Article
Materials Science, Multidisciplinary
Wenrui Zhang, Wei Wang, Jingxuan Wei, Shihong Xia, Jianguo Zhang, Li Chen, Dongyang Han, Keming Jiang, Zhenhai Yang, Shen Hu, Li Ji, Jichun Ye
Summary: In this study, we integrate an ultrathin Al2O3 capping layer to improve the performance of ε-Ga2O3 MSM photodetectors. The Al2O3 layer effectively reduces the dark current, increases the photocurrent and response speed. The surface passivation mechanism involves the reduction of surface defects and the reconstruction of a faster surface transport channel. The Al2O3/ε-Ga2O3 MSM photodetector achieves high responsivity, detectivity, photo-to-dark ratio, and UV-vis rejection ratio.
MATERIALS TODAY PHYSICS
(2023)
Article
Physics, Applied
Mei Cui, Yang Xu, Xinyu Sun, Zhengpeng Wang, Hehe Gong, Xuanhu Chen, Tiancheng Hu, Yijun Zhang, Fang-fang Ren, Shulin Gu, Jiandong Ye, Rong Zhang
Summary: In this study, Ga2O3 solar blind photodetectors with different metal-semiconductor contact configurations were constructed and their performance was compared. The Ti/Ga2O3/Ti device operated in a photoconductive mode with high responsivity and rejection ratio, but exhibited sub-gap response and high dark current. The Ni/Ga2O3/Ni device operated in a mixed photovoltaic and photoconductive mode with decent photoresponsivity, high rejection ratio, and eliminated slow photoresponse.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Yong Ha Choi, Kwang Hyeon Baik, Suhyun Kim, Jihyun Kim
Summary: The etching process of beta-Ga2O3 semiconductor using phosphoric acid as demonstrated in this study showed an anisotropic etch pit formation along the [001] direction. The new exposed facet (-201) was found to be stable, and the optoelectronic performance was greatly improved through the effective removal of defects by PEC etching.
APPLIED SURFACE SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Titao Li, Wei Zheng, Siqi Zhu, Fei Wang, Yanming Zhu, Lemin Jia, Zeguo Lin, Feng Huang
Summary: (AlxGa1-x)(2)O-3 is a promising wide-band-gap sesquioxide for VUV photodetectors and high-power field-effect transistors. This study proposed a high-pressure O-2 (20 atm) annealing strategy to improve the crystallinity of beta-(AlxGa1-x)(2)O-3 and achieve a tunable optical band gap, revealing the local structure of Al3+ and the kinetic mechanism of Al3+ diffusion. The combination of HPOA-treated beta-(Al0.69Ga0.31)(2)O-3 films with p-type graphene led to the fabrication of a VUV photovoltaic detector with improved photovoltage and fast temporal response, providing an important strategy for enhancing the band-gap tunability of sesquioxides and zero-power-consumption photodetectors.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Nanoscience & Nanotechnology
MengQi Cui, Zhitao Shao, LiHang Qu, Xin Liu, Huan Yu, Yunxia Wang, Yunxiao Zhang, Zhendong Fu, Yuewu Huang, Wei Feng
Summary: This study explored the photoresponse of an indium oxide (In2O3)-based photoelectrochemical (PEC) ultraviolet photodetector (UV PD) for the first time. The results demonstrate that In2O3 has good UV photoresponse and stability, indicating great potential for application in high-performance PEC UV PDs.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Review
Crystallography
Wannian Fang, Qiang Li, Jiaxing Li, Yuxuan Li, Qifan Zhang, Ransheng Chen, Mingdi Wang, Feng Yun, Tao Wang
Summary: The application of deep ultraviolet detection (DUV) in military and civil fields has gained increasing attention from researchers. Inorganic materials are widely used in DUV detection due to their good stability and controllable growth, compared to the complex molecular structure and poor stability of organic materials. Rapid advances in preparing high-quality ultrawide-bandgap (UWBG) semiconductors have enabled the development of high-performance DUV photodetectors with different geometries, overcoming disadvantages in traditional detectors. This article provides a brief introduction to the development history and types of DUV detectors, and comprehensively summarizes and reviews typical UWBG detection materials and their methods of preparation, as well as their research and application status, including III-nitride semiconductors, gallium oxide, diamond, etc. Additionally, problems related to DUV detection materials, such as material growth, device performance, and future development, are discussed.
Article
Materials Science, Multidisciplinary
Yancheng Chen, Yingjie Lu, Xun Yang, Shunfang Li, Kaiyong Li, Xuexia Chen, Zhiyang Xu, Jinhao Zang, Chongxin Shan
Summary: The bandgap engineering of gallium oxide (Ga2O3) through controlling the oxygen vacancy density and crystalline disorder has been demonstrated to improve conductivity and significantly reduce the bandgap. Practical applications of bandgap engineering by crystalline disorder have led to the development of deep-ultraviolet photodetectors with high responsivity and detectivity. These findings pave the way for high-performance Ga2O3 optoelectronic and electronic devices.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Weiming Liu, Xudan Zhu, Junbo He, Yan Yang, Tiantian Huang, Xin Chen, Rongjun Zhang
Summary: This study demonstrates the tailored optical properties of Ti-doped/incorporating Ga2O3 thin films in the UV region through plasma-enhanced atomic layer deposition. The controlled Ti content in amorphous TGO thin films leads to bandgap tuning and redshifted absorption edges, as well as wide absorption for DUV photoelectronic responses in photodetectors.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Mohammad M. Afandi, Jongsu Kim
Summary: A dual-mode device capable of emitting UV-A light and detecting solar-blind UV light was fabricated using a ZnGa2O4 (ZGO) film in a metal-oxide-semiconductor (MOS) structure. The device demonstrated bi-functionality by changing the electric configurations. This research provides a feasible method for developing multifunctional electronic devices based on MOS structure.
JOURNAL OF SCIENCE-ADVANCED MATERIALS AND DEVICES
(2023)
Article
Nanoscience & Nanotechnology
Yunwei Ma, Yuan Qin, Matthew Porter, Joseph Spencer, Zhonghao Du, Ming Xiao, Boyan Wang, Yifan Wang, Alan G. Jacobs, Han Wang, Marko Tadjer, Yuhao Zhang
Summary: The key obstacle to developing multidimensional power devices in wide-bandgap and ultra-wide bandgap semiconductors is the difficulty of native p-type doping. In this study, nickel oxide (NiO) is investigated as an alternative p-type material. By modulating the acceptor concentration in NiO through oxygen partial pressure, the charge balance and high breakdown field values are achieved. Multidimensional diodes with NiO field-modulation structure demonstrate superior performance compared to prior devices. The promising results suggest that p-type NiO can push the performance limits of power devices.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Electrochemistry
Yan-Fong Lin, You-Yi Jiang, Bo-Lin Huang, Po-Yen Huang, Wen-Jeng Hsueh, Chun-Ying Huang
Summary: In this study, the effects of UVTA on the electrical properties of In-free amorphous ZnSnO thin films were investigated. It was found that UVTA greatly improved the quality of the films and enhanced their gas sensing characteristics. The strategy of UV-assisted thermal annealing allows for the fabrication of gas sensors at low temperature and is applicable to flexible electronics.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Review
Physics, Applied
Zhengpeng Wang, Xuanhu Chen, Fang-Fang Ren, Shulin Gu, Jiandong Ye
Summary: Gallium oxide (Ga2O3) as an ultrawide bandgap semiconductor has excellent physical properties and shows promise in power electronics and deep-ultraviolet optoelectronics applications. However, understanding the defect chemistry in Ga2O3, particularly acceptor dopants and carrier compensation effects, remains a challenge. This review summarizes recent advances in investigating defect properties, carrier dynamics, and optical transitions in Ga2O3, shedding light on the microstructures and origins of defects in various forms of Ga2O3.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Jian-Wei Liang, Yuliar Firdaus, Chun Hong Kang, Jung-Wook Min, Jung-Hong Min, Redha H. Al Ibrahim, Nimer Wehbe, Mohamed Nejib Hedhili, Dimitrios Kaltsas, Leonidas Tsetseris, Sergei Lopatin, Shuiqin Zheng, Tien Khee Ng, Thomas D. Anthopoulos, Boon S. Ooi
Summary: The study enhances the electrical properties of CuSCN thin films by treating them with chlorine and demonstrates their application in photodetectors, achieving favorable performance.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Review
Optics
Chen Xing, Zhou Chang, Liu Ke-wei, Shen De-zhen
Summary: Ultraviolet photodetection technology, using wide bandgap oxide materials, is a promising dual-use detection technology with advantages of easy preparation, high response, and high gain.
Article
Engineering, Environmental
Yikai Liao, You Jin Kim, Munho Kim
Summary: In this research, a high sensitivity self-powered UV photodetector with low dark current and low power consumption was developed by constructing a heterojunction on a commercially available substrate. The detector exhibited excellent performance with a dark current as low as 0.45 pA, a detectivity of 1.9 x 1013 Jones, and fast response times. This work provides a cost-effective approach for the development of highly sensitive UV detecting devices.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Wei Guo, Li Chen, Houqiang Xu, Qiushuang Chen, Kunzi Liu, Tian Luo, Jiean Jiang, Haichen Wu, Guoxin Chen, Huanming Lu, Jichun Ye
Summary: This study investigates the atomic structure and lateral migration of randomly distributed Al-polar inversion domains (IDs) in N-polar AlN films subjected to high-temperature thermal annealing. The IDs gradually shrink and are completely removed with increasing annealing time and temperature due to the lateral migration of the inversion domain boundary induced by strain imbalance. This research clarifies the evolution mechanism of AlN IDs during high-temperature annealing.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Physical
Jianguo Zhang, Wei Wang, Simiao Wu, Zhiming Geng, Jinfu Zhang, Li Chen, Ningtao Liu, Xuejun Yan, Wenrui Zhang, Jichun Ye
Summary: This study reports the controlled growth of metastable gallium oxide films by pulsed laser deposition (PLD) and explores a comprehensive phase evolution picture tuned by synthesis parameters, substrate orientations, and Sn dopants. The stabilization of both undoped and Sn-doped α-Ga2O3 films on a-plane sapphire substrates is demonstrated, and Sn dopants can broaden the growth window of α-Ga2O3. Sn-doped ε-Ga2O3 is more favored than β-Ga2O3 to be stabilized on c-plane substrates, and oxygen pressure is critical for ε-Ga2O3 formation. The structural impact on thermal transport among these metastable Ga2O3 films is investigated, showing different thermal conductivities. This study provides a synthesis guideline for metastable Ga2O3 polymorphs and insights into selective phase stabilization of transition metal oxides.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Applied
Shudong Hu, Dongyang Han, Kemin Jiang, Ningtao Liu, Wei Wang, Jinfu Zhang, Kaisen Liu, Tan Zhang, Wenrui Zhang, Jichun Ye
Summary: In this study, we investigate the influence of oxygen vacancy content and electrode contact on the performance of deep ultraviolet photodetectors based on amorphous Ga2O3 films. By fine-tuning the oxygen ratio, the oxygen vacancy content can be effectively reduced, resulting in optimized device performance with a responsivity of 5.78 A W^-1 and a rise/fall time of 301/89 ms. The formation of metal contacts and its impact on device performance are also studied, showing that Schottky-type devices using Au and Al electrodes exhibit a shorter rise time and lower dark current compared to Ohmic-type devices using Ti electrodes.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Physical
Zilong Wang, Wenrui Zhang, Yang Song, Ningtao Liu, Li Chen, Na An, Deyu Liu, Qitao Liu, Shengcheng Shen, Yongbo Kuang, Jichun Ye
Summary: This study explores the impact of site-selective doping on the structural variation and electron transport in BVO, as well as its implications for designing photoanodes with improved PEC performance. Two types of doped BVO films, with V site substituted with Mo ions or Bi site substituted with Gd ions, are prepared and compared to pristine BVO. It is suggested that Gd-Bi doping facilitates carrier transport through introducing structural distortion and increasing the oxygen vacancy concentration, while MoV doping enhances the donor density and facilitates carrier hopping.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Engineering, Electrical & Electronic
Li Chen, Qiushuang Chen, Cong Chen, Houqiang Xu, Xianchun Peng, Long Yan, Jianzheng Hu, Shiping Guo, Wei Guo, Jichun Ye
Summary: The low electrical conductivity of p-type contact layer is the main reason for the current crowding issue in AlGaN-based deep-ultraviolet light-emitting-diodes (DUV-LEDs), hindering their prosperity. Understanding the current distribution in p-AlGaN is crucial for the rational design of advanced device architectures. This study deposited a fish-bone-shaped p-type electrode on a 280 nm AlGaN DUV-LED to investigate localized emissions. It was found that a significantly raised junction temperature, attributed to high localized current density, caused efficiency droop in DUV-LEDs with fish-bone-shaped p-type electrodes.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Physical
Yuxia Yang, Liu Wang, Shudong Hu, Dongyang Han, Simiao Wu, Zilong Wang, Wenrui Zhang, Jichun Ye
Summary: Ternary complex oxides show significant dependence on structure and functionalities based on their composition. The effect of cation stoichiometry on the physical properties of ZnGa2O4 is well known, but its impact on ultraviolet photodetection behavior is not clear. In this study, a combinatorial pulsed laser deposition technique is used to create graded composition in ZnxGa1-xO films, and their effects on phase, crystallinity, and bandgap are investigated. The photodetection performance is compared by fabricating metal-semiconductor-metal (MSM) photodetectors. The study reveals the optimal compositional range for the best device performance and sheds light on composition-dependent evolution in ultrawidebandgap semiconductors for high-performance ultraviolet photodetection.
APPLIED SURFACE SCIENCE
(2023)
Article
Physics, Applied
Jinfu Zhang, Ningtao Liu, Wenrui Zhang, Jichun Ye
Summary: La-doped BaSnO3 (BLSO) has potential applications in oxide electronic devices due to its high electron mobility and good thermal stability. The interaction between extrinsic La dopants and intrinsic oxygen vacancies in BLSO films influences the transport behavior, but the dominant factor is unclear when the La dopant ratio varies. In this study, BLSO films with lightly doped (0.2%) and heavily doped (7%) regimes were fabricated, and the impact of oxygen vacancies on the structure, optical, and transport properties of these films was investigated systematically. The presence of ozone during film growth resulted in larger strain and lower oxygen vacancy concentrations, as well as decreased mobility and carrier concentration for both lightly doped and heavily doped films. These findings indicate that oxygen vacancies enhance carrier concentration and electron mobility independent of the La dopant ratio and provide an effective strategy for optimizing the electrical properties of BLSO films.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Yuheng Zeng, Zunke Liu, Mingdun Liao, Wei Liu, Zhenhai Yang, Jichun Ye
Summary: The study showed that the carbon or nitrogen-doped polysilicon can mitigate the passivation damage caused by the metallization processes, leading to a smaller decrease in implied open-circuit voltage and a smaller increase in recombination current. However, the higher contact resistivity of the novel polysilicon in finger-metal electrodes overshadowed its advantage in resisting metallization damage. Numerical simulations demonstrated that solar cells with the novel polysilicon still achieved a higher efficiency than those with standard polysilicon.
Article
Materials Science, Multidisciplinary
Wenrui Zhang, Wei Wang, Jingxuan Wei, Shihong Xia, Jianguo Zhang, Li Chen, Dongyang Han, Keming Jiang, Zhenhai Yang, Shen Hu, Li Ji, Jichun Ye
Summary: In this study, we integrate an ultrathin Al2O3 capping layer to improve the performance of ε-Ga2O3 MSM photodetectors. The Al2O3 layer effectively reduces the dark current, increases the photocurrent and response speed. The surface passivation mechanism involves the reduction of surface defects and the reconstruction of a faster surface transport channel. The Al2O3/ε-Ga2O3 MSM photodetector achieves high responsivity, detectivity, photo-to-dark ratio, and UV-vis rejection ratio.
MATERIALS TODAY PHYSICS
(2023)
Article
Physics, Applied
Dongyang Han, Yuxia Yang, Lin Meng, Shudong Hu, Kaisen Liu, Haobo Lin, Ningtao Liu, Wenrui Zhang, Jichun Ye
Summary: In this paper, a self-powered solar-blind UV photodetector based on a 4H-SiC/ZnGa2O4 heterojunction is demonstrated, along with its application in optical communication. The device shows excellent performance, mainly attributed to the characteristics of the 4H-SiC/ZnGa2O4 heterojunction.
APPLIED PHYSICS LETTERS
(2023)
Article
Energy & Fuels
Jingming Zheng, Zhiqin Ying, Zhenhai Yang, Zedong Lin, He Wei, Li Chen, Xi Yang, Yuheng Zeng, Xiaofeng Li, Jichun Ye
Summary: Perovskite/silicon tandem solar cells have made rapid advancements. The recombination layer connecting top and bottom sub-cells plays a critical role in improving efficiency. Researchers have developed a new perovskite/tunnel oxide passivating contact silicon tandem cell with a tunneling recombination layer composed of boron- and phosphorus-doped polycrystalline silicon. The device achieves an efficiency of 29.2% and retains 85% of its initial efficiency after 500 hours. The study also provides insights into carrier transport and tunneling mechanisms, offering guidance for designing high-efficiency tandem solar cells.