The effect of dielectric constant on ion adsorption in liquid crystal devices

Abstract

Image quality is a key parameter of liquid crystal displays that has been shown to be adversely affected by ion adsorption on the interior surfaces of the liquid crystal display cell. This paper studies the correlation between ion adsorption and the dielectric properties of the alignment layers on the inside surface of a liquid crystal cell. Both organic alignment materials (fluorinated and non-fluorinated) and inorganic alignment materials (SiO_x, SiO₂ and Al₂O₃) are investigated by experimentally characterising the residual DC and voltage holding ratio value. Ion adsorption on a surface in contact with liquid crystals is shown to be strongly dependent on the dielectric constant of the alignment layer.

Keywords:

• ion adsorption
• liquid crystal
• dielectric constant
• electrostatic adsorption
• low power consumption
• image quality