Abstract:

Nematic liquid crystals(NLC) materials are widely used in liquid crystal display. However, due to the presence of impurities, the driving voltage of the liquid crystal becomes large, which results in the increasing energy consumption. In order to decrease the threshold voltage and saturation voltage, nanoparticles are usually added to liquid crystal to improve the electro-optical performance. In this paper, rough and smooth cubic ferric oxide nanoparticles with uniform shape and size of ~550 nm were prepared by a hydrothermal method. NLC E7 was doped with cubic Fe₂O₃ nanoparticles in different doping mass percent. Compared with the smooth Fe₂O₃/E7 composite and NLC E7, the rough Fe₂O₃/E7 composite has superior electro-optical properties. When the doping mass percent is 0.4%, the electro-optical properties reach the best. The threshold voltage and saturation voltage decrease by 9.9% and 11.6%, respectively, the contrast ratio increases by 80%, and the response time decreases to 6.0 ms. The superior electro-optical properties can be attributed to the sufficient surface area and more charge on the surface of rough cubic Fe₂O₃, which is beneficial to absorb the impurity ions in the NLC system and weaken the shielding effect of impurity ions, thus improving the electro-optical properties.

Key words: liquid crystal display, semiconductor nanomaterials, cubic Fe₂O₃, nematic liquid crystal(NLC) electro-optical properties