Effect of pulse voltage and aluminum purity on the characteristics of anodic aluminum oxide using hybrid pulse anodization at room temperature

Most of the anodic aluminum oxide (AAO) templates are performed by potentiostatical method at 0-10 °C to inhibit the Joule's heat enhanced dissolution in aluminum oxide for well-ordered cell configuration. In this article, we propose the hybrid pulse anodization (HPA) method with effective suppression of Joule's heat generation to fabricate AAO at room temperature. Effects of purity of aluminum (Al) foils and pulse voltage on the evolution of pore characteristics have been investigated. The AAO morphology is captured by scanning electron microscope and analyzed via gray-scale imaging in order to identify the pore size distribution. The increased applied potential results in the widened pores and non-uniform cell arrangement due to the increased current density and variation. Moreover, low-purity Al foils lead to the reduced AAO distribution uniformity owing to the uneven electric field induced pits on the Al surface for inferior pore arrangement. Extending both the positive and negative pulse period from 1 s to 5 s during HPA can enhance the distribution uniformity of AAO from high-purity Al by up to about 95%. In addition, the relationship between AAO configuration and Al purity and pulse voltage is further discussed and established.     

流导可控的AAO分子流漏孔的制作与动态测试

随着分子流漏孔的广泛应用, 迫切需要一种制作简单、成本低廉且流导可控的分子流漏孔制作方法。本文基于阳极多孔氧化铝 (AAO) 模板, 利用打孔硅片作为掩膜和支撑材料, 制作出不同有效面积的AAO新型分子流漏孔, 然后使用自主设计的动态差压法漏孔测量设备, 以氮气、氦气和氩气作为测试气体对所制作的直径分别为2和13 mm圆形AAO分子流漏孔流导进行了测量。实验结果表明, 漏孔的流导测量值接近理论计算值, 流经AAO漏孔的气体始终保持分子流状态, 即流导维持不变。AAO分子流漏孔具有制备工艺简单、成本低、流导可控且可预测不同种类气体流导等优点。     

Porous alumina nano-membranes: Soft replica molding for large area UV-nanoimprint lithography

High-density ordered arrays of h-PDMS nanopillars were fabricated using an anodic aluminium oxide (AAO) template. The pore diameter and the interpore distance of the replica h-PDMS molding are well consistent with that of AAO template. The inverse h-PDMS has the surface characteristic of hydrophobic and surface energy of 130°. Hexagonally arranged array can be obtained by UV-nanoimprint lithography using our proposed h-PDMS mold, and their morphologies can be transferred truly. Besides, the h-PDMS mold has been used to fabricate photonic crystal structure on GaN by nanoimprint process, which could be found an application in the light output of GaN LED.     

阳极氧化铝模板制备过程的分析和应用

用电化学法制备了阳极氧化铝模板,采用计算机对反应电流监控的方法,分析电流曲线与模板生长过程的关系,实现了模板生长过程的精密控制。     

Anodized Aluminum Oxide/Polydimethylsiloxane Hybrid Mold for Roll‐to‐Roll Nanoimprinting

Two types (hard and soft) of the molds are widely used in nanoimprint lithography for a high throughput over a large area, and high‐resolution parallel patterning. Although hard molds have proven excellent resolutions and can be used at high temperatures, cracks often occur in the mold in addition to the requirement of high imprinting pressure. On the other hand, though soft molds can operate at lower pressures, they give poor pattern resolution. Here, a novel hybrid mold of anodized aluminum oxide (AAO) template attached to a flexible polydimethylsiloxane (PDMS) plate is introduced. Due to the flexible nature of PDMS, various polymer nanostructures are obtained on flat and curved substrates without crack formation on the AAO mold surface. Furthermore, the hybrid mold is successfully used for roll‐to‐roll imprinting for the fabrication of high density array of various shaped polymeric nanostructures over a large area.     

Characteristics of ACPDP test panels with aluminum fence electrode formed via anodic bonding with soda‐lime glass

Abstract— In an attempt to reduce materials and processing costs of ACPDPs, aluminum fence electrodes were prepared on soda‐lime glass substrates by chemically etching aluminum foil bonded directly onto the substrate via an anodic‐bonding process. Several different fence‐electrode patterns were designed and coated either with a glass dielectric layer or with an anodic aluminum oxide layer. Firing voltages, operation margin, luminance, and luminous efficiency of such test panels were evaluated. The results indicated that the performance of test panels with aluminum fence electrodes is comparable with conventional test panels with ITO/Ag electrodes, demonstrating the possibility of a dramatic reduction in the costs of ACPDPs.     

Preparation and electrochemical capacitance of cobalt oxide (Co3O4) nanotubes as supercapacitor material

Cobalt oxide (Co₃O₄) nanotubes have been successfully synthesized by chemically depositing cobalt hydroxide in anodic aluminum oxide (AAO) templates and thermally annealing at 500 °C. The synthesized nanotubes have been characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The electrochemical capacitance behavior of the Co₃O₄ nanotubes electrode was investigated by cyclic voltammetry, galvanostatic charge-discharge studies and electrochemical impedance spectroscopy in 6 mol L⁻¹ KOH solution. The electrochemical data demonstrate that the Co₃O₄ nanotubes display good capacitive behavior with a specific capacitance of 574 F g⁻¹ at a current density of 0.1 A g⁻¹ and a good specific capacitance retention of ca. 95% after 1000 continuous charge-discharge cycles, indicating that the Co₃O₄ nanotubes can be promising electroactive materials for supercapacitor.     

Niobium and hafnium grown on porous membranes

In this work we report on a method for fabricating highly ordered nanostructures of niobium and hafnium metals by physical vapour deposition using two different templates: anodized aluminum oxide membranes (AAO) and zirconium onto AAO membranes (Zr/AAO). The growth mechanism of these metal nanostructures is clearly different depending on the material used as a template. A different morphology was obtained by using AAO or Zr/AAO templates: when the metal is deposited onto AAO membranes, nanospheres with ordered hexagonal regularity are obtained; however, when the metal is deposited onto a Zr/AAO template, highly ordered nanocones are formed. The experimental approach described in this work is simple and suitable for synthesizing nanospheres or nanoholes of niobium and hafnium metals in a highly ordered structure.     

Cd1-xMnxS稀磁半导体纳米线的制备和研究

采用多孔氧化铝模板,通过直流电化学沉积法成功制备出不同掺杂浓度的Cd1-xMnxS纳米线,用XRD、SEM、HRTEM对纳米线的成分、形貌、结构进行了系统分析,并用SQUID对样品进行了磁性测量,结果表明,制得的Cd1-xMnxS纳米线呈单晶CdS纤锌矿结构,而且沿002方向有择优取向性,没有发现其它含Mn的化合物生成。从ZFC/FC曲线看出样品的居里温度接近于室温,且在低温处存在奇异现象。45K和300K下测量的的M-H曲线显示磁滞现象,测得的矫顽力分别是300Oe和100Oe,说明样品具有铁磁性。样品的紫外-可见光反射谱显示Cd1-xMnxS纳米线的吸收边并不随掺杂浓度x单调变化,而是随着掺杂量的增大能隙先减小后增大。掺杂度在1%处能隙有最小值。     

A mini review: Functional nanostructuring with perfectly-ordered anodic aluminum oxide template for energy conversion and storage

Nanostructures have drawn great attentions for functional device applications. Among the various techniques developed for fabricating arrayed nanostructures of functional materials, nanostructuring technique with porous anodic aluminum oxide (AAO) membrane as templates becomes more attractive owing to the superior geometrical characteristics and low-cost preparation process. In this mini review, we summarize our recent progress about functional nanostructuring based on perfectly-ordered AAO membrane to prepare perfectly-ordered nanostructure arrays of functional materials toward constructing high-performance energy conversion and storage devices. By employing the perfectly-ordered AAO membrane as templates, arrayed nanostructures in the form of nanodot, nanorod, nanotube and nanopore have been synthesized over a large area. These as-obtained nanostructure arrays have large specific surface area, high regularity, large-scale implementation, and tunable nanoscale features. All these advanced features enable them to be of great advantage for the performance improvement of energy conversion and storage devices, including photoelectrochemical water splitting cells, supercapacitors, and batteries, etc.

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