Challenges to Fabricate Large Size-Controllable Submicron-Structured Anodic-Aluminum-Oxide Film

Abstract

Anodic aluminum oxide (AAO) is well known for its unique controllable structure and functional contributions in research and developments. However, before AAO can be widely used in the industry, some engineering problems should be overcome. In this study, we designed a novel electrochemical mold, which can resolve the exothermal problem for large-size aluminum sheets during high-voltage anodization process. AAO film with a large sample size of 11 x 11 cm2 in area, 148 μm in thickness and 450 nm in average pore diameter, decorated with ordered-pattern structure, was successfully obtained through a 200 V anodization process. It was noticed that the local heat was generated with increasing the anodizing voltage, resulting in undesired pits and burr defects on the AAO surface. In order to retain AAO’s quality and reduce the producing cost of the anodization process, a mass producing system combining with an overhead conveyor was proposed. The convenient anodization system, novel electrochemical mold and bath may help to fabricate high-quality AAO films efficiently.

High Aspect Ratio Single Crystal of Cesium Iodide Column

“…As same as the above process, for 60 nm pore diameter AAO template, the electrolyte is 3 vol.% (COOH) 2 at 25℃, and applied voltage is 40 V, the time of pore widening is 90 min. And for 400 nm pore diameter AAO template, the electrolyte is 1 vol.% H 3 PO 4 at 0℃, and applied voltage is 200 V, the time of pore widening is 120 min [16][17][18][19][20].…”