DOPANT EFFECTS OF PHOTOREACTIVE ZnO NANOPARTICLES ON FAST RESPONSE LC MATERIALS IN OPTICAL COMPENSATED BEND (OCB) MODE LIQUID CRYSTAL DISPLAYS

Abstract

Photoreactive ZnO nanoparticles containing surface-modified acrylate groups were synthesized and applied to improve the threshold voltage in optical compensated bend (OCB) mode liquid crystal display (LCD) cells. The dopant effects of ZnO nanoparticles with or without commercial reactive monomer additives (1 wt% doping ratio) on the values of threshold voltage (V(th)) and response time in OCB cells were explored by applying different voltages to photo-reactive ZnO nanoparticles during UV curing processes in OCB cells to compare the influences of doped ZnO nanoparticles. As a result, we successfully eliminated or reduced the splay state of OCB mode and thus reduced threshold voltage. However, lower transmissions and higher values of the response time were observed in OCB cells doped with photoreactive ZnO nanoparticles, and the decreasing of V(th), is independent of various doping materials. Moreover, lower transmission and high response time could be improved through sequential voltage-applied procedures, i.e., bend black mode (10 V) -> bend white mode (2.5 V), under the immobile minimum threshold voltage at the bent state during UV curing processes to achieve lower pre-transition and fast response time properties by only doping photoreactive ZnO nanoparticles.