Efficient synthesis of the ordered nanostructures of semiconductors is important issue to be solved for the preparation of the photo-energy conversion systems with high efficiency . For the effective preparation of the ordered nanostructures of semiconductors, the use of the naturally occurring ordered nanomaterials is promising for the synthesis due to its capability of the preparation of ordered nanostructures with high efficiency. Among them, anodic porous alumina, which is formed by anodization of Al in acidic electrolyte, is one of promising material due to ist precisely controllable geometrical nanostructures . In the present report, the synthesis of the ordered nanostructures of semiconductors using anodic porous alumina templates will be described. The template synthesis using highly ordered anodic porous alumina allows the preparation of ordered nanostructures of the semiconductors. In addition, the application of the highly ordered anodic porous alumina with reduced hole intervals (~25 nm) and hole sizes (~10 nm) prepared under the low voltage anodization  generated the ordered structures of semiconductors with small dimensions. In the experiment, semiconductor (ZnO [4,5], CdS) nanorod arrays were prepared by electrochemical or hydrothermal synthesis of semiconductors using anodic porous alumina templates. The geometrical structure of the obtained nanorod arrays of semiconductors could be precisely controlled based on the ordered structures of anodic porous alumna. The synthesis of the nanorod arrays on the conducting substrates (ITO etc.) could provide the current collection electrodes with large surface area. The present process will be used for the preparation of nanostructures of semiconductors, which are required for the preparation of various kinds of photoenergy conversion systems with high efficiency, such as organic photovoltaic solar cells .
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