An improved alignment layer grown by oblique evaporation for liquid crystal devices

Abstract

In this paper, we present a new approach to aligning liquid crystal (LC) molecules on thin SiO2 films. The SiO2 film is obliquely deposited using electron beam evaporation. The effectiveness of the oblique SiO2 films is determined through measurements of optical and electrical properties. The columnar topography of the SiO2 alignment layer is observed using atomic force microscope (AFM) images. Using an oblique deposition angle of 35°, the deposited SiO2 films reach optimal surface morphology regarding transmittance (92.4%) and roughness (1.643 nm). With this new optimal film, LCD applications show improvements in response time and contrast ratio when compared to LCD applications, which use the typical 90° deposition method. The improvements are about 135 and 40%, respectively.