Evaluation of surface azimuthal anchoring energy between grating surface and nematic liquid crystal layer using geometric model

  • 林 進龍

Student thesis: Doctoral Thesis

Abstract

A simple geometric model is proposed for estimating the azimuthal anchoring energy between grating surface and nematic liquid crystal layer of a liquid crystal display (LCD) device as a function of the grating height and grating pitch The model parameters are determined directly from experimental or finite element method (FEM) data and the model is then used to predict the surface azimuthal anchoring energy for gratings with various pitches heights and shapes (sinusoidal relief rectangular V-shaped and trapezoidal grating) It is shown that a good agreement exists between the predicted results for the surface azimuthal anchoring energy and the experimental data Moreover a good agreement is also observed between the estimated results and those obtained from Berreman’s expression and FEM simulations respectively A saturation tendency of the surface azimuthal anchoring energy is observed as the square of the grating height increases for all three calculation methods (i e Berreman’s model FEM simulations and geometric model) Overall the experimental and numerical results show that for the nematic liquid crystal considered in the present study (4-n-pentyl-4'-cyanobiphenyl (5CB)) the surface azimuthal anchoring energy increases with an increasing grating height or a reducing grating pitch
Date of Award2017 Jan 24
Original languageEnglish
SupervisorTei-Chen Chen (Supervisor)

Cite this

'