Article
Optics
Katarzyna Pieniak, Witold Trzeciakowski, Grzegorz Muziol, Anna Kafar, Marcin Siekacz, Czeslaw Skierbiszewski, Tadeusz Suski
Summary: The study examined electroluminescence from In0.17Ga0.83N/GaN quantum wells of LEDs and LDs, finding a transition from ground-states recombination to excited states recombination with increasing QW width. The effect is accompanied by partial or complete screening of the built-in electric field with increasing driving current, which was studied using a high pressure method. Investigations were supported by simulations of the variation with driving current of electron and hole wavefunctions overlap affecting the recombination channel and built-in electric field.
Article
Physics, Applied
Zhen Huang, Renchun Tao, Duo Li, Zexing Yuan, Tai Li, Zhaoying Chen, Ye Yuan, Junjie Kang, Zhiwen Liang, Qi Wang, Pengfei Tian, Bo Shen, Xinqiang Wang
Summary: In this work, a method is proposed to improve the modulation bandwidth of green mu-LEDs by enhancing p-type conductivity. The polarization-induced p-type doping with graded AlGaN significantly enhances the conductivity of the p-type layer, leading to improved light output power and modulation bandwidth.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Abu Bashar Mohammad Hamidul Islam, Tae Kyoung Kim, Dong-Soo Shin, Jong-In Shim, Joon Seop Kwak
Summary: This study investigates the effect of current stress on InGaN/GaN multiple-quantum-well flip-chip blue micro light-emitting diodes (mu-LEDs) and reveals the mechanisms of defect aggregation and generation that cause changes in the optoelectronic performance of the devices. The aging test shows that the improvement in crystal quality due to defect aggregation initially enhances the light output power and external quantum efficiency (EQE), but the generation of sidewall point defects eventually leads to performance degradation. The findings highlight the importance of both defect aggregation and generation in understanding the degradation mechanisms of mu-LEDs.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
A. Pandey, Y. Malhotra, P. Wang, K. Sun, X. Liu, Z. Mi
Summary: This paper demonstrates the performance of N-polar InGaN/GaN nanowire sub-microscale red light emitting diodes (LEDs) for the first time. These LEDs exhibit higher efficiency and brightness compared to conventional red-emitting micro-LEDs. In-situ annealing significantly enhances the optical emission intensity, and the fabricated LED sizes are extremely small.
PHOTONICS RESEARCH
(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)
Review
Materials Science, Multidisciplinary
Muhammad Usman, Munaza Munsif, Urooj Mushtaq, Abdur-Rehman Anwar, Nazeer Muhammad
Summary: Efficiency issues in green light-emitting diodes are a major concern in the solid-state lighting industry. Researchers are exploring methods to address this issue by reducing inherent problems such as defect density and internal electric fields in order to improve the performance of green light-emitting diodes.
CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES
(2021)
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)
Article
Physics, Applied
Sheikh Ifatur Rahman, Zane Jamal-Eddine, Zhanbo Xia, Mohammad Awwad, Robert Armitage, Siddharth Rajan
Summary: This study provides an accurate prediction of the characteristics of GaN/InGaN light emitting diodes by incorporating low and high indium compositions within quantum wells at the submicrometer scale. Previous explanations for the transport mechanisms across InGaN/GaN heterostructures in these devices have been lacking.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Mei Cui, Chenyu Guo, Zhenhai Yang, Li Chen, Yijun Dai, Houqiang Xu, Wei Guo, Jichun Ye
Summary: This paper investigates the application of conductive dielectric distributed Bragg reflectors (DBRs) in GaN-based light emitters. A conductive DBR was fabricated using the electrical breakdown technique. The optical simulations and electrical tests demonstrated its excellent performance. The conductive mechanisms were elaborated by comparing different metal electrodes. Ultimately, a conductive DBR with high reflectivity was successfully prepared.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Optics
Jinpeng Huang, Zelin Hu, Xiang Gao, Yi Xu, Liancheng Wang
Summary: This study proposes a single-chip micro-LED display technology with unidirectional emission through the integration of a resonant cavity and metasurface, which can achieve efficient naked-eye 3D display with a wide viewing angle and multiple viewpoints. The research promotes the application of GaN-based micro-LEDs in displays, especially in 3D displays.
Article
Optics
Zhen Huang, Renchun Tao, Duo Li, Zhiwei Rao, Zexing Yuan, Tai Li, Zhaoying Chen, Ye Yuan, Junjie Kang, Zhiwen Liang, Qi Wang, Pengfei Tian, Bo Shen, Xinqiang Wang
Summary: A GaN-based blue micro-LED array with InGaN barriers has been fabricated, showing a two-fold increase in light output power compared to a conventional device. Additionally, an improved data transmission rate of up to 1.50 Gbps has been achieved in a visible light communication prototype.
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
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
Nanoscience & Nanotechnology
Yanqing Jia, Jing Ning, Jincheng Zhang, Boyu Wang, Chaochao Yan, Yu Zeng, Haidi Wu, Yachao Zhang, Xue Shen, Chi Zhang, Haibin Guo, Dong Wang, Yue Hao
Summary: The use of O-2 plasma-assisted patterned graphene can change the wettability of sapphire surface and lead to precise control of the growth of large-area and transferable nitride films. Experimental results demonstrate that LEDs prepared using this method exhibit high stability and high light output power.
ACS APPLIED MATERIALS & INTERFACES
(2021)
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)