Vertical alignment of liquid crystals using an in situ self-assembled molecular layer of saturated fatty acids

Abstract

ABSTRACTWe used four saturated fatty acids as the simple alignment agent for orienting liquid crystals (LCs) vertically on an indium tin oxide (ITO) substrate without using a conventional polyimide (PI) layer. The carboxylic acid group of fatty acids doped in LC media forms hydrogen bonds with the ITO substrate, leading to the formation of self-assembled molecular layer containing alkyl chains for LC alignment. The proposed method offered uniform vertical alignment of LCs under cross-polarization. Further, the electro-optical characteristic of the proposed LC device showed better performance than that of the LC cell with conventional PI alignment layer.