High-contrast thin-film polarizers by photo-crosslinking of smectic guest-host systems

The preparation of high-contrast thin-film polarizers by photo-crosslinking of smectic guest-hosts systems for use in liquid crystal displays (LCDs) is presented. Thin-film polarizers has the advantages of significant reduction in display and weight, and the positioning of the polarizers inside the cell eliminates all parallax-related issues and is beneficial to the robustness of the display. One possible approach to obtaining thin, coatable polarizers based on the use of lyotropic liquid-crystalline dyes that form a crystalline polarizer with sub-micrometer film thickness after coating and evaporation of the solvent. The low viscosity of the reactive liquid crystals facilitates easy alignment, while the in setu photopolymerization provides freedom in choosing the photopolymerization temperature and conditions enabling the selection of the optimum phase and molecular order. This thin-film technology could be an alternative to traditional sheet polarizers in LCD.