Pretilt control of nematic liquid crystal by deposition of $SiO_x$ film

비정질 $SiO_x$ 박막을 이용한 nematic 액정의 선경사각 제어

Liquid crystal (LC) alignment on $a-SiO_x$ thin film was investigated by means of X-ray photoemission spectroscopy and optical transmittance as we varied the deposition temperature and the target-to-substrate distance. LC molecules can be aligned vertically on $a-SiO_x$ film when the stoichiometric parameter x of $a-SiO_x$ is smaller than 1.56, but they can be aligned homogeneously when x is larger than 1.56. We also found that whether liquid crystals can be aligned vertically or homogeneously on $a-SiO_x$ film can be predicted simply by measuring the change in optical transmittance by deposition of $a-SiO_x$ thin film layers.