硅基Zn2SiO4:ZnO薄膜的电致发光

利用溶胶-凝胶法在重掺硼硅片(p-Si)上制备Zn2SiO4∶ZnO(ZnO嵌入Zn2SiO4基体)薄膜,在此基础上,制备了Zn2SiO4∶ZnO薄膜发光器件。实验表征了Zn2SiO4∶ZnO薄膜的晶体结构和形貌,并研究了该器件的载流子输运和电致发光特性。研究表明:器件表现出一定的整流特性;此外,器件在正向偏压(p-Si接正极)下可以产生来自于ZnO的电致发光,而在反向偏压(p-Si接负极)下几乎不发光。通过对上述器件在正向和反向偏压的能带图进行分析,对其载流子输运和电致发光机理进行了解释。     

联柱状ZnO微晶的微波合成及其光催化活性

以醋酸锌和六次甲基四胺为起始原料,表面活性剂CTAB和SDS为形貌控制剂,采用微波法合成了联柱状ZnO微晶,借助XRD、XPS、FT-IR、FT-Ra-man、TEM、SEM和UV-vis等测试技术对其进行了表征,并以甲基橙为模型污染物考察了样品的光催化活性.结果表明,所得样品均为六方纤锌矿ZnO;同时添加两种表面活性剂CTAB和SDS时所获样品形貌最佳,为六棱柱对接而成的联柱状结构,其在200～420nm波长范围内对光有较强吸收,对卷烟厂蒸叶车间废水的光降解表现出较高的催化活性,自然光照5h,废水COD去除率为84.7%;另外,对联柱状ZnO微晶的形成机理进行了初步探讨.     

多孔结构ZnO及其电致发光性能

利用Sol-gel法制备了含制孔剂P123的ZnO前驱体,通过无皂乳液聚合法和分步乳液聚合法制备了不同粒径的PS小球,采用共沉积法得到P123-PS-ZnO凝胶。高温煅烧去除有机模板剂P123和PS,从而制备出系列孔径可控的多孔ZnO电致发光材料。研究表明,多孔结构可以显著改善ZnO的电致发光性能;ZnO发光强度随PS粒度的改变而改变,当使用100nm PS小球为模板时,多孔ZnO材料的相对发光强度较未使用PS模板提高了4.03倍。     

纳米ZnO的制备

本文研究了以Zn (No3 ) 2 、尿素为原料 ,加入表面活性剂改性制备纳米氧化锌粉体的方法。实验讨论了Zn (NO3 ) 2 浓度、尿素浓度、pH值、焙烧温度对纳米氧化锌粒径的影响。用扫瞄电镜和粒度分析仪确定纳米氧化锌的形貌和粒径     

Zn1-xMgxO的溶胶凝胶法合成及其特性研究

由溶胶凝胶法、利用草酸盐在水相中合成了干凝胶前体粉末,经过热处理得到了纳米Zn1-x MgxO(x≤0．15)粉体;XRD表明所制得的材料具有ZnO的六方晶系结构;经UV—Vis分析,比较了量子尺寸的ZnO与热处理的ZnO和Mg掺杂的ZnO及其混合溶胶的紫外吸收差异;通过Mg的掺杂,使ZnO的禁带宽度从3、31eV调节至3．65eV。     

无机粉末电致发光材料的研究进展

无机粉末电致发光材料包括硫化物系和金属氧化物系。主要从引入杂质缺陷和结构缺陷的角度阐述了国内外无机粉末电致发光材料在制备、性能及应用的最新研究进展情况，介绍了电致发光材料与超材料和纳米激光领域的结合进展。结合当前纳米材料科学的发展状况，展望了无机粉末电致发光材料的应用前景和发展趋势。     

ZnO:Zn的光致发光和电致发光性能

在N2 H2还原气氛中以ZnO粉末为原料制备了ZnO:Zn发光膜和粉末.利用X射线衍射、电子扫描显微镜、红外光谱仪、XPS、荧光分光光度计等测试手段表征了样品的结构、形貌、缺陷和发光性能.ZnO:Zn发光膜具有六角纤锌矿晶体结构和良好的c轴取向,结晶性较好,晶粒颗粒均匀.ZnO:Zn发光膜和粉末具有绿色的单谱光致发光和电致发光.发光薄膜的O1s结合能表明,此绿色发光与薄膜内的点缺陷状态密切相关.     

氟表面活性剂特性及其合成方法

对氟表面活性剂进行了特性分析 ;并对其 3种生产方法进行了比较。证实通过调聚法生成全氟烷基碘化物 ,再进一步反应合成各类氟表面活性剂 ,这一工艺路线不论在成本、性能上 ,还是在工业化以及工业操作方面都有着明显的优势 ,也已替代了电解氟化法成为该行业世界性的发展趋势。     

电致发光共轭高聚物的合成

近年来，电致发光共轭高聚物的合成及其器件的研究引起了人们广泛的关注。本文介绍了此类聚合物的一般合成方法，并对其进行了简单的评述。     

针状氧化锌的控制合成

采用简单的低温陈化法,以ZnCl2和NaOH为原料,阴离子表面活性剂SDS或SDBS为添加剂,成功制备了不同长径比的一维结构ZnO晶体.利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对样品进行了表征.通过跟踪ZnO形成过程中Zn(Ⅱ)离子浓度的变化情况,初步探讨了阴离子表面活性剂对ZnO晶体生长的作用机理.结果表明,阴离子表面活性剂能够有效降低ZnO的成核、生长速率,促进其沿[0001]方向生长成为长径比较大的针状形貌.     

导电氧化锌粉体的掺杂和制备

阐述了掺杂氧化锌粉体的导电机理,介绍了常用的制备方法并比较分析了各种方法的优缺点,指出导电氧化锌粉体制备技术中所存在的问题和可能的解决途径.     

Study of photocatalytic properties of pure and doped ZnO powders

In this paper pure ZnO and doped Bi–ZnO powders annealed at 200 °C were prepared using conventional solid state reaction and were applied as photocatalysts for Cr(VI) reduction. Structural properties were studied using X‐ray diffraction (XRD) and optical properties were investigated using photoluminescence (PL) spectrophotometry and ultraviolet‐visible (UV‐vis) absorbance spectroscopy. Based on the obtained results, it was found that bismuth (Bi) had a strong impact in varying the electronic structure of ZnO. This was mainly referred to Bi that existed in different states as an acceptor, donor and plasmonic nanostructure metal. According to the literature Bi was known to be acted as an acceptor and donor without knowing how it acted in this manner. A new mechanism was proposed describing the different states of Bi as waves having different orientations when interacting within ZnO. The time at which an interaction of incident UV light with the oriented Bi wave within ZnO occurred must be less than the duration of existence of such wave at this orientation.     

CdS/ZnO复合颗粒的制备与电致发光性能

以sol-gel法制备了ZnO前驱体,并通过水热反应得到了CdS/ZnO复合颗粒.采用红外光谱(IR)、X射线衍射(XRD)、扫描电镜(SEM)表征其结构、组成及形貌,并对其电致发光(EL)特性进行表征.结果表明CdS纳米晶生长在ZnO基体上;EL谱表明没有煅烧的CdS/ZnO复合颗粒表现为CdS的激子发射,发光强度较纯CdS有了明显的提高;而煅烧后的CdS/ZnO复合颗粒则表现为ZnO的缺陷发射,发光谱的半高宽较纯ZnO有所减小.     

Study of ZnO layers growth by pulsed laser deposition from Zn and ZnO targets

The article deals with structural properties of ZnO thin layers prepared on Si (111) by pulsed laser deposition at different pressures (1-35 Pa) of ambient oxygen in the deposition chamber. The growth temperature was 400 °C and a pulsed Nd:YAG laser was used at a wavelength of 355 nm. Two parallel sets of samples deposited by ablation of different targets (a sintered ceramic pellet of ZnO and a pure metallic Zn target) were examined. The samples were characterized by different analytical methods: scanning electron microscope (SEM), secondary ion mass spectroscopy (SIMS), and X-ray diffraction (XRD). The prepared layers exhibited columnar structure and uniform preferred c-axis orientation. The results showed that deposition of the high quality of ZnO films fabricated from both targets is comparable, except for those obtained at low (1 Pa) pressures.     

Ultraviolet electroluminescence from ZnO/polymer heterojunction light-emitting diodes

We report ultraviolet electroluminescence at 390 nm from diode structures consisting of electrodeposited ZnO nanorods sandwiched between a transparent SnO(2) film and a p-type conducting polymer. The nanorods are embedded in an insulating polystyrene layer. ZnO deposition occurs at 90 degrees C and produces vertically oriented nanorods with very high uniformity over areas of approximately 20 cm(2). Electron diffraction shows the nanorods to be single crystalline wurtzite ZnO. As-grown films show a broad electroluminescence band over the visible spectrum. Annealing at moderate temperatures (T = 300 degrees C) increases the emission and strongly raises the excitonic contribution. Optimally processed films show a narrow ultraviolet electroluminescence line at approximately 390 nm.     

高温固相法制备ZnO:Zn荧光粉的研究

采用高温固相法制备ZnO∶Zn绿色发光粉体。XRD分析、荧光光谱分析结果表明 :在固相法制备ZnO∶Zn中 ,制备原料所用ZnO、C的最佳摩尔比在 2∶3,反应最佳温度为 110 0 0C。     

Combustion synthesized ZnO powders for varistor ceramics

Commercial ZnO varistor ceramics are multicomponent, with minor amounts of added oxides that play important roles, both in the strict electrical sense and for the control of the microstructure. The present work describes the straightforward combustion synthesis of pure and doped ZnO powders from stoichiometric mixtures of the relevant water soluble metal nitrates as cation precursors and urea as fuel. The mixtures were ignited at 500°C resulting in a dry, very fine powder. The as-prepared combustion products, characterized by XRD, SEM, TEM and BET, show high specific surface area, have very small particle sizes and are crystalline, with atomic level homogeneity. Implications on sintering and electrical behaviour are discussed.     

Aqueous combustion synthesis and characterization of ZnO powders

New organic fuels (β-alanine, valine, zinc acetate and acrylamide) have been successfully tested for the preparation of nanocrystalline ZnO powders via aqueous combustion synthesis. In all cases, ZnO resulted directly from the combustion process and no subsequent annealing was required. Properties of the as-prepared ZnO powders were investigated and it was found that morphology, specific surface area, crystallite size and cumulative volume of pores are determined by the used fuel. A correlation has been found between the total volume of generated gases, adiabatic temperature, the amount of ZnO and the characteristics of the resulting powders. Largest surface area (42.0 m² g⁻¹) and smallest ZnO crystallite size (21 nm) were obtained for acrylamide.     

氧化锌压敏陶瓷粉体的研究进展

综述了氧化锌压敏陶瓷粉体的研究进展,分析了粉体特性对压敏电阻微观结构和电性能的影响以及粉体制备中存在的问题.对粉体的制备方法和应用前景进行了展望,指出化学法合成复合粉体和高能球磨法制备纳米粉体是氧化锌压敏陶瓷粉体的两个主要发展趋势.