Article
Engineering, Electrical & Electronic
Jonathan J. D. McKendry, Enyuan Xie, Jordan Hill, Hichem Zimi, Johannes Herrnsdorf, Erdan Gu, Robert K. Henderson, Martin D. Dawson
Summary: This article reports a deep ultraviolet AlGaN micro-LED array driven by electronic drivers implemented in CMOS technology. The integrated device allows independent control of each micro-LED and has potential applications in various fields.
IEEE PHOTONICS JOURNAL
(2023)
Article
Optics
Longheng Qi, Peian Li, Xu Zhang, Ka Ming Wong, Kei May Lau
Summary: A prototype of full-color micro-LED micro-display with a pixel density of 391 ppi is demonstrated using InGaN/AlGaInP heterogeneous integration. This display shows the feasibility and prospects of high brightness, good color performance, and high-resolution micro-LED micro-displays in future metaverse applications.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Review
Engineering, Electrical & Electronic
Keith Behrman, Ioannis Kymissis
Summary: Micro light-emitting diodes (microLEDs) are an emerging display technology with advantages in brightness, color, pixel size, and lifetime. They can be used to create novel display applications and have the potential to become the next prominent display technology in consumer electronics.
NATURE ELECTRONICS
(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
Longheng Qi, Xu Zhang, Wing Cheung Chong, Peian Li, Kei May Lau
Summary: This paper describes the fabrication processes of a high-brightness micro-LED display using GaN-on-Si epi-wafers, showcasing high resolution and excellent performance. The Si growth substrate was removed using wet etching, and optical crosstalk was mitigated through design and process modifications.
Article
Nanoscience & Nanotechnology
Ziquan Guo, Zhihui Li, Shouqiang Lai, Xiaoyang Hou, Xiaotong Fan, Chenming Zhong, Yue Lin, Guolong Chen, Guoheng Qin, Tao Gao, Nuoyi Fu, Yuan Shi, Xinqin Liao, Yi Lin, Yijun Lu, Weijie Guo, Zhong Chen
Summary: The temperature-dependent external quantum efficiency (EQE) droop of AlGaN-based UVC-LEDs with different Al contents at wavelengths of 265 nm, 275 nm, 280 nm, and 285 nm was comprehensively investigated. The recombination mechanisms in these UVC-LED samples were analyzed using the modified ABC model, revealing that the contribution of Shockley-Read-Hall recombination exceeds those of Auger recombination and carrier leakage at low electrical-current levels. At high electrical-current levels, Auger recombination and carrier leakage jointly dominate the EQE droop phenomenon. Experimental investigation of the inactivation efficiencies of various UVC light sources against Escherichia coli provides a technical reference for combating COVID-19.
Article
Optics
Xiaoyan Liu, Zexing Yuan, Gufan Zhou, Pan Yin, Xinyi Shan, Langyi Tao, Jinghao Yu, Xugao Cui, Pengfei Tian
Summary: This paper proposes and fabricates a micro-current spreading layer (mCSL)-confined micro-LED, and demonstrates its effect on the efficiency of LED. The study shows that the mCSL can enhance the efficiency of the micro-LED at high current densities. Furthermore, the efficiency decreases at low current densities but increases at high current densities as the size of the mCSL decreases.
APPLIED PHYSICS B-LASERS AND OPTICS
(2022)
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.
Article
Chemistry, Multidisciplinary
Chungen Hsu, Shun Tian, Yaxiao Lian, Guoling Zhang, Qian Zhou, Xuhui Cao, Baodan Zhao, Dawei Di
Summary: The study demonstrates an efficient single-pixel PeLED technology with high external quantum efficiency. By using a nanometer-thin lithium fluoride interlayer and preparing uniform and highly luminescent perovskite layers, successful manufacturing and integration of microPeLEDs are achieved.
CELL REPORTS PHYSICAL SCIENCE
(2021)
Article
Optics
Jinlong Piao, Junhua Wu, Ziqi Ye, Hao Zhang, Jinjia Li, Pengzhan Liu, Hao Wang, Ziping Cao, Yongjin Wang
Summary: In this study, a monolithic integration of a metal oxide semiconductor field effect phototransistor and a light-emitting diode on a GaN-on-Si LED epitaxial wafer was achieved. The integrated device showed promising performance as a UV detector and had potential applications in visible light communication.
Review
Materials Science, Multidisciplinary
Zhaojun Liu, Byung-Ryool Hyun, Yujia Sheng, Chun-Jung Lin, Mengyuan Changhu, Yonghong Lin, Chih-Hsiang Ho, Jr-Hau He, Hao-Chung Kuo
Summary: Micro-light-emitting diodes (Micro-LEDs) based on gallium nitride (GaN) materials offer versatile platforms for various applications, including displays, data communication tools, photodetectors, and sensors. By combining with quantum dots, Micro-LEDs can achieve efficient full-color displays and high-speed visible light communications.
ADVANCED MATERIALS TECHNOLOGIES
(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
Multidisciplinary Sciences
Po-Wei Chen, Po-Wen Hsiao, Hsuan-Jen Chen, Bo-Sheng Lee, Kai-Ping Chang, Chao-Chun Yen, Ray-Hua Horng, Dong-Sing Wuu
Summary: The mechanism of carrier recombination in downsized mu-LED chips was investigated, showing that the smallest chip size exhibited the highest ideality factor due to carrier recombination in high-defect-density zones. The use of a passivation layer and a maskless technology improved the performance and efficiency of the mu-LED chips. The blue-shift phenomenon in the electroluminescence spectrum was attributed to carrier screening and band filling effects, with high EQE values observed in the high current density region for the 10 x 10 μm(2) mu-LED chip.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Applied
S. Mukhangali, V. Neplokh, F. Kochetkov, A. Vorobyev, D. Mitin, M. Mukhin, D. K. Krasnikov, J. Tian, R. Islamova, A. G. Nasibulin, I. Mukhin
Summary: This paper presents an elastic pixel matrix based on patterned films of single-walled carbon nanotubes, which maintain their initial resistivity even under 10% stretching. The authors also demonstrate the application of this elastic pixel matrix in an array of III-V semiconductor nanowires, providing potential for highly deformable inorganic light-emitting or photodetector devices.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Yu-Hsuan Hsu, Kang-Wei Peng, Yi-Hsin Lin, Ming-Chun Tseng, Su-Hui Lin, Meng-Chun Shen, Ting-Zhu Wu, Zhong Chen, Ray-Hua Horng
Summary: This study fabricated high-voltage, low-current DUV-LEDs with better current spreading and enhanced reflective mirror effect, resulting in higher power output and efficiency compared to traditional devices. It has potential applications in high-voltage circuits to eliminate extra power consumption.
Article
Computer Science, Hardware & Architecture
Shenjie Huang, Yichen Li, Cheng Chen, Mohammad Dehghani Soltani, Robert Henderson, Majid Safari, Harald Haas
Summary: In recent years, there has been a growing interest in using a single-photon avalanche diode (SPAD) in optical wireless communication (OWC). SPAD is operated in the Geiger mode and acts as a photon counting receiver, eliminating the need for a transimpedance amplifier. However, SPAD suffers from dead-time-induced nonlinearity. To improve the data rates of SPAD-based OWC systems, optical orthogonal frequency division multiplexing (OFDM) can be used. This paper provides a comprehensive theoretical analysis of SPAD-based OWC systems using direct-current-biased optical OFDM signaling, considering various factors such as signal clipping, SPAD nonlinearity, and signal-dependent shot noise. The impact of receiver nonlinearity on system performance is investigated through numerical results.
JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING
(2023)
Correction
Optics
Christopher L. Panuski, Ian Christen, Momchil Minkov, Cole J. Brabec, Sivan Trajtenberg-Mills, Alexander D. Griffiths, Jonathan J. D. McKendry, Gerald L. Leake, Daniel J. Coleman, Cung Tran, Jeffrey St Louis, John Mucci, Cameron Horvath, Jocelyn N. Westwood-Bachman, Stefan F. Preble, Martin D. Dawson, Michael J. Strain, Michael L. Fanto, Dirk R. Englund
Article
Optics
Hanning Mai, Anneliese Jarman, Ahmet T. Erdogan, Conor Treacy, Neil Finlayson, Robert K. Henderson, Simon P. Poland
Summary: We developed a novel line-scanning microscope capable of high-speed TCSPC-based FLIM imaging. The system includes a laser line focus optically connected to a 1024 x 8 SPAD-based line-imaging CMOS with high acquisition rates. The high-speed FLIM platform demonstrated imaging capability in various biological applications.
Article
Optics
Graeme E. Johnstone, Johannes Herrnsdorf, Martin D. Dawson, Michael J. Strain
Summary: Challenging imaging applications that require ultra-short exposure times or imaging in photon-starved environments often have extremely low numbers of photons per pixel (<1 photon per pixel). To improve the image quality in such photon-sparse images, post-processing techniques, such as Bayesian retrodiction and bilateral filtering, can be used to estimate the number of photons detected and improve the spatial distributions in single-photon imaging applications. In this study, we demonstrate that at high frame rates (>1 MHz) and low incident photon flux (<1 photon per pixel), image post-processing techniques can provide better grayscale information and spatial fidelity of reconstructed images compared to simple frame averaging, with up to a 3-fold improvement in SSIM.
Article
Engineering, Biomedical
Yao Ge, Ahmad Taha, Syed Aziz Shah, Kia Dashtipour, Shuyuan Zhu, Jonathan Cooper, Qammer H. Abbasi, Muhammad Ali Imran
Summary: WiFi sensing has gained significant attention as a potential mechanism for remote monitoring of the aging population without deploying devices on users' bodies. It has the potential to detect critical events such as falls, sleep disturbances, and respiratory disorders. Unlike other sensing methods, WiFi technology is easy to implement and unobtrusive. This paper reviews the current state-of-the-art research on WiFi-based sensing and discusses its healthcare applications and open research challenges.
IEEE REVIEWS IN BIOMEDICAL ENGINEERING
(2023)
Article
Optics
Aurora Maccarone, Kristofer Rummond, Aongus Mccarthy, Ulrich K. S. Teinlehner, Julian Achella, Diego A. Guirre G. Arcia, Agata Pawlikowska, Robert A. Lamb, Robert K. Henderson, Stephen Mclaughlin, Yoann Altmann, Gerald S. Buller
Summary: We developed a fully submerged underwater LiDAR transceiver system using single-photon detection technologies. The system utilized a silicon single-photon avalanche diode (SPAD) detector array and picosecond resolution time-correlated single-photon counting for photon time-of-flight measurement. Real-time three-dimensional imaging was achieved through a joint surface detection and distance estimation algorithm. The system demonstrated high-resolution imaging of stationary and moving targets at depths of 1.8 meters and stand-off distances of up to 5.5 attenuation lengths.
Article
Engineering, Electrical & Electronic
Yao Ge, Wenda Li, Muhammad Farooq, Adnan Qayyum, Jingyan Wang, Zikang Chen, Jonathan Cooper, Muhammad Ali Imran, Qammer H. Abbasi
Summary: The LoGait system utilizes LoRa signals to recognize gait in indoor environments, overcoming challenges such as video quality, occlusion, and privacy concerns. It enables a larger sensing range of gait recognition compared to WiFi-based systems.
IEEE SENSORS JOURNAL
(2023)
Article
Chemistry, Analytical
Filip Taneski, Istvan Gyongy, Tarek Al Abbas, Robert K. Henderson
Summary: This paper introduces a guided dToF approach for self-driving vehicles, which utilizes external guidance from other onboard sensors to provide an efficient solid-state lidar solution. It reduces data processing and storage requirements while mitigating multipath reflections.
Review
Optics
Robert h. Hadfield, Jonathan Leach, Fiona Fleming, Douglas j. Paul, Chee hing Tan, Jo shien Ng, Robert k. Henderson, Gerald s. Buller
Summary: The development of single-photon detectors with picosecond timing resolution has driven progress in time-correlated single-photon counting applications, including quantum optics, life sciences, and remote sensing. Advanced optoelectronic device architectures offer high-performance single-pixel devices and the ability to scale up to detector arrays, increasing single-photon sensitivity.
Article
Optics
German Mora-Martin, Stirling Scholes, Lice Ruget, Robert Henderson, Jonathan Leach, Istvan Gyongy
Summary: In this paper, a 3D convolutional neural network (CNN) is trained using synthetic depth sequences to denoise and upscale (x4) depth data. Experimental results using synthetic and real ToF data demonstrate the effectiveness of the approach. With GPU acceleration, the approach achieves processing speeds of >30 frames per second, making it suitable for low-latency imaging.
Article
Engineering, Electrical & Electronic
Benoit Guilhabert, Sean P. Bommer, Nils K. Wessling, Dimitars Jevtics, Jack A. Smith, Zhongyi Xia, Saptarsi Ghosh, Menno Kappers, Ian M. Watson, Rachel A. Oliver, Martin D. Dawson, Michael J. Strain
Summary: Transfer printing technology has been widely used for integrating planar membrane devices on photonic and electronic circuits. This work introduces an advanced transfer print system that allows printing of optical devices in non-planar geometries and enables in-situ optical monitoring. The system demonstrates the printing of micro-resonators coupled to on-chip waveguides, inverted device printing, and the assembly of micro-cavities with semiconductor micro-lenses and nanowire lasers. Non-standard substrates such as optical chip facets and single-mode fibre ends are also successfully printed. The in-situ optical coupling through the transfer printing system enables real-time active alignment of the printed devices.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Jonathan J. D. McKendry, Enyuan Xie, Jordan Hill, Hichem Zimi, Johannes Herrnsdorf, Erdan Gu, Robert K. Henderson, Martin D. Dawson
Summary: This article reports a deep ultraviolet AlGaN micro-LED array driven by electronic drivers implemented in CMOS technology. The integrated device allows independent control of each micro-LED and has potential applications in various fields.
IEEE PHOTONICS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Jordan Hill, Cheng Chen, Enyuan Xie, Jonathan J. D. Mckendry, Johannes Herrnsdorf, Erdan Gu, Harald Haas, Martin D. Dawson
Summary: We systematically investigate the performance of UV-C LEDs for optical wireless communication, focusing on the device size dependence. Smaller devices exhibit lower optical power but faster modulation speed. The study finds that a 60 μm diameter LED transmitter achieves the highest average SNR and SE, with a data transmission rate of up to 5.53 Gbps.
IEEE PHOTONICS JOURNAL
(2023)
Article
Biochemical Research Methods
Yunus Aslan, Olivia McGleish, Julien Reboud, Jonathan M. Cooper
Summary: This study presents an alignment-free spatial hydrophilic PDMS patterning technique for the generation of double emulsion droplets. The method successfully produces reliable and reproducible water-in-oil-in-water droplet emulsions without the need for complex processing steps. It can be applied to various fields, further expanding the applications of microfluidic techniques.
