Effect of Doped Insulating Nanoparticles on the Electro-Optical Characteristics of Nematic Liquid Crystals

In this paper, the transient currents and the voltage holding ratio (VHR) generated by an applied direct voltage in nematic liquid crystal (LC) cells are measured. The experimental results show that doping insulating nanoparticles such as ZnO, TiO2, and Si3N4 in nematic LCs leads to a reduction in the moving-ion density in LC cells and drastically reduces the transient currents as well as threshold voltage. This doping method improves the electro-optical characteristics in nematic LC cells. Moreover, we found that the VHR values maintained higher than 95% in these doped LC cells. Such a high VHR observed in insulating nanoparticle-doped LC cells is a superior feature for LC display applications. (c) 2009 The Japan Society of Applied Physics