ZnO∶Sn/Ag/ZnO∶Sn复合薄膜电极的防氧化性能研究

随着分辨率的提高,传统金属电极在电阻率和抗氧化性能方面已经不适合作为需要高温热处理的场致发射显示器件中的薄膜电极.本文采用5.77%(原子比)Sn掺杂的ZnO∶Sn作为Ag层的保护层,利用磁控溅射法制备ZnO∶Sn/Ag/ZnO∶Sn复合薄膜及其电极,并采用X射线衍射、光学显微镜、扫描电子显微镜和电性能测试系统研究复合薄膜及其电极在经过不同温度退火后的晶体结构、表面形貌和电学性能的变化.ZnO∶Sn膜层致密,25 nm厚的ZnO∶Sn 足以保护Ag层在530℃的高温中不被明显氧化,电极电阻率低达2.0×10-8Ω·m左右.     

Cr/Cu/Ag/Cu/Cr新型银基复合薄膜电极的防氧化性能研究

采用直流磁控溅射技术和光刻工艺制备了Cr/Cu/Ag/Cu/Cr复合薄膜及其电极,研究不同温度热处理对复合薄膜和电极结构、表面形貌和电性能的影响。Ag层与最外层的Cr层之间的Cu层不仅增强了Cr和Ag之间的粘附力,而且起到了牺牲层和氧气阻挡层的作用;Cr和Cu对Ag的双重保护使得薄膜电极在温度小于500℃时电阻率保持较为稳定,约为3.0×10-8~4.2×10-8Ω·m之间。然而由于电极表面氧化和边沿氧化的共同作用,薄膜电极的电阻率在热处理温度超过575℃出现了显著的上升。尽管如此,Cr/Cu/Ag/Cu/Cr薄膜电极仍然是一种能够承受高温热处理并且保持较低电阻率的新型电极,满足场发射平板显示器封接过程中的热处理要求。     

ZnO/CdO复合薄膜的制备及其性能研究

通过脉冲激光沉积法首次制备了ZnO/CdO复合薄膜。采用X射线衍射、光致发光和电阻率测量分析了薄膜的结构、光学和电学性能。光致发光谱表明所有ZnO/CdO复合薄膜都具有相同的PL发光峰,保持了未掺杂ZnO的发光特性。同时,复合薄膜的电阻率大大地下降了几个数量级,接近了纯CdO薄膜的电阻率。这可以用Matthiessen公式来解释。与传统掺杂方法相比,制备的ZnO/CdO复合薄膜可同时具有ZnO的发光特性和CdO的电学特性,从而获得单一TCO材料所不具备的性能,满足某些特殊需求。     

应用于FED Al/Ag/Al导电复合薄膜的研究

利用Ag的高温抗氧化能力,采用磁控溅射沉积Al/Ag/Al导电复合薄膜,并在480℃下进行热处理。扫描电子显微镜（SEM）和能谱分析（EDS）研究表明磁控溅射的Al/Ag/Al导电复合薄膜表面平整,热处理后表面Al膜生成致密的氧化层。溅射沉积和热处理过程中Ag和Al原子的相互扩散,最后形成富Ag的Ag-Al合金和Ag3Al化合物。Al/Ag/Al导电复合薄膜比Ag/Al复合薄膜的电阻率增大了一个数量级,导电复合薄膜热处理后导电性能更优,电阻率约为19.4×10-6Ω.cm。     

基于ZnO模板原位合成Cu/Zn/Al-LDHs/ZnO薄膜的工艺及性能研究

采用多金属片于Na2CO3溶液中在ZnO模板表面原位合成了Cu/Zn/Al-CO3-LDHs/ZnO薄膜前体和La-Cu/Zn/Al-CO3-LDHs/ZnO复合薄膜,优化了工艺条件。借助XRD、FT-IR、UV、TG/DTA及电化学测试等手段对LDHs薄膜结构及其性能进行了表征与分析。结果表明,该薄膜中水滑石晶体的ab面平行于基体,薄膜在ZnO模板表面形成多层叠加结构;月桂酸根修饰LDHs薄膜能增强其疏水性能,薄膜与基体结合牢固,对金属锌表现出优异的耐蚀性。     

退火温度对ZnO/Mo/ZnO透明导电薄膜结构及光电性能的影响

采用电子束蒸发法成功制备了透明导电的ZnO/Mo/ZnO(ZMZ)复合薄膜,研究了不同的退火温度对其电学和光学性质的影响规律。利用X射线衍射仪、扫描电子显微镜、X射线能谱仪、紫外可见分光光度计和四探针测试仪等检测手段对样品的性能进行了分析。实验结果表明:随着退火温度的升高,薄膜的结晶程度提高,晶粒尺寸增大;薄膜的电阻率先降低后升高;薄膜的光学透过率先升高后降低。当退火温度为250℃时,ZnO/Mo/ZnO薄膜具有最佳的综合光电性能,在400nm~900nm波长范围内最高透过率为81.4%,平均透过率高于80%,最低电阻率为1.71×10-4Ω·cm,表面电阻为15.5Ω/sq。研究表明所制备的ZMZ复合透明导电薄膜可应用于太阳能电池、液晶显示器等领域。     

溶胶-凝胶法制备ZnO:Sn(TZO)薄膜

以普通玻璃为衬底,采用溶胶-凝胶旋涂法制备出c轴择优取向性、高可见光透过率以及低电阻率的ZnO:Sn(TZO)薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、四探针及紫外-可见分光光度计(UV-VIS)等手段,研究了不同Sn掺杂浓度对薄膜的晶体结构、表面形貌、电学和光学特性的影响。实验结果表明,在500℃的空气中热处理,然后在低温环境快速冷却,得到的TZO薄膜均具有六角纤锌矿结构,且呈c轴择优取向,薄膜在可见光范围内平均透光率超过90%,同时当Sn掺杂浓度为3 at.%时,薄膜的电阻率达到最小值8.2×10-1Ω.cm。     

退火对ZnO/Cu/ZnO透明导电薄膜性能的影响

室温下利用磁控溅射制备了ZnO/Cu/ZnO透明导电薄膜,采用X射线衍射(XRD)、原子力显微镜(AFM)、扫描电子显微镜(SEM)、霍尔效应测量仪和紫外-可见分光光度计研究了薄膜的结构、形貌、电学及光学等性能与退火温度之间的关系。结果表明:退火前后薄膜均具有ZnO(002)择优取向,随着退火温度的升高,薄膜的晶化程度、晶粒粒径及粗糙度增加,薄膜电阻率先降低后升高,光学透过率和禁带宽度先升高后降低。150℃下真空退火的ZnO/Cu/ZnO薄膜的性能最佳,最高可见光透光率为90.5%,电阻率为1.28×10-4Ω·cm,载流子浓度为4.10×1021cm-3。     

ZnO/Ag纳米复合材料的制备及电学性能研究

在室温下,利用超声活化法将机械研磨13h的Zn粉在V(水)∶V(环己烷)=19∶1的分散体系中合成ZnO纳米颗粒悬浮液,然后通过光还原AgNO3制备出ZnO/Ag纳米复合材料。并用X射线粉末衍射仪(XRD)、透射电子显微镜(TEM)对ZnO/Ag复合颗粒表征,用扫描电子显微镜(SEM)和探针台I-V测试仪对ZnO/Ag复合薄膜表征和电学性能测试,通过XRD和TEM得出,超声合成的ZnO具有六方纤锌矿结构,长约20nm的短棒状;经光还原沉积在其表面的纳米Ag呈现面心立方结构,直径约为5nm。通过SEM和I-V伏安特性曲线得出,干燥温度对复合结构有较大影响,60℃干燥的复合薄膜比较致密均匀,导通电压大约2V左右,在100℃时开始转变为有氧化锌附着的枝状银网状复合物,导通电压在0.02V左右,通过控制干燥温度可改变复合薄膜中ZnO和Ag的结合方式以及相应的电学性能。     

纤维基ZnO/Ag/ZnO多层膜的制备、结构及性能研究

利用射频磁控溅射法,室温下通过交替溅射ZnO和Ag,在PET纤维基材上制备ZnO／Ag／ZnO纳米结构多层膜。运用扫描电镜和原子力显微镜对薄膜表面形貌进行分析,用分光光度计测试其透光性能,用四探针电阻测试仪测试其方块电阻。结果表明：纤维基Zno／Ag／ZnO多层膜致密、均匀,对紫外光表现为较强的吸收能力;Ag膜厚度的改变可以调控多层膜的光电性能;ZnO（40nm）／Ag（20nm）／ZnO（40m）多层膜呈现多晶结构,方块电阻为4．4Ω;透光率接近30％。     

Design of ZnO/Ag/ZnO multilayer transparent conductive films

We have studied the properties of ZnO/Ag/ZnO multilayers prepared on glass substrates by simultaneous RF magnetron sputtering of ZnO and dc magnetron sputtering of Ag. The electrical and optical performance of Ag and ZnO single layer films was also investigated. Different optimization procedures were used for good transparent conductive film. Several analytical tools such as spectrophotometer, scanning electron microscope (SEM), four-point probes were used to explore the causes of the changes in electrical and optical properties. Low sheet resistance of 3 Ω/sq. and transmittance over 90% at 580 nm was achieved. The results of optimization condition of both oxide layers and metallic Ag layers were illustrated.     

High quality transparent conductive ZnO/Ag/ZnO multilayer films deposited at room temperature

We have fabricated, by simultaneous DC and RF magnetron sputtering, multilayer transparent electrodes having much lower electrical resistance than the widely used transparent conductive oxide electrodes. The multilayer structure consists of three layers (ZnO/Ag/ZnO). Ag films with different film thickness were used as metallic layers. Optimum thicknesses of Ag and ZnO films were determined for high optical transmittance and good electrical conductivity. Several analytical tools such as spectrophotometer, atomic force microscopy, scanning electron microscopy and four-point probe were used to explore the possible changes in electrical and optical properties. A high quality transparent electrode, having resistance as low as 3 Ω/sq and high optical transmittance of 90% was obtained at room temperature and could be reproduced by controlling the preparation process parameters. The electrical and optical properties of ZnO/Ag/ZnO multilayers were determined mainly by the Ag film properties. The performance of the multilayers as transparent conducting materials was also compared using a figure of merit.     

Real time spectroscopic ellipsometry of Ag/ZnO and Al/ZnO interfaces for back-reflectors in thin film Si:H photovoltaics

Real time spectroscopic ellipsometry (RTSE) has been applied to analyze the optical characteristics of Ag/ZnO and Al/ZnO interfaces used in back-reflector (BR) structures for thin film silicon photovoltaics. The structures explored here are relevant to the substrate/BR/Si:H(n-i-p) solar cell configuration and consist of opaque Ag or Al films having controllable thicknesses of microscopic surface roughness, followed by a ZnO layer up to ~ 3000 Å thick. The thicknesses of the final surface roughness layers on both Ag and Al have been varied by adjusting magnetron sputtering conditions in order to study the effects of metal film roughness on interface formation and interface optical properties. The primary interface loss mechanisms in reflection are found to be dissipation via absorption through localized plasmon modes for Ag/ZnO and through intraband and interband transitions intrinsic to metallic Al for Al/ZnO.     

Synthesis,characterization, and dispersion behavior of ZnO/Ag nanocomposites

ZnO/Ag nanocomposites that are composed of quasi-spherical nanoparticles with diameters of several nanometers have been successfully generated by a two-step liquid precipitation method. The as-prepared ZnO/Ag nanocomposites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). The dispersion behaviors of the ZnO/Ag nanocomposites in isopropanol with using nonionic dispersants such as stearic acid, PVP K17, and PVP K30 were investigated by conventional sedimentation method, dynamic light scattering method (DLS) and TEM observation. Both the PVP K17 and PVP K30 could disperse the ZnO/Ag nanoparticles effectively in isopropanol. It is proposed that the nonionic dispersants could form absorbed PVP molecule layers on the surfaces of the ZnO/Ag nanoparticles, prohibiting their agglomeration and enhancing their dispersion stability in isopropanol. This work is helpful for further investigating the potential applications of ZnO/Ag nanocomposites in the fields of medical plastics and sterilization.     

Rapid thermal annealing of sputter-deposited ZnO/ZnO:N/ZnO multilayered structures

Rapid thermal annealing (RTA) of sputter-deposited ZnO/ZnO:N/ZnO multilayered structures formed by a combination of radio-frequency magnetron sputtering and a microwave plasma source was investigated for the fabrication of highly-crystallized ZnO:N films. The assistance of the microwave plasma source resulted in the enhancement of nitrogen incorporation into the ZnO films and the deterioration of film crystallization. On the other hand, crystallization of the ZnO:N layer was improved by RTA with no significant effusion and diffusion of N atoms using a ZnO/ZnO:N/ZnO multilayered structure. The role of the front and bottom ZnO layers during RTA of ZnO/ZnO:N/ZnO multilayered structures is demonstrated.     

Effects of seed layers on structural, morphological, and optical properties of ZnO nanorods

We studied the effects of seed layers on the structural and optical properties of ZnO nanorods. ZnO and Ag-doped ZnO (ZnO:Ag) seed layers were deposited on glass substrates by magnetron co-sputtering. ZnO nanorods were grown on these seed layers by the chemical bath deposition in an aqueous solution of Zn(NO3)2 and hexamethyltetramine. SEM micrographs clearly reveal that ZnO nanorods were successfully grown on both kinds of seed layers. The XRD patterns indicate that crystallization of ZnO nanorods is along the c-axis. Meanwhile, the packing density and the vertical alignment of the ZnO nanorods on the ZnO seed layer are better than those of the ZnO nanorods on ZnO:Ag. The enhanced growth of nanorods is thought to be due to the fact that the ZnO layer exhibits a higher crystalline quality than the ZnO:Ag layer. According to the low-temperature photoluminescence spectra, the ZnO nanorods on the ZnO seed layer show a narrow strong ultraviolet emission band centered at 369 nm, while those on ZnO:Ag exhibit multiple bands. These results are thought to be related with the crystallinity of ZnO nanorods, the morphologies of ZnO nanorods, and the reflectivities of seed layers. More detailed studies for clarification of the seed layer effect on the growth of ZnO nanorods are desirable.     

Photoelectron spectroscopy on metal-polymer interfaces: Ag/polybutene (Ag/PB-1) and epitaxial Sn/polybutene (Sn/PB-1)

The interaction of metals with polymer surfaces is studied by photoelectron spectroscopy for the case of Ag/polybutene (Ag/PB-1) and Sn/polybutene (Sn/PB-1). While Ag/PB-1 shows the normal behaviour as observed for small particles, e.g., Ag/graphite; Sn/polybutene (Sn/PB-1), which grows epitaxially, shows, in addition, a component at very low coverage, which can be attributed to a Sn-O-C bond at the Sn/PB-1 interface.     

ZnO/Ag/CdCO_3纳米复合光催化剂的制备及性能研究

采用配位均匀共沉淀法制备出ZnO/Ag/CdCO3纳米复合光催化剂,用TEM、XRD、FT-IR、ICP等对产物的形貌、微观结构及组成进行了表征,着重研究了反应物配比及Cd(NO3)2浓度对ZnO/Ag/CdCO3纳米复合光催化剂催化降解甲基橙光催化活性的影响规律,结果表明,n(Zn2+):n(Ag+):n(Cd2+)=21:1.76:1.75,Cd(NO3)2浓度为0.168mol·dm-3时制得的纳米复合光催化剂对甲基橙(MO)的降解率较ZnO/Ag提高51%,ZnO/Ag/CdCO3对MO的光催化降解符合一级反应动力学方程,表观速率常数为1.4551h-1,是ZnO/Ag的7倍。     

Optimization of ZnO/Ag/ZnO multilayer electrodes obtained by Ion Beam Sputtering for optoelectronic devices

We investigated the electrical and optical properties of ZnO/Ag/ZnO multi-layer electrodes obtained by ion beam sputtering for flexible optoelectronic devices. This multi-layer structure has the advantage of adjusting the layer thickness to favor antireflection and the surface plasmon resonance of the metallic layer. Inserting a thin (Ag) metallic layer between two (ZnO) oxide layers decreases the sheet resistance while widening the optical transmittance window in the visible. We found that the optimal electrode is made up of a 10 nm thin Ag layer between two 35 nm and 20 nm thick ZnO layers, which resulted in a low sheet resistance (R_sq = 6 Ω/square), a high transmittance (T ≥ 80% in the visible) and the highest figure of merit of 1.65 × 10^-2 square/Ω.     

MOF衍生的多孔ZnO/C、Ag/ZnO/C复合材料光催化性能研究

以金属有机骨架(MOF-5)为前驱体, 通过高温热处理和湿化学法获得ZnO/C和Ag/ZnO/C两种光催化复合材料。采用X 射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱(EDS)和紫外-可见分光漫反射(UV-Vis DRS)等方法对所得样品的晶体结构、形貌特征、组成及光谱特性进行了表征。结果显示, 高温热处理保留了MOF-5的原始结构。ZnO/C比表面积为390 m²/g, 载银后比表面积仍达232 m²/g, 负载的银颗粒尺寸约30 nm。光催化降解实验表明ZnO/C和Ag/ZnO/C复合材料对亚甲基蓝(MB)都具有很高的降解效率, 均优于商业TiO₂。Ag/ZnO/C的光催化性能更好, 且具有较好的重复利用和稳定性。因此, 适度的高温碳化和掺杂贵金属是获得优良光催化性能的根本原因。