A study of color modulation of porous alumina processed by physical vapor deposition

• Published in: Journal of physics. Conference series 2011-02, Vol.276 (1), p.012048-6
• Main Authors: Wang, Xulongqi, Zhang, Dongxian, Zhang, Haijun
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Anodizing; Colors (materials); Modulation; Optical properties; Oxalic acid; Physical vapor deposition; Physics; Titanium dioxide
• ISSN: 1742-6596; 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/276/1/012048

With the development of the porous alumina(PA)fabrication technology, more and more scholars plough into the research of its properties, especially optical properties. Recently, we observed an interesting phenomenon that the PA templates processed by Physical Vapor Deposition (PVD) show color differences related to light path difference. Our work attempts to make the principle clear and to find an effective method to modulate the color of PA samples. This article describes the details of our experimental and theoretical results. We successfully prepared some PA templates with different pore-depth by controlling the time of anodization in oxalic acid solution. In order to enhance the reflectivity of air-PA interface, a layer of TiO2 film of 18 nm is coated with PVD technique, which makes PA templates display quite distinct colors with different hole-depth. By modelling and analyzing PA samples, we make the interpretation of this optical property by taking the PA sample with 150 nm pore-depth as an example, and then put forward a way to simulate sample's color within its hole-depth and material refraction-index. The results are in good agreement with our theoretical analysis, which proves the feasibility of our simulation mode.