Title :
A Study of the Liquid Crystal Alignment Mechanism of Bond-Breaking Via Ion-Beam Irradiation of an Amorphous Aluminum-Oxide Surface
Author :
Kim, Dai-Hyun ; Jung, Hae-Yoon ; Kang, Young-Gu ; Kim, Young-Hwan ; Park, Hong-Gyu ; Kim, Byoung-Yong ; Seo, Dae-Shik
Author_Institution :
Dept. of Electr. & Eng., Yonsei Univ., Seoul, South Korea
Abstract :
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.
Keywords :
X-ray photoelectron spectra; alumina; amorphous semiconductors; liquid crystals; molecular orientation; sputter deposition; Al2O3; RF magnetron sputtering; X-ray photoelectron spectroscopy measurements; amorphous aluminum-oxide surface; bond-breaking; ion-beam irradiation; liquid crystal alignment mechanism; molecular orientation; vertical-aligned-LC displays; Educational institutions; Glass; Liquid crystal displays; Liquid crystals; Radiation effects; Surface treatment; Thermal stability; Ion-beam (IB) bombardment; a- ${hbox{Al}}_{2} {hbox{O}} _{3}$; liquid crystals (LCs); vertical alignment (VA);
Journal_Title :
Display Technology, Journal of
DOI :
10.1109/JDT.2010.2086432
