Article
Optics
Longheng Qi, Peian Li, Xu Zhang, Ka Ming Wong, Kei May Lau
Summary: A prototype of full-color micro-LED micro-display with a pixel density of 391 ppi is demonstrated using InGaN/AlGaInP heterogeneous integration. This display shows the feasibility and prospects of high brightness, good color performance, and high-resolution micro-LED micro-displays in future metaverse applications.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Seungmin Myeong, Bumsoo Chon, Samir Kumar, Ho-Jin Son, Sang Ook Kang, Sungkyu Seo
Summary: This study reports a QD photolithography technique using a custom-developed QD photoresist, which successfully fabricates various QD micro-patterns and holds great promise in various fields of QD-based applications.
NANOSCALE ADVANCES
(2022)
Article
Chemistry, Physical
Lianna Chen, Zhiyuan Qin, Shuming Chen
Summary: In this study, a new method has been developed to achieve high-resolution pixelated emission by controlling the thickness of transparent electrodes, resulting in a color-converting cavity that can selectively convert unpatterned quantum-dot white emission into saturated red, green, and blue emission. This method enables ultrahigh density red, green, and blue emission with a resolution of approximately 1700 pixels per inch, as well as achieving a color gamut of 111% NTSC.
Article
Engineering, Electrical & Electronic
Yu-Ming Huang, Tanveer Ahmed, An-Chen Liu, Sung-Wen Huang Chen, Kai-Ling Liang, Yu-Hau Liou, Chao-Cheng Ting, Wei-Hung Kuo, Yen-Hsiang Fang, Chien-Chung Lin, Hao-Chung Kuo
Summary: The study demonstrates a 3-in-1 mini-LED with blue LED combined with red and green quantum dots through ink-jet printing, achieving a high-quality full-color mini-LED array. The use of low-temperature passivation by ALD enhances color purity and environmental stability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Review
Chemistry, Multidisciplinary
Jiwoong Yang, Moon Kee Choi, U. Jeong Yang, Seo Young Kim, Young Seong Kim, Jeong Hyun Kim, Dae-Hyeong Kim, Taeghwan Hyeon
Summary: The focus is on developing efficient red, green, and blue monochromatic QLEDs and heavy-metal-free QLEDs, as well as exploring patterning techniques for manufacturing pixelated displays with RGB QDs.
Article
Engineering, Electrical & Electronic
Feifan Xu, Tao Tao, Dongqi Zhang, Yang Zhang, Yimeng Sang, Junchi Yu, Ting Zhi, Zhe Zhuang, Zili Xie, Rong Zhang, Bin Liu
Summary: We have developed a simple method for producing green and red colors on GaN-based blue micro-light-emitting diodes (mu LEDs) by patterning quantum dots (QDs) using standard photolithography and dry etching. The fabricated QDs exhibited ultra-high resolution and throughput, with a minimum size of 2 μm on a 4-inch wafer. The individual color converted green and red mu LEDs achieved a peak external quantum efficiency (EQE) of 9.6% and 14.7%, respectively. We further demonstrated the monolithic integration of red, green, and blue (RGB) mu LEDs as a single pixel by sequentially patterning red and green QDs. The resulting RGB mu LEDs covered 83.4% of the Rec. 2020 color space in the CIE 1931 diagram. This method enables high-performance red/green mu LEDs with small feature sizes and scalable fabrication of full-color mu LED displays.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Guanding Mei, Weigao Wang, Dan Wu, Philip Anthony Surman, Kai Wang, Wallace C. H. Choy, Xiaochuan Yang, Wenwei Xu, Xiao Wei Sun
Summary: This study explores the use of microcavities to fabricate full-color quantum dot light-emitting diodes (QLEDs) with a single QD layer. It demonstrates that by enhancing the microcavity and selecting the appropriate spacer thickness, the emitting color of the QLEDs can be tuned. The experimental results align well with the theoretical design and show high color purity and an expanded color gamut.
IEEE PHOTONICS JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Kyeong Min Song, Moohyun Kim, Hyunjin Cho, Hongjoo Shin, Geon Yeong Kim, Soonmin Yim, Tae Won Nam, Yeon Sik Jung
Summary: This article introduces a noninvasive surface-wetting approach to pattern multicolor quantum-dot (QD) arrays on a photoprogrammed hole transport layer (HTL). By modifying the surface of HTLs and controlling solvent evaporation kinetics, the area-selective wetting of QD patterns is achieved, while preventing cross-contamination between different QD colloids. Prototype electroluminescent quantum dot light-emitting diode arrays with high current efficiency and brightness were successfully realized.
Article
Materials Science, Multidisciplinary
Gun-Woo Lee, Jae-Hyeok Oh, Sung-Nam Lee
Summary: This study demonstrates the achievement of full-color monolithic LEDs using hexagonal epitaxial lateral overgrowth and pulse modulation modes. By reducing crystal defects and controlling indium incorporation, the LEDs emit red, green, and blue light with the same intensity, leading to the development of high-performance multifunctional lighting sources.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Optics
Konthoujam James Singh, Xiaotong Fan, Annada Sankar Sadhu, Chun-Ho Lin, Fang-Jyun Liou, Tingzhu Wu, Yu-Jung Lu, Jr-Hau He, Zhong Chen, Tom Wu, Hao-Chung Kuo
Summary: A flexible white-light system for high-speed visible-light communication (VLC) applications is proposed, consisting of a high-bandwidth CsPbBr3 quantum-dot paper and semipolar blue micro-LEDs, which could pave the way for VLC wearable devices.
PHOTONICS RESEARCH
(2021)
Article
Materials Science, Multidisciplinary
Wenhao Bai, Tongtong Xuan, Haiyan Zhao, Shuchen Shi, Xiaoyu Zhang, Tianliang Zhou, Le Wang, Rong-Jun Xie
Summary: This study proposes a cost-effective and full-color micro-LED display technology using microscale perovskite quantum dot LEDs (micro-PeLEDs) as emitters. The researchers fabricated bright and uniform RGB micro-PeLED arrays through in situ inkjet printing, demonstrating their potential applications in future ultrahigh-definition displays, light communication, and artificial intelligence.
ADVANCED OPTICAL MATERIALS
(2022)
Review
Chemistry, Physical
Zinan Chen, Haotao Li, Cuixia Yuan, Peili Gao, Qiang Su, Shuming Chen
Summary: Colloidal quantum-dot-based light-emitting diodes (LEDs) with narrow emission linewidth show great potential for high-precision color displays. However, the industrialization of QLED displays still faces challenges including unclear device mechanisms, low blue performance, and immature color patterning processes. This paper provides a comprehensive review of recent advancements in QLED displays and focuses on device mechanisms, blue QLEDs, and color patterning. Opportunities, challenges, solutions, and future research directions are also summarized.
Article
Materials Science, Multidisciplinary
Yong-Ho Ra, Cheul-Ro Lee
Summary: A new approach to reduce the size of photonic device chips is reported, utilizing a monolithic light reflector-nanowire LED system. Vertical cavity nanowire structure for surface-lighting emission is developed using selective area epitaxy, with the light reflection provided by Al metal reflector deposited by MBE technique. The approach shows significantly improved light efficiency at specific spectral wavelength, promising a new route for next-generation photonic and electronic devices.
ADVANCED MATERIALS TECHNOLOGIES
(2021)
Article
Optics
Tingtao Meng, Yueting Zheng, Denglin Zhao, Hailong Hu, Yangbin Zhu, Zhongwei Xu, Songman Ju, Jipeng Jing, Xiang Chen, Hongjin Gao, Kaiyu Yang, Tailiang Guo, Fushan Li, Junpeng Fan, Lei Qian
Summary: The demonstration of high-resolution quantum-dot light-emitting diodes using transfer printing and Langmuir-Blodgett film technology has been achieved. A honeycomb-patterned layer of wide-bandgap quantum dots is embedded to reduce leakage current, and both red and green QLEDs are demonstrated. The red devices exhibit high brightness and peak external quantum efficiency.
Review
Chemistry, Physical
Taesoo Lee, Minhyung Lee, Hansol Seo, Minjun Kim, Beomsoo Chun, Jeonghun Kwak
Summary: This review summarizes previous studies on top-emitting device structures and discusses ways to improve the performance of top-emitting quantum dot-based light-emitting diodes (TQLEDs). The relevant theories for the optoelectrical properties of TQLEDs are introduced, and advancements in device optimization are presented. Multilateral strategies for TQLEDs to be widely applied in advanced industries are also discussed. This review aims to provide valuable insights for realizing commercial TQLEDs applicable to a broad range of applications.
Article
Engineering, Electrical & Electronic
Yi-Yang Li, Fang-Zhong Lin, Kuo-Lin Chi, Shao-Yi Weng, Guan-Ying Lee, Hao-Chung Kuo, Chien-Chung Lin
Summary: In this study, AlGaInP-based red micro-light-emitting diodes (LEDs) of different sizes were fabricated and analyzed. The researchers found that the quantum efficiency decreased faster than predicted under high currents, and a leakage current component needed to be added to the model to fully explain this phenomenon. Size dependency analysis revealed the Shockley-Read-Hall coefficient and surface recombination velocity of the micro-LEDs.
IEEE PHOTONICS JOURNAL
(2022)
Correction
Chemistry, Multidisciplinary
Yu-Ming Huang, Jo-Hsiang Chen, Yu-Hau Liou, Konthoujam James Singh, Wei-Cheng Tsai, Jung Han, Chun-Jung Lin, Tsung-Sheng Kao, Chien-Chung Lin, Shih-Chen Chen, Hao-Chung Kuo
Article
Optics
Tzu-Yi Lee, Yu-Ming Huang, Hsin Chiang, Chu-Li Chao, Chu-Yin Hung, Wei-Hung Kuo, Yen-Hsiang Fang, Mu-Tao Chu, Chih- Wu, Chien-chung Lin, Hao-Chung Kuo
Summary: This study investigates the effect of atomic-layer deposition (ALD) sidewall passivation on the enhancement of electrical and optical efficiency of micro-light-emitting diodes (mu-LEDs). The results show that mu-LED devices with ALD-Al2O3 sidewall passivation exhibit lower leakage and better external quantum efficiency (EQE) compared to samples without ALD-Al2O3 treatment. Furthermore, the EQE values and output power of 5 x 5 and 10 x 10 mu m(2) devices significantly increase after ALD-Al2O3 sidewall treatment. The observed reduction in surface recombination velocity suggests reduced recombination in the ALD samples.
Article
Crystallography
Shu-Hsiu Chang, Che-Hsuan Huang, Chatherine Langpoklakpam, Konthoujam James Singh, Chien-Chung Lin, Hao-Chung Kuo
Summary: Fine-pitch backlight technology is advancing rapidly in parallel with display technology. This study utilizes distributed Bragg reflector (DBR) to develop mini light-emitting diode (mini-LED) backlights with high dynamic contrast and introduces a digital twin design using light-emitting diode (LED) and distributed Bragg reflector (DBR).
Article
Engineering, Electrical & Electronic
Chung-Ping Huang, Guan-Teng Lin, Jhen-Jia Yang, Chien-Chung Lin
Summary: A CQD package with convex-surface solder reflectors showed improved thermal characteristics and optical reliability compared to traditional in-chip packages. Solder balls provided a direct cooling path and reflected blue photons to enhance recycling. Metal structures extended the device lifetime and provided a lower operating temperature for the packaged CQDs. This study advances the integration of high-thermal-conductivity components into quantum dot photonic devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Ting-Wei Lu, Yue Huang, Shou-Qiang Lai, Su-Hui Lin, Shi-Biao Liu, Xiao-Tong Fan, Yi-Jun Lu, Yue Lin, Zhong Chen, Ting-Zhu Wu
Summary: This study investigated the performance of GaN-based LEDs as photodetectors and improved their responsivity through sidewall passivation. High-speed data transmission was achieved over a distance of 1m. This method simplifies the system structure, reduces power consumption, and facilitates the integration of multifunctional small LED devices.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Rongliang Deng, Xiaotong Fan, Guolong Chen, Changzhi Yu, Xiao Yang, Yue Lin, Hao-Chung Kuo, Tingzhu Wu, Zhong Chen
Summary: In this study, we introduced zero-dimensional perovskites Cs4PbI6 as a protective layer for CsPbI3 perovskite nanocrystals (PNCs) in addition to SiO2 encapsulation. The CsPbI3-Cs4PbI6 nano-composite not only maintains the emission peak location of CsPbI3 PNCs at 700 nm with excellent oxygen and water resistances, but also exhibits enhanced thermal stability compared to samples with less Cs4PbI6. The passivation of defects on the interface of CsPbI3-Cs4PbI6 contributes to an 8% increase in photoluminescence quantum yield. These ultra stable CsPbI3-Cs4PbI6 nano-composites show potential in the luminous and display industries.
JOURNAL OF LUMINESCENCE
(2023)
Article
Materials Science, Multidisciplinary
Xiao Yang, Zi-Jun Yan, Chen-Ming Zhong, Hui Jia, Guo-Long Chen, Xiao-Tong Fan, Shu-Li Wang, Ting-Zhu Wu, Yue Lin, Zhong Chen
Summary: High-resolution perovskite quantum dots (PeQDs) arrays printed by electrohydrodynamic (EHD) inkjet printing show great application prospects in fields of micro-display. A morphology uniformization strategy using a nonpolar binary solvent system of 1,3,5-triethylbenzene and n-tetradecane is proposed to prepare the didodecyldimethylammonium bromide (DDAB)/PbBr2 passivated PeQDs inks. The high-resolution logo and miniature quick response code printed by EHD inkjet reach far higher resolution than micro-LED.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Analytical
Kai-Ling Liang, Wei-Hung Kuo, Chien-Chung Lin, Yen-Hsiang Fang
Summary: Colloidal CdSe/ZnS quantum dots (QD) enhanced micro-LEDs with sizes ranging from 10 to 100 μm were fabricated and characterized. The color conversion layer in the form of quantum-dot-contained photoresists was directly placed on top of an InGaN-based micro-LED using photolithography, demonstrating high throughput and precision. The QD-enhanced micro-LEDs exhibited higher brightness compared to AlGaInP counterparts under the same current level. Furthermore, these devices showed low redshift of emission wavelength and demonstrated efficient color stability and angular color match, making them promising for future micro-display technology.
Article
Optics
Saijun Li, Meng-Chun Shen, Shouqiang Lai, Yurong Dai, Jinlan Chen, Lijie Zheng, Lihong Zhu, Guolong Chen, Su-Hui Lin, Kang-Wei Peng, Zhong Chen, Tingzhu Wu
Summary: The effects of different p-GaN layer thickness on the photoelectric and thermal properties of AlGaN-based DUV-LEDs were investigated. Thinning the p-GaN layer appropriately enhances the photoelectric performance and thermal stability of the DUV-LEDs.
Article
Physics, Multidisciplinary
Meng-Chun Shen, Wenan Guo, Jinlan Chen, Su-Hui Lin, Saijun Li, Shouqiang Lai, Tingwei Lu, Min Huang, Hao-Chung Kuo, Zhong Chen, Tingzhu Wu
Summary: Double dielectric sidewall passivation can improve the electroluminescence characteristics and communication performance of green mini-LED.
Article
Engineering, Electrical & Electronic
Guan-Ying Lee, Shao-Yi Weng, Wan-Hua Ho, Chun-Wei Huang, Han-Yu Chao, Sheng-Kai Huang, Hao-Chung Kuo, Chung-Chih Wu, Chien-Chung Lin
Summary: We proposed a new method for fabricating arrays of colloidal quantum dots with ALD encapsulation. Semiconductor processes were used to transfer the arrays onto a glass substrate, allowing for small pixel sizes. A dual-color array suitable for microdisplay applications was demonstrated, and the color conversion efficiency reached 20.7%. Distributed Bragg reflector mirrors were used to increase photon recycling, resulting in a 35.7% increase in peak intensity. The use of ALD allowed for long-term storage of the CCL and projected lifetime of 44,041 hours.
IEEE PHOTONICS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Li-Hong Zhu, Wu-Jun Du, Jia-En Huang, Huan-Ting Chen, Yu-Lin Gao, Hong-Lin Gong, Chang-Dong Tong, Ting-Zhu Wu, Wei-Jie Guo, Zi-Quan Guo, Hao-Chung Guo, Zhong Chen, Yi-Jun Lu
Summary: In this article, a 2D junction temperature measurement method, called microscopic hyperspectral imaging (mu-HSI), was proposed for investigating the photo-thermal distribution of flip-chip mini-LEDs. The mu-HSI technique allows for direct acquisition of the 2D spectral distributions of the LED chips and extraction of the FWHM matrix to deduce the 2D junction temperature distributions. This work provides an effective tool for improving the quality and thermal management of mini-LEDs.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Review
Optics
Xiao Yang, Yue Lin, Tingzhu Wu, Zijun Yan, Zhong Chen, Hao-Chung Kuo, Rong Zhang
Summary: Augmented reality (AR) and virtual reality (VR) are two novel display technologies that require high pixel densities for full-color display. Inkjet printing is a promising method for positioning the fluorescent color conversion layers, but some issues still need to be addressed.
OPTO-ELECTRONIC ADVANCES
(2022)
Correction
Nanoscience & Nanotechnology
Yen-Wei Yeh, Su-Hui Lin, Tsung-Chi Hsu, Shouqiang Lai, Po-Tsung Lee, Shui-Yang Lien, Dong-Sing Wuu, Guisen Li, Zhong Chen, Tingzhu Wu, Hao-Chung Kuo
NANOSCALE RESEARCH LETTERS
(2022)
