Grass-Like Al2O3 for Conformal, Scalable, Omnidirectional, Broadband Anti-Reflective Coating on Glass by Atomic Layer Deposition

Description

We present a novel anti-reflective coating from grass-like nanoporous Al2O3 with low refractive index and vertical index profile gradient. Fabrication of the coating includes atomic layer deposition of Al2O3 using thermal trimethylaluminium/water process and immersion of the deposited film in heated deionized water. Average optical transmittance in the range of 350--800 nm was 99.0% at normal incidence for double-side coated glass, the transmittance maximum of 99.5% was achieved at 500 nm. Transmittance spectra were also measured at different incident angles, average transmittance in the 350--800 nm range was 94.0% at 60 deg, 85.0% at 70 deg, and 53.1% at 80 deg incident angles, respectively. The grass-like Al2O3 ARC manufacturing technique is applicable to mass production, as ALD provides a possibility to coat hundreds of optical components at once. Additionally, unlike many other ARC deposition techniques used today (spin-coating, physical vapour deposition), grass-like Al2O3 fabrication is suitable for coating surfaces with extremely complex topography.

Period	27 Jul 2018
Event title	IEEE International Conference on Nanotechnology
Event type	Conference
Conference number	17th
Location	Pittsburgh, United States, Pennsylvania
Degree of Recognition	International