Pretilt angle generation and liquid crystal (LC) aligning capabilities for a nematic (N) LC with obliquely polarized UV exposure on a homeotropic polyimide (PI) surface by an in-situ photoalignment method were studied. The high pretilt angle of 300 for NLC with obliquely polarized UV exposure on the PI surface for 20 min can be achieved. The pretilt angle generated in NLC by the in-situ photoalignment method was higher than that generated by a conventional photoalignment method on a homeotropic alignment layer. Also, we suggest that the generation of pretilt angle in NLC with obliquely polarized UV exposure during imidization of the polymer for homeotropic alignment is a promising method to generate a high pretilt angle. Lastly, the good electro-optical (EO) characteristics of the photoaligned vertical alignment (VA)-liquid crystal, display (LCD) by UV exposure on the PI surface for 10 min were observed.
|Journal||Molecular Crystals and Liquid Crystals|
|Publication status||Published - 2004|
|Event||Proceedings of the 19th International Liquid Crystal Conference, ILCC2002 - Edinburgh, United Kingdom|
Duration: 2002 Jun 30 → 2002 Jul 5
Bibliographical noteFunding Information:
Keywords: homeotropic alignment; in-situ photoalignment method; nematic liquid crystal; photodissociation; polyimide; pretilt angle This work was supported by National Research Laboratory program (M1-0203-00-0008). Address correspondence to Dae-Shik Seo, Dept. of Electrical and Electronic Engineering (C-724), College of Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-749, Korea.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics