Viewing angle compensation of vertical alignment liquid crystal display using a triphenylene-based discotic reactive mesogen

We synthesised a triphenylene-based discotic reactive mesogen 2,3,6,7,10,11-hexakis(but-3-enyloxy)triphenylene (HABET) and investigated its performance as the compensation film for a vertical alignment-liquid crystal display (VA-LCD). The HABET molecule has a negative birefringence with an extraordinary refractive index (n_e) that is smaller than the ordinary refractive index (n_o). The optic axis of the HABET is parallel to the n_e direction and was vertically aligned to function as a negative C-plate. We measured the refractive indices and birefringence of the HABET layer in the visible wavelength range. Using the experimental data, we simulated the viewing angle property of the VA-LCD with the HABET negative C-plate and a positive A-plate. The viewing angle property of the VA-LCD with the HABET compensation film was wider than those without the compensation film and those using triacetylcellulose films.