Article
Engineering, Electrical & Electronic
Mingzhuo Hua, Zhourui Xu, Xusheng Tian, Zhengxing Wang, Chunfu Zhang, Shenglei Zhao, Yachao Zhang, Jing Ning, Qian Feng, Jincheng Zhang, Hao Yue
Summary: The radiation effect of swift heavy ions on Au/Ni/beta-Ga2O3 vertical Schottky barrier diodes was investigated at different fluences. The Schottky barrier height and ideality factor decreased, while the turn-on voltage increased after radiation, along with a decrease in the reverse breakdown voltage. The carrier concentration also decreased significantly. Trap density at the Ni/beta-Ga2O3 interface was extracted and found to be dependent on the energy level.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Qihao Zhang, Jiangwei Liu, Chunming Tu, Dongyuan Zhai, Min He, Jiwu Lu
Summary: High-performance beta-Ga2O3-based Schottky barrier diodes (SBDs) and metal-semiconductor field-effect transistors (MESFETs) were fabricated on a highly doped epitaxial wafer. The electrical properties and stabilities of these devices after annealing were investigated. The results showed excellent ON/OFF ratios for all SBDs, and the MESFETs exhibited pinch-off and saturation characteristics with high drain currents, surpassing previous reports. The study provides valuable insights for the development of practical applications of beta-Ga2O3-based electronic devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Applied
Takaya Sugiura, Nobuhiko Nakano
Summary: This study focuses on the breakdown operations modeling of gallium oxide (Ga2O3), proposing models that consider both soft and hard breakdown phenomena. The impact ionization model of β-Ga2O3 in <001> orientation is improved, reproducing hard breakdown operations. A barrier lowering model is also determined for reproducing soft breakdown operations. These modeling outcomes are crucial for predicting reverse-biased operations and further technological development and applications of Ga2O3.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Coatings & Films
A. Parisini, P. Mazzolini, O. Bierwagen, C. Borelli, K. Egbo, A. Sacchi, M. Bosi, L. Seravalli, A. Tahraoui, R. Fornari
Summary: SnO/ ε-Ga2O3 vertical p-n diodes with planar geometry have been fabricated and investigated. The in-plane conduction through the Si-doped ε-Ga2O3 layer significantly affects the performance of the diodes, showing typical features of variable range hopping transport.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Engineering, Electrical & Electronic
Haodong Hu, Yibo Wang, Xiaole Jia, Yuewen Li, Bochang Li, Zhengdong Luo, Xiangyu Zeng, Cizhe Fang, Yan Liu, Jinggang Hao, Yiyang Shan, Hong Dong, Yue Hao, Genquan Han
Summary: We propose a method to enhance the electrical performance of Pt/beta-Ga2O3 Schottky barrier diodes (SBDs) by treating the surface with low-temperature O-2 gas annealing. The pretreatment of beta-Ga2O3 surface with O-2 gas for 5 minutes at 400 degrees C increases the breakdown voltage (Vbr) by 18% and improves power figure-of-merit (PFOM) by 42% compared to control devices. X-ray photoelectron spectroscopy (XPS) analysis reveals that O-2 gas pretreatment leads to oxidation of Ga2+ states on the surface, resulting in increased Schottky barrier height (q phi(b)) and improved ideality factor of the SBDs. However, prolonging the pretreatment time to 15 minutes leads to reduction of the oxidized Ga2+, causing degraded Vbr and reduced qfb of the SBDs. Overall, our study demonstrates the promising potential of low-temperature O-2 gas annealing for optimizing the Schottky interface of beta-Ga2O3 SBDs and enhancing their performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Zhenyu Qu, Wenhui Xu, Tiangui You, Zhenghao Shen, Tiancheng Zhao, Kai Huang, Ailun Yi, David Wei Zhang, Genquan Han, Xin Ou, Yue Hao
Summary: Surface activated bonding was used to fabricate n-Ga2O3/n(+)-Si heterojunction with an amorphous layer to decrease the current density of Ga2O3/Si Schottky barrier diodes. Simulation results showed that decreasing the Ga2O3 mole fraction and increasing the thickness of amorphous layers in the Ga2O3/Si hetero-interface dramatically reduced the current density and specific on-resistance in Ga2O3/Si SBDs. These findings provide guidance for improving the performance of vertical heterogeneous integration beta-Ga2O3 devices.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Jian-Sian Li, Chao-Ching Chiang, Xinyi Xia, Hsiao-Hsuan Wan, Fan Ren, S. J. Pearton
Summary: Large area vertical NiO/β n-Ga2O/n(+) Ga2O3 heterojunction rectifiers with high breakdown voltage (3.6 kV) and large conducting currents (4.8 A) are demonstrated. The performance exceeds the unipolar 1D limit for GaN, indicating the potential of β-Ga2O3 for future high-power rectification devices. The breakdown voltage is strongly dependent on the carrier concentration in the drift region.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Qiming He, Weibing Hao, Xuanze Zhou, Yu Li, Kai Zhou, Chen Chen, Wenhao Xiong, Guangzhong Jian, Guangwei Xu, Xiaolong Zhao, Xiaojun Wu, Junfa Zhu, Shibing Long
Summary: This work demonstrates vertical beta-Ga2O3 Schottky barrier diodes (SBDs) breaking through the power figure of merit of 1 GW/cm(2) without edge termination. The unreliable surface on the top of the drift region, which naturally formed in air, was removed by inductively coupled plasma etching. The repaired surface was exposed to ambient air for less than 10 minutes during the entire preparation process. Compared with the excessive air exposure samples, the leakage current was well suppressed for the Ni/beta-Ga2O3 SBDs fabricated on a clean surface. Moreover, the blocking voltage reaches a maximum value of 1720 V, and the forward/reverse characteristics of the diodes on the same wafer show good uniformity. These results pave the way for further improving the performance of beta-Ga2O3 devices and verify the potential of beta-Ga2O3 SBDs for power applications.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yuxi Wei, Xiaorong Luo, Yuangang Wang, Juan Lu, Zhuolin Jiang, Jie Wei, Yuanjie Lv, Zhihong Feng
Summary: This study proposes an ultrafast reverse recovery beta-Ga2O3 Schottky barrier diode with improved breakdown voltage, featuring a compound termination design. The compound termination effectively reduces reverse leakage current, enhances reverse recovery and breakdown characteristics, showing great potential for high power and high-frequency applications.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Shaozhong Yue, Xuefeng Zheng, Yuehua Hong, Xiangyu Zhang, Fang Zhang, Yingzhe Wang, Xiaohua Ma, Yue Hao
Summary: This study investigates the effect of neutron irradiation on the electrical performance of the beta-Ga2O3 Schottky barrier diode (SBD) device. The results show that after neutron irradiation, there is a decrease in forward current density (J(F)), reduction in reverse current density (J(R)), and increase in breakdown voltage (V-br) based on current-voltage (I-V) measurements. The density of interface states slightly increases, and there is an increase in trap activation energy after neutron irradiation according to frequency-dependent conductance technique. The carrier concentration across the Ga2O3 drift layer decreases after neutron irradiation based on capacitance-voltage (C-V) measurements.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
Hojoong Kim, Hae-Jun Seok, Joon Hui Park, Kwun-Bum Chung, Sinsu Kyoung, Han-Ki Kim, You Seung Rim
Summary: The study demonstrates an all oxide-based beta-Ga2O3 photodiode with excellent photoelectric performance for deep ultraviolet detection. The use of transparent conductive InZnSnO and InSnO as contacts allows for clear rectifying characteristics, while post-annealing treatment can modify the Schottky interface properties and influence the photoresponse.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Multidisciplinary Sciences
Jincheng Zhang, Pengfei Dong, Kui Dang, Yanni Zhang, Qinglong Yan, Hu Xiang, Jie Su, Zhihong Liu, Mengwei Si, Jiacheng Gao, Moufu Kong, Hong Zhou, Yue Hao
Summary: In this study, Ga2O3 heterojunction PN diodes are demonstrated to overcome the challenges of high breakdown voltage and low doping, achieving high power figure-of-merit and showing great potential for next-generation power electronics applications.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Thomas Bierschenk, Werner Wesch, Boshra Afra, Matias D. Rodriguez, Flyura Djurabekova, Levi Keller, Olli H. Pakarinen, Kai Nordlund, Mark C. Ridgway, Patrick Kluth
Summary: Swift heavy ion irradiation leads to the self-organization of nano-porosity in amorphous Ge, with pores segregating into layers parallel to the sample surface. The self-organization mechanism depends on ion energy, thickness of the amorphous Ge layer, and ion incidence angle, with a characteristic length determined by ion energy and irradiation angle. Molecular dynamics simulations show that voids form due to the transition from low-density amorphous to high-density liquid phase, resulting in a flow away from large pores and surfaces and supporting void formation at the amorphous/crystalline interface.
Article
Chemistry, Physical
Shankar Dutt, Christian Notthoff, Xue Wang, Christina Trautmann, Pablo Mota-Santiago, Patrick Kluth
Summary: This study investigates the annealing kinetics of high energy ion damage in amorphous silicon dioxide (a-SiO2), focusing on the effects of annealing temperature, duration, and ambient environment. Using synchrotron-based small-angle X-ray scattering (SAXS) and etching methods, the track annealing kinetics and ion track morphology were analyzed. The study found that annealing proceeds quicker near the sample surface and showed small changes in the radial density distribution profile of the ion tracks. This research enhances the understanding of ion track damage recovery and its implications for materials used in radioactive waste storage and solid state nanopores.
APPLIED SURFACE SCIENCE
(2023)
Article
Physics, Applied
Yue-Hua Hong, Xue-Feng Zheng, Yun-Long He, Hao Zhang, Zi-Jian Yuan, Xiang-Yu Zhang, Fang Zhang, Ying-Zhe Wang, Xiao-Li Lu, Wei Mao, Xiao-Hua Ma, Yue Hao
Summary: In this study, a beta-Ga2O3 Schottky barrier diode (SBD) with a p-type NiOx guard ring was fabricated, and the functional mechanisms of NiOx in leakage reduction were studied. The experimental results demonstrate that NiOx can increase the barrier height, passivate interfacial defects, and suppress subthreshold leakage and the current crowding effect.
APPLIED PHYSICS LETTERS
(2022)
Article
Spectroscopy
Peipei Hu, Jian Zeng, Shengxia Zhang, Pengfei Zhai, Lijun Xu, Wensi Ai, Khan Maaz, Haizhou Xue, Zongzhen Li, Youmei Sun, Jie Liu, Yuan He
Summary: This comprehensive study reports on damage evolution in InP crystal irradiated by swift heavy ions, revealing that the I-TO/I-LO intensity ratio can be utilized as a nondestructive tool to evaluate lattice damages in zincblende-type crystals. The experimental results show an increase in I-TO/I-LO with increased ion fluences and electron energy loss, along with red-shifts of the LO peak indicating induced tensile strain. Theoretical analysis suggests that defects and disorders strongly impact the intensity ratio.
JOURNAL OF RAMAN SPECTROSCOPY
(2021)
Article
Physics, Multidisciplinary
Tian Cheng, Lan Jian-Xiong, Wang Cang-Long, Zhai Peng-Fei, Liu Jie
Summary: The high-pressure behavior of BaF2 has been studied, and it was found that there are two structural phase transitions at certain pressures. The variations in lattice constants and phonon dispersion curves provide information about the phase transition pressures and structural stability of the material. The hysteresis phenomenon of the P6(3)/mmc structure was explained by kinetic stability.
ACTA PHYSICA SINICA
(2022)
Article
Chemistry, Multidisciplinary
Shuai Nan, Jingjing Niu, Lin Liang, Ziyao Lu, Qikun Wang, Pengfei Zhai, Yingxin Liu, Shan Qin, Weixing Li
Summary: The study suggests that nanoparticles require a higher critical pressure to initiate the transition to high-pressure phase reidite compared to bulk zircons, but the growth of reidite is similar between nanoparticles and bulk zircons after reaching critical pressures, indicating that the growth of reidite is dependent on the core rather than the surface.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Spectroscopy
Peipei Hu, Lijun Xu, Pengfei Zhai, Jian Zeng, Shengxia Zhang, Khan Maaz, Wensi Ai, Zongzhen Li, Youmei Sun, Yuan He, Jie Liu
Summary: This study investigates the effect of swift heavy-ion irradiation on the lattice quality of indium phosphide. The results show that the irradiation activates defects and affects the lattice quality, and there is a competition between defect generation and annealing.
JOURNAL OF RAMAN SPECTROSCOPY
(2022)
Article
Materials Science, Ceramics
Jianxiong Lan, Pengfei Zhai, Shuai Nan, Lijun Xu, Jingjing Niu, Cheng Tian, Zongzhen Li, Weixing Li, Jie Liu, Rodney Charles Ewing
Summary: This study investigates the high-pressure phase stability of CeO2 irradiated by swift heavy ions using high-pressure Raman spectroscopy. The results show that high-fluence ion irradiation significantly enhances the phase stability of CeO2, attributed to the formation of large interstitial-type defect clusters.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Physics, Applied
Li Liu, Jie Liu, PengFei Zhai, ShengXia Zhang, Jian Zeng, PeiPei Hu, LiJun Xu, ZongZhen Li
Summary: YBCO films irradiated with different ions showed the existence of columnar defects, confirmed by TEM analysis. The study found that pinning efficiency η increased monotonically with temperature in all irradiated samples, but in films with latent tracks, η reached its maximum at low magnetic field and then decreased slowly as the magnetic field increased. This phenomenon, along with the peak position Bp below the matching field and the characteristics of samples with larger columnar defects, provide important insights for future applications.
PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS
(2022)
Article
Chemistry, Physical
J. Zeng, P. C. Ma, S. X. Zhang, L. J. Xu, Z. Z. Li, P. F. Zhai, P. P. Hu, K. Maaz, Y. M. Sun, J. Liu
Summary: This study investigates the effects of irradiation on graphene-based devices and the evolution of defects in device materials after thermal annealing. The results show that irradiation with swift heavy ions deteriorates the electrical properties of graphene, while thermal annealing improves the carrier mobility to some extent. However, the defects in graphene are irreparable after annealing. Additionally, high temperature annealing further damages the graphene structure.
APPLIED SURFACE SCIENCE
(2022)
Article
Crystallography
Zongzhen Li, Jie Liu, Pengfei Zhai, Li Liu, Lijun Xu, Shengxia Zhang, Peipei Hu, Jian Zeng
Summary: In this study, the phase transition of pure HfO2 thin films was induced by swift heavy ions irradiation, which stabilized the higher-k phase HfO2 and optimized the interface between HfO2 and Si.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Physics, Applied
Shengxia Zhang, Lijun Xu, Peipei Hu, Khan Maaz, Jian Zeng, Pengfei Zhai, Zongzhen Li, Li Liu, Jie Liu
Summary: In this study, defects were introduced into monolayer WSe2 in a controlled manner using swift heavy ion irradiation, and the excitonic performances in defective WSe2 were investigated using temperature-dependent photoluminescence and transient absorption spectroscopy. It was found that defects introduced by SHI irradiation affect the optical signatures of the excitons by localizing carriers, weakening the exciton-phonon coupling, and suppressing the formation of excitons.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Lijun Xu, Ruslan A. Rymzhanov, Pengfei Zhai, Shengxia Zhang, Peipei Hu, Xuan Meng, Jian Zeng, Youmei Sun, Jie Liu
Summary: In this study, a new method to directly fabricate size- and density-controllable sub-10 nm nanopores in WO3 nanosheets using single swift heavy ions (SHIs) without any chemical etching process was demonstrated. Nanopores with sizes from 1.8 to 7.4 nm can be created in WO3 nanosheets by selecting ions of different electronic energy losses (Se). The viscosity and surface tension of the transient molten phase caused by SHIs were proposed as the key factors for the formation of nanopores. This method provides a way to fabricate solid-state nanopores in materials with a low viscosity and surface tension.
Article
Nanoscience & Nanotechnology
Xiaoyu Gui, Jianjun Xie, Wentao Wang, Borui Hou, Jianping Min, Pengfei Zhai, Linfeng Cai, Jiao Tang, Rui Zhu, Xuanxuan Wu, Jinglai Duan, Jie Liu, Huijun Yao
Summary: The flexible nanoporous SERS substrate developed in this study, synthesized through the in situ synthesis of gold nanostars on an ion-track-etched polycarbonate membrane, can enrich analytes and exhibit excellent Raman performance by taking advantage of hot spots on the gold nanostars. The substrate shows highly repeatable and uniform signals for analytes over a wide concentration range and remains stable even after 2000 times bending. In-body experiments demonstrate that the wearable nanoporous SERS substrates can effectively identify sweat contents and monitor diet-induced variations. This research opens up possibilities for autonomous and noninvasive medical health monitoring.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Zhonghua Zhao, Liuqing Yang, Yang Feng, Daomin Min, Pengfei Zhai, Jie Liu, Shengtao Li
Summary: In this study, the monoclinic to tetragonal phase transition in HfO2 was simulated using molecular dynamics and the two-temperature model. The key factors contributing to the phase transition, including thermal spike and oxygen defects, as well as their coupling effects, were investigated.
Article
Geochemistry & Geophysics
Weixing Li, Yahui Shen, Yueqing Zhou, Pengfei Zhai, Shuai Nan, Jie Liu, Rodney C. Ewing
Summary: Fission events in minerals produce damage tracks that contain critical information about events occurring over different time scales. However, the exact location of fission occurrence along these tracks has never been identified. This study utilizes a novel technique to observe unexpectedly narrow fission tracks near the fission event site, contrary to the conventionally assumed largest diameter. These narrow tracks provide vital spatial information for understanding atomic-scale processes, such as track formation and annealing, with significant implications for fission track thermochronology.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Shuai Nan, Meng Xiao, Zhou Guan, Chuangshi Feng, Chao Huo, Gong Li, Pengfei Zhai, Fuxiang Zhang
Summary: Atomic-scale defects in ion irradiated 4H-SiC were identified using integrated differential phase contrast technique on aberration-corrected transmission electron microscopy and Raman scattering spectrometer. Si- and C-related vacancies and interstitials were imaged in 21 MeV Ni+ ions irradiated 4H-SiC, where electronic energy loss dominates the whole penetration depth. On the other hand, 900 keV Si+ ions produce more point defects, lattice distortions, and dislocations at the depth of damage peak. These point defects provide detailed information for the vibration modes in the Raman spectrum of damaged 4H-SiC. This study provides important fundamental information for nuclear and electronic applications.
MATERIALS CHARACTERIZATION
(2023)
