%0 Journal Article
%T Fabrication of Orderly Copper Particle Arrays on a Multi-Electrolyte-Step Anodic Aluminum Oxide Template
%A Chun-Ko Chen
%A Der-Sheng Chan
%A Cheng-Chung Lee
%A Sheng-Hui Chen
%J Journal of Nanomaterials
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/784927
%X A multi-electrolyte-step (MES) anodic aluminum oxide (AAO) method was used to achieve nanochannel arrays with good circularity and periodic structure. The nano-channel array fabrication process included immersion in a phosphoric acid solution with a 120¨C150 bias voltage. Bowl-shaped structures were then formed by removing the walls of the nano-channel arrays. The nano-channel arrays were grown from the bottom of the bowl structure in an oxalic solution using a 50£¿V bias voltage. A comparison of this new MES process with the one-step and five-step AAO process showed a 50% improvement in the circularity over the one-step process. The standard deviation of the average period in the MES array was 25£¿nm which is less than that of one-step process. This MES method also took 1/4 of the growing time of the five-step process. The orderliness of the nano-channel arrays for the five-step and MES process was similar. Finally, Cu nanoparticle arrays with a 200£¿nm period were grown using an electroplating process inside the MES nano-channel arrays on fluorine doped tin oxide glass. Stronger surface plasmon resonance absorption from 550£¿nm to 750£¿nm was achieved with the MES process than was possible with the one-step process. 1. Introduction In recent years, surface plasmon resonance (SPR) in nanoparticle array has attracted a lot of attention because of the adjustable absorption band [1, 2]. SPR assisted energy conversion in dye-sensitized solar cell has also been studied [3]. The SPR effect is dependent on the shape and the arrangement of the nanoparticles but it is not easy to achieve good circularity and periodicity in metallic nanoparticle arrays. It has been shown that carbon nanotubes, nanoparticles, quantum dots, and nanopillars can be grown in nanochannel arrays utilizing various methods for their fabrication [4]. The use of the anodic aluminum oxide (AAO) method for the fabrication of nanochannel arrays to nanoparticle arrays has matured [5]. However, the positioning of the nanochannel arrays grown using the AAO method is random making it very difficult to control the hole quality and to form orderly arrays. There have been some methods for growing good quality AAO nanochannel arrays developed. They require either an increase in circularity or improvement in the period of the channels, so it becomes a long process [6]. For example, in the multistep AAO process [7], channels are repeatedly grown and removed to achieve periodic arrays. The problem is the thickness of the raw material, Al, has to be greater than 1£¿¦Ìm, which is too thick for the deposition of a
%U http://www.hindawi.com/journals/jnm/2013/784927/