Enhanced Electrooptical Characteristics of Twisted Nematic Liquid Crystal Display With $\hbox {ZrO}_{2}$ Thin Films

A rubbing-free liquid crystal (LC) alignment method is highly desirable for future generations of large high-resolution LC-display technology. In this paper, ion-beam (IB) bombardment was carried out as an LC alignment method in order to modify the ZrO₂ surface, and unidirectional LCs were achieved. The pretilt angle was found to be a function of the IB incident energy, and a possible mechanism of the LC alignment was investigated with X-ray photoelectron spectroscopy (XPS). XPS analysis showed that the LC alignment on the IB-irradiated ZrO₂ surface was primarily due to the reformation of O-Zr bonds. The response time of a twisted nematic cell with IB-irradiated ZrO₂ thin films was superior to those with rubbed polyimide films.