Liquid Crystal (8CB) Molecular Adsorption on Lithium Niobate Z-Cut Surfaces

Density functional theory is used to study the adsorption of 4′-n-octyl-4-cyanobiphenyl (8CB) liquid crystal molecules on the lithium niobate (0001) and (0001) surfaces. The interface energy and configuration are found to depend strongly on the surface polarization and the molecular coverage. A flat adsorption configuration is most favored in the case of positive Z-cuts as well as for single, isolated molecules on both the positive and the negative Z-cut. With increasing coverage on negative Z-cuts, however, an upright-bonding configuration is preferred.