Title :
Strong Vertical Alignment of Liquid Crystal on Porous Anodic Aluminum Oxide Film
Author :
Tang, Tsung-Ta ; Kuo, Cheng-Ying ; Pan, Ru-Pin ; Shieh, Jia-Min ; Pan, Ci-Ling
Author_Institution :
Dept. of Photonics, Nat. Chiao Tung Univ. (NCTU), Hsinchu, Taiwan
Abstract :
Properties of anodic aluminum oxide (AAO) film as a liquid crystal (LC) alignment material is studied. We deposit the transparent porous AAO film on glass with the diameter of the pores controlled between 17-65 nm. The liquid crystal can be aligned vertically against the substrate with the AAO film. The measured polar anchoring strength is about 1.5 times 10-5 J/m, which is comparable to that of N,N-dimethyl-N-octadecyl-3-aminopropyl -trimethoxysilyl chloride (DMOAP) layer. AAO films with smaller pore diameters exhibit higher anchoring strengths. On the other hand, the uniformity of the pore array in the AAO films does not affect the alignment quality significantly.
Keywords :
aluminium compounds; liquid crystals; porous materials; Al2O3; N,N-dimethyl-N-octadecyl-3-aminopropyl -trimethoxysilyl chloride layer; liquid crystal; polar anchoring strength; pore array; porous anodic aluminum oxide film; size 17 nm to 65 nm; Aluminum oxide; Glass; Liquid crystal displays; Liquid crystals; Nanostructured materials; Photonics; Polyimides; Semiconductor films; Substrates; Surface morphology; Anodic aluminum oxide (AAO); liquid crystals (LCs); vertical alignment;
Journal_Title :
Display Technology, Journal of
DOI :
10.1109/JDT.2009.2021541
