Superior Electro-thermo-optical Properties of Homogeneous Liquid Crystals Aligned on Transparent Carbon Nanotube Sheet*

Highly-aligned carbon nanotube (CNT) sheet is examined as an outstanding alternative alignment layer for liquid crystal display, conventionally consisting of indium tin oxide transparent electrode combined with rubbed polyimide. A single CNT sheet, mechanically drawn from multi-walled CNT forest, is attached on the silane-treated glass substrate, followed by the deposition of an alumina thin film for a better adhesion and a complete insulation. The test liquid crystal (LC) display cell has the LC molecule of 4-Cyano-4'-pentylbiphenyl, sandwiched by the CNT-sheet-on-glass substrates. The thermal–optical characterization under the polarizing microscopy and the LC switching driven by the electric field supports the synergistic effects between aligned CNT bundles and LC molecules. These results present an opportunity to deploy the new alignment layer of CNT sheet for the liquid crystal display application.