Hybrid alignment induced by asymmetric photopolymerization of liquid crystal-reactive mesogen composition between two plastic substrates

A hybrid aligned liquid crystal layer was prepared between plastic substrates by the asymmetric photopolymerization of the reactive mesogen. The planar alignment of liquid crystal molecules was induced on the top substrate facing the UV light by the predominant photopolymerization at this substrate, whereas a homeotropic orientation was induced on the bottom substrate. The extinction ratio of the hybrid aligned samples vs the polymer concentration and the thickness of the liquid crystal layer was examined.