A Study of the Liquid Crystal Alignment Mechanism of Bond-Breaking Via Ion-Beam Irradiation of an Amorphous Aluminum-Oxide Surface

In this paper, we study the Ion-beam (IB) irradiated amorphous (a)-aluminum oxide () inorganic layer deposited by RF magnetron sputtering as an liquid crystal (LC) alignment layer. Uniformly vertical-aligned (VA)-LC on a- surface resulted from IB irradiation energy above 1800 eV. We assumed that LC molecular orientation depends on the intensity of Al 2p, O 1s peaks, which were confirmed through X-ray photoelectron spectroscopy (XPS) measurements. XPS showed that IB irradiation changed the chemical structure, breaking Al-O bonds by altering Al-O and O-Al bonding intensity. Also, electro-optical characteristics of vertical-aligned-LC displays (VA-LCDs) on the alignment layers were measured, which showed reduced threshold voltage and power consumption, as compared with IB irradiated and rubbed polyimide (PI) layers.