Facet dependent electro-optical properties of liquid crystals doped with Au nanocrystals

[摘要] Doping nanoparticles into liquid crystal (LC) systems can effectively improve the electro-optical (E-O) properties of LCs. The authors introduced three types of (cubic, octahedral, and rhombic dodecahedral) Au nanocrystals (NCs) into a nematic LC 4-cyano-4′-n-pentylbiphenyl (5CB) and investigated the facet-dependent Au NCs in improving the E-O properties of 5CB. The surface energies of Au facets decreased in the order {110}>{100}>{111}. The improvement in the E-O properties of LC is related to the interaction between LC and different exposed crystal planes of dopants. Dodecahedral Au NCs, exposing {110} facets, are the most effective in improving the E-O properties because of their highest surface energy, resulting in a 30.15% reduction of the threshold voltage (V th ) and a 29.08% of the saturation voltage (V sat ) at a doping concentration of 0.4 wt%. The Au NCs trapped impurity particles. The screening effect could be suppressed, and the electric field could be strengthened, resulting in outstanding E-O properties. This work provides a novel way to enhance the E-O properties of LC molecules by doping with noble metal nanomaterials, thus improving their potential applications in energy-saving LC displays.

[学科分类] 计算机科学（综合）

[关键词] nematic liquid crystals;surface energy;electro-optical effects;nanoparticles;gold;doping profiles;impurities;surface energy;doping concentration;screening effect;electro-optical properties;nematic liquid crystals;octahedral Au nanocrystals;4-cyano-4′-n-pentylbiphenyl;rhombic dodecahedral Au nanocrystals;cubic Au nanocrystals;crystal planes;threshold voltage;saturation voltage;impurity particles;electric field;Au