Nanoparticles Doped, Photorefractive Liquid Crystals

摘要

This report results from a contract tasking University of Southampton as follows: The main objectives of this exploratory, short project will concern the study of the quality of liquid crystal cells with diluted suspensions of ferroelectric nanoparticles and their photorefractive properties. We will use ferroelectric nanoparticles of photorefractive material: thiohypodiphosphate (Sn2P2S6). The actual nano-particles have been produced by a method (fine mechanical grinding), tested earlier. Sn2P2S6 nanoparticles proved, so far, to be the most efficient in enhancing dielectric anisotropy of liquid crystals. As liquid crystal hosts, Merck E7 or ZLI 4801 will be used and cells will be prepared in two configurations. The first configuration will have standard, non-photosensitive aligning layers on both substrates, such as polyimide or low-ionic surfactant. The second configuration will include a photosensitive PVK:C60 layer on one substrate of the cell, instead of polyimide. The LC DSFNP cells with the highest quality will be tested for two-beam coupling gain and the magnitude of diffraction.