Vertically Aligned Nematic Liquid Crystal on Anodic Porous Alumina

A nematic liquid crystal that vertically aligns against the substrate was obtained on an anodic porous alumina (Al2O3) film fabricated by anodizing Al. As with a SiO rotation oblique evaporation film, the orientation mechanism is thought to be based on a nanostructure ranging in size from 5 to 30 nm that extends perpendicularly with respect to the substrate. This film is transparent and colorless, making it a suitable alignment layer for a liquid crystal display. Because it is inorganic and known as a stable material, an anodic porous alumina film would be particularly promising for use as an alignment layer in a projection display and other applications where a highly reliable, high-contrast, vertically aligned (VA) liquid crystal mode is used.