Monomolecular vertical alignment layer with room temperature processibility for flexible liquid crystal displays

Abstract

In this article, we disclose a vertical alignment material using alkylphosphonic acid for liquid crystals that only requires simple room temperature treatments to secure good vertical alignment for liquid crystals. Alkylphosphonic acid forms a monomolecular layer on the substrate providing strong vertical alignment. The proposed alignment layer shows decent electro-optical properties, such as high voltage holding ratio, low residual direct current voltage, low image sticking parameter, etc. Later, we combine the alkylphosphonic acid with photo-rewritable azo-dye to fabricate a hybrid alignment of nematic cells and study its stability and anchoring energy. The material shows great compatibility with flexible substrates. Thus, the proposed alignment layer of alkylphosphonic acid can potentially find application as the alignment layer for flexible liquid crystal displays.