双模板辅助化学电沉积法制备金属银树枝状结构阵列

采用双模板辅助化学电沉积法,以二维聚苯乙烯胶体晶体为初级模板,二维ZnO有序多孔薄膜为二级模板,制备了周期性排列的银树枝状结构阵列.实验证明,银树枝状结构的周期性由初级模板的有序性决定,电极间距是控制银树枝状结构生长在ZnO多孔薄膜内的关键因素.     

纳米树枝状银的电化学制备及其光学性质

采用化学电沉积的方法在导电玻璃表面制备了银的二维纳米树枝状结构.通过调节沉积电压可以得到不同形貌和尺寸的树枝状银结构.研究发现,在一定范围内,沉积电压越高,制备的树枝状结构密度和尺寸越小.在银树枝表面沉积绝缘薄膜,将它与未沉积绝缘薄膜的银树枝组合成"三明治"结构,测试了它的光透过率.实验表明,由0.9V沉积电压下制备的树枝状银组成的"三明治"复合结构在360～800nm范围内对多种频率的光有吸收,光透射曲线呈锯齿状,这种特殊的光透射行为可能是光波在"三明治"结构间电磁响应引起的.     

红外波段铜树枝状结构磁响应特性研究

提出一种可用于实现红外波段负磁导率的树枝状磁谐振模型,采用基于有限差分技术的CST微波工作室软件确定了树枝状结构参数与磁谐振响应之间的关系,实现了红外波段的负磁导率.以碳纤维为阴极,采用化学电沉积的方法制备了铜树枝状结构,利用傅立叶变换红外光谱仪测量了样品的空间红外透射行为,结果表明铜树枝状结构实现了红外波段的磁谐振响应,最大透过率达到-7.95dB,实验结果与数值模拟吻合.研究了铜树枝状结构的分形维数和磁响应波段与沉积电压的关系以及两个铜树枝状结构之间的耦合作用,结果表明随着沉积电压的增大分形维数与磁响应波长随之增加,样品之间的耦合作用导致磁谐振响应的波长和强度发生变化.     

致密ZnO薄膜的电化学制备及光学性能研究

采用电化学沉积法在ITO导电玻璃上沉积1层致密的ZnO薄膜。用扫描电镜（SEM）对在不同电解液浓度、电压和时间下制备的ZnO薄膜的表面形貌作了表征,并观测了ZnO薄膜的厚度,结果表明当电解液的质量分数为1.2%,电压为1.0V,时间为60s时,制备的ZnO薄膜致密且厚度仅为120nm,利用分光光度计测得ZnO薄膜在可见光波段的透射率高于50%,为ZnO薄膜在多层光学超材料中的应用奠定了基础。     

多孔氧化铝表面方便制备纳米-微米ZnO薄膜材料

利用双通多孔阳极氧化铝(AAO)和非双通的AAO(含有Al基底)为模板通过液相沉积法制备了ZnO纳米-微米材料。结果显示在两种模板上面生成ZnO的过程比较相似,ZnO在表面择优生成,随着反应时间延长到72h,生成了比较独特的纳米-微米结构。这样的制备方法为非双通的AAO为模板方便地制备纳米材料提供了一定的依据,制备的ZnO薄膜结构有望可以在传感器,催化剂等领域得到应用。     

模板辅助电化学沉积三维有序大孔Fe-Ni合金膜

三维有序大孔磁性材料在光子晶体和新功能磁性材料方面具有潜在优势.采用电化学沉积方法制备三维有序大孔Fe-Ni合金,将聚苯乙烯(PS)微球在ITO导电玻璃上自组装高度有序的胶体晶体阵列作为模板,向模板空隙中电沉积Fe-Ni合金,去除PS模板后获得六方密排多孔结构的Fe-Ni合金薄膜.采用金相显微镜和扫描电子显微镜对多孔薄膜的微观结构进行表征,结果表明,多孔薄膜孔径的大小由模板聚苯乙烯微粒的粒径决定,不同孔径的薄膜由于布拉格衍射呈现出不同的颜色.通过调整沉积时间和沉积温度可以控制有序大孔材料的结构和厚度.     

纳米晶ZnO薄膜的电化学沉积及其光电化学性能研究

以Zn(NO3)2和曙红的混合溶液为沉积液,采用阴极电化学沉积法在ITO导电玻璃上制备了纳米多孔ZnO/曙红复合膜.该复合膜中的曙红用KOH溶液溶解脱附后得到晶粒尺寸为10～20nm的ZnO纳米多孔薄膜.XRD结果表明该薄膜为ZnO六方纤锌矿结构,EDS表明薄膜中的主要成份为Zn和O,未检测到其他杂质成分.以该薄膜为光阳极制作了太阳能电池原型器件,其开路电压为0.68V,短路电流为0.79 mA/cm2,总光电转换效率为0.26%..     

电沉积法制备ZnO纳米棒/管阵列及其机理研究

采用恒电位电沉积法在未经修饰的ITO导电玻璃基底上用一步法制备了ZnO纳米棒阵列结构,并经碱蚀制备了ZnO纳米管阵列结构.通过阴极线性扫描分析了通氧及添加剂六次甲基四铵(HMT)对沉积ZnO薄膜的电化学行为的影响.结果表明,电沉积体系中通入氧气对阴极还原反应起到了加速作用,而电沉积体系中的HMT通过水解作用对电沉积反应起到了稳定剂作用.在氧气和HMT的协同作用下可使ZnO更加充分地成核生长,得到结构清晰分明的六方棱柱ZnO晶种,进而形成规则均一的ZnO薄膜.     

氧化铝模板制备ZnO纳米有序阵列及其光致发光性能研究

介绍了在多孔氧化铝模板(AAM)中沉积Zn阵列后将其加热氧化,得到单晶六角纤锌矿结构的ZnO／AAM纳米线有序阵列体系。研究了不同的氧化温度对Zn向ZnO转化和ZnO纳米阵列光致发光性能的影响。     

酞菁铜/氧化钛纳米复合薄膜的制备及其光导性能的研究

通过电化学阳极氧化法在Ti片上制备了氧化钛(TiO2)纳米管阵列.用这种高度有序的阵列结构作为模板,利用电泳沉积的方法在模板表面沉积了一种有机半导体材料酞菁铜(CuPc),从而得到了CuPc/TiO2有机/无机纳米复合结构.通过场发射扫描电镜(FESEM),透射电镜(TEM)等手段对这种复合结构的表面形貌及结构进行了表征.能谱数据证实了复合结构中有机物的存在.此外,CuPc薄膜的形貌和结构可以通过改变电泳沉积参数(如沉积时间和电压)进行调控,从而得到相应的纳米晶、纳米线和微米线薄膜.用该复合薄膜作为载流子发生层制备的双层光导体的光导性能测试结果表明,与复合前的氧化钛薄膜相比,该复合薄膜的光敏性有明显的提高.     

Sputter deposition of self-organized nanoclusters through porous anodic alumina templates

Silver nanoparticles were sputter deposited through self organized hexagonally ordered porous anodic alumina templates that were fabricated using a two-step anodization process. The average pore diameter of the template was 90 nm and the interpore spacing was 120 nm. Atomic force microscope studies of the sputter-deposited silver nanoparticle array on a Si substrate indicate an approximate replication of the porous anodic alumina mask. The nature of the deposition depends strongly on the process parameters such as sputtering voltage, ambient pressure and substrate temperature. We report a detailed study of the sputtering conditions that lead to an optimal deposition through the template.     

金属有序纳米孔道阵列模板合成法

评述了采用母板复型法合成金属有序纳米孔道阵列模板合成方法、金属模板的特点及应用的研究进展.用于合成金属模板的母板有:多孔阳极氧化铝、径迹刻蚀高分子聚合物、具有纳米孔道的玻璃及氧化锌晶体阵列等,金属模板的金属沉积方法有化学镀、电镀、物理气相沉积法等.由于金属模板具有金属特性,在纳米阵列材料组装、电极制备及过滤膜制备领域具有重要应用前景,研究直接制备金属模板的方法是一个很有发展前途的方向.     

Sol-gel assisted ZnO nanorod array template to synthesize TiO(2) nanotube arrays

A TiO(2) nanotube array with a large surface area is fabricated on a glass substrate using a ZnO nanorod array and sol-gel process, and the structural characteristics of the TiO(2) nanotube array are investigated. The well-aligned ZnO nanorod array, which is deposited on ZnO seed layer coated glass substrates by the wet-chemical route, is used as a template to synthesize TiO(2)/ZnO composite nanostructures through the sol-gel process. Then, by selectively removing the ZnO template, a TiO(2) nanotube with contours of the ZnO nanorods is fabricated on the ZnO seed layer coated glass. The resultant TiO(2) nanotubes are 1.5?μm long and 100-120?nm in inner diameter, with a wall thickness of ～10?nm. In addition, by adjusting the experimental parameters, such as the dip-coating cycle number or heating rate, porous TiO(2) thick films can also be obtained.     

Ordered ZnO/AZO/PAM nanowire arrays prepared by seed-layer-assisted electrochemical deposition

An Al-doped ZnO (AZO) seed layer is prepared on the back side of a porous alumina membrane (PAM) substrate by spin coating followed by annealing in a vacuum at 400 °C. Zinc oxide in ordered arrays mediated by a high aspect ratio and an ordered pore array of AZO/PAM is synthesized. The ZnO nanowire array is prepared via a 3-electrode electrochemical deposition process using ZnSO₄ and H₂O₂ solutions at a potential of − 1 V (versus saturated calomel electrode) and temperatures of 65 and 80 °C. The microstructure and chemical composition of the AZO seed layer and ZnO/AZO/PAM nanowire arrays are characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS). Results indicate that the ZnO/AZO/PAM nanowire arrays were assembled in the nanochannel of the porous alumina template with diameters of 110–140 nm. The crystallinity of the ZnO nanowires depends on the AZO seed layer during the annealing process. The nucleation and growth process of ZnO/AZO/PAM nanowires are interpreted by the seed-layer-assisted growth mechanism.     

Electrochemical synthesis using a self-assembled Au nanoparticle template of dendritic films with unusual wetting properties

This report describes the electrochemical preparation of dendritic silver films with unusual wetting properties coming from the use of a self-assembled gold nanoparticle (Au NP) template. It shows that the Au NP self-assembled monolayer on the highly ordered pyrolytic graphite (HOPG) surface is responsible for the formation of the dendritic morphology, which is not observed for the same deposition conditions on a bare HOPG substrate. An interesting evolution of the wetting properties of these films during the electrodeposition process is observed. Field emission scanning electron microscopy (FEGSEM), energy-dispersive spectrometry (EDS), x-ray photoelectron spectroscopy (XPS) and contact angle measurements are used to reveal the dendritic structure of the deposited silver film at a later stage of the electrodeposition process. They also reveal surprising wetting properties in terms of hydrophobic surface.     

Preparation and characterization of bowl-like porous ZnO film by electrodeposition using two-dimensional photonic crystal template

A rapid and low-cost method combining electrodeposition with two-dimensional (2D) photonic crystal template technique to prepare large scale bowl-like porous ZnO films is described. The 2D photonic crystal templates were fabricated by self-assembly of monodispersed polystyrene (PS) microspheres on indium-tin-oxide coated glass substrates using spinning coating method. The interstitial spaces among the spheres of the templates were filled with ZnO via electrodeposition from an aqueous solution containing 0.02 M zinc nitrate as electrolyte under a constant potential of ?1.0 V at 65 °C for 10 min. After removal of the PS photonic crystal template, bowl-like porous ZnO film was obtained. The entire process can be accomplished within 30 min. Scanning electron microscopic images showed good homogeneity in morphology, X-ray diffraction spectra demonstrated the wurtzite structure of the obtained ZnO film, and transmission electron microscopy indicated the single-crystallinity of the ZnO. Ultraviolet–visible (UV–vis) spectrophotometer was used to detect the absorption in UV–vis region of the PS template, opal ZnO-PS composite and inverse opal ZnO respectively. Two strong emission bands at 400 and 550 nm were displayed in photoluminescence spectrum.     

Assembly of ordered ZnO porous thin films by cooperative assembly method using polystyrene spheres and ultrafine ZnO particles

Ordered ZnO porous thin films were fabricated by cooperative assembly method using polystyrene sphere (PS) and ultrafine ZnO particles, in which ultrafine ZnO particles were directly assembled in the voids of PS while the template was being assembled by capillary forces. The influence of experimental parameters, such as evaporation temperature, ZnO concentration and the concentration ratio of PS/ZnO on morphology of the porous structure was mainly studied. The results showed that an ordered porous structure could be obtained by this method. X-ray diffraction (XRD) spectra indicated the porous ZnO thin film was wurtzite structure. The transmissivity decreased with the decrease of wavelength, but still kept above 80% beyond the wavelength of 550 nm. Optical band gap of the ZnO thin film was 3.13 eV.     

Ordered porous diamond films fabricated by colloidal crystal templating

We have developed a colloidal crystal templating method for preparation of diamond films with 2D and 3D ordered porous structures. The technological process involved breaks down into (a) impregnation into the pores of silica colloidal crystal (opal) films of detonation nanodiamond (DND) particles from their hydrosol; (b) microwave plasma-enhanced chemical vapor deposition (MWPECVD) regrowth with diamond of pores with high DND filling; (c) Ar(+) ion dry etching of fragments of shells of coalesced diamond crystallites which form in the course of MWPECVD on the surface of the SiO(2) beads making up the outer surface of a film and (d) wet etching of the SiO(2) template in aqueous HF solution. The final samples are either connected to the substrate or free-standing films of various thicknesses having 2D or 3D ordered porous structures. The morphology of the diamond films fabricated by this method replicates the pore network of the opal template. Raman measurements confirm the diamond structure of the synthesized ordered porous material.     

An advanced fabrication method of highly ordered ZnO nanowire arrays on silicon substrates by atomic layer deposition

In this work, the controlled fabrication of highly ordered ZnO nanowire (NW) arrays on silicon substrates is reported. Si NWs fabricated by a combination of phase shift lithography and etching are used as a template and are subsequently substituted by ZnO NWs with a dry-etching technique and atomic layer deposition. This fabrication technique allows the vertical ZnO NWs to be fabricated on 4 in Si wafers. Room temperature photoluminescence and micro-photoluminescence are used to observe the optical properties of the atomic layer deposition (ALD) based ZnO NWs. The sharp UV luminescence observed from the ALD ZnO NWs is unexpected for the polycrystalline nanostructure. Surprisingly, the defect related luminescence is much decreased compared to an ALD ZnO film deposited at the same time ona plane substrate. Electrical characterization was carried out by using nanomanipulators. With the p-type Si substrate and the n-type ZnO NWs the nanodevices represent p–n NW diodes.The nanowire diodes show a very high breakthrough potential which implies that the ALD ZnO NWs can be used for future electronic applications.     

3D Nanofabrication of Fluidic Components by Corner Lithography

A reproducible wafer‐scale method to obtain 3D nanostructures is investigated. This method, called corner lithography, explores the conformal deposition and the subsequent timed isotropic etching of a thin film in a 3D shaped silicon template. The technique leaves a residue of the thin film in sharp concave corners which can be used as structural material or as an inversion mask in subsequent steps. The potential of corner lithography is studied by fabrication of functional 3D microfluidic components, in particular i) novel tips containing nano‐apertures at or near the apex for AFM‐based liquid deposition devices, and ii) a novel particle or cell trapping device using an array of nanowire frames. The use of these arrays of nanowire cages for capturing single primary bovine chondrocytes by a droplet seeding method is successfully demonstrated, and changes in phenotype are observed over time, while retaining them in a well‐defined pattern and 3D microenvironment in a flat array.