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A 357.9 nm GaN/AlGaN multiple quantum well ultraviolet laser diode

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Journal of Semiconductors 2022年第1期43卷 15-17页

作者： Jing Yang Degang Zhao zongshun liu Feng Liang Ping Chen Lihong Duan Hai Wang Yongsheng Shi State Key Laboratory of Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China

Ultraviolet(UV)and deep-UV light emitters are prom-ising for various applications including bioagent detection,wa-ter and air purification,dermatology,high-density optical stor-age,and lithography.However,to achieve shorter UV laser di-odes(LDs),especially for the LDs with lasing wavelength less than 360 nm,requires high AlN mole fraction AlGaN clad-ding layer(CL)and waveguide(WG)layers,which usually leads to generate cracks in AlGaN epilayer due to lack of lat-tice-matched substrates.Meanwhile,due to high resistivity of high AlN mole fraction Mg doped AlGaN layers,only few groups have reported GaN-based LDs with emission wavelength shorter than 360 nm[1−8],and up to now,there is no room temperature continuous-wave(CW)operation UV LDs with a lasing wavelength shorter than 360 nm ever repor-ted.Previously,we have reported a UV LD with lasing wavelength of 366 nm[9].In this paper,a higher AlN mole frac-tion of AlGaN WG layers is employed to shorten the LD emis-sion wavelength to less than 360 nm.A lasing wavelength of 357.9 nm is achieved.

关键词： AlGaN laser waveguide

Fabrication of room temperature continuous-wave operation GaN-based ultraviolet laser diodes

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Journal of Semiconductors 2017年第5期38卷 1-3页

作者： Degang Zhao Jing Yang zongshun liu Ping Chen Jianjun Zhu Desheng Jiang Yongsheng Shi Hai Wang Lihong Duan Liqun Zhang Hui Yang State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of Sciences School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of Sciences Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of Sciences

Two kinds of continuous-wave GaN-based ultraviolet laser diodes（LDs） operated at room temperature and with different emission wavelengths are demonstrated.The LDs epitaxial layers are grown on GaN substrate by metalorganic chemical vapor deposition,with a 10 × 600 μm^2 ridge waveguide structure.The electrical and optical characteristics of the ultraviolet LDs are investigated under direct-current injection at room temperature.The stimulated emission peak wavelength of first LD is 392.9 nm,the threshold current density and voltage is 1.5kA/cm^2 and 5.0 V,respectively.The output light power is 80 mW under the 4.0 kA/cm^2 injection current density.The stimulated emission peak wavelength of second LD is 381.9 nm,the threshold current density the voltage is2.8 kA/cm^2 and 5.5 V,respectively.The output light power is 14 mW under a 4.0 kA/cm^2 injection current density.

关键词： GaN-based ultraviolet laser diodes continuous-wave operation threshold current

GaN-based blue laser diode with 6.0 W of output power under continuous-wave operation at room temperature

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Journal of Semiconductors 2021年第11期42卷 70-72页

作者： Feng Liang Degang Zhao zongshun liu Ping Chen Jing Yang Lihong Duan Yongsheng Shi Hai Wang State Key Laboratory of Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China University of Chinese Academy of Sciences Beijing 100049China

In this work,we reported the room-temperature continuous-wave operation of 6.0 W GaN-based blue laser diode(LD),and its stimulated emission wavelength is around 442 nm.The GaN-based high power blue LD is grown on a c-plane GaN substrate by metal organic chemical vapor deposition(MOCVD),and the width and length of the ridge waveguide structure are 30 and 1200μm,respectively.The threshold current is about 400 mA,and corresponding threshold current density is 1.1 kA/cm2.

关键词： GaN blue laser diode high power

Z型Cl-PhC_(2)Cu/Bi_(2)WO_(6)异质结的构建及光催化降解四环素的机制研究

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环境科学学报 2024年第2期44卷 59-70页

作者：张晋帆吕文英刘国光林子力陈颖怡张誉丹张广治余宗舜李宇琳刘德柱张筱昱陈雨广东工业大学环境科学与工程学院粤港澳污染物暴露与健康联合实验室广东省环境催化与健康风险控制重点实验室广州510006

通过简易的超声自组装方法制备了氯掺杂苯乙炔铜(PCl)/三维中空球状钨酸铋(BS)直接Z型异质结光催化材料,并通过场发射扫描电镜、傅里叶变换红外光谱、紫外-可见光漫反射光谱、X射线光电子能谱等手段对PCBS的形貌及其化学性能进行表征.... 详细信息

通过简易的超声自组装方法制备了氯掺杂苯乙炔铜(PCl)/三维中空球状钨酸铋(BS)直接Z型异质结光催化材料,并通过场发射扫描电镜、傅里叶变换红外光谱、紫外-可见光漫反射光谱、X射线光电子能谱等手段对PCBS的形貌及其化学性能进行表征.结果表明,当BS与PCl的质量比为0.3时,对四环素(TC)展现出了最优异的光催化反应速率(0.3411 min^(-1)),分别是BS和PCl的2.66和4.16倍.环境影响因素(pH、不同离子、实际水体等)及循环实验结果表明,PCBS具有极大的实际应用潜力.通过淬灭实验的结果可知,超氧自由基(·O_(2)^(-))和单线态氧(^(1)O_(2))在PCBS降解TC的过程中起到了重要作用.光电化学等测试的结果表明,PCBS的光生载流子分离效率得到明显改善,能更有效率地生成活性物种,其中,PCBS产生·O_(2)^(-)的速率分别是PCl和BS的1.94和44.74倍.此外,循环伏安曲线证明了光生电子在PCBS中的迁移路径复合Z型异质结载流子迁移机制.本研究对基于苯乙炔铜的新型光催化剂开发及应用提供了理论指导和科学依据.

关键词：苯乙炔铜钨酸铋四环素 Z型异质结光催化

Room-temperature continuous-wave operation of GaN-based blue-violet laser diodes with a lifetime longer than 1000h

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Journal of Semiconductors 2019年第2期40卷 39-42页

作者： Feng Liang Jing Yang Degang Zhao zongshun liu Jianjun Zhu Ping Chen Desheng Jiang Yongsheng Shi Hai Wang Lihong Duan Liqun Zhang Hui Yang State Key Laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of Sciences

GaN-based continuous-wave operated blue-violet laser diodes(LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm^2 ridge waveguide structure.The electrical and optical characteristics of a blue-violet LD are investigated under direct-current injection at room temperature(25 °C). The stimulated emission wavelength and peak optical power of the LD are around 413 nm and over 600 mW, respectively.In addition, the threshold current density and voltage are as small as 1.46 kA/cm^2 and 4.1 V, respectively. Moreover, the lifetime is longer than 1000 hours under room-temperature continuous-wave operation.

关键词： GaN-based blue-violet laser diodes long lifetime threshold voltage

Distribution of electric field and design of devices in GaN avalanche photodiodes

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Science China(Physics,Mechanics & Astronomy) 2012年第4期55卷 619-624页

作者： WU LiangLiang ZHAO DeGang DENG Yi JIANG DeSheng ZHU JianJun WANG Hui liu zongshun ZHANG ShuMing ZHANG BaoShun YANG Hui State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of SciencesSuzhou 215125China

We have investigated the distribution of the electric field in p-i-n type and separate absorption and multiplication(SAM) type GaN avalanche photodiodes under different reverse bias values.We have also analyzed the influences of the parameters of each layer,including width and concentration,on the distribution of the electric field,especially on the breakdown voltage.It is found that a relatively high concentration of p-GaN(higher than 1×10 18 cm 3) and low carrier concentration of i-GaN(lower than 5×10 16 cm 3) are helpful to restrict the electric field and reduce the breakdown voltage.In a SAM(p-i-n-i-n) structure,a suitable choice should be made for the concentration and thickness of the intermediate n-GaN layer in order to decrease breakdown voltage and prevent the device from degenerating into a p-i-n structure.Finally,the optimized material parameters of each layer are proposed.

关键词：雪崩光电二极管电场分布氮化镓设备 pin结构设计击穿电压反向偏压

Statistical properties of kinetic-scale magnetic holes in terrestrial space

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Earth and Planetary Physics 2021年第1期5卷 63-72页

作者： ShuTao Yao zongshun Yue QuanQi Shi Alexander William Degeling HuiShan Fu AnMin Tian Hui Zhang Andrew Vu RuiLong Guo ZhongHua Yao Ji liu Qiu-Gang Zong XuZhi Zhou JingHuan Li WenYa Li HongQiao Hu YangYang liu WeiJie Sun Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai Shandong 264209China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China School of Space and Environment Beihang UniversityBeijing 100191China Physics Department and Geophysical Institute University of Alaska FairbanksFairbanksAK99775USA Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Laboratoire de Physique Atmosphérique et Planétaire STAR InstituteUniversitéde LiègeLiègeB-4000Belgium School of Earth and Space Sciences Peking UniversityBeijing 100871China SOA Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China Department of Climate and Space Sciences and Engineering University of MichiganAnn ArborMI48109USA

Kinetic-scale magnetic holes(KSMHs)are structures characterized by a significant magnetic depression with a length scale on the order of the proton gyroradius.These structures have been investigated in recent studies in near-Earth space,and found to be closely related to energy conversion and particle acceleration,wave-particle interactions,magnetic reconnection,and turbulence at the kineticscale.However,there are still several major issues of the KSMHs that need further study—including(a)the source of these structures(locally generated in near-Earth space,or carried by the solar wind),(b)the environmental conditions leading to their generation,and(c)their spatio-temporal characteristics.In this study,KSMHs in near-Earth space are investigated statistically using data from the Magnetospheric Multiscale mission.Approximately 200,000 events were observed from September 2015 to March 2020.Occurrence rates of such structures in the solar wind,magnetosheath,and magnetotail were obtained.We find that KSMHs occur in the magnetosheath at rates far above their occurrence in the solar wind.This indicates that most of the structures are generated locally in the magnetosheath,rather than advected with the solar wind.Moreover,KSMHs occur in the downstream region of the quasi-parallel shock at rates significantly higher than in the downstream region of the quasi-perpendicular shock,indicating a relationship with the turbulent plasma environment.Close to the magnetopause,we find that the depths of KSMHs decrease as their temporal-scale increases.We also find that the spatial-scales of the KSMHs near the subsolar magnetosheath are smaller than those in the flanks.Furthermore,their global distribution shows a significant dawn-dusk asymmetry(duskside dominating)in the magnetotail.

关键词： kinetic scale magnetic hole magnetic dip electron vortex turbulence

High Power 940 nm Al-free Active Region Laser Diodes and Bars with a Broad Waveguide

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Chinese Journal of Lasers 2002年第1期11卷 10-14页

作者： FANG Gaozhan XIAO Jianwei MA Xiaoyu XU Zuntu ZHANG Jinming TAN Manqing liu zongshun liu Suping FENG Xiaoming (Institute of Semiconductors, The Chinese Academy of Sciences, National Engineering Research Center for Optoelectronics Devices, Beijing Institute of Semiconductors The Chinese Academy of Sciences National Engineering Research Center for Optoelectronics Devices 北京 100083

The 940 nm Al-free active region laser diodes and bars with a broad waveguide were designed and fabricated. The stuctures were grown by metal organic chemical vapour deposition. The devices show excellent performances. The maximum output power of 6.7 W in the 100 μm broad-area laser diodes has been measured, and is 2.5 times higher than that in the Al-containing active region laser diodes with a narrow waveguide and 1.7 times higher than that in Al-free active region laser diodes with a narrow waveguide. The 19% fill-factor laser diode bars emit 33 W, and they can operate at 15W with low degradation rates.

关键词： laser diode bar waveguide Al-free

融合教育中特殊需要幼儿的社会参与状况及其影响因素--基于H市42个融合班级的调查数据分析

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学前教育研究 2022年第1期 46-58页

作者：刘双全朱宗顺董翌暄徐任红信阳学院教育学院信阳464000 浙江师范大学杭州幼儿师范学院杭州311231

实现特殊需要幼儿的社会参与是学前融合教育的目标之一,这使得特殊需要幼儿的社会参与状况成为衡量学前融合教育质量的重要指标之一。本研究以来自H市14所幼儿园42个融合班级的89名特殊需要幼儿及其1133名同班普通幼儿为调查对象,基于... 详细信息

实现特殊需要幼儿的社会参与是学前融合教育的目标之一,这使得特殊需要幼儿的社会参与状况成为衡量学前融合教育质量的重要指标之一。本研究以来自H市14所幼儿园42个融合班级的89名特殊需要幼儿及其1133名同班普通幼儿为调查对象,基于同伴社会计量报告以及教师对特殊幼儿互动的评估,从同伴接纳、友谊/社会关系、同伴互动三方面考察特殊需要幼儿社会参与状况及其影响因素。结果发现,特殊需要幼儿社会参与状况总体堪忧,同伴接纳水平总体较低,消极互动水平较高且积极互动水平很低;个人维度中的外化问题行为和性别可以预测特殊需要幼儿社会参与,女童比男童更容易被同伴接纳,问题行为严重的幼儿则更容易被拒绝。提升特殊需要幼儿的社会参与,需要加强幼儿园资源教室建设,改善特殊需要幼儿的问题行为,强化家庭、幼儿园以及康复或干预机构之间的合作,等等。

关键词：融合教育社会参与特殊需要幼儿