Liquid crystal alignment capability by the UV alignment method in a-C:H thin films

We studied the nematic liquid crystal (NLC) alignment capability by the UV alignment method on a a-C:H thin-film surface. A good LC alignment by UV irradiation on a a-C:H thin-film surface at a layer thickness of 200 Å was achieved. Also, a good LC alignment by the UV alignment method on the a-C:H thin film surface was observed at an annealing temperature of 180°C However, the alignment defect of the NLC was observed at an annealing temperature above 200°C Consequently, a good thermal stability of LC alignment by the UV alignment method on the a-C:H thin-film surface can be achieved.