Formation of the anisotropic ITO-based orienting layers for the liquid crystal devices

In this paper, the influence of the CO2 laser ablation on the indium-tin oxide (ITO) and ITO with carbon nanotubes (CNTs) was considered. The ITO and CNTs were deposited on the Crown K8 substrates via the laser-oriented deposition technique. The anisotropy of the wetting angle for the laser-ablated pure ITO and ITO with the CNTs thin films was considered and compared. The ablation of pure ITO thin films under the CO₂-laser provides the arithmetical mean deviation of the profile in the range of 1.0-1.3 nm (in parallel direction relative to laser ablation) and in the range of 1.6.-1.7 nm (in perpendicular direction). In the case for the ITO with CNTs the mean deviation of the profile corresponds to the ranges of 6.2-9.1 nm and of 10.9-24.3 nm for the parallel and perpendicular directions respectively. The anisotropy of the height distribution leads to the same tendency in the wetting angle. The mean value of the wetting angle anisotropy for pure ITO is 31.6° and for ITO with CNTs it is 48.3°. The possibility to control the anisotropy of the wetting angle via the deposition of the CNTs and the laser ablation allow considering the ITO modifications as the universal electrical contacts and alignment layers for the twisted-nematic liquid crystal devices.