复合介质L型侧墙形成技术

:给出了 E- B之间复合介质 L型侧墙的形成技术。这种工艺技术控制容易 ,成品率高 ,均匀性好。已将这种工艺技术应用于双层多晶硅双极晶体管的制作工艺中 ,器件具有良好的电学特性。     

Mode of crosslinking of degradable poly(vinylpyridine N-oxide) gels

The degradation mechanism of gels from poly(vinylpyridine N-oxide) was investigated by differential scanning calorimetry, C, H, N analysis, infra-red spectroscopy and degradability tests. It was found that poly(2-vinyl pyridine N-oxide) gels, regardless of the persulphate initiator used, were weaker than poly(4-vinyl pyridine N-oxide) gels. C, H, N analysis and infra-red spectroscopy indicated that the initiator becomes an integral part of the gels. A mechanism for the formation of the gels is proposed.     

温度对非晶硅薄膜二次晶化的影响

为研究温度对固相晶化的影响,用玻璃作衬底,在不同温度下用PECVD法直接沉积非晶硅(a-Si:H)薄膜,把在室温、350℃和450℃下沉积的样品,在600℃和850℃下退火3h,把前后样品用拉曼光谱和扫描电镜分析,发现二次晶化后的晶化效果比直接沉积的薄膜好,850℃下退火的薄膜比600℃好。在450℃下沉积、850℃退火3h,SEM观察,表面最大晶粒尺寸为900nm左右。     

Room‐Temperature Tailoring of Vertical ZnO Nanoarchitecture Morphology for Efficient Hybrid Polymer Solar Cells

A ZnO nanoarchitecture, i.e., ZnO nanosheet (NS) framework, is demonstrated to be a promising electron acceptor and direct electron transport matrix for polymer‐inorganic hybrid solar cells. The ZnO NS framework is constructed on nanoneedles/indium tin oxide substrate via a room‐temperature chemical bath deposition (RT CBD). The framework morphology can be simply tailored by varying the concentration of precursor solution in the RT CBD. The ZnO nanoarchitecture with an appropriate free space between the NSs is consequently demonstrated to facilitate poly(3‐hexylthiophene) (P3HT) infiltration, resulting in superior interface properties, i.e., more efficient charge separation and less charge recombination, in the hybrid. Moreover, apart from the characteristics similar to the ZnO nanorod (NR) array, including vertical feature and single crystalline structure, the ZnO NS framework exhibits a slightly larger absorption edge and a faster electron transport rate. A notable efficiency of 0.88% is therefore attained in the ZnO NS‐P3HT hybrid solar cell, which is higher than that of the ZnO NR‐P3HT hybrid solar cell.     

Durable electrochromic coatings prepared from electronically conductive poly(3HT-co-3TPP)-silica hybrid materials

In this paper, a series of organic-inorganic hybrid materials, consisting of heterocyclic conjugated poly(3-hexylthiophene), P3HT, network, and silica particles, were successfully prepared for electrochromic studies. First, the heterocyclic co-polymer of poly[3-hexylthiophene-co-N-(3-trimethoxysilylpropyl) pyrrole], P(3HT-co-3TPP), containing trimethoxysilyl functional groups in the co-polymer backbone as the sol-gel precursor were prepared by conventional oxidative polymerization. Subsequently, P(3HT-co-3TPP)-silica hybrid sol-gel materials in the form of coatings were prepared by baking the microslides and ITO-coated electrodes that had been cast with homogeneous blending solutions containing co-polymer, acid-dopant, tetraethyl orthosilicate (TEOS), and a few drops of water. The microstructures of silica particles formed in the P(3HT-co-3TPP)-silica hybrid materials were investigated by transmission electron microscopy (TEM). The as-prepared hybrid coatings had improved adhesion capability on inorganic glass substrates relative to the pure P3HT on the basis of electrochemical cyclic voltammetric studies and Scotch tape test evaluations. During potential cycling, the film color of P(3HT-co-3TPP)-silica hybrid materials and P3HT coated on ITO electrode changed from orange yellow (i.e., reduced form) to dark blue (i.e., oxidized form) as the redox reactions proceeded. Effects of the material composition of P3HT along with hybrid materials on the electrochemistry, spectroelectrochemistry, thermal stability, and electrical conductivity were also studied.     

Temperature gradient controlled crystal growth from TIPS pentacene-poly(α-methyl styrene) blends for improving performance of organic thin film transistors

6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) from simple drop casting typically forms crystals with random orientation and poor areal coverage, which leads to device-to-device performance variation of organic thin film transistors (OTFTs). Previously, a temperature gradient technique was developed to address these problems. However, this approach simultaneously introduced thermal cracks due to the thermally induced stress during crystallization. These thermal cracks accounted for a reduction of charge transport, thereby impacting the device performance of TIPS pentacene based OTFTs. In this work, an insulating polymer, poly(α-methyl styrene) (PαMS) was blended with TIPS pentacene to relieve the thermal stress and effectively prevent the generation of thermal cracks. The results demonstrate that the incorporation of PαMS polymer combined with the temperature gradient technique improves both the hole mobility and performance consistency of TIPS pentacene based OTFTs.     

一种新型高速宽带数字下变频器的FPGA实现

数字下变频器是软件无线电宽带数字接收机的核心组成部分,经典的数字下变频结构难以实现高速率的混频与滤波,因此针对软件无线电系统小型化和低功耗的要求,提出一种新型的宽带数字接收机中数字下变频器的设计与FPGA实现方法,该方法采用基于多相滤波正交化处理从而实现数字接收机。文中分析了其设计原理以及FPGA实现,测试结果表明,设计具有良好的可扩展性和灵活性。     

可溶性聚吡咯甲烯衍生物的光电性能研究

在酸性条件下制备可溶性聚{(3-丙酰基)吡咯-[2,5-二(对硝基苯甲烯)]}(PPPDNBE),并且对PPPDNBE的热稳定性能、光物理性能和电化学性能进行研究.热失重曲线显示,PPPDNBE的初始分解温度为187.41℃.紫外-可见吸收光谱表明,PPPDNBE溶液和薄膜的共轭吸收峰分别位于476 nm和484 nm.PPPDNBE为橙色发光材料,最大发射波长为612 nm.PPPDNBE的光学带隙和电化学带隙分别为1.68 eV和1.62 ev.此外,PPPDNBE还可以用作电容器的阴极材料,随着电压扫描速率增加,储存的电量逐渐增大.     

Self‐Crosslink Method for a Straightforward Synthesis of Poly(Vinyl Alcohol)‐Based Aerogel Assisted by Carbon Nanotube

As a new concept, a self‐crosslink mechanism for hydrothermal synthesis of poly(vinyl alcohol) (PVA) aerogel, assisted by multiwall carbon nanotubes, is reported. PVA, working as a low‐cost and commercially available raw material, exempts the complicated synthesis process and reserves its nontoxic nature since no organic crosslinkers are used in the synthesis process. The crosslink density and many other properties of the products can be easily tuned by simply altering the concentration of PVA precursors, which is considered to be another feature of our method. Dehydration between hydroxyl groups occurs in the hydrothermal process, leading to a reverse wettability of the products from hydrophilic to hydrophobic, thus their absorbing capacity for several organic solvents, such as bean oil and crude oil, is investigated. The absorbate has 10–52 times the original weight of the aerogel. As exhibited by the cytotoxic tests, the product has neglectable toxicity, suitable for application in environmental bioengineering. Furthermore, the product can be used as a facile substrate for transformation into conductive aerogel by in situ hybridizing with polypyrrole, showing a conductivity of 0.16 S m^?1. As it is rich in hydroxyl groups, the aerogels are believed to be further functionalized by the reactions related to the hydroxyl group.     

碳纳米管及其批量制备研究进展

从碳纳米管的优异性能和应用出发,综述了碳纳米管的制备方法以及我国目前在碳纳米管研究中面临的问题;分析了碳纳米管产业化对的我国纳米技术产业化发展的积极意义,特别介绍了清华-南风纳米粉体产业化工程中心开发的、具有我国自主知识产权的纳米聚团流态化技术。