Enhanced electro-optic characteristics of polymer-dispersed nano-sized liquid crystal droplets utilizing PEDOT:PSS polymer composite

Flexible devices require much higher reliability upon device driving. Because the voltage-driven liquid crystal devices show higher reliability than current-driven devices, flexible liquid crystal devices are relatively suit to open a new application fused with flexible electronics in displays and photonic devices. One plausible approach is to utilize polymer-dispersed liquid crystals with nanoscale droplets of liquid crystals dispersed in a polymer matrix. One of the most significant shortcomings with that approach is high operating voltage due to the strong molecular interaction between liquid crystals and polymer matrices, low fill factor of the system, and a voltage drop in the dielectric polymer matrix. Herein, we show a polymer composite that is blended with conductive PEDOT:PSS polymer to enhance the dielectric property of the system. The composite polymer matrix we show in this work provides a pathway of electric fields via the PEDOT:PSS when applying voltages and eventually reduces the voltage drop in the composite matrix. As a consequence of the enhanced electric field, the Kerr constant and transmittance of probe light passing through the sample mixing with 3.5 wt% of PEDOT:PSS increases up to 11.7 and 37.3% and the operating field decreases up to 17.2%. Furthermore, the rising times are enhanced up to 30% while the decaying times remain the same. We believe that this approach will greatly contribute to the realization of flexible liquid crystal devices.