Zinc oxide nanolevel surface transformation for liquid crystal orientation by ion bombardment
- Department of Electrical and Electronic Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)
This paper introduces the characteristics of the zinc oxide (ZnO) inorganic film deposited by radio-frequency magnetron sputtering as an alternative alignment layer for liquid crystal display (LCD) applications. The crystalline structure related to the texture formation of ZnO (1013) was observed with a tilt angle of approximately 28.1 deg. to the ZnO (0001) plane, leading to a smooth surface and high-density structure. Ion beam (IB) bombardment at various incident angles was used to induce liquid crystal (LC) alignment and cause the measured pretilt angle on ZnO films to assume a triangular contour. The orientation order of liquid crystal molecules was due to the van der Waals force for the vertical alignment of LCs with selective breaking of O-Zn bonds by IB bombardment. The contact angle contour as a function of the IB incident angle resembled the behavior of the pretilt angle. The pretilt angle is controllable by adjusting the surface features on ZnO films with IB bombardment. The electro-optic characteristics of vertically aligned (VA)-LCD based on ZnO film were comparable to those of VA-LCD based on polyimide, showing good potential of ZnO film as a LC alignment layer.
- OSTI ID:
- 21190065
- Journal Information:
- Journal of Applied Physics, Vol. 105, Issue 5; Other Information: DOI: 10.1063/1.3080159; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Surface reformation and electro-optical characteristics of liquid crystal alignment layers using ion beam irradiation
Variable liquid crystal pretilt angles on various compositions of alignment layers