Article
Materials Science, Multidisciplinary
Markus Pristovsek
Summary: This article presents a method for directly obtaining the maximum internal quantum efficiency (IQE) of light-emitting diodes (LEDs) from experimental data without the need for fitting. This method also allows for the observation of changes in the A, B, or C parameters over the current range.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Asim Onal, Sadra Sadeghi, Rustamzhon Melikov, Onuralp Karatum, Guncem Ozgun Eren, Sedat Nizamoglu
Summary: This study demonstrates efficient white LEDs by utilizing the dot to dot-in-rod transition of CdSe/CdS and near-unity PLQY ZnCdSe/ZnSe quantum dots (QDs). The combination significantly reduces absorption losses and improves the external quantum efficiency of white LEDs.
Article
Chemistry, Multidisciplinary
Kunsik An, Chaewon Kim, Sunkuk Kim, Taesoo Lee, Dongyeol Shin, Jaemin Lim, Donghyo Hahm, Wan Ki Bae, Jun Young Kim, Jeonghun Kwak, Jaehoon Kim, Kyung-Tae Kang
Summary: This paper presents a novel light extraction structure called RaDiNa, which enhances the light extraction capability of top-emitting quantum dot light-emitting diodes (TE-QLEDs). By detaching a polydimethylsiloxane (PDMS) film from a ZnO nanorod (ZnO NR) layer and laying it on top of the TE-QLED, the RaDiNa-attached TE-QLED achieves significantly improved external quantum efficiency (EQE) compared to the reference device. This study provides essential information for the commercialization of TE-QLEDs.
Review
Chemistry, Multidisciplinary
Bas Van der Zee, Yungui Li, Gert-Jan A. H. Wetzelaer, Paul W. M. Blom
Summary: The various contributions to the external quantum efficiency (EQE) of polymer light-emitting diodes (PLEDs) are discussed. It is found that the inclusion of triplet-triplet annihilation (TTA) contributes significantly to the enhancement of EQE in PLEDs.
ADVANCED MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Asim Onal, Guncem Ozgun Eren, Sadra Sadeghi, Rustamzhon Melikov, Mertcan Han, Onuralp Karatum, Melek Sermin Ozer, Houman Bahmani Jalali, Itir Bakis Dogru-Yuksel, Iskender Yilgor, Onder Metin, Sedat Nizamoglu
Summary: In the next decade, a majority of conventional light sources will be replaced by LEDs. Quantum dots are considered to have high potential for future LED technology because of their sensitive band-gap tuning, high PLQY, and mass-production capacity. This study successfully demonstrated high-performance white LEDs using quantum dots, showing their promise for next-generation lighting devices.
Article
Chemistry, Multidisciplinary
Lyuye Lin, Remo Proietti Zaccaria, Denis Garoli, Roman Krahne
Summary: Layered architectures for LEDs should consider factors such as photon outcoupling efficiency and the Purcell effect. By adjusting the refractive index and thickness of layers, combined with optimizing dipole orientation and layer thickness, the efficiency of LEDs can be significantly improved.
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
Nanoscience & Nanotechnology
Songman Ju, Chaomin Mao, Jinping Zheng, Kaiyu Yang, Lihua Lin, Tailiang Guo, Hailong Hu, Fushan Li
Summary: This work proposes a new strategy to enhance the electroluminescent performance of perovskite quantum dots (PQDs) by creating a PQD film. By manipulating the ion distribution and trap density in the PQD film through varying pre-bias voltage and time, the device's capacitance value and luminous efficiency can be modified. The external quantum efficiency of the device increased from 2.81% to 7.95% through this strategy. This research provides a new approach for achieving perovskite quantum dot light-emitting devices with high luminous efficiency.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yarong He, Jiaxu Yan, Lei Xu, Bangmin Zhang, Qian Cheng, Yu Cao, Ju Zhang, Cong Tao, Yingqiang Wei, Kaichuan Wen, Zhiyuan Kuang, Gan Moog Chow, Zexiang Shen, Qiming Peng, Wei Huang, Jianpu Wang
Summary: Room-temperature-high-efficiency light-emitting diodes based on metal halide perovskite FAPbI(3) exhibit excellent performance at low temperatures, with increased quantum efficiency and stability. The enhanced EQE at low temperatures is attributed to the increased photoluminescence quantum efficiencies of the perovskite, leading to an increased radiative recombination rate.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Gencai Pan, Xue Bai, Xinyu Shen, Lei Wang, Yanli Mao, Xu Chen, Wen Xu, He Shao, Donglei Zhou, Biao Dong, Lin Xu, Junhua Hu, Hongwei Song
Summary: A direct synthetic method for CsPbI3 nanorods was developed using YCl3 promotion, resulting in high-efficiency red emitting CsPbI3 NCs with small aspect ratio and improved performance. The YCl3-promoted CsPbI3 NRs showed promising prospects in optoelectronic devices, exhibiting excellent luminescence and conductivity in LED applications.
Review
Crystallography
Panpan Li, Hongjian Li, Matthew S. Wong, Philip Chan, Yunxuan Yang, Haojun Zhang, Mike Iza, James S. Speck, Shuji Nakamura, Steven P. Denbaars
Summary: InGaN-based red micro-size light-emitting diodes (μLEDs) are highly attractive due to their less influenced external quantum efficiency (EQE) by size effect compared to common AlInGaP-based red μLEDs. Additionally, InGaN red μLEDs exhibit robust device performance even at high temperatures up to 400K. This review discusses the progress of InGaN red μLEDs and explores novel growth methods to relax the strain and increase the growth temperature of InGaN red quantum wells.
Article
Chemistry, Multidisciplinary
Oskar Sachnik, Yungui Li, Xiao Tan, Jasper J. Michels, Paul W. M. Blom, Gert-Jan A. H. Wetzelaer
Summary: Efficient single-layer organic light-emitting diodes (OLEDs) have been demonstrated, utilizing a thermally activated delayed fluorescence emitting layer sandwiched between a polymeric conducting anode and a metal cathode. The single-layer OLED exhibits an external quantum efficiency of 27.7% with minimal roll-off at high brightness. The results show that highly simplified single-layer OLEDs without confinement layers can achieve state-of-the-art performance, while greatly reducing the complexity of the design, fabrication, and device analysis.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yunke Zhu, Yunzhou Deng, Peng Bai, Xinan Wu, Yige Yao, Qinyun Liu, Jingjing Qiu, An Hu, Zhenyu Tang, Wenjin Yu, Yaolong Li, Pengzuo Jiang, Zhetong Liu, Peng Gao, Yanlei Hao, Wangxiao Jin, Desui Chen, Xitong Zhu, Yizheng Jin, Yunan Gao
Summary: This study demonstrates efficient, bright, and long lifetime red Nc-LEDs based on anisotropic nanocrystals. By modifying the substrate's surface properties and controlling the interactions among nanocrystals, a self-assembled layer with a high distribution of in-plane transitions dipole moment of 95% is successfully achieved, resulting in an out-coupling factor of 37%.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Qun Wan, Lu Huang, Long Kong, Qinggang Zhang, Congyang Zhang, Mingming Liu, Xinrong Liao, Wenji Zhan, Weilin Zheng, Changwei Yuan, Mengda He, Liang Li
Summary: In the field of translucent displays, using an alkali metal/inert metal bilayer metal electrode and perovskite nanocrystals as an emitter layer allows for the fabrication of high-efficiency, high-color-purity, and high-brightness semitransparent LEDs, with great potential for applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Haotao Li, Fengshou Tian, Shuming Chen
Summary: By synergistically optimizing the optical and electrical performances, the efficiency of quantum-dot light-emitting diodes (QLEDs) can approach the theoretical limit. With the introduction of a high refractive index indium zinc oxide (IZO) electrode and the optimization of its thickness, the light outcoupling efficiency is significantly improved, resulting in an external quantum efficiency (EQE) of 33.2% for red QLEDs. By using a high refractive index plastic substrate and a microlens array, the EQE can be further improved to a record value of 37.5%.