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NH_(3)/N_(2)复合热退火技术改善高浓度Mg掺杂GaN材料性能

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发光学报 2024年第8期45卷 1325-1333页

作者：蒋宗霖闫丹张宁魏同波王军喜魏学成中国科学院半导体研究所宽禁带半导体研发中心北京100083 中国科学院大学材料科学与光电技术学院北京100049

研究了NH_(3)/N_(2)复合热退火技术对高浓度Mg掺杂GaN材料晶体质量、发光性质及导电性能的影响。实验结果表明,相较于传统N_(2)氛围高温热退火后处理工艺而言,NH_(3)氛围高温热退火后处理工艺可以改善高浓度Mg掺杂GaN材料的晶体质量,同... 详细信息

研究了NH_(3)/N_(2)复合热退火技术对高浓度Mg掺杂GaN材料晶体质量、发光性质及导电性能的影响。实验结果表明,相较于传统N_(2)氛围高温热退火后处理工艺而言,NH_(3)氛围高温热退火后处理工艺可以改善高浓度Mg掺杂GaN材料的晶体质量,同时可以增进Mg受主原子的有效掺杂,使得其光致发光谱中蓝光峰强度增强。采用NH_(3)氛围高温热退火结合N_(2)氛围低温热退火后处理工艺复合技术制备得到的高浓度Mg掺杂GaN材料内部背景电子浓度显著降低。这是由于在NH_(3)氛围高温热退火后处理工艺中,NH_(3)的热分解产物能够有效降低材料内N空位和间隙Ga原子等浅施主型缺陷浓度,最终改善高浓度Mg掺杂GaN材料的导电性能。

关键词：氮化镓 Mg掺杂热退火工艺氨气

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平台经济下的生产社会化与产权公有化:变化与趋势

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经济论坛 2024年第9期 128-138页

作者：王君玺谢春燕中国社会科学院大学马克思主义学院北京102488 中国人民大学经济学院北京100872

平台经济是以数字化信息作为劳动对象,利用互联网通信设备等劳动资料进行生产的经济形式,在这个基础上重塑劳动过程,产生新的劳动产品,带来了生产社会化的诸多新变化。文章运用马克思的生产社会化理论剖析平台经济的发展,通过研究平台... 详细信息

平台经济是以数字化信息作为劳动对象,利用互联网通信设备等劳动资料进行生产的经济形式,在这个基础上重塑劳动过程,产生新的劳动产品,带来了生产社会化的诸多新变化。文章运用马克思的生产社会化理论剖析平台经济的发展,通过研究平台经济生产社会化的表现,以及平台经济生产社会化与产权私有之间的矛盾,试图阐明平台经济下生产社会化的发展趋势,即产权的公有化。平台经济呈现公有化的趋势既是生产社会化的必然要求,也具有一定的现实基础,同时中国推进平台经济公有化也具有相应的优势。因此,逐步实现对于大型平台的国有化和平台财富的全民共享是平台经济生产社会化发展的应有之义。

关键词：平台经济生产社会化公有化

4H-SiC衬底上生长参数对AlGaN基深紫外多量子阱受激辐射特性的影响

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发光学报 2024年第6期45卷 894-904页

作者：张睿洁郭亚楠吴涵刘志彬闫建昌李晋闽王军喜中国科学院半导体研究所宽禁带半导体研发中心北京100083 中国科学院大学材料科学与光电技术学院北京100049 山西中科潞安紫外光电科技有限公司山西长治046000

SiC衬底是制备高性能AlGaN基深紫外激光器的良好候选衬底。采用金属有机化学气相沉积方法在4H-SiC衬底上生长了深紫外AlGaN/AlN多量子阱结构(MQWs),系统研讨了MQWs生长参数对深紫外激光结构自发辐射和受激辐射特性的影响规律。综合分析M... 详细信息

SiC衬底是制备高性能AlGaN基深紫外激光器的良好候选衬底。采用金属有机化学气相沉积方法在4H-SiC衬底上生长了深紫外AlGaN/AlN多量子阱结构(MQWs),系统研讨了MQWs生长参数对深紫外激光结构自发辐射和受激辐射特性的影响规律。综合分析MQWs的表面形貌和发光性能后发现,随着NH_(3)流量增加和生长温度升高,MQWs表面粗糙度降低,内量子效率提升。经优化,MQWs的内量子效率达到74.1%,室温下的激射阈值光功率密度和线宽分别为1.03 MW/cm~2和1.82 nm,发光波长为248.8 nm。这主要归因于高的NH3流量和生长温度抑制了有源区中的碳杂质并入,载流子辐射复合效率和材料增益增加;同时生长速率降低,改善了MQWs结构的表面形貌,降低了界面散射损耗。采用干法刻蚀和湿法腐蚀的复合工艺制备了光滑陡直的谐振腔,激光器的腔面损耗降低,阈值光功率密度和线宽进一步降低至889 kW/cm~2和1.39 nm。

关键词： AlGaN SiC 光泵浦激光器 Ⅴ/Ⅲ比生长温度

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Ultraviolet communication technique and its application

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Journal of Semiconductors 2021年第8期42卷 32-44页

作者： Liang Guo Yanan Guo junxi wang Tongbo Wei Research and Development Center for Semiconductor Lighting Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Engineering Research Center for the 3rd Generation Semiconductor Materials and Application Beijing 100083China

With recent developments of deep ultraviolet(DUV)light-emitting diodes and solar-blind detectors,UV communication(UVC)shows great potential in replacing traditional wireless communication in more and more *** on the atmospheric scattering of UV radiation,UVC has gained considerable attention due to its non-line-of-sight ability,omnidirectional communication links and low background *** advantages make UVC an ideal option for covert secure communication,especially for military *** this review,we present the history and working principle of UVC with a special focus on its light sources and *** comparison and application of its light sources and detectors are provided to the best of our *** further discuss the future application and outlook of ***,this review will offer valuable insights into the future development of UVC.

关键词： ultraviolet communication non-line-of-sight optical wireless communication

Growth and Characterization of Semi-Insulating GaN Films Grown by MOCVD

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Journal of Rare Earths 2006年第z1期24卷 14-18页

作者： Fang Cebao wang Xiaoliang Hu Guoxin wang junxi wang Cuimei Li Jinmin Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

High resistivity unintentionally doped GaN films were grown on (0001) sapphire substrates by metalorganic chemical vapor deposition. The surface morphology of the layer was measured by both atomic force microscopy and scanning electron microscopy. The results show that the films have mirror-like surface morphology with root mean square of 0.3 nm. The full width at half maximum of double crystal X-ray diffraction rocking curve for (0002) GaN is about 5.22 arcmin, indicative of high crystal quality. The resistivity of the GaN epilayers at room temperature and at 250 ℃ was measured to be approximate 109 and 106 Ω·cm respectively, by variable temperature Hall measurement. Deep level traps in the GaN epilayers were investigated by thermally stimulated current and resistivity measurements.

关键词： MOCVD GaN resistivity TSC

Improving the incorporation of indium component for InGaN-based green LED through inserting photonic crystalline in the GaN layer

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Journal of Semiconductors 2022年第7期43卷 84-88页

作者： Yunqi Li Xinwei wang Ning Zhang Xuecheng Wei junxi wang Institute of First Medical Center Chinese PLA General HospitalBeijing 100853China State Key Laboratory of Solid-State Lighting Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

We report on the effect of inserted photonic crystalline(Ph-C) in the GaN epitaxial layer on the incorporation of the indium component for the InGaN-based green LED. The adoption of Ph-C in the GaN layer shifted the Raman peak value of E2mode of GaN to lower frequency and resulted in a tensive stress relief. The stress relief can be attributed to strained lattices restoring in the matrix of Ph-C and the GaN pseudo-epitaxy over the air-void of the Ph-C. Moreover, the HRXRD rocking curves and AFM results show that the insertion of Ph-C also improves the crystal quality. With the inserted Ph-C, the indium component in the multiple quantum wells of the green LED(Ph-C LED) was enhanced. This resulted in a 6-nm red-shift of the peak wavelength. Furthermore, the LOP of the Ph-C LED was enhanced by 10.65% under an injection current of 20 mA.

关键词： epitaxial growth nanocrystalline materials semiconductors Raman stress relief X-ray techniques

SIMULATION IN THERMAL DESIGN FOR ELECTRONIC CONTROL UNIT OF ELECTRONIC UNIT PUMP

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Chinese Journal of Mechanical Engineering 2008年第5期21卷 1-7页

作者： XU Quankui ZHU Keqing ZHUO Bin MAO Xiaojian wang junxi nstitute of Automotive Electronic Technology Shanghai Jiaotong University Shanghai 200240 China

The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit （ECU） design. By means of circuit simulation, the thermal design of ECU for electronic unit pump （EUP） fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time

关键词： Diesel engine Electronic unit pump Electronic control unit Circuit simulation Thermal design

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蒸汽氧化T-250钢的力学性能和耐蚀性能

金属热处理 2024年第1期49卷 234-241页

作者：张小娟王军喜白鹭周钟平倪林彧赵雨薇闵永安上海航天动力技术研究所上海201109 上海大学材料科学与工程学院省部共建高品质特殊钢冶金与制备国家重点实验室上海200444

将蒸汽氧化处理及空气氧化处理后的T-250钢进行拉伸、电化学极化曲线、湿热、盐雾等试验测试,探究蒸汽氧化对T-250钢抗拉强度及伸长率等力学性能及不同环境下耐蚀性能的影响。结果表明,经蒸汽氧化处理的T-250钢具有良好的力学性能,强度... 详细信息

将蒸汽氧化处理及空气氧化处理后的T-250钢进行拉伸、电化学极化曲线、湿热、盐雾等试验测试,探究蒸汽氧化对T-250钢抗拉强度及伸长率等力学性能及不同环境下耐蚀性能的影响。结果表明,经蒸汽氧化处理的T-250钢具有良好的力学性能,强度能够达到1700 MPa以上,且相较于空气氧化处理具有更优良的隔绝腐蚀效果,未出现蒸汽引起的氢致延迟断裂现象。

关键词： T-250钢蒸汽氧化氧化膜力学性能耐蚀性能

考虑电池能耗因子与调节速率的电化学储能电站负荷控制方法

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粘接 2024年第1期51卷 141-144页

作者：李东昆冯洎枢王俊曦国家电网有限公司华中分部湖北武汉430077

为解决常规的电化学储能电站负荷控制方法因缺乏对电池能耗因子的考虑,导致负荷控制效果不佳问题,提出考虑电池能耗因子和调节速率含风电的电化学储能电站负荷控制方法,通过对储能站的负荷率进行计算,在此基础上结合日负荷曲线的均方差... 详细信息

为解决常规的电化学储能电站负荷控制方法因缺乏对电池能耗因子的考虑,导致负荷控制效果不佳问题,提出考虑电池能耗因子和调节速率含风电的电化学储能电站负荷控制方法,通过对储能站的负荷率进行计算,在此基础上结合日负荷曲线的均方差,对用户的负荷时间弹性进行定性分析。结合储能电站的电池能耗因子,将负荷控制目标转化为储能损耗最小值求解问题,构建出目标函数,并结合调度功率的指令需求对目标函数进行约束,构建电站充放电均衡条件等式,并采用迭代法对边际负荷最优值进行求解。

关键词：电池能耗因子调节速率储能电站负荷控制