Abstract:

Liquid crystal(LC) materials are widely used in LC displays(LCD). However, due to the presence of impurities in liquid crystal, the application voltage of liquid crystal becomes large, which results in the increase of energy consumption. In order to decrease the threshold voltage and saturation voltage, nanoparticles are usually added to LC to improve the electro-optical performance. In this paper, pinecone-like ferric oxide(P-Fe₂O₃) nanoparticles with uniform shape and size were prepared by a simple chemical precipitation method. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl(5CB) is doped with pinecone-like Fe₂O₃ nanoparticles in different doping contents. The results show that the best electro-optical properties of the LC is achieved when the doping mass fraction is 0.5%. The threshold voltage and saturation voltage decrease by 24.8% and 45.2%, respectively, the contrast ratio increases by 46%, and the response time decreases to 17.6 ms. The property is superior to the ordinary Fe₂O₃ nanoparticles doped in 5CB with the threshold voltage and saturation voltage decreased by 15% and 16% under the same condition, which is attributed to the uniform dispersion of pinecone-like Fe₂O₃ in nematic LC 5CB and the adsorption of impurity ions by the rough surface of pinecone-like Fe₂O₃ abating the shielding effect.

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