Nematic Homogeneous Alignment with Pre-tilt Angle by Linearly Polarized Deep UV Exposed Polyimide

Abstract

Positive-type polyimide, exposed to linearly polarized deep UV(DUV) light (257 nm), induced nematic liquid crystals' homogeneous alignment with small pre-tilt angle. A two stage exposure was introduced to establish a pre-tilt angle. A tilted alignment mechanism was explained by anisotropic photo-depolymerization of polyimide side chains.