Article
Engineering, Electrical & Electronic
Arathy Varghese, Chinnamuthan Periasamy, Lava Bhargava, Surani Bin Dolmanan, Sudhiranjan Tripathy
Summary: The research involves the development of a C-MOSHEMT sensor for pH detection application, with modeling, fabrication, and sensitivity analysis conducted. Experimental results show the impact of increasing sensing area on sensitivity.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Minghua Zhu, Catherine Erine, Jun Ma, Mohammad Samizadeh Nikoo, Luca Nela, Pirouz Sohi, Elison Matioli
Summary: This letter presents a new concept for normally-off AlGaN/GaN-on-Si MOS-HEMTs, utilizing the combination of p-GaN, tri-gate, and MOS structures to achieve high threshold voltage and low on-resistance. The design enables excellent channel control capability, higher ON/OFF ratio, and smaller sub-threshold slope compared to similar planar p-GaN devices, showcasing promising prospects for future power electronics applications.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Chemistry, Analytical
Yu-Shyan Lin, Chi-Che Lu
Summary: This paper presents improved AlGaN/GaN metal oxide semiconductor high-electron mobility transistors (MOS-HEMTs) by using TiO2 for dielectric and passivation layers. The TiO2 film is characterized using X-ray photoemission spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM). The quality of the gate oxide is enhanced through annealing at 300°C in N-2. Experimental results demonstrate that the annealed MOS structure effectively reduces gate leakage current, enables stable operation at elevated temperatures up to 450 K, and improves output power characteristics of the MOS-HEMTs.
Article
Chemistry, Physical
Cheng-Yu Huang, Soumen Mazumder, Pu-Chou Lin, Kuan-Wei Lee, Yeong-Her Wang
Summary: In this paper, a metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT) is proposed to suppress gate leakage current, decrease flicker noise, increase high-frequency performance, improve power performance, and enhance stability. This is achieved by using a Al2O3/ZrO2 stacked layer on a conventional AlGaN/GaN HEMT.
Article
Chemistry, Analytical
Min Jae Yeom, Jeong Yong Yang, Chan Ho Lee, Junseok Heo, Roy Byung Kyu Chung, Geonwook Yoo
Summary: The study investigated AlGaN/GaN MOS-HEMTs with undoped ferroelectric HfO2, where spike annealing was used to enhance ferroelectricity without degrading the oxide/nitride interface. This approach led to achieving a subthreshold slope close to 60 mV/dec and an on/off ratio greater than 10(9), suggesting the importance of optimizing the HfO2/nitride interface for low-loss high-power switching devices.
Article
Chemistry, Physical
Navneet Bhardwaj, Bhanu B. Upadhyay, Yogendra K. Yadav, Sreenadh Surapaneni, Swaroop Ganguly, Dipankar Saha
Summary: In this study, 10 nm of amorphous Nb2O5 was successfully grown on an AlGaN/GaN heterostructure, with ideal stoichiometry and a band gap of 4.15 eV determined by XPS analysis. Additionally, TEM confirmed the thickness and crystallinity of the oxide, while AFM measured a RMS roughness of 1.32 nm. The capacitive behavior of Nb2O5 and its interface characteristics with AlGaN were estimated by CV characteristics.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
M. Meer, P. Pohekar, B. Parvez, S. Ganguly, D. Saha
Summary: In this study, the thermal oxidation of nickel as gate dielectrics is used to improve the characteristics of GaN-based metal oxide semiconductor high electron mobility transistors (HEMTs). The use of NiO as the gate dielectric leads to significant improvements in drive current, transconductance, subthreshold swing, unity current gain frequency, and gate current leakage. Additionally, a positive shift in threshold voltage is observed for the NiO-based gate dielectric devices compared to the Schottky barrier HEMTs.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Review
Engineering, Multidisciplinary
J. Ajayan, D. Nirmal, R. Ramesh, Sandip Bhattacharya, Shubham Tayal, L. M. I. Leo Joseph, Laxman Raju Thoutam, D. Ajitha
Summary: This article discusses the widespread use of hydrogen in various fields and the demand for high-performance H-2 sensors, highlighting the promising properties of the AlGaN and GaN material systems for H-2 sensor development. The sensitivity and response time of different types of H-2 sensors have been reported, showcasing the potential for future aerospace and industrial applications.
Article
Nanoscience & Nanotechnology
Alice Hospodkova, Frantisek Hajek, Tomas Hubacek, Zuzana Gedeonova, Pavel Hubik, Matej Hyvl, Jiri Pangrac, Filip Dominec, Tereza Kosutova
Summary: This study proposes a new morphology for the AlGaN/GaN interface to improve the electron mobility in the 2D electron gas of HEMT structures. The conventional method for preparing GaN channels involves high-temperature growth at around 1000 degrees C in an H2 atmosphere. However, this study shows that a smooth AlGaN/GaN interface is not necessary for achieving high electron mobility in 2DEG. Surprisingly, replacing the high-temperature GaN channel layer with a layer grown at 870 degrees C in an N2 atmosphere leads to a significant increase in electron Hall mobility, which can be attributed to the spatial separation of electrons by V-pits surrounding dislocations.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Soumen Mazumder, Parthasarathi Pal, Ting-Jia Tsai, Pu-Chou Lin, Yeong-Her Wang
Summary: A flash-like Al2O3/SiO2 stacked layer AlGaN/GaN-based MIS-HEMT was fabricated using trap assisted technique, showing a significant positive shifting of threshold voltage after applying low program voltage. The device exhibited a low threshold voltage and decent maximum drain current, along with a reduction in gate leakage current.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Condensed Matter
V Sandeep, J. Charles Pravin
Summary: The impact of graded Al0.05Ga0.95N sub-channel on the DC characteristics of AlGaN/GaN/AlInN MOS-HEMT was investigated through TCAD simulation, analyzing various device and RF parameters. The results showed that the T-gated structure enhanced the breakdown voltage of the device and the linearity improvement was achieved through the graded AlGaN sub-channel.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Physics, Applied
Xiaoning Zhan, Jianxun Liu, Xiujian Sun, Yingnan Huang, Hongwei Gao, Yu Zhou, Qian Li, Qian Sun, Hui Yang
Summary: The main issues in commercializing GaN-on-Si RF devices are wafer bowing and thermal resistance caused by the conventional AlN/AlGaN multilayer or superlattice buffer. The growth of a crack-free 2 μm thick GaN film on high-resistivity Si with a single-layer AlN buffer is reported. The quasi-2D GaN nucleation on the AlN buffer layer reduces wafer warpage and maintains high crystalline quality, with low residual stress. This work opens up possibilities for low-cost and high-performance GaN RF devices on HR-Si.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Aakash Jadhav, Takashi Ozawa, Ali Baratov, Joel T. Asubar, Masaaki Kuzuhara, Akio Wakejima, Shunpei Yamashita, Manato Deki, Shugo Nitta, Yoshio Honda, Hiroshi Amano, Sourajeet Roy, Biplab Sarkar
Summary: In this work, modified lumped small signal circuit models of AlGaN/GaN MOS-HEMTs are developed by fitting the broadband measured Y-parameters with rational functions and additional passive circuit elements. Increasing the order of rational functions improves the accuracy of the proposed models in estimating higher order poles and zeroes in the experimentally measured Y-parameters of AlGaN/GaN MOS-HEMTs, making them more accurate than conventional SSC models.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Chih-Yao Chang, Chun-Ta Hsu, Yao-Luen Shen, Tian-Li Wu, Wei-Hung Kuo, Suh-Fang Lin, Chih-Fang Huang
Summary: A fully transparent AlGaN/GaN HEMT (FT-HEMT) with indium-tin-oxide (ITO) as a transparent electrode was fabricated, showing high field-effect mobility and current density. The transmittance for a fabricated chip was over 70% in the visible range of 400 - 700 nm, demonstrating great potential for transparent and/or flexible electronics and optoelectronic devices.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Ruby Mann, Sonam Rewari, Praveen Pal, Shobha Sharma, R. S. Gupta
Summary: An AlGaN/GaN MOS-HEMT-based dosimeter is proposed to evaluate the impact of absorbed radiation doses using interface trap charges. Various electrical parameters are studied, and it is found that the threshold voltage and drain current increase proportionally to the radiation dose. The functionality of the device is affected by modifying the charge carrier concentration in the two-dimensional electron gas.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Luolan Wang, Jun Zhang, Zhenhui Wang, Wei Xiong, Shihan Yan, Zhiheng Gong, Nian Zhang, Shijun Zhao, Xinwei Wang, Yan Chen
Summary: This work presents an atomic-scale interfacial engineering strategy to construct highly-active electrocatalyst for glucose detection. Ni(OH)(2) nanosheets are decorated with an ultra-thin layer of Co9S8 using the atomic layer deposition (ALD) technique. After in-situ reconstruction, Ni@Co heterostructure consisting of Ni hydroxide nanosheets and CoOx clusters is obtained, which shows outstanding electrochemical glucose sensing performance. The presence of surface CoOx not only lowers the valence state of Ni, but also facilitates the deprotonation of Ni(OH)(2) to form NiOOH active species for glucose oxidation. The approach used in this work can be adapted to synthesizing high-performance electrocatalysts for other energy and environmental devices.
APPLIED SURFACE SCIENCE
(2023)
Article
Environmental Sciences
Laila Noureen, Qian Wang, Muhammad Humayun, Waqas Ali Shah, Qiyong Xu, Xinwei Wang
Summary: Photocatalysis is a promising method for environmental remediation, but challenges such as low efficiency, large-scale production, and stability hinder its broad application. Recent efforts have been made to advance the technology, focusing on improving light sensitivity, charge separation, and hybrid approaches. This review provides an overview of the latest progress in the field and emphasizes the current issues of low efficiency and poor stability. Future suggestions are also provided to enhance photocatalyst performance and reduce production costs. This review aims to offer valuable insights into the fundamental science and technical engineering of photocatalysis in environmental remediation.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Yuqing Zhang, Jiye Li, Jinxiong Li, Tengyan Huang, Yuhang Guan, Yuhan Zhang, Huan Yang, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: Here we present a self-aligned top gate (SATG) coplanar amorphous InGaZnO (a-IGZO) thin film transistor (TFT) technology with a down-scaled gate length (Lg) of 97 nm and a gate insulator (GI) AlOx of 4 nm (equivalent oxide thickness = 2.4 nm). The fabricated TFT exhibits excellent performance, including a large on-current (ION) of 17.9 mu A/mu m, a high on/off current ratio over 10^(9), a positive threshold voltage (V-TH) of 0.07 V, and a minimum drain-induced barrier lowering (DIBL) of 77 mV/V. These results are attributed to the abrupt homojunction at the source-drain sides and the high-quality ultrathin gate insulator of AlOx by atomic layer deposition (ALD). With the compatibility with modern integrated circuit (IC) process, the developed SATG a-IGZO TFT technology is suitable for back-end-of-line (BEOL) and 3D integrations of advanced ICs.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Chenghao Jia, Xuepeng Xiang, Jun Zhang, Zuyun He, Zhiheng Gong, Huijun Chen, Nian Zhang, Xinwei Wang, Shijun Zhao, Yan Chen
Summary: In this study, it is demonstrated that the OER pathway can be effectively shifted by activating lattice oxygen, leading to strongly enhanced intrinsic activity. The OER performance of RP-phase cobaltite is significantly enhanced as Sr doping at the A site increases, which is attributed to the shift of the reaction pathway from AEM to LOM. Advanced spectroscopic techniques and density functional theory calculations reveal that the Sr dopant effectively facilitates oxygen ligand hole formation, charge transfer, and oxygen vacancy formation and migration, hence promoting lattice oxygen to participate in surface reactions. These results provide critical insight into the role of oxygen activity and offer a potential way for constructing highly active electrocatalysts.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Zhenhui Wang, Yueyue Wang, Manyu Liu, Meili Xu, Zhixiang Jiang, Yuanhong Gao, Hong Meng, Xinwei Wang
Summary: Efficient charge transfer is achieved in narrowband organic photodiodes (OPDs) by adopting a self-assembly strategy to prepare donor/acceptor bulk heterojunctions as the photoactive layers. This method allows for the fabrication of highly smooth, phase-uniform, and low-defect-density thin films with controlled thickness. A narrowband near-infrared OPD centered at 760 nm with a full-width-at-half-maximum of around 60 nm, peak external quantum efficiency of 49%, and peak specific detectivity of over 10(13) Jones under -5 V is achieved.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Yuqing Zhang, Jiye Li, Jinxiong Li, Tengyan Huang, Yuhang Guan, Yuhan Zhang, Huan Yang, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: This paper presents a capacitor-less embedded dynamic random access memory (eDRAM) technology based on oxide semiconductor (OS) transistors and demonstrates a self-aligned top-gate (SATG) amorphous InGaZnO (a-IGZO) thin-film transistor (TFT) using a simplified three-masks (3M) process. The performance of the TFT is improved by optimizing the gate insulator and interface defects, as well as manipulating the defects in the a-IGZO channel through a rapid thermal anneal. The developed TFTs show high device performance and minimal parasitic capacitances, enabling the realization of a high-performance and high-density monolithic-3D (M3D) integration.
ADVANCED ELECTRONIC MATERIALS
(2023)
Review
Engineering, Manufacturing
Jinxiong Li, Gaoda Chai, Xinwei Wang
Summary: Atomic layer deposition (ALD) has become an essential thin-film technology in the microelectronics industry due to its self-limited layer-by-layer growth feature and the ability to deposit conformal pinhole-free thin films with precise thickness control, especially on 3D structures. This review focuses on the surface chemistry and precursor chemistry aspects of ALD, providing a comprehensive understanding of the involved chemistry to further advance and utilize this technology. The surface chemistry of the gas-solid ALD reactions and the precursor chemistry used in ALD processes are discussed, along with emerging applications in microelectronics and future perspectives of the ALD technology.
INTERNATIONAL JOURNAL OF EXTREME MANUFACTURING
(2023)
Article
Chemistry, Physical
Yuhang Guan, Yuqing Zhang, Jinxiong Li, Jiye Li, Yuhan Zhang, Zhenhui Wang, Yuancan Ding, Mansun Chan, Xinwei Wang, Lei Lu, Shengdong Zhang
Summary: In recent years, high-k gate dielectrics have received increasing attention in amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) due to the need for stronger gate controllability. This study developed an ultra-thin top-gate insulator of atomic-layer-deposited (ALD) HfOx for amorphous indium-gallium-zinc oxide (a-IGZO) TFTs. However, the reliability of the 4-nm HfOx-gated a-IGZO transistor is poor due to interface defects caused by the interface reaction between HfOx and a-IGZO during the ALD process. To improve stability, the a-IGZO channel is pre-treated with strong oxidizing plasma. However, further reducing HfOx thickness increases gate leakage current.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Environmental
Laila Noureen, Shahid Zaman, Waqas Ali Shah, Qian Wang, Muhammad Humayun, Qiyong Xu, Xinwei Wang
Summary: A solar-powered steam generating system is developed for simultaneous water purification and steam sterilization. The system incorporates a three-layer photothermal membrane to produce high-temperature steam that can condense into clean water and efficiently sterilize microbes. The bifunctional device with high-temperature steam generation and solar-steam evaporation capability is significant for sustainable clean water generation and sterilization in remote areas.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Renbo Lei, Yupu Tang, Shihan Yan, Weitao Qiu, Zheng Guo, Xu Tian, Qian Wang, Kai Zhang, Shanshan Ju, Shihe Yang, Xinwei Wang
Summary: This study demonstrates that the plasma-assisted atomic layer deposition technique can effectively improve the photovoltaic performance of BiVO4 photoanodes by installing an ultrathin FeNi layer. This technique successfully addresses the fundamental limitations of BiVO4 photoanodes, leading to enhanced photon-to-current efficiency.
Article
Engineering, Environmental
Qian Wang, Tong Wang, Noureen Laila, Ke Huang, Xinwei Wang, Renbo Lei, Xinyue Bai, Qiyong Xu
Summary: This study presented the hydrothermal synthesis of a photocatalyst by coupling carbon dots (CDs) and bulk TiO2, which exhibited improved photocatalytic performance and bacterial-deactivation ability compared to traditional TiO2. It provides a promising strategy for leachate treatment.
Article
Engineering, Manufacturing
Xinwei Wang, Rong Chen, Shuhui Sun
Summary: Atomic scale engineering is becoming increasingly important in material manufacturing, and atomic layer deposition (ALD) technology offers unique properties for achieving atomic-scale material manufacturing controllability. This article discusses the applications, attributes, technology status, and challenges of ALD technology. It is envisioned that ALD technology will continue to make significant contributions to various industries and technologies in the coming years.
INTERNATIONAL JOURNAL OF EXTREME MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Ke Lu, Yuanhong Gao, Zhenhui Wang, Xinwei Wang, Hong Meng
Summary: In this study, atomic-layer-deposition of ultrathin Co3O4 anode interlayers as hole transporting/electron blocking layers in organic photodetectors is investigated. The highly smooth Co3O4 interlayer with a deep valence band and a shallow conduction band effectively promotes charge extraction and suppresses electron injection, resulting in improved photodetection performance. At an optimal thickness of 1 nm, the Co3O4 device exhibits significantly lower dark current compared to the PEDOT:PSS device.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Wei Qian, Weitao Qiu, Shanshan Yu, Duan Huang, Renbo Lei, Xianzhen Huang, Shuang Xiao, Xinwei Wang, Shihe Yang
Summary: The emergence of organic-inorganic hybrid perovskites has enabled the use of aerosol-liquid-solid technology for direct X-ray detectors. However, the film quality from this process is often compromised when deposited in ambient conditions with uncontrolled humidity. In this study, a solvent engineering strategy is developed to obtain high-quality perovskite thick films, minimizing the negative effect of the ambient conditions and improving the overall performance of the X-ray detectors.
Article
Engineering, Electrical & Electronic
Huaqing Huang, Linxin Guo, Yunbiao Zhao, Shengyuan Peng, Wenjun Ma, Xinwei Wang, Jianming Xue
Summary: This study reports a proton detector based on the methylammonium lead tribromide (MAPbBr3) perovskite single crystal, which demonstrates remarkable radiation tolerance. The detector can quantitatively monitor fluence rate and dose up to a high dose of 45 kGy with a low bias electric field. Furthermore, the detector exhibits a desirable self-healing characteristic, rapidly recovering its dark current after irradiation, enhancing its radiation tolerance. These findings suggest that the perovskite-based proton detector shows great promise for future applications in proton therapy, proton radiography, etc.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
