Improvement of the Dielectric and Electro-Optic Properties of Phthalocyanine- and Quantum Dot-Doped Nematic Liquid Crystals Under UV Illumination

In this study, dielectric and electro-optic properties of 4-pentyl-4′-cyanobiphenyl (5CB) nematic liquid crystal (LC) and different concentrations of nickel (II) phthalocyanine (Ni(II)Pc) and cadmium selenide sulfide/zinc sulfide (CdSeS/ZnS) quantum dot (QD)-doped LC have been investigated in dark and ultraviolet (UV) illumination. Some important dielectric parameters such as the real and imaginary part of the complex dielectric constant ( ε′ and ε′′ ), relaxation frequency ( f R ), and relaxation time ( τ ) have been determined. The output of the study shows that Ni(II)Pc and CdSeS/ZnS contribution and UV illumination improved the dielectric properties. Optical band gap ( E gap ) values of all samples have been obtained using the UV spectroscopy technique. The E gap value decreased after dispersion of Ni(II)Pc and CdSeS/ZnS in the pure LC. The results may be beneficial for the design of new optoelectronic devices.