Bistable reflective cholesteric liquid crystal display with pixelated colors

Abstract

We report the fabrication of a bistable, reflective cholesteric liquid crystal display (CLCD) with pixelated colors. The bistable color CLCD is prepared, instead of using stacked color panels, by the formation of polymer barrier walls at inter-pixel areas and color tuning with a tunable chiral material (TCM), whose chirality can be rendered and reduced by exposing to various amount of UV light at a selected wavelength. The polymer barrier walls are formed at the inter-pixel areas by a photopolymerization-induced phase separation via a photomask. Some of the blue color pixels are selectively changed to reflect the green or red color by exposing the panel to various amount of UV light with the assistance of a set of photomasks. The electro-optical study of a CLCD with pixilated colors reveal that the bistable switching behavior is retained with variation in switching voltages depending on the color of cholesteric pixels.