Study of optimized curing conditions for polymer-stabilized pi-cell with compensation film

Abstract

The pi-cell is one of the candidates for replacing the twisted nematic (TN) and in-plane switching (IPS) modes. It has a fast switching speed and a good viewing angle owing to its self-compensated director configuration. In this paper, we report the optimized conditions for polymer-network stabilization to prevent the bend state from transforming into the (transitioning) splay state. Excellent electro-optical characteristic were obtained by optimizing various conditions: monomer concentrations in liquid crystal (LC), UV intensity, curing time, curing voltage, curing temperature and the retardation of the compensation film. Scanning electron microscopy (SEM) images revealed the structures of the stabilized polymer network in a pi-cell, which is the key factor for maintaining the bend state.