Well-structured holographic polymer dispersed liquid crystals by employing acrylamide and doping ZnS nanoparticles

Abstract

High diffraction efficiency and low driving voltage are typically considered to be prerequisites for the practical applications of holographic polymer dispersed liquid crystals (HPDLCs), which are especially critical for their use in the state-of-the-art low-threshold mirrorless tunable lasers. Nevertheless, high driving voltages are usually resulted for HPDLCs upon increasing the holographic diffraction efficiency via optimizing the monomer/LC formulations. Herein, we present that doping nanoparticles into HPDLCs with controlled distribution is a facile and efficient approach to circumvent the aformentioned issues. Zinc sulfide (ZnS) nanoparticle doped HPDLCs with high diffraction efficiency (94.0 ± 2.1%), and a low threshold driving voltage of 2.5 V µm⁻¹ that is decreased from 11.6 V µm⁻¹ for the pristine form, are achieved by doping 8 wt% ZnS nanoparticles into the HPDLCs based on an acrylamide monomer, N,N-dimethylacrylamide, that contributes significantly to the high diffraction efficiency up to 98.2 ± 1.4%.