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Research Progress of Reverse Monte Carlo and Its Application in Josephson Junction Barrier Layer
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作者 Junling Qiu Huihui Sun Shuya Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第12期2077-2109,共33页
As indispensable components of superconducting circuit-based quantum computers,Josephson junctions determine how well superconducting qubits perform.Reverse Monte Carlo(RMC)can be used to recreate Josephson junction’... As indispensable components of superconducting circuit-based quantum computers,Josephson junctions determine how well superconducting qubits perform.Reverse Monte Carlo(RMC)can be used to recreate Josephson junction’s atomic structure based on experimental data,and the impact of the structure on junctions’properties can be investigated by combining different analysis techniques.In order to build a physical model of the atomic structure and then analyze the factors that affect its performance,this paper briefly reviews the development and evolution of the RMC algorithm.It also summarizes the modeling process and structural feature analysis of the Josephson junction in combination with different feature extraction techniques for electrical characterization devices.Additionally,the obstacles and potential directions of Josephson junction modeling,which serves as the theoretical foundation for the production of superconducting quantum devices at the atomic level,are discussed. 展开更多
关键词 Reverse Monte Carlo Josephson junction alumina barrier layer
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A self-driven photodetector based on a SnS_(2)/WS_(2) van der Waals heterojunction with an Al_(2)O_(3) capping layer
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作者 王祥骏 林钰恒 +5 位作者 刘潇 邓煊华 贲建伟 俞文杰 朱德亮 刘新科 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期585-591,共7页
Photodetectors based on two-dimensional(2D) materials have attracted considerable attention because of their unique properties. To further improve the performance of self-driven photodetectors based on van der Waals h... Photodetectors based on two-dimensional(2D) materials have attracted considerable attention because of their unique properties. To further improve the performance of self-driven photodetectors based on van der Waals heterojunctions, a conductive band minimum(CBM) matched self-driven SnS_(2)/WS_(2) van der Waals heterojunction photodetector based on a SiO2/Si substrate has been designed. The device exhibits a positive current at zero voltage under 365 nm laser illumination.This is attributed to the built-in electric field at the interface of the SnS_(2) and WS_(2) layer, which will separate and transport the photogenerated carriers, even at zero bias voltage. In addition, the Al_(2)O_(3) layer is covered by the surface of the SnS_(2)/WS_(2) photodetector to further improve the performance, because the Al_(2)O_(3) layer will introduce tensile stress on the surface of the 2D materials leading to a higher electron concentration and smaller effective mass of electrons in the films. This work provides an idea for the research of self-driven photodetectors based on a van der Waals heterogeneous junction. 展开更多
关键词 SnS_(2)/WS_(2)heterogeneous junction Al_(2)O_(3)layer self-driven PHOTODETECTOR
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The p recombination layer in tunnel junctions for micromorph tandem solar cells 被引量:2
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作者 姚文杰 曾湘波 +4 位作者 彭文博 刘石勇 谢小兵 王超 廖显伯 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第7期490-494,共5页
A new tunnel recombination junction is fabricated for n-i-p type micromorph tandem solar cells. We insert a thin heavily doped hydrogenated amorphous silicon (a-Si:H) p^+ recombination layer between the n a-Si:H ... A new tunnel recombination junction is fabricated for n-i-p type micromorph tandem solar cells. We insert a thin heavily doped hydrogenated amorphous silicon (a-Si:H) p^+ recombination layer between the n a-Si:H and the p hydrogenated nanocrystalline silicon (nc-Si:H) layers to improve the performance of the n-i-p tandem solar cells. The effects of the boron doping gas ratio and the deposition time of the p-a-Si:H recombination layer on the tunnel recombination junctions have been investigated. The current-voltage characteristic of the tunnel recombination junction shows a nearly ohmic characteristic, and the resistance of the tunnel recombination junction can be as low as 1.5 Ω-cm^2 by using the optimized p-a-Si:H recombination layer. We obtain tandem solar cells with open circuit voltage Voc = 1.4 V, which is nearly the sum of the Vocs of the two corresponding single cells, indicating no Voc losses at the tunnel recombination junction. 展开更多
关键词 p recombination layer tunnel recombination junction micromorph tandem solar cells
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New CMOS compatible super-junction LDMOST with n-type buried layer 被引量:1
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作者 段宝兴 张波 李肇基 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第12期3754-3759,共6页
A new super-junction lateral double diffused MOSFET (LDMOST) structure is designed with n-type charge compensation layer embedded in the p^--substrate near the drain to suppress substrate-assisted depletion effect t... A new super-junction lateral double diffused MOSFET (LDMOST) structure is designed with n-type charge compensation layer embedded in the p^--substrate near the drain to suppress substrate-assisted depletion effect that results from the compensating charges imbalance between the pillars in the n-type buried layer. A high electric field peak is introduced in the surface by the pn junction between the p^--substrate and n-type buried layer, which given rise to a more uniform surface electric field distribution by modulation effect. The effect of reduced bulk field (REBULF) is introduced to improve the vertical breakdown voltage by reducing the high bulk electric field around the drain, The new structure features high breakdown voltage, low on-resistance and charges balance in the drift region due to n-type buried layer. 展开更多
关键词 super-junction LDMOST n-type buried layer REBULF breakdown voltage
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A novel LDMOS with a junction field plate and a partial N-buried layer
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作者 石先龙 罗小蓉 +6 位作者 魏杰 谭桥 刘建平 徐青 李鹏程 田瑞超 马达 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第12期423-427,共5页
A novel lateral double-diffused metal–oxide semiconductor(LDMOS) with a high breakdown voltage(BV) and low specific on-resistance(Ron.sp) is proposed and investigated by simulation. It features a junction field... A novel lateral double-diffused metal–oxide semiconductor(LDMOS) with a high breakdown voltage(BV) and low specific on-resistance(Ron.sp) is proposed and investigated by simulation. It features a junction field plate(JFP) over the drift region and a partial N-buried layer(PNB) in the P-substrate. The JFP not only smoothes the surface electric field(E-field), but also brings in charge compensation between the JFP and the N-drift region, which increases the doping concentration of the N-drift region. The PNB reshapes the equipotential contours, and thus reduces the E-field peak on the drain side and increases that on the source side. Moreover, the PNB extends the depletion width in the substrate by introducing an additional vertical diode, resulting in a significant improvement on the vertical BV. Compared with the conventional LDMOS with the same dimensional parameters, the novel LDMOS has an increase in BV value by 67.4%,and a reduction in Ron.sp by 45.7% simultaneously. 展开更多
关键词 junction field plate partial N-buried layer specific on-resistance breakdown voltage
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Effects of Fe-Oxide and Mg Layer Insertion on Tunneling Magnetoresistance Properties of CoFeB/MgO/CoFeB Magnetic Tunnel Junctions
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作者 娄永乐 张玉明 +2 位作者 郭辉 徐大庆 张义门 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第11期124-126,共3页
To study the influence of CoFeB/MgO interface on tunneling magnetoresistance (TMR), different structures of magnetic tunnel junctions (MTJs) are successfully prepared by the magnetron sputtering technique and char... To study the influence of CoFeB/MgO interface on tunneling magnetoresistance (TMR), different structures of magnetic tunnel junctions (MTJs) are successfully prepared by the magnetron sputtering technique and characterized by atomic force microscopy, a physical property measurement system, x-ray photoelectron spectroscopy, and transmission electron microscopy. The experimental results show that TMR of the CoFeB/Mg/MgO/CoFeB structure is evidently improved in comparison with the CoFeB/MgO/CoFeB structure because the inserted Mg layer prevents Fe-oxide formation at the CoFeB/MgO interface, which occurs in CoFeB/MgO/CoFeB MTJs. The inherent properties of the CoFeB/MgO/CoFeB, CoFeB/Fe-oxide/MgO/CoFeB and CoFeB/Mg/MgO/CoFeB MTJs are simulated by using the theories of density functions and non-equilibrium Green functions. The simulated results demonstrate that TMR of CoFeB/Fe-oxide/MgO/CoFeB MTJs is severely decreased and is only half the value of the CoFeB/Mg/MgO/CoFeB MTJs. Based on the experimental results and theoretical analysis, it is believed that in CoFeB/MgO/CoFeB MTJs, the interface oxidation of the CoFeB layer is the main reason to cause a remarkable reduction of TMR, and the inserted Mg layer may play an important role in protecting Fe atoms from oxidation, and then increasing TMR. 展开更多
关键词 MGO of TMR FE Effects of Fe-Oxide and Mg layer Insertion on Tunneling Magnetoresistance Properties of CoFeB/MgO/CoFeB Magnetic Tunnel junctions in is that on
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Simulation Study of CuO-Based Solar Cell with Different Buffer Layers Using SCAPS-1D
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作者 Towhid Adnan Chowdhury 《Energy and Power Engineering》 2023年第9期307-314,共8页
In copper oxide (CuO) based solar cells, various buffer layers such as CdS, In<sub>2</sub>S<sub>3</sub>, WS<sub>2</sub> and IGZO have been investigated by solar cell capacitance sim... In copper oxide (CuO) based solar cells, various buffer layers such as CdS, In<sub>2</sub>S<sub>3</sub>, WS<sub>2</sub> and IGZO have been investigated by solar cell capacitance simulator (SCAPS) in this work. By varying absorber and buffer layer thickness, photovoltaic parameters (open circuit voltage, fill factor, short-circuit current density and efficiency) are determined. The highest efficiency achieved is 19.6% with WS<sub>2</sub> buffer layer. The impact of temperature on all CuO-based solar cells is also investigated. 展开更多
关键词 Solar cell Buffer layer EFFICIENCY Hetero-junction Scaps-1D
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基于晶格大失配In_(0.58)Ga_(0.42)As材料的高效四结太阳电池
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作者 王波 周丽华 +6 位作者 施祥蕾 郭哲俊 钱勇 张占飞 李彬 孙利杰 王训春 《微纳电子技术》 CAS 2024年第5期52-58,共7页
Ⅲ-Ⅴ族晶格失配多结太阳电池是实现高效太阳电池的主要途径之一,但面临晶格失配材料的高质量生长及其所导致的子电池光电转换效率下降的难题。重点针对晶格失配子电池结构中的(AlGa)InAs缓冲层开展台阶层厚度优化研究,设计了150、200和... Ⅲ-Ⅴ族晶格失配多结太阳电池是实现高效太阳电池的主要途径之一,但面临晶格失配材料的高质量生长及其所导致的子电池光电转换效率下降的难题。重点针对晶格失配子电池结构中的(AlGa)InAs缓冲层开展台阶层厚度优化研究,设计了150、200和250 nm三组不同台阶层厚度的缓冲层结构,并完成三组样品的外延生长实验。通过材料测试和子电池电性能测试,系统分析了台阶层厚度对In_(0.58)Ga_(0.42)As材料外延生长质量和子电池电性能的影响。获得了晶格弛豫度为96.71%的In_(0.58)Ga_(0.42)As子电池材料,制备的子电池开路电压达到205.10 mV。在此基础上,结合GaInP/GaAs/In_(0.3)Ga_(0.7)As三结电池研制了晶格失配四结薄膜太阳电池,其光电转换效率达到32.41%(AM0,25℃)。 展开更多
关键词 四结太阳电池 晶格失配 In_(0.58)Ga_(0.42)As材料 缓冲层 台阶层厚度
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高阻衬底上具有n^+浮空层的横向Super Junction MOSFETs(英文) 被引量:2
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作者 段宝兴 张波 李肇基 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2007年第2期166-170,共5页
提出了一种具有n+浮空层的横向super junction结构,此结构通过磷或砷离子注入在高阻衬底上形成n+浮空层来消除传统横向super junction结构中的衬底辅助耗尽效应.这种效应来源于p型的衬底辅助耗尽了superjunction区的n型层,使p与n之间的... 提出了一种具有n+浮空层的横向super junction结构,此结构通过磷或砷离子注入在高阻衬底上形成n+浮空层来消除传统横向super junction结构中的衬底辅助耗尽效应.这种效应来源于p型的衬底辅助耗尽了superjunction区的n型层,使p与n之间的电荷不能平衡.n+层的REBULF效应通过使漏端电场减小,体电场重新分布而使新结构中的衬底承担了更多的电压.结果表明这种结构具有高的击穿电压、低的导通电阻和漂移区中电荷平衡的特点. 展开更多
关键词 super junction LDMOST 衬底辅助耗尽 n^+-浮空层 击穿电压
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三结砷化镓太阳能电池外延层表面抛光技术研究
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作者 李穆朗 《天津科技》 2024年第2期33-36,共4页
以空间用三结砷化镓(GaAs)电池外延表面抛光为研究对象,对抛光压力、抛光转速、抛光液pH等参数进行试验研究。研究结果表明:选用抛光压力40 g/cm^(3),采用55 r/min的转速,有效氯含量为5%的抛光液,对三结砷化镓太阳能电池外延表面有良好... 以空间用三结砷化镓(GaAs)电池外延表面抛光为研究对象,对抛光压力、抛光转速、抛光液pH等参数进行试验研究。研究结果表明:选用抛光压力40 g/cm^(3),采用55 r/min的转速,有效氯含量为5%的抛光液,对三结砷化镓太阳能电池外延表面有良好的抛光效果,可得到良好的表面颗粒度,即表面粗糙度小于0.4 nm、颗粒粒径大于0.2μm(含0.2/μm)的数量低于50个,颗粒粒径小于0.2μm的数量低于100个的外延片表面,为键合技术用于三结砷化镓太阳能电池的批量生产提供了可能。 展开更多
关键词 三结砷化镓 外延层表面 化学机械抛光 抛光压力 抛光转速 有效氯含量
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The study of a new n/p tunnel recombination junction and its application in a-Si:H/μc-Si:H tandem solar cells 被引量:6
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作者 李贵君 侯国付 +5 位作者 韩晓艳 袁育洁 魏长春 孙建 赵颖 耿新华 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1674-1678,共5页
This paper reports that a double N layer (a-Si:H/μc-Si:H) is used to substitute the single microcrystalline silicon n layer (n-μc-Si:H) in n/p tunnel recombination junction between subcells in a-Si:H/μc-Si... This paper reports that a double N layer (a-Si:H/μc-Si:H) is used to substitute the single microcrystalline silicon n layer (n-μc-Si:H) in n/p tunnel recombination junction between subcells in a-Si:H/μc-Si:H tandem solar cells. The electrical transport and optical properties of these tunnel recombination junctions are investigated by current voltage measurement and transmission measurement. The new n/p tunnel recombination junction shows a better ohmic contact. In addition, the n/p interface is exposed to the air to examine the effect of oxidation on the tunnel recombination junction performance. The open circuit voltage and FF of a-Si:H/μc-Si:H tandem solar cell are all improved and the current leakage of the subcells can be effectively prevented efficiently when the new n/p junction is implemented as tunnel recombination junction. 展开更多
关键词 double N layer tunnel recombination junction oxidation interface a-Si:H/μc-Si:H tan-dem solar cell
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Ultra-low specific on-resistance high-voltage vertical double diffusion metal–oxide–semiconductor field-effect transistor with continuous electron accumulation layer 被引量:1
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作者 马达 罗小蓉 +3 位作者 魏杰 谭桥 周坤 吴俊峰 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第4期450-455,共6页
A new ultra-low specific on-resistance (Ron,sp) vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is p... A new ultra-low specific on-resistance (Ron,sp) vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the Ron,sp but also makes the Ron,sp almost independent of the n-pillar doping concentration (Am). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the Nn, and further reduces the Ron,sp. Especially, the two PNjunctions within the trench gate support a high gate--drain voltage in the off-state and on-state, re- spectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the Ron,sp by 80% compared with the conventional super-junction VDMOS (CSJ-VDMOS) at the same high breakdown voltage (BV). 展开更多
关键词 electron accumulation layer PN junctions low specific on-resistance high breakdown voltage
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Multilayer Strategy for Photoelectrochemical Hydrogen Generation:New Electrode Architecture that Alleviates Multiple Bottlenecks 被引量:1
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作者 Selvaraj Seenivasan Hee Moon Do‑Heyoung Kim 《Nano-Micro Letters》 SCIE EI CAS CSCD 2022年第5期92-109,共18页
Years of research have demonstrated that the use of multiple components is essential to the development of a commercial photoelectrode to address specific bottlenecks,such as low charge separation and injection effici... Years of research have demonstrated that the use of multiple components is essential to the development of a commercial photoelectrode to address specific bottlenecks,such as low charge separation and injection efficiency,low carrier diffusion length and lifetime,and poor durability.A facile strategy for the synthesis of multilayered photoanodes from atomic-layer-deposited ultrathin films has enabled a new type of electrode architecture with a total multilayer thickness of 15–17 nm.We illustrate the advantages of this electrode architecture by using nanolayers to address different bottlenecks,thus producing a multilayer photoelectrode with improved interface kinetics and shorter electron transport path,as determined by interface analyses.The photocurrent density was twice that of the bare structure and reached a maximum of 33.3±2.1 mA cm^(−2) at 1.23 VRHE.An integrated overall water-splitting cell consisting of an electrocatalytic NiS cathode and Bi_(2)S_(3)/NiS/NiFeO/TiO_(2) photoanode was used for precious-metal-free seawater splitting at a cell voltage of 1.23 V without degradation.The results and root analyses suggest that the distinctive advantages of the electrode architecture,which are superior to those of bulk bottom-up core–shell and hierarchical architectures,originate from the high density of active sites and nanometer-scale layer thickness,which enhance the suitability for interface-oriented energy conversion processes. 展开更多
关键词 Atomic layer deposition Bismuth sulfide n-p junction PHOTOELECTROCHEMICAL Nickel sulfide
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A novel structure of a high current gain 4H-SiC BJT with a buried layer in the base
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作者 张有润 张波 +2 位作者 李肇基 邓小川 刘曦麟 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第9期3995-3999,共5页
In this paper, a new structure of a 4H-SiC bipolar junction transistor (BJT) with a buried layer (BL) in the base is presented. The current gain shows an approximately 100% increase compared with that of the conve... In this paper, a new structure of a 4H-SiC bipolar junction transistor (BJT) with a buried layer (BL) in the base is presented. The current gain shows an approximately 100% increase compared with that of the conventional structure. This is attributed to the creation of a built-in electric field for the minority carriers to transport in the base which is explained based on 2D device simulations. The optimized design of the buried layer region is also considered by numeric simulations. 展开更多
关键词 4H-SIC bipolar junction transistor (BJT) buried layer current gain
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脂多糖对妊娠周期小鼠子宫内膜上皮黏膜免疫屏障影响的研究
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作者 李慧 李晓琳 +2 位作者 李金龙 刘文君 薛虹 《中国预防兽医学报》 CAS CSCD 北大核心 2023年第12期1295-1301,共7页
为评估脂多糖(LPS)对子宫内膜免疫屏障的影响,本研究将30只健康8周龄雌性小鼠随机均分为对照组LPS(-)和LPS(+)组,适应性饲养3 d后,将两组小鼠分别与雄性小鼠(15只/组)合笼,当日计为妊娠0 d,LPS(+)组雌性小鼠从合笼前15 d至0 d以LPS灌胃... 为评估脂多糖(LPS)对子宫内膜免疫屏障的影响,本研究将30只健康8周龄雌性小鼠随机均分为对照组LPS(-)和LPS(+)组,适应性饲养3 d后,将两组小鼠分别与雄性小鼠(15只/组)合笼,当日计为妊娠0 d,LPS(+)组雌性小鼠从合笼前15 d至0 d以LPS灌胃后检测其对小鼠繁殖性能的影响,结果显示,LPS可显著抑制雌性小鼠的受孕率和仔鼠成活率(P<0.05),造成仔鼠生长性能下降,表明本研究采用小鼠作为该研究动物模型具有可行性。进一步分别在妊娠7 d、14 d和分娩后5 d采集LPS灌服组[LPS(+)]和健康对照组[LPS(-)]母鼠子宫,采用相应ELISA试剂盒检测子宫内膜主要黏蛋白(Mucins)MUC1、MUC2和MUC4的含量;采用western blot检测子宫内膜上皮细胞紧密连接蛋白Claudin、Occludin、ZO-1、JAM、E-Cadherin的表达量。ELISA结果显示:与LPS(-)组相比,妊娠7 d时LPS(+)组母鼠子宫内膜中MUC1,MUC2和MUC4的含量均极显著减少(P<0.01),妊娠14 d时上述指标均显著升高(P<0.05),但妊娠期间LPS(+)组母鼠子宫内膜中MUC1,MUC2和MUC4的总量均极显著低于LPS(-)组(P<0.01);而分娩后两组小鼠子宫各黏蛋白含量和总量均无显著差异(P>0.05)。Western blot检测结果显示,与LPS(-)组相比,LPS(+)组雌性小鼠子宫中Occludin的表达量在妊娠7 d时显著降低(P<0.05),在妊娠14 d时显著升高(P<0.05);ZO-1的表达量在妊娠7 d时显著升高(P<0.05);JAM的表达量在妊娠14 d时显著降低(P<0.05);E-Cadherin的表达量在妊娠7 d、妊娠14 d时显著下降(P<0.05)。上述结果首次证实当子宫内膜受到LPS的刺激之后,在妊娠7 d时小鼠子宫内膜黏蛋白的含量降低,子宫内膜上皮细胞紧密连接相关蛋白Occludin、JAM和E-Cadherin的表达量显著减少;妊娠14 d小鼠子宫内膜黏蛋白的表达量上升,起到屏障和保护胎儿的作用,此时紧密连接相关蛋白Claudin、JAM和E-Cadherin仍受到不同程度的损害,但紧密连接的调节蛋白Occludin表达量上调;分娩后5 d,LPS对黏蛋白和紧密连接相关蛋白均无显著影响。本实验为研究家畜子宫内膜炎引发的繁殖性能障碍机制奠定了基础。 展开更多
关键词 脂多糖 子宫 黏液层 黏蛋白 紧密连接
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TiO_(2)-x@C/MoO_(2)肖特基结:合理设计及高效电荷分离提升光催化性能
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作者 乔秀清 李晨 +2 位作者 王紫昭 侯东芳 李东升 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第8期66-79,共14页
氢能具有143 MJ/kg的高能量密度,光催化技术可以利用太阳能实现水分解制氢,被认为是缓解能源危机和环境污染的理想途径之一.自1972年TiO_(2)被发现具有光电催化性能以来,研究者致力于通过多种策略提升TiO_(2)的光催化活性.然而,其进一... 氢能具有143 MJ/kg的高能量密度,光催化技术可以利用太阳能实现水分解制氢,被认为是缓解能源危机和环境污染的理想途径之一.自1972年TiO_(2)被发现具有光电催化性能以来,研究者致力于通过多种策略提升TiO_(2)的光催化活性.然而,其进一步应用仍然受到光响应差和光生载流子重组等问题的制约.负载助催化剂可以促进电子空穴的分离,降低产氢的过电位,是构建高效光催化体系的有效策略.电子从助催化剂向TiO_(2)半导体的反向流动可降低电荷分离效率;此外,在多组分体系中,不同组分之间的界面电荷转移阻力制约光催化性能的进一步提升.因此,同时实现可见光吸收、组分间强界面耦合和抑制电子回流是构筑高效TiO_(2)光催化剂的关键.本文开发了一种简单的一步原位相变调节策略,构筑了一种新颖的TiO_(2)-x@C/MoO_(2)肖特基结用于光催化水分解制氢,并采用X射线衍射、扫描/透射电镜、拉曼光谱、电子顺磁共振、X射线光电子能谱和时间分辨光致发光曲线对催化剂进行了表征.结果表明,该肖特基结具有以下优点:(1)丰富的氧空位.还原性气氛使得TiO_(2)-x中产生丰富的氧空位,氧空位的存在明显的降低了TiO_(2)-x的带隙并引入缺陷能级,从而提高了可见光吸收能力.(2)强键合碳层.柠檬酸原位相变产生的碳包覆在TiO_(2)-x表面,在TiO_(2)-x及MoO_(2)之间形成强化学键合,不仅可以作为电荷传输的快速通道提高层间电荷传递效率,还可以保护氧空位不被氧化从而提高肖特基结的稳定性.(3)肖特基结异质结构中产生的肖特基势垒可以有效地抑制电子从MoO_(2)向TiO_(2)-x的反向转移,从而抑制电子和空穴的复合,提升光生电子的利用率.(4)助催化剂效应.金属性MoO_(2)充当助催化剂,极大地降低了H2生成过程所需的吉布斯自由能,提升了热力学产氢性能.得益于上述效应的协同作用,TiO_(2)-x@C/MoO_(2)催化剂的光催化析氢速率显著提高,达到506μmolg^(-1)h^(-1),分别比TiO_(2)-x和TiO_(2)-x@C大125.5倍和15.8倍.同时,由于表面碳层的保护作用,该催化剂在循环使用27 h后产氢速率无明显变化,表现出较好的稳定性.此外,光催化四环素降解及Cr(Ⅵ)还原实验进一步证实了该肖特基结中光生电荷的有效分离.综上,本文设计思路和合成策略为构筑强耦合肖特基结光催化剂提供一定的参考. 展开更多
关键词 氧空位 二氧化钛 氧化钼 碳层 产氢 肖特基结
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Manipulating Nanowires in Interconnecting Layer for Efficient Tandem Organic Photovoltaics
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作者 Yanjie Tang Jiaming Fu +9 位作者 Hao Li Du Hyeon Ryu Won Suk Shin Jianqi Zhang Yi Yang Yiming Yang Deyuan Li Zhong Zheng Shaoqing Zhang Jianhui Hou 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第4期377-383,共7页
Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in preci... Owing to the function of manipulating light absorption distribution,tandem organic solar cells containing multiple sub-cells exhibit high power conversion efficiencies.However,there is a substantial challenge in precisely controlling the inter-subcells carrier migration which determines the balance of charge transport across the entire device.The conductivity of"nanowires"-like conducting channel in interconnecting layer between sub-cells should be improved which calls for fine engineering on the morphology of polyelectrolyte in interconnecting layer.Here,we develop a simple method to effectively manipulating the domains of conductive components in commercially available polyelectrolyte PEDOT:PSs.The use of poor solvent could effectively modify the configuration of polystyrene sulfonic acid and thus the space for conductive components.Based on our strategy,the insulated shells wrapping conductive domains are thinned and the efficiencies of tandem organic solar cells are improved.We believe our method might provide guidance for the manufacture of tandem organic solar cells. 展开更多
关键词 Tandem organic solar cells Power conversion efficiency interconnecting layer Tunneling junction Interfacial layers Conformationanalysis π-πstacking Donor-acceptorsystems
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益生菌调节肠道上皮屏障功能及作用机制 被引量:51
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作者 高侃 汪海峰 +1 位作者 章文明 刘建新 《动物营养学报》 CAS CSCD 北大核心 2013年第9期1936-1945,共10页
动物肠道是一个具有生物多样性的微环境,单层的上皮细胞将共生微生物和病原菌与下层的免疫细胞分割构成肠道屏障。益生菌是一类对宿主有益的微生物,益生菌与肠道上皮细胞、下层免疫细胞共同构成了3个屏障,分别是机械屏障、化学屏障和免... 动物肠道是一个具有生物多样性的微环境,单层的上皮细胞将共生微生物和病原菌与下层的免疫细胞分割构成肠道屏障。益生菌是一类对宿主有益的微生物,益生菌与肠道上皮细胞、下层免疫细胞共同构成了3个屏障,分别是机械屏障、化学屏障和免疫屏障。本文主要综述肠道上皮屏障及微生态系统组成、益生菌增强肠道上皮屏障功能作用以及微生物与肠道上皮之间的相互作用以及机制。 展开更多
关键词 益生菌 上皮屏障 黏液层 紧密连接 肠道
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焊料层空洞对IGBT器件热稳定性的影响 被引量:18
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作者 肖飞 罗毅飞 +1 位作者 刘宾礼 夏燕飞 《高电压技术》 EI CAS CSCD 北大核心 2018年第5期1499-1506,共8页
为了查明封装疲劳对绝缘栅双极型晶体管(IGBT)热特性的影响,从封装结构的角度分析了焊料层空洞对IGBT器件热稳定性的影响规律。首先建立了IGBT芯片封装的有限元模型,然后结合传热学分析了焊料层空洞大小、位置以及分布对IGBT芯片最高... 为了查明封装疲劳对绝缘栅双极型晶体管(IGBT)热特性的影响,从封装结构的角度分析了焊料层空洞对IGBT器件热稳定性的影响规律。首先建立了IGBT芯片封装的有限元模型,然后结合传热学分析了焊料层空洞大小、位置以及分布对IGBT芯片最高结温的影响规律并进行了仿真,最后基于加速寿命实验进行了验证。结果表明:空洞率相同时,芯片对角线上的空洞对芯片最高结温的影响最大;位置相同时,芯片顶点位置空洞大小的变化对芯片最高结温的影响最大;2种情况下,单个空洞的影响均大于相同空洞率下的空洞分布影响,而空洞分布中的中心集中分布对芯片最高结温的影响最大;芯片最高结温随空洞率增大而近似呈线性关系增大,芯片结壳热阻与空洞率也近似呈线性关系增大,验证了理论分析的正确性。研究结论可从封装疲劳的角度对IGBT尽限应用提供指导。 展开更多
关键词 焊料层空洞 器件热稳定性 空洞率 3维有限元模型 结温 结壳热阻
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粘结层空洞对功率器件封装热阻的影响 被引量:16
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作者 吴昊 陈铭 +1 位作者 高立明 李明 《半导体光电》 CAS CSCD 北大核心 2013年第2期226-230,共5页
功率器件的热阻是预测器件结温和可靠性的重要热参数,其中芯片粘接工艺过程引起的粘结层空洞对于器件热性能有很大的影响。采用有限元软件Ansys Workbench对TO3P封装形式的功率器件进行建模与热仿真,精确构建了不同类型空洞的粘结层模型... 功率器件的热阻是预测器件结温和可靠性的重要热参数,其中芯片粘接工艺过程引起的粘结层空洞对于器件热性能有很大的影响。采用有限元软件Ansys Workbench对TO3P封装形式的功率器件进行建模与热仿真,精确构建了不同类型空洞的粘结层模型,包括不同空洞率的单个大空洞和离散分布小空洞、不同深度分布的浅层空洞和沿着对角线分布的大空洞。结果表明,单个大空洞对器件结温和热阻升高的影响远大于相同空洞率的离散小空洞;贯穿粘结层的空洞和分布在芯片与粘结层之间的浅空洞会显著引起热阻上升;分布在粘结层边缘的大空洞比中心和其他位置的大空洞对热阻升高贡献更大。 展开更多
关键词 有限元分析 粘结层 热阻 结温 空洞率
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