Article
Optics
Xiaofeng Rong, Yumin Yang, Shenzhe Peng, Cheng Yang, Degui Wang
Summary: For the first time, diode-pumped continuous-wave and passively Q-switched Nd:LuAG ceramic microchip lasers at 1064 nm and 1053 nm have been demonstrated. The continuous-wave operation achieved maximum output powers of 1.62 W and 0.75 W for the two lasers, respectively. Using a Cr:YAG crystal as a saturable absorber, the lasers can also operate in passively Q-switched regimes with sub-nanosecond pulse durations of 489 ps and 556 ps, respectively. The all solid-state microchip lasers show great potential for high performance laser generation with sub-nanosecond short pulse duration, high single pulse energy, and high pulse peak power.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Mengling Xia, Zuoxiang Xie, Hanqi Wang, Tong Jin, Linyue Liu, Jun Kang, Ziru Sang, Xianchang Yan, Boning Wu, Hao Hu, Jiang Tang, Guangda Niu
Summary: A rational design strategy is presented to shorten the scintillation decay time by maximizing the dielectric difference in 2D organic-inorganic hybrid perovskites. Inserting benzimidazole (BM) with low dielectric constant between [PbBr6](2-) layers significantly enhances the exciton binding energy and reduces the emitting decay time to 0.97 ns with a high light yield of 3190 photons MeV-1. This material shows excellent performance in gamma-ray, neutron, and alpha-particle detection, as well as the best coincidence time resolution compared to the reference sample.
ADVANCED MATERIALS
(2023)
Article
Optics
Felipe Maia Prado, Tomas Junqueira Franco, Niklaus Ursus Wetter
Summary: A sub-nanosecond, diode-stack side-pumped, passively Q-switched Nd3+:YLF4/Cr4+:YAG Laser with a pulse width of 894 ps and peak output power of 46 MW is reported. The focus distance can be adjusted to generate a pulse train with energy ranging from 41 mJ to 111 mJ and optical efficiency of 23.7%. This laser resonator can also emit high-power simultaneous Q-switched laser at 1047 nm and 1053 nm.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Zheng Li, Jin Xue, Marc de Cea, Jaehwan Kim, Hao Nong, Daniel Chong, Khee Yong Lim, Elgin Quek, Rajeev J. Ram
Summary: In this letter, an electrically driven Si light-emitting diode with a sub-wavelength emission area is reported. It has a high spatial intensity of >50 mW/cm² and exhibits a high degree of spatial coherence due to sub-wavelength confinement. This on-chip light source can be used in integrated photonics systems.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
R. J. E. Hueting, H. de Vries, S. Dutta, A. J. Annema
Summary: The study conducted TCAD simulations on low-voltage SJLEDs, showing that a more aggressive charge balance condition is required to achieve a constant field compared to traditional approaches. This is important for realizing optimized RESURF and SJLEDs in advanced CMOS nodes.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Optics
Jing-Qi Wang, Zhen-Wei Qin, Yan-Ling Ma, Yang Yang, Hong-Yi Huang, Cheng-Shan Guo, Qing-Yang Yue
Summary: In this study, we propose a solution for the integration of resonant cavity and high refractive index contrast dielectric metasurfaces on OLED to endow the device with unidirectional light emission for naked-eye 3D display. Simulation results show that top crystalline silicon (c-Si) metasurfaces are superior to other metasurfaces structures in terms of deflection efficiency and aspect ratio. We believe that this proposed single-chip resonant cavity OLED integrated with a top c-Si metasurfaces structure could be a very promising candidate for naked-eye 3D OLED display.
OPTICS COMMUNICATIONS
(2023)
Article
Optics
Seung-Hye Baek, Dae-Choul Choi, Yoon Seok Kim, Hyunseok Na, Sung-Nam Lee
Summary: This paper investigates the impact of surface V-shaped defects on the electrical and optical characteristics of GaN-based LEDs, particularly under reverse bias conditions. The size of these defects plays a critical role, with larger defects generating more indium-rich regions and elevated tensile stress, leading to increased reverse leakage current and the formation of giant dot-like luminescence (GDL). However, localized failure predominantly occurs at the defect experiencing the highest tensile stress, significantly reducing the breakdown voltage. Micro-Raman analysis further reveals distinct Raman shifts and increased tensile stress in these regions. These findings highlight the complexity of V-shaped defects' effects and their importance in GaN-based LED design and optimization. Recognizing their influence on electrical and optical properties can significantly impact device reliability and performance, particularly in reverse bias conditions.
Article
Physics, Applied
Edward Butler-Caddle, Nicholas E. E. Grant, Sophie L. L. Pain, John D. D. Murphy, K. D. G. Imalka Jayawardena, James Lloyd-Hughes
Summary: Optical pump terahertz probe spectroscopy (OPTP) is a non-contact technique that measures photoconductance decays with femtosecond temporal resolution. We extended the temporal range of OPTP to milliseconds by electrical synchronization and demonstrated its capabilities for studying semiconductors.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Ceramics
Yuki Nakashima, You Zhou, Keisuke Tanabe, Souhei Arima, Kiyoshi Hirao, Tatsuki Ohji, Norimitsu Murayama, Manabu Fukushima
Summary: Silicon nitride ceramics were prepared using a sintered reaction-bonded method, and the microstructure and dielectric breakdown strength of the ceramics were evaluated. The study found a correlation between the thickness of the ceramics and their dielectric breakdown strength.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Engineering, Multidisciplinary
Guancong Liu, Xia Xiao, Min Lu, Xiaofeng Zhang, Takamaro Kikkawa
Summary: This article presents a compact and low-cost UWB sub-nanosecond monocycle pulse generator based on step recovery diodes (SRDs). The generator achieves a pulse width of 406 ps with a high peak-to-peak amplitude and a wide bandwidth. Experimental results demonstrate its attractiveness for UWB breast cancer detection.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
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
Chemistry, Analytical
Maricela Meneses-Meneses, Mario Moreno-Moreno, Alfredo Morales-Sanchez, Arturo Ponce-Pedraza, Javier Flores-Mendez, Julio Cesar Mendoza-Cervantes, Liliana Palacios-Huerta
Summary: This study investigated the feasibility of fabricating PIN light-emitting diodes (LEDs) using a-Si1-xCx:H thin films and c-Si wafers, successfully demonstrating both positive and negative electroluminescence characteristics in the devices.
Article
Engineering, Electrical & Electronic
Satadal Dutta, Raymond J. E. Hueting, Gerard J. Verbiest
Summary: In this study, we present an avalanche-mode light-emitting transistor (AMLET) in silicon, which emits light with a record low bandwidth. The AMLET achieves high optical power efficiency through a combination of a resonant cavity and carrier injection, providing new possibilities for improving the performance of silicon optical interconnects and sensors.
IEEE ELECTRON DEVICE LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Samuel J. Shin, Taek Dong Chung
Summary: This minireview elucidates the fundamental electron transfer mechanism of silicon oxide in the electrolyte solution and discusses possible electrochemical reactions in detail, providing numerous potential areas of application for future research guidance.
CHEMISTRY-AN ASIAN JOURNAL
(2021)
Article
Nanoscience & Nanotechnology
Huilian Hao, Yue Zhao, Tianliang Song, Xu Wang, Changwang Li, Wenyao Li, Wenzhong Shen
Summary: In this study, enhanced red emission from colloidal silicon nanocrystals (c-Si NCs) solution-processed light-emitting diode was reported. The c-Si NCs were synthesized by facile femtosecond laser ablation. Both photoluminescence and electroluminescence were found to arise from the radiative recombination of carriers due to quantum confined effect. The optical power density and highest external quantum efficiency obtained were 0.79 mW cm(-2) and around 6.6%, respectively, indicating the potential of Si NCs as an attractive optical source for future integrated chips.
Article
Automation & Control Systems
Yi-Tse Chang, Kuan-Yi Hung, Hong-Tsu Young, Kuan-Ming Li, Roland K. Chen
Summary: The study found that UV curing does not need to be optimized for good results, and it also reduces curing time and improves sensor performance.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Automation & Control Systems
Kuan-Ming Li, Chi-Wen Chang, Chia-Hao Chang
Summary: This paper presents a method for measuring tool tip temperature using an ink-jet printed thermistor array. The method has high temperature sensitivity and fast response time. By using the finite element method and model order reduction method, it is possible to achieve online monitoring of tool tip temperature.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Wan-Ju Lin, Jian-Wen Chen, Hong-Tsu Young, Che-Lun Hung, Kuan-Ming Li
Summary: The study introduced a smart sorting screw system that integrates IoT techniques and anomaly networks to automatically detect defective areas on screw products, achieving favorable results in experiments.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Multidisciplinary
Ping-Han Wu, Hong-Tsu Young, Kuan-Ming Li
Summary: This study discussed the ablation thresholds of picosecond laser dual pulses in fused silica with different temporal separations. The results indicated that the lowest damage threshold of the dual-pulse ablation was at a temporal separation of 100 ps, and the energy ratios of two sub-pulses were optimized to minimize the thresholds. The study also revealed that the first sub-pulses excited the electrons of the fused silica and induced free-electron shielding and self-trapped exciton seed generation, which affected the material absorption of the second sub-pulses.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Ming-Chan Lee, Cheng-Hsin Chuang, Da-Huei Lee, Cheng-Tang Pan, Kuan-Ming Li
Summary: This paper presents the design and implementation of fuzzy logic control for human walking using lab-developed sensors and the second lower limb robotic exoskeleton (LLRE-II) to detect gait phases. The proposed sensor with grid structures fabricated using polymer composites of multi-walled carbon nanotubes (MWCNTs) combined with polydimethylsiloxane (PDMS) can accurately measure foot pressure and predict human walking behavior. The performance of the proposed algorithm for gait phase detection was verified experimentally, showing the ability to detect both regular and irregular walking patterns.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Physical
Tien-Fu Ko, Po-Wen Chen, Kuan-Ming Li, Hong-Tsu Young
Summary: This study successfully prepared an electrochromic device (ECD) with good electrochromic performance and excellent optical transmittance modulation by inserting an IrO2 buffer layer on the Ti:V2O5 electrode using the low-cost vacuum cathodic arc plasma deposition process.
Article
Chemistry, Multidisciplinary
Yi-Tse Chang, Kuan-Yi Hung, Chih-Hsuan Chien, Hong-Tsu Young, Wen-Tse Hsiao, Kuan-Ming Li
Summary: In this study, nickel oxide thin films were fabricated using an aerosol jet printer and sintered by a UV laser. The UV laser sintering not only improved the electrical properties of the thin films but also reduced the treatment time. The effects of laser parameters on the resistance and morphology of the thin films were analyzed. The experiments revealed the possible cracks that may occur during the UV laser sintering process.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Multidisciplinary
Che-Shu Lin, Hsin-Fang Hsieh, Chien-Fang Ding, Kuan-Ming Li, Hong-Tsu Young, Wen-Tse Hsiao
Summary: The research utilized a nanosecond pulsed ultraviolet laser to modify graphene composite materials, leading to improved gas sensing response. The modified specimens showed a significant increase in response to NO2 gas, particularly at higher concentrations.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Computer Science, Artificial Intelligence
Ta-Wei Tang, Hakiem Hsu, Kuan-Ming Li
Summary: With the maturity of deep learning image recognition technology and the popularity of automated production lines, deep learning industrial anomaly detection has become an important research topic in recent years. In this study, an anomaly detection model with a multi-scale autoencoder and deep feature extractor is proposed. This model achieved the highest area under the curve (AUC) in 14 out of 17 industrial detection tasks and demonstrated a suitable threshold for balancing false-positive and true-positive rates. Additionally, the study discusses the influence of different feature extractors on the method and shows that the proposed method maintains good detection ability with most feature extractors, making it suitable for industrial optical inspection systems with different hardware conditions.
IET IMAGE PROCESSING
(2023)
Article
Automation & Control Systems
Kuan-Ming Li, Yi-Yen Lin
Summary: This paper presents a Random Forest model for predicting tool wear under varied cutting conditions and studies the extracted signal features. The study shows that data normalization excludes frequency domain signals related to spindle speeds from important features. Instead, spectrum energy related to structure vibration and time domain signals are found to be the important features.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Chemistry, Analytical
Ta-Wei Tang, Hakiem Hsu, Wei-Ren Huang, Kuan-Ming Li
Summary: This paper proposes a novel deep learning model for improving the accuracy of anomaly detection in automatic optical detection. By utilizing a pre-trained feature extractor and skip connection, the proposed method achieves better feature extraction and image reconstructing capabilities. Experimental results demonstrate that the proposed method outperforms previous anomaly detection models in most categories, allowing for appropriate adjustments to maximize economic benefits based on the needs of production lines.
Article
Radiology, Nuclear Medicine & Medical Imaging
T. -W. Tang, W. -Y. Lin, J. -D. Liang, K. -M. Li
Summary: This study aims to develop a high-accuracy low-dose computed tomography (LDCT) lung nodule diagnosis system by combining artificial intelligence (AI) technology with the Lung CT Screening Reporting and Data System (Lung-RADS) for future AI-aided diagnosis of pulmonary nodules. The study compares and selects the best deep-learning segmentation method and uses the Image Biomarker Standardization Initiative (IBSI) for feature extraction and reduction. The performance of the established system shows promising results.
CLINICAL RADIOLOGY
(2023)
Article
Computer Science, Artificial Intelligence
Chao-Chang Liao, Chih-Ching Hsu, Hong-Tsu Young, Kuan-Ming Li
Summary: An innovative integrated approach is proposed to develop a design schema for automatic defect detection system, which has been successfully implemented in an empirical factory setting and authorized a new patent. This approach combines vertical thinking mode (DMAIC, 8D methodology, and ECRS techniques) with lateral mode (Design Thinking and 3I Design Methodology), resulting in improved efficiency and effectiveness. The empirical implementation focuses on automated defect detection in manufacturing cell phone cases, showing significant savings in labor expenditures and costs.
JOURNAL OF INTELLIGENT MANUFACTURING
(2023)
Review
Engineering, Manufacturing
Hsiang-Chun Tseng, Meng-Shiun Tsai, Bu-Ci Yeh, Kuan-Ming Li
Summary: In this study, a bending moment model that considers cutting forces was developed, and the polar plot of the bending moment was used to investigate cutting behavior. Experimental results verified that different cutting parameters result in different polar plots. By incorporating a tool wear model, the modified model can predict the level of tool wear accurately.
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING
(2022)
Article
Engineering, Electrical & Electronic
Cheng-Tang Pan, Ming-Chan Lee, Jhih-Syuan Huang, Chun-Chieh Chang, Zheng-Yu Hoe, Kuan-Ming Li
Summary: This paper introduces a lightweight lower limb rehabilitation exoskeleton robot with adjustable rods and four degrees of freedom, utilizing a self-tuning multi-axis control system and demonstrating good system performance through experiments.
Article
Engineering, Electrical & Electronic
Zhiqiang Wang, Siyang Dai, Yao Zhao, Guofeng Li, Bing Ji, Volker Pickert, Bowen Gu, Shuai Ding
Summary: This paper proposes a lumped-charge model for IEGT single chip, considering the effect of carrier injection enhancement in the emitter. The parasitic inductance of the parallel branches in PP-IEGT is extracted using Ansys simulation, and the validity of Ansys simulation is verified. Furthermore, the switching inconsistency is evaluated by combining the electrical model and the effect of mutual inductance, and it is found that mutual inductance is an important factor influencing electrical parameter distribution.
MICROELECTRONICS RELIABILITY
(2024)
Article
Engineering, Electrical & Electronic
Sankha Subhra Ghosh, Surajit Chattopadhyay, Arabinda Das, Nageswara Rao Medikondu, Abdulkarem H. M. Almawgani, Adam R. H. Alhawari, Sudipta Das
Summary: This article describes a method for identifying the IGBT switch breakdown failure in a 3-phase, 3-level Voltage Source Converter linked to the photovoltaic grid. Comparative learning has been used to detect the specific parameter suitable for the detection of the failure.
MICROELECTRONICS RELIABILITY
(2024)
Article
Engineering, Electrical & Electronic
Milad Khajehvand, Henri Seppanen, Panthea Sepehrband
Summary: Using SEM/EDX analysis, microscale fracture at the bond-pad is detected during the wedge bonding process of Cu wire to a Cu or Al substrate. It is observed that the fracture of the bond leads to the formation of a bulge on the wire and a cavity in the substrate, causing fracture in the original substrate. 3D optical profiler reveals that the depth, radius, and surface area of the cavity increase with bond time for a constant bond force and power. These metrics are suggested as new factors for optimizing the wedge bonding process. The optimal bonding parameters should maximize the cavity's surface area (related to bond's pull force) while minimizing the cavity's depth relative to the substrate's thickness to avoid substrate damage. Furthermore, Molecular Dynamics simulations propose a potential plastic deformation mechanism for bond-pad damage, suggesting the benefits of using a small-grain-sized substrate, low transducer's vibration amplitude, and high transducer's frequency to minimize the cavity's depth.
MICROELECTRONICS RELIABILITY
(2024)
