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Lee D, Kim SB, Kim T, Choi D, Sim JH, Lee W, Cho H, Yang JH, Kim J, Hahn S, Moon H, Yoo S. Stretchable OLEDs based on a hidden active area for high fill factor and resolution compensation. Nat Commun 2024; 15:4349. [PMID: 38834548 DOI: 10.1038/s41467-024-48396-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 04/29/2024] [Indexed: 06/06/2024] Open
Abstract
Stretchable organic light-emitting diodes (OLEDs) have emerged as promising optoelectronic devices with exceptional degree of freedom in form factors. However, stretching OLEDs often results in a reduction in the geometrical fill factor (FF), that is the ratio of an active area to the total area, thereby limiting their potential for a broad range of applications. To overcome these challenges, we propose a three-dimensional (3D) architecture adopting a hidden active area that serves a dual role as both an emitting area and an interconnector. For this purpose, an ultrathin OLED is first attached to a 3D rigid island array structure through quadaxial stretching for precise, deformation-free alignment. A portion of the ultrathin OLED is concealed by letting it 'fold in' between the adjacent islands in the initial, non-stretched condition and gradually surfaces to the top upon stretching. This design enables the proposed stretchable OLEDs to exhibit a relatively high FF not only in the initial state but also after substantial deformation corresponding to a 30% biaxial system strain. Moreover, passive-matrix OLED displays that utilize this architecture are shown to be configurable for compensation of post-stretch resolution loss, demonstrating the efficacy of the proposed approach in realizing the full potential of stretchable OLEDs.
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Affiliation(s)
- Donggyun Lee
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Su-Bon Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Taehyun Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Dongho Choi
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jee Hoon Sim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Woochan Lee
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hyunsu Cho
- Electronics Telecommunications Research Institute (ETRI), Daejeon, 34129, Republic of Korea
| | - Jong-Heon Yang
- Electronics Telecommunications Research Institute (ETRI), Daejeon, 34129, Republic of Korea
| | - Junho Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Sangin Hahn
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hanul Moon
- Department of Semiconductor; Department of Chemical Engineering (BK21 FOUR Graduate Program), Dong-A University, Busan, 49315, Republic of Korea.
| | - Seunghyup Yoo
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
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Roshan H, Zhu D, Piccinotti D, Dai J, De Franco M, Barelli M, Prato M, De Trizio L, Manna L, Di Stasio F. Near Infrared Light-Emitting Diodes Based on Colloidal InAs/ZnSe Core/Thick-Shell Quantum Dots. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400734. [PMID: 38622892 DOI: 10.1002/advs.202400734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/10/2024] [Indexed: 04/17/2024]
Abstract
Heavy-metal-free III-V colloidal quantum dots (QDs) exhibit promising attributes for application in optoelectronics. Among them, InAs QDs are demonstrating excellent optical performance with respect to absorption and emission in the near-infrared spectral domain. Recently, InAs QDs attained a substantial improvement in photoluminescence quantum yield, achieving 70% at a wavelength of 900 nm through the strategic overgrowth of a thick ZnSe shell atop the InAs core. In the present study, light-emitting diodes (LEDs) based on this type of InAs/ZnSe QDs are fabricated, reaching an external quantum efficiency (EQE) of 13.3%, a turn-on voltage of 1.5V, and a maximum radiance of 12 Wsr-1m-2. Importantly, the LEDs exhibit an extensive emission dynamic range, characterized by a nearly linear correlation between emission intensity and current density, which can be attributed to the efficient passivation provided by the thick ZnSe shell. The obtained results are comparable to state-of-the-art PbS QD LEDs. Furthermore, it should be stressed not only that the fabricated LEDs are fully RoHS-compliant but also that the emitting InAs QDs are prepared via a synthetic route based on a non-pyrophoric, cheap, and commercially available as precursor, namely tris(dimethylamino)-arsine.
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Affiliation(s)
- Hossein Roshan
- Photonic Nanomaterials, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Dongxu Zhu
- Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Davide Piccinotti
- Photonic Nanomaterials, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Jinfei Dai
- Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Manuela De Franco
- Photonic Nanomaterials, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Genova, Via Dodecaneso 31, Genova, 16146, Italy
| | - Matteo Barelli
- Photonic Nanomaterials, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Mirko Prato
- Materials Characterization Facility, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Luca De Trizio
- Chemistry Facility, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Liberato Manna
- Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
| | - Francesco Di Stasio
- Photonic Nanomaterials, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy
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Fan J, Han C, Yang G, Song B, Xu R, Xiang C, Zhang T, Qian L. Recent Progress of Quantum Dots Light-Emitting Diodes: Materials, Device Structures, and Display Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2312948. [PMID: 38813832 DOI: 10.1002/adma.202312948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/05/2024] [Indexed: 05/31/2024]
Abstract
Colloidal quantum dots (QDs), as a class of 0D semiconductor materials, have generated widespread interest due to their adjustable band gap, exceptional color purity, near-unity quantum yield, and solution-processability. With decades of dedicated research, the potential applications of quantum dots have garnered significant recognition in both the academic and industrial communities. Furthermore, the related quantum dot light-emitting diodes (QLEDs) stand out as one of the most promising contenders for the next-generation display technologies. Although QD-based color conversion films are applied to improve the color gamut of existing display technologies, the broader application of QLED devices remains in its nascent stages, facing many challenges on the path to commercialization. This review encapsulates the historical discovery and subsequent research advancements in QD materials and their synthesis methods. Additionally, the working mechanisms and architectural design of QLED prototype devices are discussed. Furthermore, the review surveys the latest advancements of QLED devices within the display industry. The narrative concludes with an examination of the challenges and perspectives of QLED technology in the foreseeable future.
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Affiliation(s)
- Junpeng Fan
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315000, P. R. China
| | - Changfeng Han
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315000, P. R. China
| | - Guojian Yang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315000, P. R. China
| | - Bin Song
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Department of Materials Science and Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Rui Xu
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham Ningbo China, Ningbo, 315100, P. R. China
| | - Chaoyu Xiang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315000, P. R. China
| | - Ting Zhang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315000, P. R. China
| | - Lei Qian
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
- Laboratory of Advanced Nano-Optoelectronic Materials and Devices, Qianwan Institute of CNITECH, Ningbo, 315000, P. R. China
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Kwon Y, Lee S, Kim J, Jun J, Jeon W, Park Y, Kim HJ, Gierschner J, Lee J, Kim Y, Kwon MS. Ultraviolet light blocking optically clear adhesives for foldable displays via highly efficient visible-light curing. Nat Commun 2024; 15:2829. [PMID: 38565557 PMCID: PMC10987679 DOI: 10.1038/s41467-024-47104-y] [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: 08/31/2023] [Accepted: 03/18/2024] [Indexed: 04/04/2024] Open
Abstract
In developing an organic light-emitting diode (OLED) panel for a foldable smartphone (specifically, a color filter on encapsulation) aimed at reducing power consumption, the use of a new optically clear adhesive (OCA) that blocks UV light was crucial. However, the incorporation of a UV-blocking agent within the OCA presented a challenge, as it restricted the traditional UV-curing methods commonly used in the manufacturing process. Although a visible-light curing technique for producing UV-blocking OCA was proposed, its slow curing speed posed a barrier to commercialization. Our study introduces a highly efficient photo-initiating system (PIS) for the rapid production of UV-blocking OCAs utilizing visible light. We have carefully selected the photocatalyst (PC) to minimize electron and energy transfer to UV-blocking agents and have chosen co-initiators that allow for faster electron transfer and more rapid PC regeneration compared to previously established amine-based co-initiators. This advancement enabled a tenfold increase in the production speed of UV-blocking OCAs, while maintaining their essential protective, transparent, and flexible properties. When applied to OLED devices, this OCA demonstrated UV protection, suggesting its potential for broader application in the safeguarding of various smart devices.
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Affiliation(s)
- Yonghwan Kwon
- Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
| | - Seokju Lee
- Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
| | - Junkyu Kim
- Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
| | - Jinwon Jun
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea
| | - Woojin Jeon
- Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
| | - Youngjoo Park
- Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea
| | - Hyun-Joong Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, Republic of Korea
| | - Johannes Gierschner
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Calle Faraday 9, Campus Cantoblanco, 28049, Madrid, Spain
| | - Jaesang Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea.
| | - Youngdo Kim
- Samsung Display Co., Ltd., Cheonan, Republic of Korea.
| | - Min Sang Kwon
- Department of Materials Science and Engineering, Seoul National University, Seoul, Republic of Korea.
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Lebedeva IV, Jornet-Somoza J. Optical properties and exciton transfer between N-heterocyclic carbene iridium(III) complexes for blue light-emitting diode applications from first principles. J Chem Phys 2024; 160:084107. [PMID: 38391015 DOI: 10.1063/5.0193161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/05/2024] [Indexed: 02/24/2024] Open
Abstract
N-heterocyclic carbene (NHC) iridium(III) complexes are considered as promising candidates for blue emitters in organic light-emitting diodes. They can play the roles of the emitter as well as of electron and hole transporters in the same emission layer. We investigate optical transitions in such complexes with account of geometry and electronic structure changes upon excitation or charging and exciton transfer between the complexes from first principles. It is shown that excitation of NHC iridium complexes is accompanied by a large reorganization energy ∼0.7 eV and a significant loss in the oscillator strength, which should lead to low exciton diffusion. Calculations with account of spin-orbit coupling reveal a small singlet-triplet splitting ∼0.1 eV, whereas the oscillator strength for triplet excitations is found to be an order of magnitude smaller than for the singlet ones. The contributions of the Förster and Dexter mechanisms are analyzed via the explicit integration of transition densities. It is shown that for typical distances between emitter complexes in the emission layer, the contribution of the Dexter mechanism should be negligible compared to the Förster mechanism. At the same time, the ideal dipole approximation, although giving the correct order of the exciton coupling, fails to reproduce the result taking into account spatial distribution of the transition density. For charged NHC complexes, we find a number of optical transitions close to the emission peak of the blue emitter with high exciton transfer rates that can be responsible for exciton-polaron quenching. The nature of these transitions is analyzed.
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Affiliation(s)
- Irina V Lebedeva
- Nano-Bio Spectroscopy Group and ETSF, Universidad del País Vasco, CFM CSIC-UPV/EHU, 20018 San Sebastián, Spain
| | - Joaquim Jornet-Somoza
- Nano-Bio Spectroscopy Group and ETSF, Universidad del País Vasco, CFM CSIC-UPV/EHU, 20018 San Sebastián, Spain
- Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
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Park H, Kim DC. Structural and Material-Based Approaches for the Fabrication of Stretchable Light-Emitting Diodes. MICROMACHINES 2023; 15:66. [PMID: 38258185 PMCID: PMC10821428 DOI: 10.3390/mi15010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024]
Abstract
Stretchable displays, capable of freely transforming their shapes, have received significant attention as alternatives to conventional rigid displays, and they are anticipated to provide new opportunities in various human-friendly electronics applications. As a core component of stretchable displays, high-performance stretchable light-emitting diodes (LEDs) have recently emerged. The approaches to fabricate stretchable LEDs are broadly categorized into two groups, namely "structural" and "material-based" approaches, based on the mechanisms to tolerate strain. While structural approaches rely on specially designed geometries to dissipate applied strain, material-based approaches mainly focus on replacing conventional rigid components of LEDs to soft and stretchable materials. Here, we review the latest studies on the fabrication of stretchable LEDs, which is accomplished through these distinctive strategies. First, we introduce representative device designs for efficient strain distribution, encompassing island-bridge structures, wavy buckling, and kirigami-/origami-based structures. For the material-based approaches, we discuss the latest studies for intrinsically stretchable (is-) electronic/optoelectronic materials, including the formation of conductive nanocomposite and polymeric blending with various additives. The review also provides examples of is-LEDs, focusing on their luminous performance and stretchability. We conclude this review with a brief outlook on future technologies.
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Affiliation(s)
- Hamin Park
- Department of Electronic Engineering, Kwangwoon University, 20, Gwangun-ro, Nowon-gu, Seoul 01897, Republic of Korea
| | - Dong Chan Kim
- Department of Chemical and Biological Engineering, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Republic of Korea
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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, SCIENCE & APPLICATIONS 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] [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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Fan K, Zheng K, Lv J, Zhao B, Zhao Y, Chen Y, Qin Y, Wang Q, Wang W, Liang J. Analysis of size-dependent optoelectronic properties of red AlGaInP micro-LEDs. OPTICS EXPRESS 2023; 31:36293-36303. [PMID: 38017784 DOI: 10.1364/oe.503024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 09/20/2023] [Indexed: 11/30/2023]
Abstract
We have theoretically investigated the size-dependent optoelectronic properties of InGaP/AlGaInP-based red micro-LEDs through an electro-optical-thermal coupling model. The model considers thermal effects due to current crowding near the electrodes, non-thermal efficiency droop due to electron leakage, and etch defects on the LED sidewall. Sidewall defects reduce the carrier concentration at the light-emitting surface's edge and exacerbate the current crowding effect. In addition, p-side electron leakage at high current densities is the leading cause of the efficiency droop of AlGaInP LEDs. In contrast, the effect of temperature on the overall efficiency degradation of LEDs is even more significant.
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