Article
Engineering, Electrical & Electronic
Qiang Su, Heng Zhang, Shuming Chen
Summary: By utilizing transparent QLED elements, individually addressable red/green/blue emissions can be achieved in tandem QLEDs, with the ability to connect QLED elements in series or in parallel to improve external quantum efficiency.
This new implementation strategy for tandem QLEDs shows promising applications in both display and lighting fields, with enhanced EQE.
NPJ FLEXIBLE ELECTRONICS
(2021)
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
Nanoscience & Nanotechnology
Natsuko Urushihara, Tadahiko Hirai, Akansha Dager, Yuta Nakamura, Yuma Nishi, Ken Inoue, Ryo Suzuki, Makoto Tanimura, Kazuteru Shinozaki, Masaru Tachibana
Summary: Natural product-derived carbon dots have successfully achieved electroluminescence, showing great potential for applications in LEDs.
ACS APPLIED NANO MATERIALS
(2021)
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
Engineering, Electrical & Electronic
Cheuk Ping Germaine Wong, Albert Ting Leung Lee, Kerui Li, Siew-Chong Tan, S. Y. Hui
Summary: This article introduces a new nonlinear empirical model for achieving precise control over an RGB LED system. The proposed model is experimentally validated and the measured results closely match the predicted values from the model.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Bochen Liu, Yue Guo, Qiang Su, Yunfeng Zhan, Zhao Chen, Yang Li, Baogui You, Xiaonan Dong, Shuming Chen, Wai-Yeung Wong
Summary: A new strategy is developed to synthesize red, green, and blue quantum dots using CdZnS as the outermost shell. The inner ZnS and ZnSe shells confine the excitons inside the QD cores, while the CdZnS shell reduces the energy barrier for hole injection, resulting in high-performance QLEDs.
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
Optics
Zhou Wang, Shijie Zhu, Xinyi Shan, Zexing Yuan, Zeyuan Qian, Xinyi Lu, Yi Fu, Kui Tu, Hui Guan, Xugao Cui, Pengfei Tian
Summary: This study demonstrates the characteristics of RGB InGaN micro-LEDs and investigates the effects of temperature and current density on their display performance. The results show that changes in temperature and current density affect electrical characteristics, electroluminescence spectra, and power parameters, presenting challenges for practical applications. However, the RGB display maintains a relatively high and stable color gamut under varying temperature and current density.
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
Chemistry, Multidisciplinary
Peili Gao, Zinan Chen, Shuming Chen
Summary: This study investigates the degradation mechanism of blue quantum-dot light-emitting diodes (B-QLEDs) and reveals the accumulation of electrons in the quantum-dots (QDs) as the main cause of device degradation. The accumulated electrons induce the detachment of ligands and degrade the hole transport layer (HTL), while surface defects and HTL decomposition also contribute to B-QLEDs' stability.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Qibin Shen, Yanlei Hao, Luying Ma, Xiaoyu Wang
Summary: A comparative study on quantum-dot light-emitting diodes (QLEDs) using time-resolved transient electroluminescence (TREL) revealed that insufficient electron injection at the type II heterojunction affected the performance of B-QLEDs. By applying a polymer as the hole-transporting layer, the efficiency of B-QLEDs improved with an increase in turn-on voltage and the appearance of a transient electroluminescence spike after voltage turn-off.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Inorganic & Nuclear
Manh Trung Tran, Do Quang Trung, Nguyen Tri Tuan, Nguyen Trong Tuan, Nguyen Tu, Nguyen Van Du, Nguyen Duy Hung, Nguyen Van Quang, Tong Thi Hao Tam, Nguyen Duc Trung Kien, Nguyen Minh Hieu, Pham Thanh Huy
Summary: Researchers have successfully synthesized a new green-emitting ZnO:Cu2+ phosphor and applied it in NUV-pumped white LEDs. The phosphor demonstrates high emission intensity and quantum efficiency, making it a promising candidate for NUV-pumped WLED applications.
DALTON TRANSACTIONS
(2023)
Article
Optics
Wei Li, Nan Ma, Balaji Devakumar, Xiaoyong Huang
Summary: This study presents a new efficient blue-light-excited Ce3+-doped CaY2HfScAl3O12 green phosphor with broad emission bandwidth and high quantum efficiency. The potential application of this phosphor in fabrication of full-spectrum LED lighting is demonstrated.
JOURNAL OF LUMINESCENCE
(2023)
Article
Chemistry, Multidisciplinary
Mingyuan Xie, Jie Guo, Xiaoyu Zhang, Chenghao Bi, Lin Zhang, Zema Chu, Weitao Zheng, Jingbi You, Jianjun Tian
Summary: This study presents a solution to achieve high-efficiency pure-red perovskite light-emitting diodes (PeLEDs) by stabilizing the structure of quantum dots and reducing adverse effects. The use of composite ligands helped stabilize the strong-confined quantum dots and suppress Auger recombination in the devices. Additionally, adjustments in the valence band of the quantum dots improved charge injection balance in the PeLEDs.
Article
Polymer Science
Zong-Liang Tseng, Shih-Hung Lin, Jian-Fu Tang, Yu-Ching Huang, Hsiang-Chih Cheng, Wei-Lun Huang, Yi-Ting Lee, Lung-Chien Chen
Summary: This study investigates the performance of red CsPbI3-based all-inorganic perovskite quantum-dot light-emitting diodes using different hole transporting layers (HTLs), with VB-FNPD showing the best external quantum efficiency. Improvements in the polymerization of VB-FNPD lead to enhanced device performance.
Article
Nanoscience & Nanotechnology
Hee Chang Yoon, Soyoung Lee, Jae Kyu Song, Heesun Yang, Young Rag Do
ACS APPLIED MATERIALS & INTERFACES
(2018)
Article
Chemistry, Physical
Jung-Ho Jo, Min-Seok Kim, Chang-Yeol Han, Eun-Pyo Jang, Young Rag Do, Heesun Yang
APPLIED SURFACE SCIENCE
(2018)
Article
Engineering, Environmental
Jong-Hoon Kim, Bu-Yong Kim, Eun-Pyo Jang, Suk-Young Yoon, Kyung-Hye Kim, Young Rag Do, Heesun Yang
CHEMICAL ENGINEERING JOURNAL
(2018)
Article
Chemistry, Physical
Seonghyun Jeong, Soyeon Yoon, So Yeon Chun, Hee Chang Yoon, Noh Soo Han, Ji Hye Oh, Seung Min Park, Young Rag Do, Jae Kyu Song
JOURNAL OF PHYSICAL CHEMISTRY C
(2018)
Article
Engineering, Electrical & Electronic
Changwook Kim, Hee Chang Yoon, Dae Hwan Kim, Young Rag Do
IEEE PHOTONICS JOURNAL
(2018)
Article
Multidisciplinary Sciences
Hee Chang Yoon, Kouhara Yoshihiro, Heeyeon Yoo, Seung Woo Lee, Ji Hye Oh, Young Rag Do
SCIENTIFIC REPORTS
(2018)
Article
Materials Science, Multidisciplinary
Hyelim Kang, Sohee Kim, Ji Hye Oh, Hee Chang Yoon, Jung-Ho Jo, Heesun Yang, Young Rag Do
ADVANCED OPTICAL MATERIALS
(2018)
Article
Nanoscience & Nanotechnology
Soyoung Lee, Gang Yeol Yoo, Byungwoo Kim, Min Kyu Kim, Changwook Kim, Sang Yeun Park, Hee Chang Yoon, Woong Kim, Byoung Koun Min, Young Rag Do
ACS APPLIED MATERIALS & INTERFACES
(2019)
Article
Chemistry, Physical
Suk-Young Yoon, Jong-Hoon Kim, Eun-Pyo Jang, Sun-Hyoung Lee, Dae-Yeon Jo, Yuri Kim, Young Rag Do, Heesun Yang
CHEMISTRY OF MATERIALS
(2019)
Article
Optics
Song Eun Lee, Ji Hye Oh, Hyun Jung Baek, Sohee Kim, Young Rag Do, Young Kwan Kim
JOURNAL OF LUMINESCENCE
(2019)
Article
Nanoscience & Nanotechnology
Hee Chang Yoon, Young Rag Do
ACS APPLIED MATERIALS & INTERFACES
(2019)
Article
Chemistry, Physical
Suk-Young Yoon, Jong-Hoon Kim, Kyung-Hye Kim, Chang-Yeol Han, Jung-Ho Jo, Dae-Yeon Jo, Seungki Hong, Jun Yeon Hwang, Young Rag Do, Heesun Yang
Article
Chemistry, Multidisciplinary
Yun Jae Eo, Seohyeon Kim, Keyong Nam Lee, Dae Hwan Kim, Changwook Kim, Seung Min Lee, Young Rag Do
Summary: A simple circadian light meter was fabricated to assess the effects of light on the human circadian rhythm, and was found to show significant differences in light exposure levels between daytime and nighttime, which may impact melatonin levels. The developed light meter is a valuable tool for real world circadian lighting studies that require actual light dose to the eyes of the test subjects.
APPLIED SCIENCES-BASEL
(2021)
Article
Nanoscience & Nanotechnology
Yun Jae Eo, Gang Yeol Yoo, Hyelim Kang, Young Ki Lee, Chan Sik Kim, Ji Hye Oh, Keyong Nam Lee, Woong Kim, Young Rag Do
ACS APPLIED MATERIALS & INTERFACES
(2017)
Article
Materials Science, Multidisciplinary
Hee Chang Yoon, Hyeongjin Lee, Hyelim Kang, Ji Hye Oh, Young Rag Do
JOURNAL OF MATERIALS CHEMISTRY C
(2018)
