Article
Physics, Applied
Xin Chen, Yaozong Zhong, Shumeng Yan, Xiaolu Guo, Hongwei Gao, Xiujian Sun, Haodong Wang, Fangqing Li, Yu Zhou, Meixin Feng, Ercan Yilmaz, Qian Sun, Hui Yang
Summary: The characteristics of an AlGaN/GaN high-electron-mobility transistor buffer structure are studied and optimized by employing an AlN/GaN superlattice (SL) structure. The influence of buffer traps on carrier transport behaviors and electrical performance for SL buffer structures under a high electric field is analyzed. The AlN/GaN SL buffer structures are further optimized with various AlN/GaN thickness ratios and their total thickness, achieving a high breakdown voltage and suppressing the buffer trapping effect.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Computer Science, Information Systems
Yuchen Li, Sen Huang, Xinhua Wang, Qimeng Jiang, Xinyu Liu
Summary: In this study, the temperature-dependent ON-state breakdown BVON of AlGaN/GaN HEMTs with an AlGaN back barrier was investigated using the gate current extraction technique. It was found that the impact ionization of acceptor-like traps is responsible for the ON-state breakdown in HEMTs when the 2DEG channel is marginally turned on. Additionally, the characteristic electric field of impact ionization was extracted and shown to have a U-shaped temperature dependence.
Article
Engineering, Electrical & Electronic
Wen Yang, Jiann-Shiun Yuan
Summary: In this study, the effects of substrate bias on time-dependent dielectric breakdown in GaN MIS-HEMTs were investigated through experiment. It was found that different substrate biases led to varying behaviors of trap effects, with distinct roles of acceptor-like buffer traps and donor-like buffer traps in TDDB failure mechanisms.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Materials Science, Multidisciplinary
V. Hemaja, D. K. Panda
Summary: An n-polar GaN MIS-HEMT based biosensor is proposed for label-free detection of various bio-molecules by immobilizing the analytes in the underlap region to alter the electrostatic properties of the device, resulting in a significant increase in drain current and output conductance with the addition of different biomolecules in the nanocavity, with a maximum shift in threshold voltage observed for uricase due to its low dielectric constant.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Junya Yaita, Koichi Fukuda, Atsushi Yamada, Takuya Iwasaki, Shu Nakaharai, Junji Kotani
Summary: The study identified the primary reason for the reduced electron mobility in QW GaN-HEMT and proposed a solution to alleviate the electric field and increase electron mobility. As a result, the electron mobility of the QW GaN-HEMT structure was significantly improved.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Physics, Applied
Rui Shan Low, Joel T. Asubar, Ali Baratov, Shunsuke Kamiya, Itsuki Nagase, Shun Urano, Shinsaku Kawabata, Hirokuni Tokuda, Masaaki Kuzuhara, Yusui Nakamura, Kenta Naito, Tomohiro Motoyama, Zenji Yatabe
Summary: This study fabricates AlGaN/GaN metal-insulator-semiconductor (MIS) capacitors and high-electron-mobility transistors (MIS-HEMTs) using a 5 nm thick Al2O3 dielectric deposited by mist chemical vapor deposition (mist-CVD) technique. The results show that the mist-Al2O3/AlGaN interface has high quality, and the mist MIS-HEMTs exhibit improved performance compared to traditional HEMTs, indicating the potential of mist-CVD Al2O3 in high-performance GaN-based MIS-HEMT development.
APPLIED PHYSICS EXPRESS
(2021)
Article
Engineering, Electrical & Electronic
Wei-Min Wu, Shih-Hung Chen, Chun-An Shih, Bertrand Parvais, Nadine Collaert, Ming-Dou Ker, Tian-Li Wu, Guido Groeseneken
Summary: Gallium nitride (GaN)-on-Si technologies for advanced RF applications have been drawing attention in the semiconductor industry, along with challenges in RF electrostatic discharge (ESD) reliability. Investigating both positive and negative ESD stress polarities is equally important. In this study, four scenarios of positive and negative human body model (HBM) stresses were conducted on GaN-on-Si (MIS-HEMTs) with gate-tied-to-source and gate-tied-to-drain configurations. It was found that the negative GS MIS-HEMT exhibited a failure mechanism different from the constant-power 2DEG failure mechanism in the typical positive GS (MIS-HEMT).
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Ankit Soni, Mayank Shrivastava
Summary: This study investigated the impact of various charge sources on the electric field distribution and breakdown mechanism of HEMTs, revealing strong correlations between different charges and breakdown voltage. Insights were developed to explain the dependence of HEMT breakdown on surface states, polarization charge, and buffer traps, aiding in the design of efficient surface passivation schemes.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Computer Science, Information Systems
Wei Lin, Maojun Wang, Haozhe Sun, Bing Xie, Cheng P. Wen, Yilong Hao, Bo Shen
Summary: This paper proposes an HEMT structure with a source-connected p-GaN embedded in a carbon-doped semi-insulating buffer to suppress the buffer-induced current collapse effect. Two-dimensional transient simulation demonstrates the successful suppression of current collapse in SCPG-HEMTs compared to conventional HEMTs. The mechanism of ejecting holes from SCPG into the high resistive buffer layer after off-state stress is illustrated to potentially solve the buffer-induced degradation of dynamic on-resistance in GaN power devices.
Article
Engineering, Electrical & Electronic
Jungho Ahn, Dahee Kim, Kyung-Ho Park, Geonwook Yoo, Junseok Heo
Summary: The study presents an ultrahigh sensitive hydrogen sensor based on Pt-decorated graphene gate AlGaN/GaN MIS-HEMT, which operates at room temperature. The sensor demonstrates remarkably high sensitivity even at very low concentrations of hydrogen (<1 ppm).
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Mohammad Sajid Nazir, Pragya Kushwaha, Ahtisham Pampori, Sheikh Aamir Ahsan, Yogesh Singh Chauhan
Summary: In this work, a phenomenological cryogenic model for GaN HEMTs is proposed and validated with experimental characterization results. The model accurately captures the negative threshold voltage shifts and kink effects observed at cryogenic temperatures. The impact of temperature, impact ionization, and field-dependent trapping/detrapping on performance is explored and implemented in the model to explain these phenomena.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Automation & Control Systems
Aaron Wadsworth, Matthew G. S. Pearce, Duleepa J. Thrimawithana
Summary: This article presents the design of a cryogenic gallium nitride (GaN) enhancement mode high-electron-mobility transistor (E-HEMT) synchronous buck converter, which achieves high efficiency and uses a nanocrystalline filter inductor within the cryogenic environment. The article also evaluates the selection of magnetic materials and litz wire at cryogenic temperatures. Cryogenically cooling the GaN switches reduces their losses by half compared to operating at room temperature under the same conditions.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Fuping Huang, Zhizhong Wang, Chunshuang Chu, Qianqian Liu, Yongjian Li, Zhen Xin, Yonghui Zhang, Qian Sun, Zi-Hui Zhang
Summary: In this study, we conducted systematic studies on the interfacial conditions for Gallium Nitride-based trench Metal/Insulator/Semiconductor (MIS) type Barrier Schottky Rectifier using T-CAD tool. Our findings suggest that donor-type traps reduce the Schottky barrier height, resulting in increased leakage current and reduced breakdown voltage. On the other hand, acceptor-type traps at the contact interface and mesa sidewall increase the barrier height and turn-on voltage. We propose using an MIS structure with a 1-nm Al2O3 insulation layer to solve the complicated interfacial conditions and reduce reverse leakage significantly.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Yasuyuki Miyamoto, Kozo Makiyama
Summary: The high breakdown voltage achieved by loading a high-k film in the gate-drain region was recently studied. However, the uniform high-k film has limitations in modulating the electric field distribution, resulting in a stronger electric field near the gate side compared to the drain side. This study proposes the modulation of high-k film thickness in the lateral direction to control the electric field distribution in the channel of a gallium nitride (GaN) high electron mobility transistor (HEMT). Compared to a uniform film, this modulation weakens the electric field near the gate and creates a negative gradient. Simulation results show a 20% increase in the voltage at which impact ionization occurs, attributed to reduced gate leakage current and improved electric field distribution. The maximum electric field also increases in the proposed structure when the electric field slope is negative.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Pengfei Wan, Jianqun Yang, Hao Jiang, Yuanting Huang, Ling Lv, Lei Dong, Xiaoqing Yue, Bin Zhang, Gang Lin, Guojian Shao, Weiqi Li, Xiaodong Xu, Xiuhai Cui, Xingji Li
Summary: This article investigates the synergistic radiation effects on AlGaN/GaN high electron mobility transistors (HEMTs) under different irradiation conditions. The results show that HEMTs have excellent resistance to ionization radiation, but the drain current and carrier mobility decrease significantly under proton irradiation. The degradation rate caused by combined irradiation is three times higher than that caused by individual proton irradiation, indicating a synergistic effect between ionization and displacement effects.
IEEE TRANSACTIONS ON NUCLEAR SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Xiaoyu Yang, Deying Luo, Yuren Xiang, Lichen Zhao, Miguel Anaya, Yonglong Shen, Jiang Wu, Wenqiang Yang, Yu-Hsien Chiang, Yongguang Tu, Rui Su, Qin Hu, Hongyu Yu, Guosheng Shao, Wei Huang, Thomas P. Russell, Qihuang Gong, Samuel D. Stranks, Wei Zhang, Rui Zhu
Summary: Research has shown that losses at buried interfaces in perovskite photovoltaics are mainly caused by sub-microscale extended imperfections and lead-halide inhomogeneities, which are major obstacles to improving device performance. By utilizing passivation molecules for microstructural reconstruction, these losses can be significantly reduced, unlocking the full potential for enhancing device performance.
ADVANCED MATERIALS
(2021)
Article
Medicine, Research & Experimental
Lihua Liu, Aosong Duan, Qiaoyan Guo, Guangdong Sun, Wenpeng Cui, Xuehong Lu, Hongyu Yu, Ping Luo
Summary: The study found that the levels of miR-33a-5p in the serum, urine, and kidney tissues of IgA nephropathy (IgAN) patients were significantly lower compared to healthy individuals. Furthermore, the levels of miR-33a-5p decreased with the severity of renal injury and the progression of renal failure in IgAN patients. This suggests that miR-33a-5p detected in the serum and urine could serve as a non-invasive biomarker to reflect the progression of renal injury and renal failure in IgAN patients.
EXPERIMENTAL AND THERAPEUTIC MEDICINE
(2021)
Article
Optics
Jiahao Yin, Liang Chen, Yumeng Luo, Qing Wang, Hongyu Yu, Kwai Hei Li
Summary: This work demonstrates the superior optical and thermal performance of InGaN-based green LEDs with flip-chip design compared to conventional wire-bonding design. The flip-chip LED-PD device shows significant improvements in light output and detected photocurrent under an LED current of 200 mA. Analysis of optical, electrical, and thermal properties under varying LED currents provides important guidance for LED-PD integrated systems design at different current densities.
Article
Geochemistry & Geophysics
Bei Wang, Alessandro Verdecchia, Honn Kao, Rebecca M. Harrington, Yajing Liu, Hongyu Yu
Summary: The study investigates the causative mechanisms for the M-w 4.6 earthquake, finding that pore pressure increase associated with injected fluid migration is the key factor. Injection activities at W1 may have altered the local stress field and brought local faults closer to failure at sites W2 and W3, explaining the simultaneous appearance of injection and induced seismicity.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2021)
Review
Nanoscience & Nanotechnology
Jiaqi He, Wei-Chih Cheng, Qing Wang, Kai Cheng, Hongyu Yu, Yang Chai
Summary: This review discusses various effective approaches to enhance the performance of GaN-based power HEMTs, such as modified epistructures, recess-free processes, dielectric effects on MIS structure, metal/semiconductor contact engineering, and field plate effects.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Geochemistry & Geophysics
Xuejuan Zhang, Lei Zhang, Dandan Wang, Kuo Lan, Xuesong Zhou, Hongyu Yu, Ruhao Liu, Xueying Lv
Summary: The article introduces a nonuniform grid method based on geological characteristics and discretizes uniform and composite reservoirs using different strategies. By constructing these alternative grid upscaling strategies, computational efficiency can be significantly increased.
INTERPRETATION-A JOURNAL OF SUBSURFACE CHARACTERIZATION
(2021)
Article
Engineering, Electrical & Electronic
Guangnan Zhou, Fanming Zeng, Yang Jiang, Qing Wang, Lingli Jiang, Guangrui Xia, Hongyu Yu
Summary: In this study, the gate breakdown mechanisms of p-GaN gate AlGaN/GaN HEMTs were investigated using a novel multiple-gate-sweep-based method. Three different breakdown mechanisms were observed and identified separately in the same devices, which were further confirmed by scanning electron microscopy. The temperature dependences of the breakdown mechanisms were measured and compared, showing the applicability of the analysis method in devices with different passivation materials.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Multidisciplinary Sciences
Rui Su, Zhaojian Xu, Jiang Wu, Deying Luo, Qin Hu, Wenqiang Yang, Xiaoyu Yang, Ruopeng Zhang, Hongyu Yu, Thomas P. Russell, Qihuang Gong, Wei Zhang, Rui Zhu
Summary: Regulating the dielectric properties can decrease the defect capture probability in perovskite photovoltaic devices, leading to reduced surface recombination and weaker electron-phonon coupling, thereby boosting the power conversion efficiency.
NATURE COMMUNICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Guangnan Zhou, Yang Jiang, Gaiying Yang, Qing Wang, Mengya Fan, Lingli Jiang, Hongyu Yu, Guangrui Xia
Summary: The study reported a significant current reduction in two common-anode Au/Ti/p-GaN Schottky junctions annealed within a specific annealing condition window, with the layers of gold, titanium, and p-GaN playing essential roles in increasing resistance. Characterization techniques including scanning-transmission electron microscopy, Hall measurements, and Raman spectroscopy were utilized to investigate the mechanisms involved. The high-resistance Schottky junction structure was successfully applied to p-GaN gate AlGaN/GaN high electron mobility transistors, enhancing the gate breakdown voltage with minimal impact on other device parameters.
Review
Chemistry, Multidisciplinary
Deying Luo, Xiaoyue Li, Antoine Dumont, Hongyu Yu, Zheng-Hong Lu
Summary: The focus of the research is on discussing surface and interface engineering to reduce deep-level defects, and by selecting appropriate materials and processing methods to enhance the device performance of both solar cells and light-emitting diodes.
ADVANCED MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Wei-Chih Cheng, Jiaqi He, Minghao He, Zepeng Qiao, Yang Jiang, Fangzhou Du, Xiang Wang, Haimin Hong, Qing Wang, Hongyu Yu
Summary: This study focuses on improving the electric performance of GaN-based power devices by preoxidizing the GaN surface and using ozone-based atomic-layer-deposited HfO2 gate oxide to reduce trap densities at the HfO2/GaN interface.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2022)
Meeting Abstract
Medicine, Research & Experimental
Rulong Shen, Tong Cheng, Xing Li, John Pineda, Hongyu Yu, Wenbin Huang, Shaohua Lu, Jian Zhou, Jie Hu, Encheng Li, Ming Ding, Xiaonan Wang, Han Si, Panying Shi, Ning Zhou, Chunxue Bai
LABORATORY INVESTIGATION
(2021)
Meeting Abstract
Pathology
Rulong Shen, Tong Cheng, Xing Li, John Pineda, Hongyu Yu, Wenbin Huang, Shaohua Lu, Jian Zhou, Jie Hu, Encheng Li, Ming Ding, Xiaonan Wang, Han Si, Panying Shi, Ning Zhou, Chunxue Bai
Article
Chemistry, Physical
Mingyang Du, Zihan Zhang, Hao Song, Hongyu Yu, Tian Cui, Vladimir Z. Kresin, Defang Duan
Summary: The discovery of new MoH5, MoH6 and MoH11 compounds, with MoH11 being a high-Tc material with a Tc range of 165-182 K at high pressure, is a significant finding. Similar structures are also found in NbH11, TaH11, and WH11, with Tc values ranging from 117 to 168 K. The high values of Tc are mainly attributed to the presence of high frequency optical modes, with acoustic modes also playing a noticeable role.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Medicine, General & Internal
Binbin Li, Jiaxuan Liu, Xuan Xin, Lifen Zhang, Jiaming Zhou, Chunyan Xia, Weijian Zhu, Hongyu Yu
Summary: miR-34c plays a crucial role in hepatic stellate cell activation and liver fibrosis by targeting ACSL1 and regulating fatty acid synthesis.
INTERNATIONAL JOURNAL OF MEDICAL SCIENCES
(2021)
