Electro optic characteristics of polymer-dispersed liquid-crystal films for flexible display

Abstract

The electro optic properties of a polymer-dispersed liquid-crystal (PDLC) film were investigated by varying the driving conditions such as applied voltage and frequency. The PDLC was formed from a mixture of a liquid crystal (TL205) and prepolymer consisting of 2-ethylhexyl acrylate, Darocur 4265, 1,6-hexanediol diacrylate, and Ebecryl 810. When driven by applied voltage, the PDLC film showed contrast ratio of 17.59-23.64 at frequencies of 1 ×102-1 × 106 Hz, but the contrast ratio decreased to 4.01-6.46 within specific voltage ranges. With an increase in frequency, the dielectric anisotropy of the LC decreased, causing an increase in both the threshold voltage and driving voltage. Thus, the electro optic properties of the PDLC film could be modified by varying the voltage and frequency conditions. © 2014 The Japan Society of Applied Physics.