Generation of pretilt angles of liquid crystals on cinnamate-based photoalignment layer by a simple directional peel-off process.

As an alternative to the rubbing method, the photoalignment method has been extensively developed for liquid crystal displays owing to its various advantages including the absence of any contamination problems, feasibility of multi-domain structure formation, and low temperature processing capability. However, cinnamate-based photo-reactive materials that are widely used in photoalignment suffer from several limitations including low pretilt angle and limited control of tilted-up direction of the liquid crystals compared to that of the rubbing process. In this work, we demonstrate a simple and convenient method to generate the pretilt angle, compared to that achieved via the rubbing method, by means of a simple directional peel-off process using a photo-reactive cinnamate oligomer having flexible molecular chain.