
- Department of Computer Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Jun Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Arup Ghorai
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Gilwoon Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Seungmoon Choi
- Department of Computer Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Wonkyu Moon
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
| | - Unyong Jeong
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, 37673, Republic of Korea
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Jiang W, Lee S, Zan G, Zhao K, Park C. Alternating Current Electroluminescence for Human-Interactive Sensing Displays. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2304053. [PMID: 37696051 DOI: 10.1002/adma.202304053] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 09/04/2023] [Indexed: 09/13/2023]
Abstract
The development of stimuli-interactive displays based on alternating current (AC)-driven electroluminescence (EL) is of great interest, owing to their simple device architectures suitable for wearable applications requiring resilient mechanical flexibility and stretchability. AC-EL displays can serve as emerging platforms for various human-interactive sensing displays (HISDs) where human information is electrically detected and directly visualized using EL, promoting the development of the interaction of human-machine technologies. This review provides a holistic overview of the latest developments in AC-EL displays with an emphasis on their applications for HISDs. AC-EL displays based on exciton recombination or impact excitations of hot electrons are classified into four representative groups depending upon their device architecture: 1) displays without insulating layers, 2) displays with single insulating layers, 3) displays with double insulating layers, and 4) displays with EL materials embedded in an insulating matrix. State-of-the-art AC HISDs are discussed. Furthermore, emerging stimuli-interactive AC-EL displays are described, followed by a discussion of scientific and engineering challenges and perspectives for future stimuli-interactive AC-EL displays serving as photo-electronic human-machine interfaces.
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Affiliation(s)
- Wei Jiang
- Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Seokyeong Lee
- Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Guangtao Zan
- Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Kaiying Zhao
- Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Cheolmin Park
- Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
- Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02791, Republic of Korea
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3
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Lee H, Kang DH, Cho S, Kim YR, Lee Y, Na S, Cho H, Lee S, Lim G, Yeom J, Ko H. Low-Voltage Stretchable Electroluminescent Loudspeakers with Synchronous Sound and Light Generation. ACS APPLIED MATERIALS & INTERFACES 2023; 15:16299-16307. [PMID: 36926796 DOI: 10.1021/acsami.3c00732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Stretchable sound-in-displays, which can generate synchronous sound and light directly from the display without a separate speaker, allow immersive audio and visual perception even on curved surfaces. In stretchable sound-in-displays, alternating current electroluminescent (ACEL) devices have been used as light-emitting sources owing to their high brightness and stability. However, stretchable ACEL devices that use low dielectric constant (κ) materials require a high operating voltage for generating light and sound. Herein, we demonstrate a stretchable ACEL loudspeaker with a low operating voltage using stretchable high-κ dielectrics and strain-insensitive electrodes. Our device exhibits 87.7 cd/m2 of luminance and 79.70 dB of sound pressure level at an operating voltage of 120 V and 10 kHz. As the next platform of wearable devices, the suggested ACEL loudspeaker exhibits high-quality synchronous light and sound generation performance even under various types of mechanical deformation, such as finger flexion and wrist bending.
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Affiliation(s)
- Hyejin Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Dong-Hee Kang
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Seungse Cho
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Young-Ryul Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Youngoh Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Sangyun Na
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Haryeong Cho
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Seungjae Lee
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Geumseok Lim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Jeonghee Yeom
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
| | - Hyunhyub Ko
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Metropolitan City 44919, Republic of Korea
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Yu K, He T. Silver-Nanowire-Based Elastic Conductors: Preparation Processes and Substrate Adhesion. Polymers (Basel) 2023; 15:polym15061545. [PMID: 36987325 PMCID: PMC10058989 DOI: 10.3390/polym15061545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
The production of flexible electronic systems includes stretchable electrical interconnections and flexible electronic components, promoting the research and development of flexible conductors and stretchable conductive materials with large bending deformation or torsion resistance. Silver nanowires have the advantages of high conductivity, good transparency and flexibility in the development of flexible electronic products. In order to further prepare system-level flexible systems (such as autonomous full-software robots, etc.), it is necessary to focus on the conductivity of the system's composite conductor and the robustness of the system at the physical level. In terms of conductor preparation processes and substrate adhesion strategies, the more commonly used solutions are selected. Four kinds of elastic preparation processes (pretensioned/geometrically topological matrix, conductive fiber, aerogel composite, mixed percolation dopant) and five kinds of processes (coating, embedding, changing surface energy, chemical bond and force, adjusting tension and diffusion) to enhance the adhesion of composite conductors using silver nanowires as current-carrying channel substrates were reviewed. It is recommended to use the preparation process of mixed percolation doping and the adhesion mode of embedding/chemical bonding under non-special conditions. Developments in 3D printing and soft robots are also discussed.
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Affiliation(s)
- Kai Yu
- College of Mechanical and Electrical Engineering, Qingdao University, Qingdao 266071, China
| | - Tian He
- College of Mechanical and Electrical Engineering, Qingdao University, Qingdao 266071, China
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Yoo J, Li S, Kim DH, Yang J, Choi MK. Materials and design strategies for stretchable electroluminescent devices. NANOSCALE HORIZONS 2022; 7:801-821. [PMID: 35686540 DOI: 10.1039/d2nh00158f] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Stretchable displays have recently received increasing attention as input and/or output interfaces for next-generation human-friendly electronic systems. Stretchable electroluminescent (EL) devices are a core component of stretchable displays, and they can be classified into two types, structurally stretchable EL devices and intrinsically stretchable EL devices, according to the mechanism for achieving their stretchability. We herein present recent advances in materials and design strategies for stretchable EL devices. First, stretchable devices based on ultrathin EL devices are introduced. Ultrathin EL devices are mechanically flexible like thin paper, and they can become stretchable through various structural engineering methods, such as inducing a buckled structure, employing interconnects with stretchable geometries, and applying origami/kirigami techniques. Secondly, intrinsically stretchable EL devices can be fabricated by using inherently stretchable electronic materials. For example, light-emitting electrochemical cells and EL devices with a simpler structure using alternating current have been developed. Furthermore, novel stretchable semiconductor materials have been presented for the development of intrinsically stretchable light-emitting diodes. After discussing these two types of stretchable EL devices, we briefly discuss applications of deformable EL devices and conclude the review.
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Affiliation(s)
- Jisu Yoo
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
| | - Shi Li
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea.
| | - Dae-Hyeong Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.
- School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul 08826, Republic of Korea
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Jiwoong Yang
- Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea.
- Energy Science and Engineering Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea
| | - Moon Kee Choi
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
- Graduate School of Semiconductor Materials and Devices Engineering, Center for Future Semiconductor Technology (FUST), Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
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Cho S, Chang T, Yu T, Lee CH. Smart Electronic Textiles for Wearable Sensing and Display. BIOSENSORS 2022; 12:bios12040222. [PMID: 35448282 PMCID: PMC9029731 DOI: 10.3390/bios12040222] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 05/13/2023]
Abstract
Increasing demand of using everyday clothing in wearable sensing and display has synergistically advanced the field of electronic textiles, or e-textiles. A variety of types of e-textiles have been formed into stretchy fabrics in a manner that can maintain their intrinsic properties of stretchability, breathability, and wearability to fit comfortably across different sizes and shapes of the human body. These unique features have been leveraged to ensure accuracy in capturing physical, chemical, and electrophysiological signals from the skin under ambulatory conditions, while also displaying the sensing data or other immediate information in daily life. Here, we review the emerging trends and recent advances in e-textiles in wearable sensing and display, with a focus on their materials, constructions, and implementations. We also describe perspectives on the remaining challenges of e-textiles to guide future research directions toward wider adoption in practice.
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Affiliation(s)
- Seungse Cho
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA;
| | - Taehoo Chang
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA;
| | - Tianhao Yu
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA;
| | - Chi Hwan Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA;
- School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA;
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA;
- Center for Implantable Devices, Purdue University, West Lafayette, IN 47907, USA
- Correspondence:
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Li J, Zhang Z, Luo X, Zhu L, Wang ZL. Triboelectric Leakage-Field-Induced Electroluminescence Based on ZnS:Cu. ACS APPLIED MATERIALS & INTERFACES 2022; 14:4775-4782. [PMID: 35020344 DOI: 10.1021/acsami.1c23155] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The related studies and applications of ZnS-based phosphorescent materials involve various aspects such as lighting, display, sensing, electronic signatures, and confidential information. Here, triboelectrification-induced electroluminescence (TIEL) of the ZnS:Cu due to the triboelectric leakage field is discovered via a gently horizontal sliding between a ZnS:Cu particle-doped polydimethylsiloxane (PDMS) film and a polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP) film, whose intensity is positively correlated with the temperature, the doping ratio of ZnS:Cu, the pressure, and the frequency. It is also demonstrated that the TIEL mainly occurs inside the bulk film, where the ZnS:Cu phosphor particles can be polarized instantaneously by the leakage electric field of triboelectrification. The polarization will lead to a tilted energy band of the ZnS, resulting in an emitting of green light due to electrons detrapped into the conduction band and recombined with holes in the impurity state. This study not only reveals great fundamental physics for understanding of luminescence induced by a simple sliding between two triboelectric materials but also indicates another way for triboelectrification to be used in advanced optoelectronic devices.
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Affiliation(s)
- Jiayu Li
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P.R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Zhiwei Zhang
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P.R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Xiongxin Luo
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P.R. China
- Center on Nanoenergy Research, School of Physical Science & Technology, Guangxi University, Nanning 530004 China
| | - Laipan Zhu
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P.R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Zhong Lin Wang
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 101400, P.R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
- CUSTech Institute, Wenzhou, Zhejiang 325024, China
- School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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An EY, Lee S, Lee SG, Lee E, Baek JJ, Shin G, Choi KH, Cho JH, Bae GY. Self-Patterned Stretchable Electrode Based on Silver Nanowire Bundle Mesh Developed by Liquid Bridge Evaporation. NANOMATERIALS 2021; 11:nano11112865. [PMID: 34835632 PMCID: PMC8621255 DOI: 10.3390/nano11112865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/25/2022]
Abstract
A new strategy is required to realize a low-cost stretchable electrode while realizing high stretchability, conductivity, and manufacturability. In this study, we fabricated a self-patterned stretchable electrode using a simple and scalable process. The stretchable electrode is composed of a bridged square-shaped (BSS) AgNW bundle mesh developed by liquid bridge evaporation and a stretchable polymer matrix patterned with a microcavity array. Owing to the BSS structure and microcavity array, which effectively concentrate the applied strain on the deformable square region of the BSS structure under tensile stretching, the stretchable electrode exhibits high stretchability with a low ΔR/R0 of 10.3 at a strain of 40%. Furthermore, by exploiting the self-patterning ability—attributable to the difference in the ability to form liquid bridges according to the distance between microstructures—we successfully demonstrated a stretchable AgNW bundle mesh with complex patterns without using additional patterning processes. In particular, stretchable electrodes were fabricated by spray coating and bar coating, which are widely used in industry for low-cost mass production. We believe that this study significantly contributes to the commercialization of stretchable electronics while achieving high performance and complex patterns, such as stretchable displays and electronic skin.
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Affiliation(s)
- Eun Young An
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, Cheonan 31056, Korea; (E.Y.A.); (J.J.B.); (G.S.); (K.H.C.)
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Korea
| | - Siyoung Lee
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, Korea;
| | - Seung Goo Lee
- Department of Chemistry, University of Ulsan, Ulsan 44610, Korea;
| | - Eunho Lee
- Department of Chemical Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea;
| | - Jeong Ju Baek
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, Cheonan 31056, Korea; (E.Y.A.); (J.J.B.); (G.S.); (K.H.C.)
| | - Gyojic Shin
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, Cheonan 31056, Korea; (E.Y.A.); (J.J.B.); (G.S.); (K.H.C.)
| | - Kyung Ho Choi
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, Cheonan 31056, Korea; (E.Y.A.); (J.J.B.); (G.S.); (K.H.C.)
| | - Jeong Ho Cho
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Korea
- Correspondence: (J.H.C.); (G.Y.B.)
| | - Geun Yeol Bae
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, Cheonan 31056, Korea; (E.Y.A.); (J.J.B.); (G.S.); (K.H.C.)
- Correspondence: (J.H.C.); (G.Y.B.)
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Tsuneyasu S, Watanabe R, Takeda N, Uetani K, Izakura S, Kasuya K, Takahashi K, Satoh T. Enhancement of Luminance in Powder Electroluminescent Devices by Substrates of Smooth and Transparent Cellulose Nanofiber Films. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:697. [PMID: 33802162 PMCID: PMC8001356 DOI: 10.3390/nano11030697] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/02/2021] [Accepted: 03/08/2021] [Indexed: 11/17/2022]
Abstract
Powder electroluminescent (EL) devices with an electric field type excitation are surface light sources that are expected to have a wide range of practical applications, owing to their high environmental resistance; however, their low luminance has hindered their use. A clarification of the relationship between the properties of the film substrates and the electroluminescence is important to drastically improve light extraction efficiency. In this study, powder EL devices with different substrates of various levels of surface roughness and different optical transmittances were fabricated to quantitatively evaluate the relationships between the substrate properties and the device characteristics. A decrease in the surface roughness of the substrate caused a clear increase in both the current density and the luminance. The luminance was found to have a direct relationship with the optical transmittance of the substrates. The powder EL device, which was based on a cellulose nanofiber film and was the smoothest and most transparent substrate investigated, showed the highest luminance (641 cd/cm2) when 300 V was applied at 1 kHz.
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Affiliation(s)
- Shota Tsuneyasu
- Department of Media Engineering, Graduate School of Engineering, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan; (S.T.); (R.W.); (N.T.)
| | - Rikuya Watanabe
- Department of Media Engineering, Graduate School of Engineering, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan; (S.T.); (R.W.); (N.T.)
| | - Naoki Takeda
- Department of Media Engineering, Graduate School of Engineering, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan; (S.T.); (R.W.); (N.T.)
| | - Kojiro Uetani
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan;
| | - Shogo Izakura
- Graduate School of Engineering, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan; (S.I.); (K.K.); (K.T.)
| | - Keitaro Kasuya
- Graduate School of Engineering, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan; (S.I.); (K.K.); (K.T.)
| | - Kosuke Takahashi
- Graduate School of Engineering, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan; (S.I.); (K.K.); (K.T.)
| | - Toshifumi Satoh
- Department of Media Engineering, Graduate School of Engineering, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa 243-0297, Japan; (S.T.); (R.W.); (N.T.)
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