Recovery of UV-degraded electrical properties of nematic liquid crystals doped with TiO2 nanoparticles

The effect of ultraviolet (UV) exposure on the electrical properties of nematic liquid crystal (LC) doped with TiO2 nanoparticles was investigated. The low-frequency dielectric data indicate that the ion-trapping ability of TiO2 descends under UV exposure and that it gradually revives after the removal of the UV light. The voltage holding ratio of the TiO2-doped LC cells, which decreased from 71% to 43% by 2-mW/cm2 UV irradiation for 60 min, remarkably recovered to 61% within 180 min. The proposed LC/TiO2 suspension holds promise for the use of outdoor LC devices characterized by regained excellence in electrical performance after UV exposure.