Orientation stabilization of light-controlling layers using liquid crystal polymers

Photo-alignment technology provides an advanced optical alignment method and high alignment quality compared to conventional rubbing techniques. However, challenges of photo-stability and response speed have hindered their practical application. This work is concerned with the stability of the photo-alignment layer, with azo dyes (SD1) employed as the photo-alignment layer material. Two solutions were investigated: the passivation of SD1 films with reactive mesogen (RM) material RM257 and the utilization of polymer–azo dye composites in lieu of the photo-alignment layer. Experimental methods, including spin-coating and UV polymerization, were employed, while optimal monomer concentrations were determined by photo-stability tests. The results demonstrate that the passivation layer enhances photo-stability. Atomic force microscopy (AFM) is employed to assess film roughness and enhance film quality. Furthermore, electro-optical tests indicate that the approach has no negative impact on the performance of LCD. These findings provide a more optimized approach to stabilizing liquid crystal (LC) alignment for advanced display technologies.