Voltage-Driven Molecular Orientation with Optical Synergy in Rare Earth Doped Polymer Dispersed Liquid Crystals

Abstract

Achieving reversible large-span photoluminescence regulation still faces difficulties due to limitations in the design or preparation conditions of related materials. Herein, a universal strategy that combines voltage-driven molecular orientation with optical synergy between rare earth (RE) doped materials and polymer dispersed liquid crystals (PDLC) is proposed to achieve large-span reversible opto-electrically synergistic induced multi-response photoluminescence regulation. The obtained Eu(tta)3phen/PDLC composites can exhibit different emission colors reversible transform from purple to purplish-pink depending on the excitation wavelength and the applied electric voltage. The interaction between PDLC and Eu(tta)3phen is analyzed and the field distribution of internal microstructures is simulated using the finite-difference time-domain method, providing a theoretical basis for the voltage-dependent photon interactions. The potential applications of Eu(tta)3phen/PDLC composites for anticounterfeiting is suggested by demonstrating a proof-of-concept anticounterfeiting system based on the composites. The strategy of opto-electrically synergistic induced multi-response photoluminescence regulation, with general applicability, can be easily extended to other RE doped materials and PDLC systems, opening up new possibilities for photoluminescence regulation research.