Impact of Dispersion of V-TiO₂/MoSe₂/MoO₃ Composite on the Dielectric Properties of 8CB Liquid Crystal

Owing to sensitivity to external perturbations such as temperature, electric field, and magnetic field, the dielectric and electro-optical properties of liquid crystals (LCs) can be easily tuned. In recent years, the dispersion of nanomaterials into LCs has proven to be an important tool for the fabrication of various devices with improved characteristics. In the present study, we have synthesized a nanocomposite of vanadium-doped titanium oxide (VTO) with the integration of molybdenum diselenide (MoSe₂) and molybdenum trioxide (MoO₃), designated as VTO-MSE (V-TiO₂/MoSe₂/MoO₃), through a hydrothermal procedure and measured the dielectric features of 4′-octyl-4-biphenylcarbonitrile (also known as 8CB) LC material doped with the VTO-MSE nanocomposite at different concentrations (0.1 wt.%, 0.25 wt.%, 0.5 wt.% and 1 wt.%) in smectic A (SmA) and nematic (N) phases of 8CB at 28 °C and 36 °C, respectively. The uniform dispersion of VTO-MSE in 8CB was confirmed using polarizing optical microscopy, and the dielectric measurements were performed using frequency-dependent dielectric spectroscopy in the frequency range of 20 Hz–2 MHz. The dielectric parameters (ɛ′ and ɛ″) decreased on the dispersion of the nanocomposite in 8CB LC in the low-frequency region due to the reduction of mobile ions. The peak of the dielectric loss factor (tan δ) also shifted towards the low-frequency side because of the decrease in the mobile ion density. The threshold voltage was found to decrease for the VTO-MSE-mixed 8CB samples and dielectric anisotropy was also obtained, which shows an increase in its value for the nanocomposite dispersed systems. These results can be beneficial for the manufacture of display devices.