Article
Chemistry, Physical
Yuxin Deng, Ziqi Yang, Tongling Xu, Huaxing Jiang, Kar Wei Ng, Chao Liao, Danni Su, Yanli Pei, Zimin Chen, Gang Wang, Xing Lu
Summary: Due to the difficulty of p-type doping in beta-Ga2O3, the NiO/beta-Ga2O3 heterojunction is considered as a promising candidate for bipolar devices. In this study, the band alignment and electrical properties of NiO/beta-Ga2O3 heterojunctions with different beta-Ga2O3 orientations were comparatively studied. It was found that there is a type-II band alignment between NiO and beta-Ga2O3, and the valence band offsets and conduction band offsets vary with different substrate orientations. The influence of substrate orientations on the properties of NiO/beta-Ga2O3 heterojunctions is of great importance for the design and optimization of beta-Ga2O3-based heterojunction devices.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Jun-Ding Zheng, Yi-Feng Zhao, Zhi-Qiang Bao, Yu-Hao Shen, Zhao Guan, Ni Zhong, Fang-Yu Yue, Ping-Hua Xiang, Chun-Gang Duan
Summary: Recently, the two-dimensional in-plane ferroelectric materials group-IV monochalcogenides MX (M = Ge, Sn; X = S, Se) have attracted much attention due to their rich physical properties. This study focuses on the flexoelectric effect on the electronic, optical and transport properties in monolayer germanium selenide (GeSe), and finds that bending can be used to fabricate p-n homojunctions.
Article
Chemistry, Physical
Georgios Chatzigiannakis, Angelina Jaros, Renaud Leturcq, Joergen Jungclaus, Tobias Voss, Spiros Gardelis, Maria Kandyla
Summary: An isotype heterojunction n(+)-ZnO/n-Si photodetector has been developed, which can operate in a wavelength-selective or broadband manner depending on the applied bias voltage. At zero bias, it can distinguish between UV, visible, and near IR photons by controlling the polarity of the photocurrent.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Jianjun Shi, Hongwei Liang, Xiaochuan Xia, Qasim Abbas
Summary: In this study, single-oriented CuGaO2 films were successfully grown on beta-Ga2O3 substrate. Investigation of energy band offsets and alignment at CuGaO2/beta-Ga2O3 heterojunction revealed a type-II band alignment. The prepared CuGaO2/beta-Ga2O3 heterojunction-based ultraviolet photodetector exhibited a significant ultraviolet photoresponse at zero bias voltage, showing potential for future self-power deep UV optoelectronic devices facilitated by the combination of beta-Ga2O3 and wide bandgap delafossite oxide semiconductor.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Haidong Yuan, Jie Su, Pengliang Zhang, Zhenhua Lin, Jincheng Zhang, Jie Zhang, Jingjing Chang, Yue Hao
Summary: The optoelectronic properties of beta-Ga2O3/Janus-TMD heterostructures were investigated with different E(in)s, revealing the impact of E-in direction on band alignments and providing guidance for designing high-performance Ga2O3 optoelectronic devices.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Hua Zhou, Hui-Qiong Wang, Jin-Cheng Zheng, Xiao-Dan Wang, Yufeng Zhang, Junyong Kang, Lihua Zhang, Kim Kisslinger, Rui Wu, Jia-Ou Wang, Hai-Jie Qian, Kurash Ibrahim
Summary: The electronic structure of the STO/ZnO heterointerface was investigated using in situ photoemission spectroscopy and X-ray absorption spectroscopy, revealing the formation of polar interfaces and electron transfer phenomena.
RESULTS IN PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Damanpreet Kaur, Riya Wadhwa, Yuchen Nisika, Yuchen Zhang, Poojan Indrajeet Kaswekar, Quinn Qiao, Anju D. Sharma, Mark Poliks, Mukesh Kumar
Summary: This study reports the band alignment modification of heterojunction formed between amorphous Ga2O3 and CdS. The annealed heterojunction device shows a reduction in dark current, enhanced photocurrent, and shorter response time. The changes at the interface due to annealing lead to a significant alteration in the band alignment and carrier dynamics, thereby completely altering the ultimate device performance.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Daqiang Hu, Ying Wang, Yandong Wang, Weiliang Huan, Xin Dong, Jingzhi Yin
Summary: The beta-Ga2O3/n-Si isotype heterojunction photodetector fabricated by depositing beta-Ga2O3 film on n-type Si substrate using metal-organic chemical vapor deposition demonstrates excellent photodetection properties with fast response speed and high sensitivity and selectivity to solar-blind ultraviolet light.
Article
Physics, Multidisciplinary
Yanting Chen, Hongkai Ning, Yue Kuang, Xing-Xing Yu, He-He Gong, Xuanhu Chen, Fang-Fang Ren, Shulin Gu, Rong Zhang, Youdou Zheng, Xinran Wang, Jiandong Ye
Summary: Ferroelectric-semiconductor heterostructures provide an alternative strategy for manipulating polarization towards advanced devices. This work focuses on the heteroepitaxial construction, band structure alignment, and polarization engineering of the kappa-Ga2O3/GaN ferroelectric/polar heterojunction. The findings of this study have implications for the rational design of ferroelectric/polar heterojunctions for applications in power electronic devices, advanced memories, and ultra-low loss negative capacitance transistors.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Crystallography
Yan Zuo, Qian Feng, Tao Zhang, HaiFeng Luo, Xusheng Tian, Yuncong Cai, Yangyang Gao, Jincheng Zhang, Chunfu Zhang, Hong Zhou, Yue Hao
Summary: Al2O3 films were successfully deposited on α-Ga2O3 and ε-Ga2O3 films using atomic layer deposition (ALD) with different oxygen sources, resulting in different band diagrams. These results suggest that ALD-grown Al2O3 can be used as a gate dielectric in α-Ga2O3 and ε-Ga2O3 power devices.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Chemistry, Physical
Meijiao Xing, Dayong Jiang, Man Zhao
Summary: A new sandwich-structured photodetector (SSPD) was designed and fabricated to solve the problem of weak light detection in traditional metal-semiconductor-metal (MSM) photodetectors. A high external quantum efficiency (EQE) was achieved by growing Ga2O3 film layer on the electrode area of the ZnO/Au MSM-structured device. The ZnO/Au/Ga2O3 SSPD showed an EQE of up to 11626% at 30 V, which is 18 times higher than the traditional ZnO/Ga2O3/Au PD.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Ekaterine Chikoidze, Jacob Leach, Zeyu Chi, Jurgen von Bardeleben, Belen Ballesteros, Anne-Marie Goncalves, Tamar Tchelidze, Yves Dumont, Amador Perez-Tomas
Summary: This study reports the discovery of an exceptional p-type 2DHG surface on a Si-doped monoclinic (010) beta-Ga2O3 crystal. The free carriers at the surface are determined to be holes with a high concentration and mobility.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Physics, Applied
Matthew Hilfiker, Rafal Korlacki, Riena Jinno, Yongjin Cho, Huili Grace Xing, Debdeep Jena, Ufuk Kilic, Megan Stokey, Mathias Schubert
Summary: In this study, a combined approach of generalized spectroscopic ellipsometry and density functional theory was used to analyze the anisotropic dielectric functions of an alpha-Ga2O3 thin film. Multiple direct band-to-band transitions and excitonic contributions were identified, shedding light on the bandgap properties and optical characteristics of the material.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Dohwan Jung, Yoonseo Jang, Prakash R. Sultane, Christopher W. Bielawski, Jungwoo Oh
Summary: The energy-band alignment between atomic layer-deposited beryllium oxide (BeO) films and beta-Ga2O3 substrates is reported. It was found that the ALD BeO dielectric on the beta-Ga2O3 substrate provides a higher conduction band offset, which has the potential to lower the gate leakage current density of beta-Ga2O3 power devices.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Lin Gu, Hong-Ping Ma, Yuan Li, An-Feng Wang, Wen-Jie Chen, Zhuo-Rui Tang, Yi Shen, Fang yuan Sun, Jing-Tao Zhu, Qing-Chun Zhang
Summary: In this work, the characteristics of Ga2O3/diamond heterostructure were thoroughly investigated after depositing Ga2O3 thin film on diamond using atomic layer deposition. The results showed that Ga2O3 film was amorphous and diamond was polycrystalline. The surfaces of both Ga2O3 film and diamond substrate were smooth. The optical properties were studied using spectroscopic ellipsometry and UV/Vis/NIR spectrophotometer. The band alignment of the heterojunction was staggered (type II). The thermal conductivity of Ga2O3 and the thermal boundary conductivity of the heterointerface were determined using time-domain thermoreflectance measurements. These findings demonstrate the feasibility and potential of Ga2O3-on-diamond hetero-integration.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Hui Guo, Hehe Gong, Pengfei Shao, Xinxin Yu, Jin Wang, Rui Wang, Le Yu, Jiandong Ye, Dunjun Chen, Hai Lu, Rong Zhang, Youdou Zheng
Summary: This study demonstrated a normally-off AlGaN/GaN HEMT using p-NiO as a gate stack, showing excellent performance and high breakdown voltage, with outstanding stability in terms of V-TH shift.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Xinyu Sun, Zhengpeng Wang, Hehe Gong, Xuanhu Chen, Yijun Zhang, Zhiyuan Wang, Xinxin Yu, Fangfang Ren, Hai Lu, Shulin Gu, Youdou Zheng, Rong Zhang, Jiandong Ye
Summary: We report on the fabrication of high-performance solar-blind photodetectors using an m-plane alpha-Ga(2)O(3) epilayer, grown by laser molecular beam epitaxy. The detector exhibits low dark current, high rejection ratio, high photo-to-dark current ratio, and high responsivity. Additionally, it demonstrates robust performance at high temperatures.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Teja Potocnik, Peter J. Christopher, Ralf Mouthaan, Tom Albrow-Owen, Oliver J. Burton, Chennupati Jagadish, Hark Hoe Tan, Timothy D. Wilkinson, Stephan Hofmann, Hannah J. Joyce, Jack A. Alexander-Webber
Summary: We present a high-throughput method for identifying and characterizing individual nanowires, and for designing electrode patterns with high alignment accuracy. Our method utilizes an optimized marker system called LithoTag, which allows for nanometer-scale position determination of nanostructures. By incorporating computer vision algorithms, we can obtain location and property data for individual nanowires. Experimental results demonstrate the effectiveness of this method in automating nanodevice processing and improving fabrication efficiency.
Article
Nanoscience & Nanotechnology
Tuomas Haggren, Julie Tournet, Chennupati Jagadish, Hark Hoe Tan, Jani Oksanen
Summary: A scalable multilayer epitaxial lift-off process is demonstrated, which allows efficient removal of epitaxially grown materials from their host substrate without external strains. The films retain good integrity after lift-off and can be further processed into devices. Cost analysis shows a 4-to-6-fold reduction in cost compared to the single-layer epitaxial lift-off process, making it significant for III-V photovoltaics and other technologies relying on thin-film III-V semiconductors.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Chong-De Zhang, Fang-Fang Ren, Mingbin Yu, Baoshan Zhang, Shulin Gu, Rong Zhang, Youdou Zheng, Jiandong Ye
Summary: This study demonstrates the rational design of an Al/Al2O3/Ga2O3 metal-insulator-semiconductor (MIS) photodetector with enhanced responsivity, suppressed sub-gap response, and ultralow dark current.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Optics
Wei Wen Wong, Naiyin Wang, Chennupati Jagadish, Hark Hoe Tan
Summary: This study presents a novel approach to realize on-chip microlasers with directional emission in an all-dielectric, bottom-up grown material system. By coupling the laser emission into a vertical nanowire, efficient optical coupling is achieved and the emission directivity and side mode suppression can be improved by tuning the geometric parameters of the system.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Zesen Liu, Xinxin Yu, Jianhong Zhang, Xinghua Liu, Jiandong Ye, Fang -fang Ren, Yiwang Wang, Wei-zong Xu, Dong Zhou, Rong Zhang, Youdou Zheng, Hai Lu
Summary: The authors demonstrated the enhanced light output of 275-nm AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) structures by employing shallow photonic crystal (PC) patterns on the p-AlGaN contact layer surface. The intensity of the emission from the top or bottom can be enhanced by up to 331% or 246%, respectively, compared to the unpatterned sample due to high-order coherent diffraction and Purcell enhancement of spontaneous emission. This study suggests a simpler way for achieving more energy-efficient DUV LEDs with high emission for various applications in disinfection and sterilization.
Article
Physics, Applied
Xinghua Liu, Fang-Fang Ren, Zhengpeng Wang, Xinyu Sun, Qunsi Yang, Yiwang Wang, Jiandong Ye, Xiufang Chen, Wei-Zong Xu, Dong Zhou, Xiangang Xu, Rong Zhang, Hai Lu
Summary: By studying the optical emission spectra of defects, the thermally-driven defect dynamic reaction in ion implanted 4H-SiC has been investigated. The conversion from silicon vacancies (V-Si) to carbon antisite-vacancy pairs (C-Si-V-C) has been observed upon annealing, which provides guidance for defect engineering in SiC.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Jun-Wei Liao, Zhen-Ting Huang, Chia-Hung Wu, Nikita Gagrani, Hark Hoe Tan, Chennupati Jagadish, Kuo-Ping Chen, Tien-Chang Lu
Summary: In this study, localized surface plasmon lasing at room temperature in the communication band was achieved using metallic nanoholes as plasmonic nanocavity and InP nanowires as gain medium. Optimization of laser performance was demonstrated through coupling between two metallic nanoholes, allowing for manipulation of lasing properties. These plasmonic nanolasers offer lower power consumption, smaller mode volumes, and higher spontaneous emission coupling factors, making them promising for high-density sensing and photonic integrated circuits.
Article
Optics
Jinjie Zhu, Qing Cai, Haifan You, Hui Guo, Jin Wang, Junjun Xue, Jiandong Ye, Dunjun Chen
Summary: In this study, an optimized design strategy for Ga2O3/GaN heterostructure bi-color Ultraviolet photodetector was presented, which achieved high responsivity and UV-to-visible rejection ratio. The electric field distribution of the optical absorption region was modified by optimizing the doping concentration and thickness ratio of the heterostructure, enabling better separation and transport of photogenerated carriers. Moreover, the band offset modulation of the Ga2O3/GaN heterostructure enhanced the photoconductive gain, leading to successful dual-band ultraviolet detection with high responsivity.
Article
Optics
Khosro Zangeneh Kamali, Lei Xu, Nikita Gagrani, Hark Hoe Tan, Chennupati Jagadish, Andrey Miroshnichenko, Dragomir Neshev, Mohsen Rahmani
Summary: Metasurfaces with dynamic tunability in their optical behaviour are highly desired for various applications. In this study, we demonstrate electrically tunable metasurfaces driven by thermo-optic effect and flash-heating in silicon. The device allows for video frame rate optical switching over multiple pixels and is compatible with modern electronic display technologies. It shows advantages such as large modulation depth, low optical loss, low input voltage requirement, and high switching speed.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Bikesh Gupta, Doudou Zhang, Hongjun Chen, Chennupati Jagadish, Hark Hoe Tan, Siva Karuturi
Summary: This study presents a novel approach for fabricating high-performance solar cells based on InP heterojunctions using a solution-processed ferri-hydrite (Fh) electron-selective contact (ESC). The champion cell efficiency of 16.6% is achieved, which is a significant improvement over those from previous studies using other solution-processed ESC materials. The Fh layer not only selectively extracts photogenerated electrons from InP but also simultaneously serves as a surface protection layer, improving the cell's long-term stability.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Wei Wen Wong, Naiyin Wang, Bryan D. D. Esser, Stephen A. A. Church, Li Li, Mark Lockrey, Igor Aharonovich, Patrick Parkinson, Joanne Etheridge, Chennupati Jagadish, Hark Hoe Tan
Summary: In this study, we utilize the selective area epitaxy method to deterministically engineer thousands of microring lasers on a single chip. By elucidating a detailed growth mechanism and controlling the adatom diffusion lengths, we achieve ultrasmooth cavity sidewalls. These engineered devices exhibit a tunable emission wavelength in the telecommunication O-band and show low-threshold lasing with high device efficacy across the chip. This work marks a significant milestone toward the implementation of a fully integrated III-V materials platform for next-generation high-density integrated photonic and optoelectronic circuits.
Article
Multidisciplinary Sciences
Feng Zhou, Hehe Gong, Ming Xiao, Yunwei Ma, Zhengpeng Wang, Xinxin Yu, Li Li, Lan Fu, Hark Hoe Tan, Yi Yang, Fang-Fang Ren, Shulin Gu, Youdou Zheng, Hai Lu, Rong Zhang, Yuhao Zhang, Jiandong Ye
Summary: In this study, NiO/Ga2O3 heterojunctions with smaller reverse recovery, higher switching speed, and a robustness competitive to that of conventional homojunctions were reported. Avalanche and surge robustness involve fundamental carrier dynamics under high electric field and current density, and are prerequisites for power devices in power electronics applications. The heterojunction formed between n-type gallium oxide and p-type nickel oxide breaks the trade-off between robustness and switching speed in conventional homojunctions, and removes a key hurdle to advance ultra-wide bandgap semiconductor devices for power industrial applications.
NATURE COMMUNICATIONS
(2023)
