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Lee TY, Huang CC, Hung YY, Chen FC, Hong YH, Kuo HC. InGaN blue resonant cavity micro-LED with RGY quantum dot layer for broad gamut, efficient displays. DISCOVER NANO 2024; 19:75. [PMID: 38691247 PMCID: PMC11063013 DOI: 10.1186/s11671-024-04018-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 04/18/2024] [Indexed: 05/03/2024]
Abstract
The technology of RGBY micro resonant cavity light emitting diodes (micro-RCLEDs) based on quantum dots (QDs) is considered one of the most promising approaches for full-color displays. In this work, we propose a novel structure combining a high color conversion efficiency (CCE) QD photoresist (QDPR) color conversion layer (CCL) with blue light micro RCLEDs, incorporating an ultra-thin yellow color filter. The additional TiO2 particles inside the QDPR CCL can scatter light and disperse QDs, thus reducing the self-aggregation phenomenon and enhancing the eventual illumination uniformity. Considering the blue light leakage, the influences of adding different color filters are investigated by illumination design software. Finally, the introduction of low-temperature atomic layer deposition (ALD) passivation protection technology at the top of the CCL can enhance the device's reliability. The introduction of RGBY four-color subpixels provides a viable path for developing low-energy consumption, high uniformity, and efficient color conversion displays.
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Affiliation(s)
- Tzu-Yi Lee
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei, 11492, Taiwan
| | - Chien-Chi Huang
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Yu-Ying Hung
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei, 11492, Taiwan
| | - Fang-Chung Chen
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Yu-Heng Hong
- Semiconductor Research Center, Hon Hai Research Institute, Taipei, 11492, Taiwan.
| | - Hao-Chung Kuo
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
- Semiconductor Research Center, Hon Hai Research Institute, Taipei, 11492, Taiwan.
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Ryu JE, Park S, Park Y, Ryu SW, Hwang K, Jang HW. Technological Breakthroughs in Chip Fabrication, Transfer, and Color Conversion for High-Performance Micro-LED Displays. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2204947. [PMID: 35950613 DOI: 10.1002/adma.202204947] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/05/2022] [Indexed: 06/15/2023]
Abstract
The implementation of high-efficiency and high-resolution displays has been the focus of considerable research interest. Recently, micro light-emitting diodes (micro-LEDs), which are inorganic light-emitting diodes of size <100 µm2 , have emerged as a promising display technology owing to their superior features and advantages over other displays like liquid crystal displays and organic light-emitting diodes. Although many companies have introduced micro-LED displays since 2012, obstacles to mass production still exist. Three major challenges, i.e., low quantum efficiency, time-consuming transfer, and complex color conversion, have been overcome with technological breakthroughs to realize cost-effective micro-LED displays. In the review, methods for improving the degraded quantum efficiency of GaN-based micro-LEDs induced by the size effect are examined, including wet chemical treatment, passivation layer adoption, LED structure design, and growing LEDs in self-passivated structures. Novel transfer technologies, including pick-up transfer and self-assembly methods, for developing large-area micro-LED displays with high yield and reliability are discussed in depth. Quantum dots as color conversion materials for high color purity, and deposition methods such as electrohydrodynamic jet printing or contact printing on micro-LEDs are also addressed. This review presents current status and critical challenges of micro-LED technology and promising technical breakthroughs for commercialization of high-performance displays.
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Affiliation(s)
- Jung-El Ryu
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sohyeon Park
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yongjo Park
- Advance Institute of Convergence Technology, Seoul National University, Suwon, 16229, Republic of Korea
| | - Sang-Wan Ryu
- Department of Physics, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Kyungwook Hwang
- Samsung Advanced Institute of Technology, Suwon, 16678, Republic of Korea
| | - Ho Won Jang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
- Advance Institute of Convergence Technology, Seoul National University, Suwon, 16229, Republic of Korea
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3
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Huang WT, Hong LX, Liu RS. Nanostructure Control of GaN by Electrochemical Etching for Enhanced Perovskite Quantum Dot LED Backlighting. ACS APPLIED MATERIALS & INTERFACES 2023; 15:39505-39512. [PMID: 37551922 DOI: 10.1021/acsami.3c06257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Upgraded technology has realized miniaturization and promoted transformation in each field. Miniaturized light-emitting diode (LED) chips enable higher resolution and create a full sense of immersion in displays. Porous GaN is a structure that can reduce excitation light leakage and enhance the light conversion efficiency. Perovskite quantum dots with the highest optical density as candidate materials for loading in pores can significantly decrease the aggregation phenomenon and increase the path of light absorption. Here, the porous tunability is explored by electrochemical etching under a range of voltages, concentrations, and etching times with acid and base electrolytes, such as oxalic acid and potassium hydroxide. Based on scanning electron microscopy images, the distribution of the pores and the morphology of pore channels can be distinguished under acid and base etching. Larger pore sizes and distorted channels (∼680 nm) are presented on the oxalic acid-etched GaN chip. In contrast, smaller pore sizes and straight-deeper channels (∼5650 nm) are demonstrated on the GaN by potassium hydroxide etching. Therefore, the hybrid nanostructure is etched by oxalic acid and potassium hydroxide, separately. The green and red light conversion efficiencies of perovskite quantum dots pumped by a blue LED can be improved by 3 and 10 times, respectively, resulting in a color gamut of approximately 124%.
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Affiliation(s)
- Wen-Tse Huang
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Ling-Xuan Hong
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Ru-Shi Liu
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
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Liang KL, Kuo WH, Lin CC, Fang YH. The Size-Dependent Photonic Characteristics of Colloidal-Quantum-Dot-Enhanced Micro-LEDs. MICROMACHINES 2023; 14:589. [PMID: 36984995 PMCID: PMC10058900 DOI: 10.3390/mi14030589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 02/25/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Colloidal CdSe/ZnS quantum dots (QD) enhanced micro-LEDs with sizes varying from 10 to 100 μm were fabricated and measured. The direct photolithography of quantum-dot-contained photoresists can place this color conversion layer on the top of an InGaN-based micro-LED and have a high throughput and semiconductor-grade precision. Both the uncoated and coated devices were characterized, and we determined that much higher brightness of a QD-enhanced micro-LED under the same current level was observed when compared to its AlGaInP counterpart. The color stability across the device sizes and injection currents were also examined. QD LEDs show low redshift of emission wavelength, which was recorded within 1 nm in some devices, with increasing current density from 1 to 300 A/cm2. On the other hand, the light conversion efficiency (LCE) of QD-enhanced micro-LEDs was detected to decrease under the high current density or when the device is small. The angular intensities of QD-enhanced micro-LEDs were measured and compared with blue devices. With the help of the black matrix and omnidirectional light emission of colloidal QD, we observed that the angular intensities of the red and blue colors are close to Lambertian distribution, which can lead to a low color shift in all angles. From our study, the QD-enhanced micro-LEDs can effectively increase the brightness, the color stability, and the angular color match, and thus play a promising role in future micro-display technology.
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Affiliation(s)
- Kai-Ling Liang
- Electronic and Optoelectronic System Research Laboratories, Industrial Technology Research Institute, Hsinchu 31057, Taiwan
- Graduate Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Hung Kuo
- Electronic and Optoelectronic System Research Laboratories, Industrial Technology Research Institute, Hsinchu 31057, Taiwan
| | - Chien-Chung Lin
- Electronic and Optoelectronic System Research Laboratories, Industrial Technology Research Institute, Hsinchu 31057, Taiwan
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Yen-Hsiang Fang
- Electronic and Optoelectronic System Research Laboratories, Industrial Technology Research Institute, Hsinchu 31057, Taiwan
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James Singh K, Huang WT, Hsiao FH, Miao WC, Lee TY, Pai YH, Kuo HC. Recent Advances in Micro-LEDs Having Yellow-Green to Red Emission Wavelengths for Visible Light Communications. MICROMACHINES 2023; 14:mi14020478. [PMID: 36838178 PMCID: PMC9960147 DOI: 10.3390/mi14020478] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/14/2023] [Accepted: 02/17/2023] [Indexed: 06/01/2023]
Abstract
Visible light communication (VLC), which will primarily support high-speed internet connectivity in the contemporary world, has progressively come to be recognized as a significant alternative and reinforcement in the wireless communication area. VLC has become more popular recently because of its many advantages over conventional radio frequencies, including a higher transmission rate, high bandwidth, low power consumption, fewer health risks, and reduced interference. Due to its high-bandwidth characteristics and potential to be used for both illumination and communications, micro-light-emitting diodes (micro-LEDs) have drawn a lot of attention for their use in VLC applications. In this review, a detailed overview of micro-LEDs that have long emission wavelengths for VLC is presented, along with their related challenges and future prospects. The VLC performance of micro-LEDs is influenced by a number of factors, including the quantum-confined Stark effect (QCSE), size-dependent effect, and droop effect, which are discussed in the following sections. When these elements are combined, it has a major impact on the performance of micro-LEDs in terms of their modulation bandwidth, wavelength shift, full-width at half maximum (FWHM), light output power, and efficiency. The possible challenges faced in the use of micro-LEDs were analyzed through a simulation conducted using Crosslight Apsys software and the results were compared with the previous reported results. We also provide a brief overview of the phenomena, underlying theories, and potential possible solutions to these issues. Furthermore, we provide a brief discussion regarding micro-LEDs that have emission wavelengths ranging from yellow-green to red colors. We highlight the notable bandwidth enhancement for this paradigm and anticipate some exciting new research directions. Overall, this review paper provides a brief overview of the performance of VLC-based systems based on micro-LEDs and some of their possible applications.
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Affiliation(s)
- Konthoujam James Singh
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Wei-Ta Huang
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
| | - Fu-He Hsiao
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Wen-Chien Miao
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
- Department of Electrophysics, College of Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Tzu-Yi Lee
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yi-Hua Pai
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Hao-Chung Kuo
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
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6
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Chen CH, Kuo SY, Feng HY, Li ZH, Yang S, Wu SH, Hsieh HY, Lin YS, Lee YC, Chen WC, Wu PH, Chen JC, Huang YY, Lu YJ, Kuo Y, Lin CF, Yang CC. Photon color conversion enhancement of colloidal quantum dots inserted into a subsurface laterally-extended GaN nano-porous structure in an InGaN/GaN quantum-well template. OPTICS EXPRESS 2023; 31:6327-6341. [PMID: 36823892 DOI: 10.1364/oe.478250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
To improve the color conversion performance, we study the nanoscale-cavity effects on the emission efficiency of a colloidal quantum dot (QD) and the Förster resonance energy transfer (FRET) from quantum well (QW) into QD in a GaN porous structure (PS). For this study, we insert green-emitting QD (GQD) and red-emitting QD (RQD) into the fabricated PSs in a GaN template and a blue-emitting QW template, and investigate the behaviors of the photoluminescence (PL) decay times and the intensity ratios of blue, green, and red lights. In the PS samples fabricated on the GaN template, we observe the efficiency enhancements of QD emission and the FRET from GQD into RQD, when compared with the samples of surface QDs, which is attributed to the nanoscale-cavity effect. In the PS samples fabricated on the QW template, the FRET from QW into QD is also enhanced. The enhanced FRET and QD emission efficiencies in a PS result in an improved color conversion performance. Because of the anisotropic PS in the sample surface plane, the polarization dependencies of QD emission and FRET are observed.
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Qiu L, Si G, Bao X, Liu J, Guan M, Wu Y, Qi X, Xing G, Dai Z, Bao Q, Li G. Interfacial engineering of halide perovskites and two-dimensional materials. Chem Soc Rev 2023; 52:212-247. [PMID: 36468561 DOI: 10.1039/d2cs00218c] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Recently, halide perovskites (HPs) and layered two-dimensional (2D) materials have received significant attention from industry and academia alike. HPs are emerging materials that have exciting photoelectric properties, such as a high absorption coefficient, rapid carrier mobility and high photoluminescence quantum yields, making them excellent candidates for various optoelectronic applications. 2D materials possess confined carrier mobility in 2D planes and are widely employed in nanostructures to achieve interfacial modification. HP/2D material interfaces could potentially reveal unprecedented interfacial properties, including light absorbance with desired spectral overlap, tunable carrier dynamics and modified stability, which may lead to several practical applications. In this review, we attempt to provide a comprehensive perspective on the development of interfacial engineering of HP/2D material interfaces. Specifically, we highlight the recent progress in HP/2D material interfaces considering their architectures, electronic energetics tuning and interfacial properties, discuss the potential applications of these interfaces and analyze the challenges and future research directions of interfacial engineering of HP/2D material interfaces. This review links the fields of HPs and 2D materials through interfacial engineering to provide insights into future innovations and their great potential applications in optoelectronic devices.
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Affiliation(s)
- Lei Qiu
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China.
| | - Guangyuan Si
- Melbourne Center for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, 151 Wellington Road, Clayton, Victoria 3168, Australia
| | - Xiaozhi Bao
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Macau SAR 999078, China
| | - Jun Liu
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China.
| | - Mengyu Guan
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China.
| | - Yiwen Wu
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China.
| | - Xiang Qi
- Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronic, Xiangtan University, Hunan 411105, China
| | - Guichuan Xing
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Macau SAR 999078, China
| | - Zhigao Dai
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China. .,Shenzhen Institute, China University of Geosciences, Shenzhen 518057, China
| | - Qiaoliang Bao
- Institute of Energy Materials Science (IEMS), University of Shanghai for Science and Technology, Shanghai 200093, China.,Nanjing kLight Laser Technology Co. Ltd., Nanjing, Jiangsu 210032, China.
| | - Guogang Li
- Engineering Research Center of Nano-Geomaterials of Ministry of Education, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China. .,Zhejiang Institute, China University of Geosciences, Hangzhou 311305, China
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Wang J, Hua Q, Sha W, Chen J, Dai X, Niu J, Xiao J, Hu W. Flexible GaN-based microscale light-emitting diodes with a batch transfer by wet etching. OPTICS LETTERS 2022; 47:5052-5055. [PMID: 36181184 DOI: 10.1364/ol.471017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/06/2022] [Indexed: 06/16/2023]
Abstract
Flexible inorganic GaN-based microscale light-emitting diodes (µLEDs) show potential applications in wearable electronics, biomedical engineering, and human-machine interfaces. However, developing cost-effective products remains a challenge for flexible GaN-based µLEDs. Here, a facile and stable method is proposed to fabricate flexible GaN-based µLEDs from silicon substrates in an array-scale manner by wet etching. Circular and square µLED arrays with a size and pitch of 500 µm were fabricated and then transferred to a flexible acrylic/copper substrate. The as-fabricated flexible µLEDs can maintain their structure intact while exhibiting a significant increase in external quantum efficiency. This Letter promotes the application of simple and low-cost flexible µLED devices, especially for virtual displays, wearables, and curvilinear displays.
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Vyas Y, Gupta S, Punjabi PB, Ameta C. Biogenesis of Quantum Dots: An Update. ChemistrySelect 2022. [DOI: 10.1002/slct.202201099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Yogeshwari Vyas
- Department of Chemistry Microwave Synthesis Laboratory University College of Science Mohanlal Sukhadia University, Udaipur- 313001 Rajasthan India
| | - Sharoni Gupta
- Department of Chemistry Microwave Synthesis Laboratory University College of Science Mohanlal Sukhadia University, Udaipur- 313001 Rajasthan India
- Department of Chemistry Aishwarya Post Graduate College affiliated to Mohanlal Sukhadia University, Udaipur- 313001 Rajasthan India
| | - Pinki B. Punjabi
- Department of Chemistry Microwave Synthesis Laboratory University College of Science Mohanlal Sukhadia University, Udaipur- 313001 Rajasthan India
| | - Chetna Ameta
- Department of Chemistry Microwave Synthesis Laboratory University College of Science Mohanlal Sukhadia University, Udaipur- 313001 Rajasthan India
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Oh J, Kim D, Yang D, Hwang K, Hwang J, Kim J, Lee S, Ryu J, Park S, Shin JK, Kim Y, Park Y, Yoon E, Jang HW. Self-Assembled Size-Tunable Microlight-Emitting Diodes Using Multiple Sapphire Nanomembranes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:25781-25791. [PMID: 35623063 DOI: 10.1021/acsami.2c05483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microlight-emitting diode (Micro-LED) is the only display production technology capable of meeting the high-performance requirements of future screens. However, it has significant obstacles in commercialization due to etching loss and efficiency reduction caused by the singulation process, in addition to expensive costs and a significant amount of time spent on transfer. Herein, multiple-sapphire nanomembrane (MSNM) technology has been developed that enables the rapid transfer of arrays while producing micro-LEDs without the need for any singulation procedure. Individual micro-LEDs of tens of μm size were formed by the pendeo-epitaxy and coalescence of GaN grown on 2 μm width SNMs spaced with regular intervals. We have successfully fabricated micro-LEDs of different sizes including 20 × 20 μm2, 40 × 40 μm2, and 100 × 100 μm2, utilizing the membrane design. It was confirmed that the 100 × 100 μm2 micro-LED manufactured with MSNM technology not only relieved stress by 80.6% but also reduced threading dislocation density by 58.7% compared to the reference sample. It was proven that micro-LED arrays of varied chip sizes using MSNM were all transferred to the backplane. A vertical structure LED device could be fabricated using a 100 × 100 μm2 micro-LED chip, and it was confirmed to have a low operation voltage. Our work suggests that the development of the MSNM technology is promising for the commercialization of micro-LED technology.
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Affiliation(s)
- Jehong Oh
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
| | - Dongho Kim
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Duyoung Yang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
| | - Kyungwook Hwang
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Junsik Hwang
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Jongmyeong Kim
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
| | - Seungmin Lee
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
| | - Jungel Ryu
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
| | - Sohyeon Park
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
| | - Jai-Kwang Shin
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Yongsung Kim
- Samsung Advanced Institute of Technology, Suwon 16678, Republic of Korea
| | - Yongjo Park
- Advanced Institute of Convergence Technology, Seoul National University, Suwon 16229 Republic of Korea
| | - Euijoon Yoon
- Korea Institute of Energy Technology, Naju 58330, Republic of Korea
| | - Ho Won Jang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826 Republic of Korea
- Advanced Institute of Convergence Technology, Seoul National University, Suwon 16229 Republic of Korea
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11
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Fang MH, Bao Z, Huang WT, Liu RS. Evolutionary Generation of Phosphor Materials and Their Progress in Future Applications for Light-Emitting Diodes. Chem Rev 2022; 122:11474-11513. [DOI: 10.1021/acs.chemrev.1c00952] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mu-Huai Fang
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Zhen Bao
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Wen-Tse Huang
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Ru-Shi Liu
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
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12
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Huang YM, James Singh K, Hsieh TH, Langpoklakpam C, Lee TY, Lin CC, Li Y, Chen FC, Chen SC, Kuo HC, He JH. Gateway towards recent developments in quantum dot-based light-emitting diodes. NANOSCALE 2022; 14:4042-4064. [PMID: 35246672 DOI: 10.1039/d1nr05288h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Quantum dots (QDs), with their excellent photoluminescence, narrow emission linewidth, and wide color coverage, provide unrivaled advantages for advanced display technologies, enabling full-color micro-LED displays. It is indeed critical to have a fundamental understanding of how QD properties affect micro-LED display performance in order to develop the most energy-efficient display device in the near future. However, to take a more detailed look at the stability issues and passivation ways of QDs is essential for accelerating the commercialization of QD-based LED technologies. Knowing about the most recent breakthroughs in QD-based LEDs can give a good indication of how they might be used in shaping the future of displays. In this review, we discuss the characteristics of QD-based LEDs for the applications of display and lighting technologies. Various approaches for synthesis and the stability improvement of QDs are addressed in detail, along with recent advancements towards QD-based LED breakthroughs. Moreover, we summarize our latest research findings in QD-based LEDs, providing valuable information about the potential of QD-based LEDs for future display technologies.
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Affiliation(s)
- Yu-Ming Huang
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
- Institute of Photonic System, National Yang Ming Chiao Tung University, Tainan 71150, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan.
| | - Konthoujam James Singh
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Tsou-Hwa Hsieh
- Technology Development Center, InnoLux Corporation, Hsinchu 35053, Taiwan
- Institute of Communications Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Catherine Langpoklakpam
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Tzu-Yi Lee
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Chien-Chung Lin
- Institute of Photonic System, National Yang Ming Chiao Tung University, Tainan 71150, Taiwan
- Graduate Institute of Photonics and Optoelectronics, Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Yiming Li
- Institute of Communications Engineering, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Fang-Chung Chen
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Shih-Chen Chen
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan.
| | - Hao-Chung Kuo
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan.
| | - Jr-Hau He
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
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Li W, Wang K, Li J, Wu C, Zhang Y, Zhou X, Guo T. Working Mechanisms of Nanoscale Light-Emitting Diodes Operating in Non-Electrical Contact and Non-Carrier Injection Mode: Modeling and Simulation. NANOMATERIALS 2022; 12:nano12060912. [PMID: 35335727 PMCID: PMC8950408 DOI: 10.3390/nano12060912] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/17/2022] [Accepted: 03/04/2022] [Indexed: 02/06/2023]
Abstract
Non-electrical contact and non-carrier injection (NEC&NCI) mode is an emerging driving mode for nanoscale light-emitting diodes (LEDs), aiming for applications in nano-pixel light-emitting displays (NLEDs). However, the working mechanism of nano-LED operating in NEC&NCI mode is not clear yet. In particular, the questions comes down to how the inherent holes and electrons in the LED can support sufficient radiation recombination, which lacks a direct physical picture. In this work, a finite element simulation was used to study the working process of the nano-LED operating in the NEC&NCI mode to explore the working mechanisms. The energy band variation, carrier concentration redistribution, emission rate, emission spectrum, and current-voltage characteristics are studied. Moreover, the effect of the thickness of insulating layer that plays a key role on device performance is demonstrated. We believe this work can provide simulation guidance for a follow-up study of NEC&NCI-LED.
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Affiliation(s)
- Wenhao Li
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
| | - Kun Wang
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
| | - Junlong Li
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
| | - Chaoxing Wu
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
- Correspondence: (C.W.); (Y.Z.); (X.Z.)
| | - Yongai Zhang
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
- Correspondence: (C.W.); (Y.Z.); (X.Z.)
| | - Xiongtu Zhou
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
- Correspondence: (C.W.); (Y.Z.); (X.Z.)
| | - Tailiang Guo
- College of Physics and Information Engineering, Fuzhou University, Fuzhou 350108, China; (W.L.); (K.W.); (J.L.); (T.G.)
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou 350108, China
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Xiong J, Hsiang EL, He Z, Zhan T, Wu ST. Augmented reality and virtual reality displays: emerging technologies and future perspectives. LIGHT, SCIENCE & APPLICATIONS 2021; 10:216. [PMID: 34697292 PMCID: PMC8546092 DOI: 10.1038/s41377-021-00658-8] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/26/2021] [Accepted: 10/04/2021] [Indexed: 05/19/2023]
Abstract
With rapid advances in high-speed communication and computation, augmented reality (AR) and virtual reality (VR) are emerging as next-generation display platforms for deeper human-digital interactions. Nonetheless, to simultaneously match the exceptional performance of human vision and keep the near-eye display module compact and lightweight imposes unprecedented challenges on optical engineering. Fortunately, recent progress in holographic optical elements (HOEs) and lithography-enabled devices provide innovative ways to tackle these obstacles in AR and VR that are otherwise difficult with traditional optics. In this review, we begin with introducing the basic structures of AR and VR headsets, and then describing the operation principles of various HOEs and lithography-enabled devices. Their properties are analyzed in detail, including strong selectivity on wavelength and incident angle, and multiplexing ability of volume HOEs, polarization dependency and active switching of liquid crystal HOEs, device fabrication, and properties of micro-LEDs (light-emitting diodes), and large design freedoms of metasurfaces. Afterwards, we discuss how these devices help enhance the AR and VR performance, with detailed description and analysis of some state-of-the-art architectures. Finally, we cast a perspective on potential developments and research directions of these photonic devices for future AR and VR displays.
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Affiliation(s)
- Jianghao Xiong
- College of Optics and Photonics, University of Central Florida, Orlando, FL, 32816, USA
| | - En-Lin Hsiang
- College of Optics and Photonics, University of Central Florida, Orlando, FL, 32816, USA
| | - Ziqian He
- College of Optics and Photonics, University of Central Florida, Orlando, FL, 32816, USA
| | - Tao Zhan
- College of Optics and Photonics, University of Central Florida, Orlando, FL, 32816, USA
| | - Shin-Tson Wu
- College of Optics and Photonics, University of Central Florida, Orlando, FL, 32816, USA.
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15
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Huang YM, Chen JH, Liou YH, James Singh K, Tsai WC, Han J, Lin CJ, Kao TS, Lin CC, Chen SC, Kuo HC. High-Uniform and High-Efficient Color Conversion Nanoporous GaN-Based Micro-LED Display with Embedded Quantum Dots. NANOMATERIALS 2021; 11:nano11102696. [PMID: 34685137 PMCID: PMC8537299 DOI: 10.3390/nano11102696] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 01/26/2023]
Abstract
Quantum dot (QD)-based RGB micro-LED technology is seen as one of the most promising approaches towards full color micro-LED displays. In this work, we present a novel nanoporous GaN (NP-GaN) structure that can scatter light and host QDs, as well as a new type of micro-LED array based on an NP-GaN embedded with QDs. Compared to typical QD films, this structure can significantly enhance the light absorption and stability of QDs. As a result, the green and red QDs exhibited light conversion efficiencies of 90.3% and 96.1% respectively, leading to improvements to the luminous uniformity of the green and red subpixels by 90.7% and 91.2% respectively. This study provides a viable pathway to develop high-uniform and high-efficient color conversion micro-LED displays.
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Affiliation(s)
- Yu-Ming Huang
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
- Institute of Photonic System, National Yang Ming Chiao Tung University, Tainan 71150, Taiwan
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
| | - Jo-Hsiang Chen
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
| | - Yu-Hau Liou
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
| | - Konthoujam James Singh
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
| | - Wei-Cheng Tsai
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
| | - Jung Han
- Department of Electrical Engineering, Yale University, New Haven, CT 06520, USA;
| | - Chun-Jung Lin
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
| | - Tsung-Sheng Kao
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
| | - Chien-Chung Lin
- Institute of Photonic System, National Yang Ming Chiao Tung University, Tainan 71150, Taiwan
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
- Correspondence: (C.-C.L.); (S.-C.C.); (H.-C.K.)
| | - Shih-Chen Chen
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
- Correspondence: (C.-C.L.); (S.-C.C.); (H.-C.K.)
| | - Hao-Chung Kuo
- Department of Photonics, Institute of Electro-Optical Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan; (Y.-M.H.); (J.-H.C.); (Y.-H.L.); (K.J.S.); (W.-C.T.); (C.-J.L.); (T.-S.K.)
- Semiconductor Research Center, Hon Hai Research Institute, Taipei 11492, Taiwan
- Correspondence: (C.-C.L.); (S.-C.C.); (H.-C.K.)
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Ye ZT, Ho WT, Chen CH. Highly Reflective Thin-Film Optimization for Full-Angle Micro-LEDs. NANOSCALE RESEARCH LETTERS 2021; 16:152. [PMID: 34628557 PMCID: PMC8502190 DOI: 10.1186/s11671-021-03611-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/29/2021] [Indexed: 05/30/2023]
Abstract
Displays composed of micro-light-emitting diodes (micro-LEDs) are regarded as promising next-generation self-luminous screens and have advantages such as high contrast, high brightness, and high color purity. The luminescence of such a display is similar to that of a Lambertian light source. However, owing to reduction in the light source area, traditional secondary optical lenses are not suitable for adjusting the light field types of micro-LEDs and cause problems that limit the application areas. This study presents the primary optical designs of dielectric and metal films to form highly reflective thin-film coatings with low absorption on the light-emitting surfaces of micro-LEDs to optimize light distribution and achieve full-angle utilization. Based on experimental results with the prototype, that have kept low voltage variation rates, low optical losses characteristics, and obtain the full width at half maximum (FWHM) of the light distribution is enhanced to 165° and while the center intensity is reduced to 63% of the original value. Hence, a full-angle micro-LEDs with a highly reflective thin-film coating are realized in this work. Full-angle micro-LEDs offer advantages when applied to commercial advertising displays or plane light source modules that require wide viewing angles.
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Affiliation(s)
- Zhi-Ting Ye
- Department of Mechanical Engineering, Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, 168, University Rd., Min-Hsiung, Chia-Yi, 62102, Taiwan.
| | - Wen-Tsung Ho
- Department of R&D, General Manager's Office, TO2M Corporation, Hsinchu, 30010, Taiwan
| | - Chia-Hui Chen
- Department of Mechanical Engineering, Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, 168, University Rd., Min-Hsiung, Chia-Yi, 62102, Taiwan
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Xu S, Yang T, Lin J, Shen Q, Li J, Ye Y, Wang L, Zhou X, Chen E, Ye Y, Guo T. Precise theoretical model for quantum-dot color conversion. OPTICS EXPRESS 2021; 29:18654-18668. [PMID: 34154118 DOI: 10.1364/oe.425556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/26/2021] [Indexed: 06/13/2023]
Abstract
Quantum-dot color conversion (QDCC) is a promising technique for next-generation full-color displays, such as QD converted organic light-emitting diodes and micro light-emitting diodes. Although present QDCC research has made some progress on the experimental aspect, the optical model and corresponding mathematical expression that can lay an indispensable foundation for QDCC have not been reported yet. In this paper, we present a theoretical model for precisely describing the complete optical behavior of QDCC, including optical transmission, scattering, absorption, and conversion process. A key parameter of QDCC, called dosage factor (DoF), is defined to quantitatively express the total consumption of QDs that can be calculated as the product of film thickness and QD concentration. Theoretical relations are established between DoF and three key performance indicators of QDCC, namely the light conversion efficiency (LCE), blue light transmittance (BLT), and optical density (OD). The maximum LCE value can be predicted based on this theoretical model, as well as the relationship between the slope of the OD curve and the molar absorption coefficient of blue light. This theoretical model is verified by both simulation and experiment. Results show that the simulation and experimental data highly match the theoretical model, and the goodness of fit reaches higher than 96% for LCE, BLT, and OD. Based on this, the optimal interval of DoF is recommended that provides key guiding significance to the QDCC related experiment.
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Wu Y, Ma J, Su P, Zhang L, Xia B. Full-Color Realization of Micro-LED Displays. NANOMATERIALS 2020; 10:nano10122482. [PMID: 33322057 PMCID: PMC7764662 DOI: 10.3390/nano10122482] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/27/2022]
Abstract
Emerging technologies, such as smart wearable devices, augmented reality (AR)/virtual reality (VR) displays, and naked-eye 3D projection, have gradually entered our lives, accompanied by an urgent market demand for high-end display technologies. Ultra-high-resolution displays, flexible displays, and transparent displays are all important types of future display technology, and traditional display technology cannot meet the relevant requirements. Micro-light-emitting diodes (micro-LEDs), which have the advantages of a high contrast, a short response time, a wide color gamut, low power consumption, and a long life, are expected to replace traditional liquid-crystal displays (LCD) and organic light-emitting diodes (OLED) screens and become the leaders in the next generation of display technology. However, there are two major obstacles to moving micro-LEDs from the laboratory to the commercial market. One is improving the yield rate and reducing the cost of the mass transfer of micro-LEDs, and the other is realizing a full-color display using micro-LED chips. This review will outline the three main methods for applying current micro-LED full-color displays, red, green, and blue (RGB) three-color micro-LED transfer technology, color conversion technology, and single-chip multi-color growth technology, to summarize present-day micro-LED full-color display technologies and help guide the follow-up research.
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