二氧化锡／多孔硅／硅的吸附特性

研究了二氧化锡／多孔硅／硅（ＳｎＯ＿２／ＰＳ／Ｓｉ）的光伏谱和吸附性质，由分析光伏谱得出在ＳｎＯ＿２／ＰＳ／Ｓｉ之间存在着二个异质结：一个是ＳｎＯ＿２／ＰＳ异质结；另一个是ＰＳ／Ｓｉ异质结，当样品吸附ＣＯ气体后，光电压明显减少，实验结果表明，利用光电压的变化可以检测ＣＯ等有害气体．本文对新气体敏感材料ＳｎＯ＿２／ＰＳ／Ｓｉ的有关气体吸附机制进行了讨论．     

PZT／SiO2／Si界面的XPS分析

采用ＳＯＬ－ＧＥＬ工艺在ＳｉＯ２／Ｓｉ衬底上制备了铁电薄膜，对ＰＺＴ／ＳｉＯ２／Ｓｉ结构进行了ＸＰＳ分析，结果表明，在ＰＺＴ铁电薄膜和硅衬底之间加ＳｉＯ２使Ｆ／Ｓ界面得到了改善。     

PECVD生长nc-Si:H膜的掺杂特性研究

采用常规ＰＥＣＶＤ工艺,以高Ｈ２ 稀释的ＳｉＨ４ 作为反应气体源,以ＰＨ３ 作为Ｐ原子的掺杂剂,在Ｐ型（１００） 单晶硅（ｃ－ Ｓｉ） 衬底上,成功地生长了掺Ｐ的纳米硅膜（ｎｃ－ Ｓｉ（Ｐ）：Ｈ） 膜。通过对膜层结构的Ｒａｍａｎ 谱分析和高分辨率电子显微镜（ＨＲＥＭ） 观测指出：与本征ｎｃ－ Ｓｉ：Ｈ 膜相比,ｎｃ－ Ｓｉ（Ｐ）：Ｈ 膜中的Ｓｉ 微晶粒尺寸更小（～３ ｎｍ） ,其排布更有秩序,呈现出类自组织生长的一些特点。膜层电学特性的研究证实,ｎｃ－ Ｓｉ（Ｐ）：Ｈ 膜具有比本征ｎｃ－ Ｓｉ：Ｈ 膜约高两个数量级的电导率,其σ值可高达１０－ １ ～１０１ Ω－１ｃｍ －１ 。这种高电导率来源于ｎｃ－ Ｓｉ（Ｐ）： Ｈ 膜中有效电子浓度ｎｅ 的增加、Ｓｉ 微晶粒尺寸ｄ 的减小和电导激活能ΔＥ的降低。     

Ag-ZSM-5分子筛上乙醇氧化过程中积碳行为的研究

用不同银含量及不同硅铝比的Ａｇ－ＺＳＭ－５分子筛催化乙醇化氧乙醛,采用高温氧化烧炭考察了银杏量,硅铝比及反应温度对催化过程中积炭行为的影响,结果表明：高ＳｉＯ２／Ａｌ２Ｏ３时积炭较慢,Ａｇ含量超过１０％,对积炭速率影响不大,反应温度高时积炭速率减慢,但是选择性及转化率降低,研究发现Ｓｎ改性的Ａｇ－ＺＳＭ－５分子筛具有较好的积炭能力。     

衬底温度对纳米硅薄膜结构性能的影响

在等离子体化学气相沉积系统中采用高氢稀释硅烷蚀刻法制备了纳米硅薄膜。系统地研究了衬底温度对ｎｃ－Ｓｉ：Ｈ薄膜的结构性能的影响。结构表明随着衬底温度从２４０℃升高到３２０℃，薄膜的晶态率从２４％增大为６５％，平均晶粒尺寸从６ｎｍ增大为１０ｎｍ。当衬底温度≤２００℃时，生成薄膜为ａ－Ｓｉ：Ｈ薄膜。文中还对纳米硅薄膜的晶化机制进行了讨论。     

混合模板剂合成钛硅分子筛

以钛酸正丁酯为钛源，正硅酸乙酯为硅源，在４４３Ｋ用罩丙基溴化铵和四乙基氢氧化铵的混合物的为模板剂，合成了Ｔｉ－Ｓｉ分子筛。经ＸＲＤ，ＦＴ－ＩＲ，ＳＥＭ以及ＢＥＴ比表面积分析，证实了在以ＴＰＡＢｒ＋ＴＥＡＯＨ为模板剂合成的样品中钛已进入ｓｉｌｉｃａｌｉｔｅ－１的骨架，而以ＴＰＡＢｒ＋二乙胺或三甲胺为模板剂则合成不出Ｔｉ－Ｓｉ分子筛。ＳＥＭ的结果表明用氨水和ＴＥＡＯＨ调节反应液的碱度，对晶体的生长和形     

重新氧化氮化n-MOSFET''''s断态栅电流的温度特性

对采用迅速热处理方法制备的重新氧化氮化ｎ－ＭＯＳＦＥＴ’ｓ 的断态栅电流Ｉｇ 的温度特性进行了实验研究和理论分析．研究表明,在合适的氮化和重新氧化条件下,Ｉｇ 随温度增加可保持几乎不变．这归因于重新氧化部分恢复了Ｓｉ／ＳｉＯ２ 界面处相应于空穴发射的氮化感应致使势垒高度的降低,从而使得在升高的温度下,热空穴注入的增加几乎抵消了雪崩区空穴产生的减小．     

计算机控制的PCVD系统

对ＬＬ－ＰＣＶＤ（真空负载保护等离子体化学气相沉积系统）进行了计算机控制的改进，改进后的设备在沉积过程中各路源气体可进行自动控制。在改进后的设备上采用逐层生长法制备了ｎｃ－Ｓｉ∶Ｈ薄膜。讨论了关键的技术问题     

硅基钠米材料发光特性的研究进展

近年，硅基低维材料物理与工艺的研究预示，硅基光电子学将是今后半导体光电子学的一个主要发展方向，而硅基低维发光材料又将成为半导体光电子集成技术的主要基础材料。随着硅基超晶格、量子阱和多孔硅研究的不断深化以及纳米科学技术的日益发展，硅基发光材料正向纳米方向开拓。本文将主要介绍硅基纳米材料，如采用各种成膜技术在不同衬底表面上制备的高质量纳米硅（ｎｃ－Ｓｉ：Ｈ）膜，镶嵌在各种介质，如　－Ｓｉ：Ｈ、ＳｉＯ２或ＳｉＮｘ中的纳米晶硅，以及利用自组织生长的Ｇｅ、Ｓｉ以及ＧｅＳｉ纳米量子点的光致发光特性及其最近研究进展。     

重新氧化氮化n—MOSFET‘s断态栅电流的温度特性

对采用迅速热处理方法制备的重新氧化氮化ｎ－ＭＯＳＦＥＴ’ｓ的断态栅电流Ｉｇ的温度特性进行了实验研究和理论分析，研究表明，在合适的氮化和重新氧化条件下，Ｉｇ随温度增另可保持几乎不变，这归因于重新氧化部分恢复了Ｓｉ／ＳｉＯ２界面处相应于空穴发射的氮化感应致使势垒高度的降低，从而使得在升高的温度下，热空穴主的增另几乎抵消了雪崩区空穴产生的减小。     

金属硅的酸洗和氧化提纯

为了降低金属硅酸洗的后续工艺难度,在成熟的常温酸洗技术的基础上加上湿氧氧化新技术对金属硅进行提纯.酸洗主要作用是去除大部分裸露在金属硅颗粒表面的金属杂质;而湿氧氧化后,使颗粒内部分凝系数(在硅和二氧化硅系统中的分凝系数)较小的硼在高温下扩散进入二氧化硅中,再腐蚀去除氧化层和其中的杂质.实验表明该方法对硼杂质有明显的提纯作用,提纯后,硼杂质的含量最低为4×10-6.两种技术在工艺上兼容,在提纯目标上互补,是非常有效的低能耗和低成本的提纯方法.     

Reaction behavior of trace oxygen during combustion of falling FeSi75 powder in a nitrogen flow

To explore the reaction behavior of trace oxygen during the flash combustion process of falling FeSi75 powder in a nitrogen flow, a flash-combustion-synthesized Fe-Si₃N₄ sample was heat-treated to remove SiO₂. The samples before and after the treatment were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and the formation mechanism of SiO₂ was investigated. The results show that SiO₂ in the Fe-Si₃N₄ is mainly located on the surface or around the Si₃N₄ particles in dense areas, existing in both crystalline and amorphous states; when the FeSi75 particles, which are less than 0.074 mm in size, fell in up-flowing hot N₂ stream, trace oxygen in the N₂ stream did not significantly hinder the nitridation of FeSi75 particles as it was consumed by the surface oxidation of the generated Si₃N₄ particles to form SiO₂. At the reaction zone, the oxidation of Si₃N₄ particles decreased the oxygen partial pressure in the N₂ stream and greatly reduced the opportunity for FeSi75 particles to be oxidized into SiO₂; by virtue of the SiO₂ film developed on the surface, the Si₃N₄ particles adhered to each other and formed dense areas in the material.     

蒸馏水润滑下Si3N4—白口铸铁摩擦面上表面膜的分析

在环－块磨损试验机上考察了蒸馏水润滑下Ｓｉ３Ｎ４分别与白口铸铁和碳钢（作对比用）配副的摩擦磨损特性．在ＳＥＭ下观察了白口铸铁磨面表面膜的形成过程，用ＸＰＳ、ＦＴＩＲ和ＸＲＤ分析了表面膜的成分、组成与结构，并对其形成机理进行了探讨．结果表明，Ｓｉ３Ｎ４在水润滑下摩擦时磨面上发生了氧化和水解反应：当Ｓｉ３Ｎ４与白口铸铁配副时，由于铸铁中碳化物的剥落而形成剥落坑，Ｓｉ３Ｎ４磨屑嵌入剥落坑并氧化和水解，其反应产物富集于剥落坑中，脱水聚合后形成硅胶，从而在磨面形成具有一定厚度和面积的含硅胶的表面膜，表面膜的形成保护了陶瓷和铸铁磨面，使其变得很光滑，从而使摩擦系数降至０．０２，并使系统磨损率几乎接近于零；当Ｓｉ３Ｎ４与碳纲配副时，由于碳钢没有能力富集Ｓｉ３Ｎ４的氧化和水解产物，故磨面不能形成有效的表面膜，所以其摩擦系数仍然较高，且系统磨损率亦较大     

MgO/Si3N4复合材料表面致密层的形成机理

研究发现MgO/Si3N4复合材料具有自阻碍氧化的性能,氧化时其表面能自发生成一层阻碍进一步氧化和提高抗侵蚀的致密层,添加Al,Si可以加厚、加宽致密层.在此基础上,研究了无添加剂和添加Al,Si的致密层的形成机理、组成和结构.提出转换氧分压为衡量气态氧化物SiO和Al2O的逸出标准,并确定气态的SiO或Al2O可以在氧化层内部生成以及由于它们在表面的再氧化和反应使表层内形成了致密层的机理.     

Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25℃ and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10-20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.     

纳晶硅氧化层中陷阱态的发光模型

纳晶硅氧化以后的PL发光带中心明显地钉扎在690nm～750nm波长之间，发光强度有显著的增加。我们通过研究纳晶硅氧化后化学键结构的改变和对应能带结构的变化，表明在较小尺寸纳晶硅的氧化过程中，有Si-O-Si桥键和Si=O双键的形成，产生对应的电子陷阱态出现在带隙中。PL发光的增强和中心波长的钉扎效应可以用纳晶硅中的量子受限理论和带隙中的陷阱态模型来解释。其中，陷阱态的位置低于量子受限激发态的位置是PL发光出现钉扎与增强效应的必要条件。     

利用FT-IR和XPS研究纳米和微米氮化硅粉体在不同气氛下的表面结构变化(英文)

采用红外光谱技术和光电子表面能谱技术比较纳米和微米氮化硅粉体表面结构在空气中和在氮气中的变化规律.研究结果显示,纳米氮化硅在空气中逐渐吸附氧气和有机物质,其表面形成了Si—OH、C—C、C—N等化学基团,而在惰性的氮气气氛中,纳米氮化硅的表面氧化被有效抑制.上述研究工作为纳米氮化硅的表面改性研究提供了一定的理论支持.     

p~+/p—Si的光电化学及电化学性能的研究

本文将外延单晶p~+/p—Si 的光电化学与电化学性能联系起来进行了研究.主要为电极在1NKOH 溶液中的表面氧化、还原以及对其光电化学性能的影响,并对电极腐蚀进行了初步探讨。     

Corrosion-wear behavior of nanocrystalline Fe88Si12 alloy in acid and alkaline solutions

The corrosion?wear behavior of a nanocrystalline Fe88Si12 alloy disc coupled with a Si3N4 ball was investigated in acid (pH 3) and alkaline (pH 9) aqueous solutions. The dry wear was also measured for reference. The average friction coefficient of Fe88Si12 alloy in the pH 9 solution was approximately 0.2, which was lower than those observed for Fe88Si12 alloy in the pH 3 solution and in the case of dry wear. The fluctuation of the friction coefficient of samples subjected to the pH 9 solution also showed similar characteristics. The wear rate in the pH 9 solution slightly increased with increasing applied load. The wear rate was approximately one order of magnitude less than that in the pH 3 solution and was far lower than that in the case of dry wear, especially at high applied load. The wear traces of Fe88Si12 alloy under dif-ferent wear conditions were examined and analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The results indicated that the tribo-chemical reactions that involve oxidation of the worn surface and hydrolysis of the Si3N4 ball in the acid solution were restricted in the pH 9 aqueous solution. Thus, water lubrication can effectively improve the wear resistance of nanocrystalline Fe88Si12 alloy in the pH 9 aqueous solution.     

碳点修饰硅在锂离子电池中的应用研究

Silicon (Si) particles were functionalized using carbon dots (CDs) to enhance the interaction between the Si particles and the binders. First, CDs rich in polar groups were synthesized using a simple hydrothermal method. Then, CDs were loaded on the Si surface by impregnation to obtain the functionalized Si particles (Si/CDs). The phases and microstructures of the Si/CDs were observed using Fourier-transform infrared reflection, X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Si/CDs were used as the active material of the anode for electrochemical performance experiments. The electrochemical performance of the Si/CD electrode was assessed using cyclic voltammetry, electrochemical impedance spectroscopy, and constant current charge and discharge experiment. The electrodes prepared with Si/CDs showed good mechanical structure stability and electrochemical performance. After 150 cycles at 0.2 C, the capacity retention rate of the Si/CD electrode was 64.0%, which is twice as much as that of pure Si electrode under the same test conditions.