Transactions on Electrical and Electronic Materials

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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A Study on Electro-optical Characteristics of the UV Aligned FFS Cell on the Organic Layer

  • Han, Jeong-Min (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Ok, Chul-Ho (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Hwang, Jeoung-Yeon (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Kim, Byoung-Yong (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Kang, Dong-Hun (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Kim, Jong-Hwan (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Kim, Young-Hwan (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Han, Jin-Woo (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Lee, Sang-Keuk (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University) ;
  • Seo, Dae-Shik (Department of Electrical & Electronic Engineering(C-724), College of Engineering, Yonsei University)
  • Published : 2007.07.26
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Abstract

In this study, we investigated the electro-optical (EO) characteristic of fringe-field switching (FFS) mode cell by the two kinds of ultraviolet (UV) alignment method on the organic thin film (polyimide: PI). The suitable organic layers for FFS cell and the aligning capabilities of nematic liquid crystal (NLC) using the in-situ photoalignment method were studied; Disclination is observed after conventional photoalignment method for 1h, and in-situ photoalignment method for 1h. Monodomain alignment of the NLC can be observed via insitu photo alignment method for 2 h and 3 h. It is considered that NLC alignment is due to photo-depolymerization of the polymer with oblique non-polarized UV irradiation on PI surface. An unstable V-T curve of UV-aligned FFS-LCD with conventional photoalignment method can be achieved. However, a stable V-T curve of UV-aligned FFS-LCD with in-situ photoalignment method (1 h), and V-T curve of UV-aligned FFS-LCD with in-situ photo alignment method was much stable comparing with that of other UV-aligned FFSLCD's. As a result, more stable EO performance of UV-aligned FFS-LCD with in-situ photoalignment method for 3h is obtained than that of the other UV-aligned FFS-LCD's.

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References

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