Article
Materials Science, Multidisciplinary
Wei-Kai Lee, Bo-Kai Wang, Kai-Chen Lin, Chung-Chih Wu
Summary: This study investigates the influence of bottom transparent electrode thickness on emission properties of OLEDs through simulation and experiments. By using a very thin ITO electrode and horizontal dipole emitters, the overall coupling efficiencies and external quantum efficiency of OLED emission into substrates can be greatly enhanced. The potential of using thin transparent electrodes for highly efficient OLEDs is clearly revealed.
ORGANIC ELECTRONICS
(2021)
Article
Optics
Gai Zhang, Bing Wang, Tong Jia, Chunshuang Chu, Chao Fan, Yonghui Zhang, Xiangpeng Zhang, Naixin Liu, Zi-Hui Zhang, Jiancahng Yan
Summary: In this study, surface-textured Ga-face n-AlGaN is fabricated using self-assembled SiO2 nanosphere as a hard mask, which improves the performance of AlGaN-based deep ultraviolet light-emitting diodes. The optical power, forward voltage, and thermal characteristics are significantly enhanced compared to conventional DUV LEDs.
Article
Engineering, Environmental
Rajendra Kumar Konidena, Junseop Lim, Jun Yeob Lee
Summary: A new molecular design strategy was proposed to transform inefficient TADF emitters into efficient ones by combining them with non-TADF chromophores, achieving excellent device performance in organic light-emitting diodes.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Yanping Wang, Yusen Yang, Dingke Zhang, Tong Zhang, Shiyi Xie, Yu Zhang, Yong-Biao Zhao, Xiaoyun Mi, Xiuling Liu
Summary: This study reports an exciton sensitizing approach to improve the performance of quantum-dot light-emitting diodes (QLEDs) by forming excitons on a phosphorescent-dye-doped layer and transferring their energies to adjacent quantum-dot layer. The fabricated red QLEDs using this method achieve record high efficiency and good stability.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Qun Wan, Weilin Zheng, Chen Zou, Francesco Carulli, Congyang Zhang, Mingming Liu, Qinggang Zhang, Long Kong, Haili Song, Lih Y. Lin, Liang Li, Sergio Brovelli
Summary: Light-emitting diodes (LEDs) based on perovskite nanocrystals (PNCs) have attracted great attention for their high color purity, brightness, and luminous efficiency. However, the development of effective light outcoupling strategies to further enhance device performance is still a challenge.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Emek G. Durmusoglu, Sujuan Hu, Pedro Ludwig Hernandez-Martinez, Merve Izmir, Farzan Shabani, Min Guo, Huayu Gao, Furkan Isik, Savas Delikanli, Vijay Kumar Sharma, Baiquan Liu, Hilmi Volkan Demir
Summary: This article presents the development of CdSe/CdTe/CdSe core/crown/crown (multi-crowned) type-II colloidal quantum wells (CQWs) and investigates their optical properties. The multi-crowned CQWs show a high quantum yield of 83% and a long fluorescence lifetime of 73.3 ns, surpassing traditional core/crown heterostructures. Proof-of-concept NPL-LEDs based on these multi-crowned CQWs achieved a record high external quantum efficiency of 7.83%.
Article
Materials Science, Multidisciplinary
Guanding Mei, Xiangtian Xiao, Sajjad Ahmad, Hong Lin, Yangzhi Tan, Kai Wang, Xiao Wei Sun, Wallace C. H. Choy
Summary: This study demonstrates the importance of microcavity design for improving the light extraction efficiency of Perovskite light-emitting diodes (PeLEDs). The experiment shows that a high-efficiency horizontal dipole in the microcavity is the key to improving the efficiency.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Xiaolong Yang, Shipan Xu, Yan Zhang, Chengyun Zhu, Linsong Cui, Guijiang Zhou, Zhao Chen, Yuanhui Sun
Summary: This study reports two NIR phosphorescent Ir(III) complexes with emission peaks around 730 nm and narrow full width at half maximum of only 43 nm. Pure NIR luminescence can be obtained without a very long emission wavelength, thus overcoming the restriction of the energy gap law and achieving impressively high photoluminescence quantum yield up to 0.70. Moreover, pure NIR organic light-emitting diodes (OLEDs) fabricated by solution-processing method show outstanding device performance with the highest external quantum efficiency of 16.43%, setting a new record for solution-processed NIR-OLEDs based on different emitters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Nanoscience & Nanotechnology
Baodan Zhao, Maria Vasilopoulou, Azhar Fakharuddin, Feng Gao, Abd. Rashid Bin Mohd Yusoff, Richard H. Friend, Dawei Di
Summary: Perovskite light-emitting diodes (LEDs) have shown great potential for display and lighting applications with external quantum efficiencies exceeding 20% for various colors. However, the majority of internally generated photons are trapped in the devices and lose energy through lossy channels, suggesting the need for effective light management strategies. By analyzing the intrinsic optical properties of perovskite materials and the extrinsic properties related to device structures, this Review highlights the possibility of substantially exceeding the conventional limits of planar organic LED devices and suggests new approaches for achieving ultrahigh efficiencies in perovskite LEDs.
NATURE NANOTECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Sejeong Um, Unhyeok Jo, Jun Yeob Lee
Summary: Two novel electron transporting materials (ETMs), DPTrz-ICz and 2DPTrz-ICz, were developed based on the ICz core combined with DPTrz. These ETMs exhibited enhanced intermolecular charge transport properties and high triplet energy, leading to improved efficiency in green phosphorescent organic light-emitting diodes.
SCIENCE CHINA-MATERIALS
(2023)
Article
Optics
Milan Kovacic, Dinara Samigullina, Felix Bouchard, Janez Krc, Benjamin Lipovsek, Marcos Soldera, Andres Fabian Lasagni, Sebastian Reineke, Marko Topic
Summary: Hierarchical textures can enhance the light outcoupling efficiency of OLEDs, and optimization can be achieved by adjusting the aspect ratios of the small and large textures. However, the application of hierarchical textures in laboratory-size samples is constrained by the lateral size of the thin film stack area and the light collection area of the measuring equipment.
Article
Materials Science, Multidisciplinary
Diyar Mousa Othman, Julia A. Weinstein, Quan Lyu, Bo Hou
Summary: Improvement of external quantum efficiency (EQE) is needed for quantum dot light emitting diodes (QLEDs) to achieve more power-efficient devices. One of the main limitations is the low light extraction efficiency (LEE). Previous studies have explored different photonics structures to address this issue. This study presents a photonics design that combines nanopillars and grating structures to significantly enhance the LEE. By changing the height, radius, and material of the nanopillars, it was found that ZnO nanopillars and TiO2 nanopillars have better light extraction efficacy at different wavelengths. Increasing the LEE can greatly reduce energy consumption, which is important considering the significant electricity consumption from lighting applications.
JOURNAL OF PHYSICS-MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Hiroyuki Yamada, Junpei Watanabe, Kazuhiro Nemoto, Hong-Tao Sun, Naoto Shirahata
Summary: Despite bulk crystals of silicon being indirect bandgap semiconductors, the quantum dots derived from silicon exhibit superior photoluminescence properties. The use of SiQDs as an emissive layer in current-driven LEDs allows for strong electroluminescence. The external quantum efficiency of Si-QLEDs was enhanced through postproduction effect.
Article
Materials Science, Multidisciplinary
Emmanuel O. Afolayan, Ibrahim Dursun, Adrian Pizano, Chao Lang, Dominique Lungwitz, Marina Kondakova, Michael Boroson, Antoine Kahn, Michael Hickner, Noel C. Giebink
Summary: This study demonstrates that the light extraction efficiency of organic light-emitting diodes (OLEDs) can be improved by diluting their hole transport layer (HTL) with a low refractive index material called trifluoropropyl oligomeric silsesquioxane (F-POSS). The addition of F-POSS increases the outcoupling efficiency of the OLEDs by approximately 12% without affecting their electrical performance or operational lifetime. This finding is significant because F-POSS is a small molecule that can be easily integrated into existing OLED manufacturing processes.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Anjali K. Sajeev, Nishkarsh Agarwal, Anjaly Soman, Shilpi Gupta, Monica Katiyar, A. Ajayaghosh, K. N. Narayanan Unni
Summary: The study demonstrates the use of an external light extraction layer made of polydimethylsiloxane and zinc oxide nanoparticles to enhance the efficiency of OLEDs. The layer significantly improves light outcoupling, with white OLEDs showing the highest enhancement of 80%. Green OLEDs also exhibit substantial improvement, followed by red and blue OLEDs.
ORGANIC ELECTRONICS
(2022)
Article
Materials Science, Multidisciplinary
Jinfei Dai, Chenjing Zhao, Jie Xu, Hossein Roshan, Hua Dong, Francesco Di Stasio, Fang Yuan, Bo Jiao, Zhaoxin Wu
Summary: In this study, the performance of perovskite nanocrystal light emitting diodes (PNC-LEDs) was enhanced through rational device structure design and the application of high-performance perovskite nanocrystal emitting layers.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Jia-Hua Yeh, Suhendro Purbo Prakoso, Leon Lukhas Santoso, Shi-Ju Chen, Bryan Chiang, Ju-Chieh Cheng, Ru-Ning Zhang, Yu-Cheng Chiu
Summary: This study demonstrates the application of a renewable material called dextrin-SMS in the production of electret filters and transistor memory. Dextrin-SMS material can maintain prolonged electrostatic charges and has a relatively wide memory window, making it suitable for the production of biodegradable face masks and green electronics.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Ahmad Telfah, Qais M. Al-Bataineh, Ahmad A. Ahmad, Rund Abu-Zurayk, Carlos J. Tavares, Johannes Etzkorn, Farzad Foadian
Summary: Polyacrylic acid complexed with polyaniline (PAA/PANI) composite materials have the potential to form organic mixed ion-electron conductive (OMIEC) films, which can be used in optoelectronic and energy storage applications. The composite films are formed through an acid-base reaction, resulting in strong electrostatic interactions and intermolecular hydrogen bonds between PANI and PAA. The separation of PANI-rich domains from PAA-rich matrix in the composite films is observed. The electrical conductivity of the composite films is higher when the content of PANI is 33 wt%, due to the high ionic-electronic coupling at the interface between phase-separated regions.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Min-Chih Hou, Dian Luo, Yu-Ting Huang, Shun-Wei Liu, Chin-Wei Lu, Chih-Hao Chang, Hai-Ching Su
Summary: Light-emitting electrochemical cells (LECs) have great potential for novel emission applications, but their relatively low device efficiency hinders their competitiveness with other emission technologies. A study finds that increasing the concentration of small TiO2 nano-particles in the diffuser film can enhance light extraction and improve the device efficiency of LECs.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Qiaoli Niu, Yao Xu, Jun Yang, Wei Hua, Baoxiang Chai, Zequan Zhang, Yuhui Ma, Wenjin Zeng, Ana Flavia Nogueira, Ruidong Xia
Summary: By introducing CPB as a defect passivation agent in the perovskite precursor solution, the optoelectronic properties of perovskite films can be significantly improved and non-radiative carrier recombination can be effectively suppressed. CPB-modified perovskite solar cells exhibit lower trap-state density and stronger carrier migration capability, leading to enhanced power conversion efficiency and stability.
ORGANIC ELECTRONICS
(2024)
Article
Materials Science, Multidisciplinary
Hulya Ozturk Dogan, Fatma Yildirim, Zeynep Orhan, Ali Ben Ahmed, Mostefa Benhaliliba, Sakir Aydogan
Summary: In this study, efficient self-powered visible and UV photodetectors based on hybrid organic-inorganic materials were demonstrated. The photodetectors showed excellent UV detecting capability and good photoresponsivity.
ORGANIC ELECTRONICS
(2024)
