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

Volume

5

Issue

9

fYear

2009

Firstpage

350

Lastpage

354

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;

fLanguage

English

Journal_Title

Display Technology, Journal of

Publisher

ieee

ISSN

1551-319X

Type

jour

DOI

10.1109/JDT.2009.2021541

Filename

5196836