Article
Chemistry, Physical
Do-Yeong Shin, Taehwan Kim, Ozgun Akyuz, Hilmi Volkan Demir, In-Hwan Lee
Summary: This study presents an improved efficiency design for white LEDs by integrating blue nanorod LEDs with green and red-emitting perovskite nanocrystal films. The design utilizes the localized surface plasmon effect of Ag@SiO2 nanoparticles to enhance the photoluminescence intensity of blue LEDs, while the high-power blue LED backlight improves the perovskite photoluminescence intensity. The resulting white LED with Ag@SiO2 nanoparticle-embedded nanorods demonstrates a 62% increase in photoluminescence intensity compared to planar white LEDs.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Applied
Ah Hyun Park, Seungjae Baek, Go Bong Choi, Yoong Ahm Kim, Jinsub Lim, Tae Hoon Seo
Summary: In this study, green light emitting diodes (LEDs) with Au nanoclusters in a micro-hole patterned p-GaN layer (ANCs-MHPP) were demonstrated to have higher internal quantum efficiencies and faster decay times compared to conventional green LEDs. The remarkable opto-electronic performance of green LEDs with ANCs-MHPP is attributed to exciton-surface plasmon coupling and surface texturing effect caused by the micro-hole patterned p-GaN layer.
APPLIED PHYSICS LETTERS
(2021)
Article
Optics
Zhe Zhuang, Daisuke Iida, Martin Velazquez-Rizo, Kazuhiro Ohkawa
Summary: The study introduced a method for fabricating ultra-small InGaN μLEDs, successfully realizing different shapes of green μLEDs. It was found that as the size of the μLED decreases, the series resistance and turn-on voltage increase, while the light output power density and external quantum efficiency also improve.
Article
Engineering, Environmental
Ying Ye, Wenchao Zhang, Yudong Zhang, Kai Li, Jianjun Han, Chao Liu
Summary: Inorganic cesium lead halide perovskite nanocrystals show great potential for electrically or optically pumped light emitting diodes. This study demonstrates highly efficient light-emitting diodes by using CsPbBr3 nanocrystals embedded glasses as a color converter. Increasing the molar ratio of bromine to lead in glasses enhances the photoluminescence quantum efficiency and photostability of the embedded nanocrystals.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Physics, Applied
Sibghatullah Khan, Muhammad Usman, Shazma Ali, Saad Rasheed, Sana Saeed
Summary: The radiative recombination rate in yellow light-emitting diodes (LEDs) can be greatly enhanced by converting the last quantum barrier and introducing a graded electron blocking layer, leading to increased carrier concentration and reduced electron-hole asymmetry.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2022)
Article
Engineering, Electrical & Electronic
Jie Song, Jin-ho Kang, Jung Han
Summary: In this study, colloidal quantum dots embedded in nanoporous gallium nitride were used as a color converter to achieve different emission colors and fabricate micro-LEDs. The optical property of NP-GaN was examined by studying light transmittance, which showed a strong light scattering effect leading to increased optical transmission path and enhanced light absorption by the QDs. A 4-inch color converter was successfully achieved with minimal wavelength deviation across the entire wafer, and monolithic red, green, and blue micro-LEDs were fabricated with a pixel size of approximately 35 x 35 μm².
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Physical
Po-Hsun Lei, Po-Chun Yang, Po-Chun Huang
Summary: The photonic-crystal-structured p-GaN nanorods were fabricated using a modified polystyrene nanosphere lithography method to enhance the light extraction efficiency of InGaN/GaN green LEDs. The optimal period, diameter, and height of the PC-structured p-GaN nanorods were found to be 150, 350, and 110 nm, resulting in a 41% enhancement of emission intensity in comparison to conventional LEDs under a driving current of 20 mA. The light output intensity and LEE of the LEDs with PC-structured p-GaN nanorods depend on the dimensions of the nanorods.
Article
Materials Science, Multidisciplinary
Zhanxu Chen, Jialing Zhang, Runhong Ding, Feng Wu, An Wang, Guanghui Liu, Wei Wan
Summary: The study investigates the patterning of p-GaN and/or indium-tin-oxide (ITO) surfaces to improve light extraction efficiency for GaN-based LEDs. The results show that nanopillar-patterned p-GaN, ITO, and dual nanopillar-patterned p-GaN and ITO layers significantly enhance light output. The study also explores the mechanism of light extraction enhancement using 3D finite-difference time-domain method, and finds that LEDs with dual nanopillar-patterned p-GaN and ITO layers offer the best light extraction efficiency.
Article
Physics, Applied
Son Phuong Le, Chih-Wei Hsu, Ivan Martinovic, Per-Olof Holtz
Summary: GaN-based pyramidal quantum structures with InGaN nanostructures on top were fabricated with high uniformity and precise interfaces, serving as building blocks for micro-emitters. Interconnected microLEDs on these structures exhibited well-defined electroluminescence in the near-ultraviolet regime with negligible spectral shifts at high currents, showcasing their potential for microLED applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Tae Kyoung Kim, Abu Bashar Mohammad Hamidul Islam, Yu-Jung Cha, Seung Hyun Oh, Joon Seop Kwak
Summary: This work proposes an InGaN/GaN multiple-quantum-well flip-chip blue ultrathin side-emitting LED and improves the light extraction efficiency for increased light output power, making it suitable for backlight units.
Article
Physics, Condensed Matter
Muhammad Usman, Sibghatullah Khan, Sana Saeed, Shazma Ali
Summary: Efficient yellow InGaN light-emitting diodes (LEDs) have been achieved by using quaternary (AlInGaN) and ternary (AlGaN) quantum barriers, resulting in a 47% increase in radiative recombination rate compared to conventional yellow LEDs. Moreover, the proposed LEDs also exhibit significantly reduced efficiency droop.
PHYSICA B-CONDENSED MATTER
(2023)
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
Optics
Jie Zhao, Weijiang Li, Lulu Wang, Xuecheng Wei, Junxi Wang, Tongbo Wei
Summary: In this study, InGaN/GaN nanorod light emitting diodes (LEDs) were fabricated on (-201) beta-Ga2O3 substrate using SiO2 nanosphere lithography and dry-etching techniques. Compared to planar LEDs, nanorod LEDs grown on beta-Ga2O3 demonstrate effective suppression of quantum confined Stark effect (QCSE) and approximately seven times higher light extraction efficiency (LEE). The results suggest that InGaN/GaN/beta-Ga2O3 nanorod LEDs show improved optical performance and may pave the way for future development of GaN-based vertical light emitting diodes (VLEDs) on beta-Ga2O3 substrate.
Review
Optics
Runnan Yu, Changxiao Li, Biao Zhao, Zhan'ao Tan
Summary: This work reviews the research history of green perovskite light-emitting diodes (GPeLEDs), introduces perovskites of different dimensions, and discusses the common synthesis methods of perovskites. Additionally, strategies to improve the stability and luminous efficiency of GPeLEDs are summarized, including component engineering, phase engineering, ligand engineering, additive engineering, interface engineering, and optical coupling structure strategy. Finally, the development state of GPeLEDs is summarized and future prospects are discussed.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Meng Tian, Huabin Yu, Muhammad Hunain Memon, Zhanyong Xing, Chen Huang, Hongfeng Jia, Haochen Zhang, Danhao Wang, Shi Fang, Haiding Sun
Summary: Micro-LEDs with smaller inclined chip sidewall angles exhibit improved external quantum efficiency due to stronger reflection of the inclined sidewall, leading to enhanced light extraction efficiency. The EQE improvement by adopting an inclined sidewall is more significant as the diameter of the LED chip reduces. Numerical optical modeling further verifies the impact of sidewall angles on the light extraction efficiency of micro-LEDs.
Review
Engineering, Electrical & Electronic
Seung Kyu Oh, James Spencer Lundh, Shahab Shervin, Bikramjit Chatterjee, Dong Kyu Lee, Sukwon Choi, Joon Seop Kwak, Jae-Hyun Ryou
JOURNAL OF ELECTRONIC PACKAGING
(2019)
Article
Materials Science, Ceramics
Seung Min Lee, Jung Hwan Yum, Eric S. Larsen, Shahab Shervin, Weijie Wang, Jae-Hyun Ryou, Christopher W. Bielawski, Woo Chul Lee, Seong Keun Kim, Jungwoo Oh
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2019)
Article
Engineering, Electrical & Electronic
Zhongjie Ren, Yi Lu, Hsin-Hung Yao, Haiding Sun, Che-Hao Liao, Jiangnan Dai, Changqing Chen, Jae-Hyun Ryou, Jianchang Yan, Junxi Wang, Jinmin Li, Xiaohang Li
IEEE PHOTONICS JOURNAL
(2019)
Article
Chemistry, Multidisciplinary
Jie Chen, Haoran Liu, Weijie Wang, Noor Nabulsi, Wenbo Zhao, Ja Yeon Kim, Min-Ki Kwon, Jae-Hyun Ryou
ADVANCED FUNCTIONAL MATERIALS
(2019)
Article
Chemistry, Multidisciplinary
Yongkuan Li, Sicong Sun, Ying Gao, Yao Yao, Eduard Galstyan, Pratap Rudra, Monika Rathi, Pavel Dutta, Sara Pouladi, Jae Hyun Ryou, Venkat Selvamanickam
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2019)
Article
Physics, Applied
Weijie Wang, Seung Min Lee, Sara Pouladi, Jie Chen, Shahab Shervin, Seonno Yoon, Jung Hwan Yum, Eric S. Larsen, Christopher W. Bielawski, Bikramjit Chatterjee, Sukwon Choi, Jungwoo Oh, Jae-Hyun Ryou
APPLIED PHYSICS LETTERS
(2019)
Article
Chemistry, Multidisciplinary
Ja-Yeon Kim, Yoo-Hyun Cho, Hyun-Sun Park, Jae-Hyun Ryou, Min-Ki Kwon
APPLIED SCIENCES-BASEL
(2019)
Article
Energy & Fuels
Jie Chen, Noor Nabulsi, Weijie Wang, Ja Yeon Kim, Min-Ki Kwon, Jae-Hyun Ryou
Article
Chemistry, Multidisciplinary
Won Hee Kim, Young Jae Jang, Ja-Yeon Kim, Myungsoo Han, MinJae Kang, Kiyong Yang, Jae-Hyun Ryou, Min-Ki Kwon
APPLIED SCIENCES-BASEL
(2020)
Article
Chemistry, Multidisciplinary
Nam-In Kim, Jie Chen, Weijie Wang, Mina Moradnia, Sara Pouladi, Min-Ki Kwon, Ja-Yeon Kim, Xiaohang Li, Jae-Hyun Ryou
Summary: This study developed a highly sensitive, noninvasive skin-attachable eye movement sensor that can accurately detect subtle eye movements, detect abnormal eye movements, and provide a continuous eye movement monitoring solution.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Physics, Applied
Wen Gu, Yi Lu, Rongyu Lin, Wenzhe Guo, Zihui Zhang, Jae-Hyun Ryou, Jianchang Yan, Junxi Wang, Jinmin Li, Xiaohang Li
Summary: The study shows that the undoped BAlN EBL can replace the conventional AlGaN EBL in LEDs, effectively addressing p-doping issues and demonstrating superior performance in electron blocking and hole injection.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Mina Moradnia, Sara Pouladi, Jie Chen, Nam-In Kim, Onosetale Aigbe, Jae-Hyun Ryou
Summary: HybCVD technique using chloride and hydride precursors is introduced to obtain ScAlN thin films, addressing the challenges in film quality and manufacturability. Numerical analysis of precursor thermodynamics and vapor-solid reactions evaluate the precursors' suitability and alloy composition control.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Chemistry, Multidisciplinary
Nam-In Kim, Miad Yarali, Mina Moradnia, Muhammad Aqib, Che-Hao Liao, Feras AlQatari, Mingtao Nong, Xiaohang Li, Jae-Hyun Ryou
Summary: To address the challenges posed by extreme environments in energy, transportation, aerospace, and defense applications, a piezoelectric sensor based on single-crystalline AlN transducers is developed. The sensor shows high sensitivities and output voltages up to 900 degrees C. Comparison with other materials highlights the importance of single crystallinity in piezoelectric devices for high-temperature operation. The use of AlN demonstrates its potential as a new solution for sensing in extreme environments.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Mina Moradnia, Sara Pouladi, Muhammad Aqib, Jae-Hyun Ryou
Summary: This study investigates the growth conditions of Group-IIIb-transition-metal-alloyed wurtzite Group-IIIa-nitride (IIIb-IIIa-N) thin films. The theoretical thermodynamic analysis reveals the relationship between the relative amount of input precursors and the solid composition in different growth conditions. The findings provide guidance for improving the piezoelectric properties of lead-free piezoelectric materials.
Editorial Material
Engineering, Electrical & Electronic
Jae-Hyun Ryou, Sukwon Choi
Summary: High-electron-mobility transistors with diamond coating effectively dissipate heat in high-power electronics applications.
NATURE ELECTRONICS
(2022)
