Facet-dependent electro-optical properties of cholesteric liquid crystals doped with Cu2O nanocrystals
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Excellent electro-optical (E-O) performances are essential for high-quality reflective cholesteric liquid crystal (LC) displays, but are often limited by the high driving voltages required by these displays. Dispersing functional nanomaterials into the LCs has emerged as a promising approach to achieve outstanding E-O properties. In this work, we report the facet-controlled E-O properties of a chiral nematic LC (N*LC) doped with cubic, octahedral, and rhombic dodecahedral Cu2O. The outstanding E-O properties of the doped systems are related to the interaction between the liquid crystals and Cu2O dopants with different exposed crystal planes. Doping with octahedral and rhombic dodecahedral Cu2O reduces the stability of the planar state, as a result of both the surface abundance of active Cu atoms that interact with the polarized LC molecules, and the large amounts of vertexes and edges on the crystal surfaces, which accelerate the transition from the planar to the focal conic state under an applied electric field. Rhombic Cu2O is the most effective dopant for improving the E-O properties of the present LCs, resulting in a 65.31% reduction of the threshold voltage. The facet and morphology effects highlighted in this work provide a new pathway to develop excellent energy-saving meso-materials with exposed high-reactivity facets, improving their potential applications in electro-optical technologies and information displays.
KeywordsCu2O nanocrystals liquid crystals electro-optical properties host-guest systems facet-dependence
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This work was supported by the National Natural Science Foundation of China (Nos. 51673008, 51203005, and 21601009).
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