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Title: Anchoring energy enhancement and pretilt angle control of liquid crystal alignment on polymerized surfaces

We demonstrate enhanced surface anchoring energy and control of pretilt angle in a nematic liquid crystal cell with vertical alignment and polymerized surfaces (PS-VA). The polymerized surfaces are formed by ultraviolet (UV) irradiation-induced phase separation of a minute amount of a reactive monomer in the vertical-aligned nematic liquid crystal. By introducing a bias voltage during UV curing, surface-localized polymer protrusions with a dimension of 100nm and a field-induced pretilt angle are observed. Experimental evidences and theoretical analyses validate that PS-VA has increased surface anchoring strength by two folds and pretilt angle has been changed from 89° to 86° compared to those of a VA cell. The enabling PS-VA cell technique with excel electro-optical properties such as very good dark state, high optical contrast, and fast rise and decay times may lead to development of a wide range of applications.
Authors:
;  [1] ;  [1] ;  [2] ; ; ; ;  [3]
  1. Liquid Crystal Institute, Kent State University, Kent, Ohio 44242 (United States)
  2. (China)
  3. AU Optronics Corporation, Hsinchu, 300, Taiwan (China)
Publication Date:
OSTI Identifier:
22492382
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 9; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALIGNMENT; COMPARATIVE EVALUATIONS; CONTROL; ELECTRIC POTENTIAL; FASTENING; IRRADIATION; LIQUID CRYSTALS; MONOMERS; OPTICAL PROPERTIES; POLYMERS; SURFACES; ULTRAVIOLET RADIATION