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Enhanced back-illuminated Ga2O3-based solar-blind ultraviolet photodetectors

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Science China Technological Sciences 2024年第11期67卷 3477-3484页

作者： YAN ZuYong ZHI YuSong JI XueQiang YUE JianYing WANG JinJin liU Zeng li Shan li peigang HOU Shanglin WU Gang LEI Jingli TANG WeiHua School of Science State Key Laboratory of Advanced Processing and Recycling of Nonferrous MetalsLanzhou University of Technology China Academy of Launch Vehicle Technology School of Integrated Circuits & State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications School of Electronic Information Engineering Inner Mongolia University College of Electronic and Optical Engineering & College of Microelectronics National and Local Joint Engineering Laboratory for RF Integration and Micro-Packing TechnologiesNanjing University of Posts and Telecommunications

Ga2O3is a promising material for deep-ultraviolet（DUV） photodetectors due to its ultra-wide bandgap and high thermal and chemical stability. However, because of their relatively low responsivity, Ga2O3-based photodetectors still have difficulty meeting the requirements of practical applications. Here, we construct a high-performance Ga2O3photodetector realized by back-illumination. Utilizing high-crystallinity epitaxially grown Ga2O3as the DUV absorbing layer and the double-polished Al2O3substrate as the transparent window for injection of photons, the device operating in the back-illuminated mode exhibits a higher DUV photoresponse and faster response speed than in the front-illuminated mode. Therefore, our experimental results have led to the development of a novel strategy for designing and fabricating high-performance Ga2O3photodetectors.

关键词： Ga2O3 back-illuminated solar-blind photodetector

Enhanced back-illuminated GaO-based solar-blind ultraviolet photodetectors

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Science China Technological Sciences 2024年

作者： YAN ZuYong ZHI Yu Song JI XueQiang YUE JianYing WANG JinJin liU Zeng li Shan li peigang HOU Shanglin WU Gang LEI Jingli TANG WeiHua School of Science State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology China Academy of Launch Vehicle Technology School of Integrated Circuits & State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications School of Electronic Information Engineering Inner Mongolia University College of Electronic and Optical Engineering & College of Microelectronics National and Local Joint Engineering Laboratory for RF Integration and Micro-Packing Technologies Nanjing University of Posts and Telecommunications

Ga2O3is a promising material for deep-ultraviolet （DUV） photodetectors due to its ultra-wide bandgap and high thermal and chemical ***,because of their relatively low responsivity,Ga2O3-based photodetectors still have difficulty meeting the requirements of practical ***,we construct a high-performance Ga2O3photodetector realized by *** high-crystallinity epitaxially grown Ga2O3as the DUV absorbing layer and the double-polished Al2O3substrate as the transparent window for injection of photons,the device operating in the back-illuminated mode exhibits a higher DUV photoresponse and faster response speed than in the front-illuminated ***,our experimental results have led to the development of a novel strategy for designing and fabricating high-performance Ga2O3photodetectors.

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吸附材料对黄河兰州段河岸带沉积物中氨氮吸附-解吸的影响

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环境工程学报 2024年第7期18卷 1828-1839页

作者：王若凡田开栋杨光李佩钢刘雨欣兰州交通大学环境与市政工程学院兰州730070 甘肃省黄河水环境重点实验室兰州730070

采用原位覆盖技术可有效提升河岸带沉积物对陆源污染物的吸附作用,且有效控制沉积物内源污染物释放。本研究以沸石、混凝土渣和活性炭作为覆盖材料的代表,结合BET、SEM-EDS、FTIR、XRD等表征手段,通过吸附动力学实验、吸附热力学实验、... 详细信息

采用原位覆盖技术可有效提升河岸带沉积物对陆源污染物的吸附作用,且有效控制沉积物内源污染物释放。本研究以沸石、混凝土渣和活性炭作为覆盖材料的代表,结合BET、SEM-EDS、FTIR、XRD等表征手段,通过吸附动力学实验、吸附热力学实验、混合实验及原位覆盖实验对覆盖材料的氨氮吸附效果及机理进行对比分析,同时研究材料对河岸带沉积物中氨氮吸附及解吸的影响。结果表明,3种材料对20 mg·L^(-1)氨氮溶液中氨氮的吸附动力学表现为:沸石和生物炭在180 min可达到吸附释放平衡,混凝土渣则需720 min。随着环境温度的升高,材料的吸附量不断增加,沸石的理论吸附量值最大。三种材料对氨氮的吸附均属于可自发进行的吸热过程,活性炭吸附主要以物理吸附为主,而沸石、混凝土渣还伴有化学吸附。表征分析结果表明,沸石、混凝土渣在吸附氨氮过程中,两者的羟基官能团与氨氮形成氢键或存在静电引力,这有利于两者对氨氮的吸附,其中混凝土渣的硅氧键及铝氧键官能团也参与了氨氮的吸附。吸附后,沸石的晶体结构未发生改变,但混凝土渣的表面结构受到一定的影响。混合吸附/释放实验结果表明,与无材料添加的对照实验组比较,沸石、混凝土渣和活性炭分别添至沉积物并吸附12 h后,对氨氮质量浓度为20 mg·L^(-1)上覆水中氨氮的吸附率分别提升了23.04%、9.41%和15.72%。但3种材料添至沉积物后对沉积物内源氨氮的控释效果存在差异,添加沸石和活性炭组对沉积物中氨氮的控释率分别提高了6.24%和0.80%,添加混凝土渣组促进了沉积物中氨氮的释放。通过综合对比,沸石吸附氨氮效果最佳,活性炭次之,混凝土渣最差。通过进一步的原位覆盖实验,连续观察14 d后,发现沸石作为原位覆盖材料对上覆水中氨氮吸附率可提升约21.58%,且无诱发沉积物中氨氮释放风险,可成为黄河兰州段河岸带面源污染控制的原位覆盖材料。

关键词：原位覆盖材料河岸带沉积物氨氮吸附固定内源释放

Factors affecting the superconductivity in the process of depositing Nd_(1.85)Ce_(0.15)CuO_(4-δ)by the pulsed electron deposition technique

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Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 747-752页

作者： GUO YanFeng CHEN LeiMing GUO Xi li peigang LEI Ming TANG WeiHua Department of Physics Center for Optoelectronics Materials and DevicesZhejiang Sci-Tech UniversityHangzhou 310018China National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100080China Department of Mathematics and Physics Zhengzhou Institute of Aeronautical Industry and ManagementZhengzhou 450015China

On SrTiO3 single crystal substrate,by using the pulsed electron deposition tech-nique,the high-quality electron doped Nd1.85Ce0.15CuO4?δ superconducting film was successfully fabricated. After careful study on the R-T curves of the obtained sam-ples deposited with different substrate temperatures,thicknesses,annealing methods and pulse frequencies,the effects of them on the superconductivity of the films were found,and the reasons were also analyzed. Additionally,by using the same model of the pulsed laser deposition technique,the relation between the target-to-substrate distance and the deposition pressure was drawn out as a quantitative one.

关键词： pulsed electron deposition Nd_(1.85)Ce_(0.15)CuO_(4-δ) film superconductivity

Large and anisotropic linear magnetoresistance in bulk stoichiometric Cd_3As_2 crystals

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Science China(Physics,Mechanics & Astronomy) 2015年第1期58卷 133-138页

作者： WU DeSheng WANG Xia ZHANG Xu YANG Chongli ZHENG Ping li peigang SHI YouGuo Department of Physics Center for Optoelectronics Materials and Devices Zhejiang Sci-Tech University Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

Cd3As2 was recently identified as a novel three-dimensional （3D） topological semimetal hosting the long-pursuing 3D Dirac Fermion. Crystals of Cd3As2 grown preferentially along the [100] and [112] directions were obtained through the modified chemical vapor transfer growth method, thus allowing the examination of transport anisotropy. The resistivity and magnetore- sistance （MR） are basically linear with respect to magnetic field （H） in the measured temperature range of 2-300 K irrespective of the directions. The linear resistivity and MR are significantly anisotropic not only along [100] and [112] directions but also with respect to tilt angle between the growth directions and H, thus providing transport signatures of the 3D Dirac Fermion as well as the possible linear and anisotropic change of Weyl Fermi surface in H. Very large MR along the [100] direction is observed, even approaching 3100% at 2 K and 14 kOe （10e = 79.5775 A m^-l）. The results would be helpful in renewing interest in studying emergent phenomena arising from bulk 3D Dirac Fermion as well as in paving the way for Cd3As2 to be used in magnetoelectronic sensors.

关键词： topological semimetal linear magnetoresistance transport anisotropy

Oxygen vacancies modulating self-powered photoresponse in PEDOT:PSS/ε-Ga_(2)O_(3)heterojunction by trapping effect

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Science China(Technological Sciences) 2022年第3期65卷 704-712页

作者： li Shan YUE JianYing LU Chao YAN ZuYong liU Zeng li peigang GUO DaoYou WU ZhenPing GUO YuFeng TANG WeiHua Laboratory of Information Functional Materials and Devices School of ScienceState Key Laboratory of Information Photonics and Optical CommunicationsBeijing University of Posts and TelecommunicationsBeijing 100876China College of Electronic and Optical Engineering&College of Microelectronics National and Local Joint Engineering Laboratory for RF Integration and Micro-Packaging TechnologiesNanjing University of Posts and TelecommunicationsNanjing 210023China Center for Optoelectronics Materials and Devices&Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of PhysicsZhejiang Sci-Tech UniversityHangzhou 310018China

Can the modulation effect of charge-carrier transfer be inherited from a single layer to its heterojunction structure?Certainly,the answer is ***,we experimentally verify that the photodetection performance modulation effect of oxygen vacancy(Vo)is transmitted from theε-Ga_(2)O_(3)layer to the PEDOT:PSS/ε-Ga_(2)O_(3)(PGO)hybrid *** adopting the annealedε-Ga_(2)O_(3)films,whose Voconcentrations are remolded by annealing ambients,the constructed PGO photodetectors(PDs)demonstrate regulable self-powered *** the V_(o)defects decrease,the photodetection properties are effectively enhanced with a high photo-to-dark current ratio of 2.37×10^(7),an excellent on/off switching ratio of 6.45×10^(5),fast rise/decay time of 121/72 ms,a large responsivity of 67.9 m A/W,superior detectivity of 9.2×10^(13)Jones,an outstanding external quantum efficiency of 33.2%,and a high rejection ratio(R_(250)/R_(400))of 5.96×10^(6)at 0 V in PGO-O;*** better photoresponse is attributed to the less V_(o)defect concentration in theε-Ga_(2)O_(3)layer,which could favor the lower electron-trapping probability and a more efficient charge-carrier *** the universality of V_(o)defects in oxide materials,the proposed regulation strategy of photoresponse will open the route of high self-powered performance for next-generation ultraviolet PDs.

关键词： oxygen vacancy self-powered photodetector heterojunction PEDOT:PSS/ε-Ga2O3

Au plasmon enhanced high performance β-Ga2O3 solar-blind photo-detector

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Progress in Natural Science:Materials International 2016年第1期26卷 65-68页

作者： Yuehua An Xulong Chu Yuanqi Huang Yusong Zhi Daoyou Guo peigang li Zhenping Wu Weihua Tang Laboratory of Optoelectronics Materials and Devices School of Science Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Center for Optoelectronics Materials and Devices Department of Physics Zhejiang Sci-Tech University

Surface plasmon polariton(SPP) is electro-magnetic wave coupled to free electron oscillations near the surface of metal, and has been used to improve the photoelectric properties in many optoelectronic devices. In the present study, the Au nanoparticles(NPs)/β-GaOcomposite thin film was fabricated through depositing Au ultra-thin film on the β-GaOthin film followed by post-thermal treatment. Compared to bare β-GaOthin film, a significant absorption around 510 nm, which is attributed to SPP of Au NPs, was observed in the UV–vis spectrum of Au NPs/β-GaOcomposite thin film. The results showed that the photoresponse of Au NPs/GaOphotodetector illuminated under 254 nm +532 nm light was much higher than that illuminated under 254 nm light, indicating an enhancement of photoelectric property for the solar-blind photodetector based on β-GaOthin film.

关键词： Au/Ga2O3 Surface plasmon polariton Enhance Solar-blind photodetector

Ultrahigh-performance planar β-Ga2O3 solar-blind Schottky photodiode detectors

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Science China(Technological Sciences) 2021年第1期64卷 59-64页

作者： liU Zeng ZHI YuSong ZHANG ShaoHui li Shan YAN ZuYong GAO Ang ZHANG ShiYu GUO DaoYou WANG Jun WU ZhenPing li peigang TANG WeiHua Laboratory of Information Functional Materials and Devices School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China Division of Interdisciplinary and Comprehensive Research&Platform for Characterization and Test Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026China Center for Optoelectronics Materials and Devices&Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of PhysicsZhejiang Sci-Tech UniversityHangzhou 310018China China Telecom Huzhou Branch Huzhou 313000China

The low dark current, high responsivity and high specific detectivity could be preferably achieved in detectors based on junctions, owing to the efficient constraint of carriers. Compared with the other junctions, planar Schottky junctions have simple structures and technological demands and are easy integrated. Herein, in this work, we prepared the β-Ga_(2)O_(3) thin film by metalorganic chemical vapor deposition method to construct planar Ti/β-Ga2O3/Ni Schottky photodiode detectors with different onstate resistances. Fortunately, all the devices exhibit state-of-the-art performances, such as responsivity of 175–1372 A W^(-1),specific detectivity of 10^(14) Jones and external quantum efficiency of 85700%–671500%. In addition, the dependences of device performances on the on-state resistances indicate that the higher dark currents, photocurrents and photoresponsivities may well be obtained when on-state resistance is smaller, due to the less external power is used to overcome the impendence and condensance at the Ti/β-Ga_(2)O_(3) and Ni/β-Ga_(2)O_(3) interfaces, but contributing to higher electric current flow both in the dark and under illuminations.

关键词： β-Ga2O3 Schotttky photodiode solar-blind device scale on-state resistance

黄河兰州段河岸带沉积物氨氮吸附特征及影响因素

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绿色科技 2024年第18期26卷 170-179页

作者：杨光李佩钢王若凡刘雨欣田开栋谢微唐悦兰州交通大学环境与市政工程学院甘肃兰州730070

通过实验室模拟研究黄河(兰州段)河岸带沉积物对氨氮的吸附特征及影响因素,有助于揭示沉积物在吸附氨氮中“源”与“汇”的特征及天然屏障的作用。研究结果表明:吸附在120 min达到平衡,吸附量达到1200.19 mg/kg。在15、20、25℃下,ENC0... 详细信息

通过实验室模拟研究黄河(兰州段)河岸带沉积物对氨氮的吸附特征及影响因素,有助于揭示沉积物在吸附氨氮中“源”与“汇”的特征及天然屏障的作用。研究结果表明:吸附在120 min达到平衡,吸附量达到1200.19 mg/kg。在15、20、25℃下,ENC0分别为4.17、3.12、2.45 mg/L。吸附过为単分子层吸附,在15、20、25℃下,Langmuir模型拟合得到的最大吸附量Qm分别为1868.57、2638.26、3025.18 mg/kg。沉积物在偏酸性条件下对氨氮的吸附效果较好,吸附量最大pH值为5,吸附量为1222.02 mg/kg。沉积物对氨氮的吸附率随扰动频率的增加而变大,扰动频率为0、50、100、150、200 r/min时,吸附率分别为25.5%、43.0%、50.6%、56.2%和74.3%。沉积物对氨氮的吸附率随氨氮的浓度增加先增大后减小,吸附率在浓度为10 mg/L时达到极值73.5%。通过皮尔逊系数相关性分析得到:R扰动频率(0.948)>R温度(0.923)>RpH(-0.862)>R初始浓度(-0.321)。

关键词：河岸带氨氮吸附影响因素