Liquid crystal alignment on inorganic film by ion beam irradiation for flexible display applications

Liquid crystal alignment using ion beam (IB) irradiated a-C:H films on either plastic or glass substrates can be affected by the type of topographical structure. Strong IB irradiation induces greater roughness to the micro-groove on a plastic substrate, leading to a device with increased pretilt angle, fast response time and reduced threshold voltage. In contrast to the hysteresis in the transmittance-voltage curve of the rubbed polyimide film, which rapidly increases with increasing thermal and UV stress time, study of the residual DC voltage revealed no hysteresis on an a-C:H film due either to thermal or UV stress.