Open AccessGrass-like Alumina with Low Refractive Index for Scalable, Broadband, Omnidirectional Antireflection Coatings on Glass Using Atomic Layer Deposition
Author(s) -
Christoffer Kauppinen,
Kirill Isakov,
Markku Sopanen
Publication year - 2017
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.7b01733
Subject(s) - materials science , atomic layer deposition , refractive index , broadband , layer (electronics) , omnidirectional antenna , deposition (geology) , optoelectronics , high refractive index polymer , optics , composite material , computer science , telecommunications , paleontology , physics , sediment , biology , antenna (radio)
We present a new type of nanoporous antireflection (AR) coating based on grass-like alumina with a graded refractive index profile. The grass-like alumina AR coating is fabricated using atomic layer deposition (ALD) of alumina and immersion in heated deionized water. Optical transmittance of 99.5% at 500 nm was achieved with average transmittance of 99.0% in the range of 350-800 nm at normal incidence for double-sided coated glass. Angular spectral transmittance (0-80°) of the double-sided AR coated glass was also measured in the range of 350-800 nm and found to have mean spectral transmittance of 94.0% at 60°, 85.0% at 70°, and 53.1% at 80° angles of incidence, respectively. The grass-like alumina AR coating is suitable for mass production with the presented technique: even hundreds of optical components can be coated in parallel. Furthermore, as an ALD-based technique, the coating can be deposited conformally on surfaces with extreme topography, unlike many spin-coating, physical vapor deposition or glancing angle deposition-based coatings used today.