Synthesis of Doped ZnO Nanoparticles and their Effect on the Dielectric and Electro-Optical Characterization of Nematic Liquid Crystals

The aim of this study is to investigate the effect of a co-doped zinc oxide (ZnO) semiconductor nanostructure (Al and Cu) on the dielectric and electro-optical properties of nematic liquid crystal structures. Firstly, Al:ZnO, Cu:ZnO, and (Al-Cu):ZnO (co-doped ZnO) semiconductor nanomaterials were synthesized by a microwave-assisted gel ignition method. Then, new composite structures were formed by doping the synthesized nanomaterial to the nematic liquid crystal. Significant physical parameters including the real and imaginary components of complex dielectric permittivity (ε′\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varepsilon^{\prime }$$\end{document} and ε″\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varepsilon^{\prime \prime }$$\end{document}), relaxation frequency (fR\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{R}$$\end{document}), relaxation time (τ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\tau$$\end{document}), dielectric strength (δε′\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\delta \varepsilon^{^{\prime}}$$\end{document}), and threshold voltage (Vth\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$V_{{{\text{th}}}}$$\end{document}) values were determined using the experimental results. The results showed that Al:ZnO and Cu:ZnO doping into liquid crystal (LC) enhanced the properties of E7 nematic LC. Furthermore, it was observed that the co-doped ZnO contribution to the LC significantly improved the dielectric properties and was found to yield the best results.