Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/86224
Title: Broad-band anti-reflective pore-like sub-wavelength surface nanostructures on sapphire for optical windows
Authors: Lin, Zhao-Qing
Wang, Gui-Gen
Tian, Ji-Li
Wang, Li-Yan
Zhao, Dong-Dong
Liu, Zheng
Han, Jie-Cai
Keywords: Sub-wavelength Structure
Engineering::Materials
Sapphire
Issue Date: 2018
Source: Lin, Z.-Q., Wang, G.-G., Tian, J.-L., Wang, L.-Y., Zhao, D.-D., Liu, Z., & Han, J.-C. (2018). Broad-band anti-reflective pore-like sub-wavelength surface nanostructures on sapphire for optical windows. Nanotechnology, 29(5), 055302-. doi:10.1088/1361-6528/aa9d14
Series/Report no.: Nanotechnology
Abstract: Compared with conventional anti-reflective film, an anti-reflective sub-wavelength surface structure provides an ideal choice for a sapphire optical window especially in harsh environments. However, it is still a challenge to obtain a sapphire anti-reflective surface microstructure because of its high hardness and chemical inertness. In this paper, combined with optical simulation, we proposed a facile method based on the anodic oxidation of aluminum film and following epitaxial annealing. Al thin film was deposited on a sapphire substrate by magnetron sputtering, and anodic oxidation was then performed to prepare surface pore-like structures on the Al film. Followed by two-step annealing, both the anodic oxidized coating and underlying unoxidized Al film were transformed totally into alumina. The parameters of anodic oxidation were analyzed to obtain the optimal pore-like structures for the antireflection in the mid-infrared and visible spectrum regions, respectively. Finally, the optimized surface sub-wavelength nanostructure on sapphire can increase the transmittance by 7% in the wavelength range of 3000–5000 nm and can increase 13.2% significantly for visible spectrum region, respectively. Meanwhile, the surface wettability can be also manipulated effectively. The preparation of surface pore-like sub-wavelength structure by the annealing of anodic oxidized aluminum film on sapphire is a feasible, economical and convenient approach and can find the applications for various optoelectronic fields.
URI: https://hdl.handle.net/10356/86224
http://hdl.handle.net/10220/49271
ISSN: 0957-4484
DOI: http://dx.doi.org/10.1088/1361-6528/aa9d14
Rights: © 2018 IOP Publishing Ltd. All rights reserved.
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:MSE Journal Articles

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