EPSRC Reference: |
GR/S08800/01 |
Title: |
HOMEOTROPIC PHOTOALIGNMENT:FUNDAMENTAL ISSUES AND NEW MATERIALS |
Principal Investigator: |
O'Neill, Professor M |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Physics |
Organisation: |
University of Hull |
Scheme: |
Standard Research (Pre-FEC) |
Starts: |
01 April 2003 |
Ends: |
31 July 2006 |
Value (£): |
174,194
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EPSRC Research Topic Classifications: |
Materials Characterisation |
Materials Synthesis & Growth |
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EPSRC Industrial Sector Classifications: |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
A range of electronic devices including some liquid crystal displays and organic thin film transistors require vertical alignment of rod-like or lath-like molecules with the molecular long axis perpendicular to the surface. The molecules adopt a small pretilt angle with respect to the vertical, determined by the surface energy and the nature of the surface interaction. The pretilt direction is not defined in the azimuthal plane so that many domains with different alignment directions exist. Oblique irradiation of the vertically aligning surface provides a unique pretilt direction determined by the direction of the incident beam. Thus photoalignment is a non-contact method to obtain monodomain, photopattemable vertical alignment over large areas. This project aims to determine the mechanism of vertical photoalignment using novel materials systematically modified by molecular design. A range of surface analysis techniques including contact angle determination, atomic force microscopy and X ray reflectivity, correlated with pretilt angle measurements of the overlying molecules, will elucidate the polar and entropic contribution to photoalignment. Novel alignment materials including polyimides and self assembled monolayers (SAMs) will be synthesized and their processing optimised for use in vertical aligned nematic displays. A new concept to obtain photoalignment is demonstrated. This also provides a novel photopatternable method to change the surface energy of SAMs, and is particualdy applicable to organic semiconductors. Finally we aim to confirm that vertical photoalignment results in monodomain alignment of
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.hull.ac.uk |