Fluorescence, UV absorbance and dielectric studies of fluorescent dye doped ferroelectric liquid crystal

• The frequency behavior of loss factor shows that relaxation process is due to Goldstone mode.
• The dielectric parameters have been determined by dielectric relaxation study.
• The higher value of UV absorption has been found for fluorescent dye doped system.

In this study UV absorption, fluorescence and dielectric studies have been performed for pure ferroelectric liquid crystal (FLC) and three different concentrations i.e. 1%, 3% and 5% of fluorescent dye in pure FLC. The dielectric study suggests that there exists an optimum concentration of fluorescent dye for which we have found highest value of dielectric parameters and after this concentration there is decrement in the dielectric parameter. The higher value of relative permittivity has observed for fluorescent dye doped system in comparison to the pure FLC system. The behavior of dielectric loss factor with frequency has been explained for pure and fluorescent dye doped FLC. The higher value of UV absorption has been found for fluorescent dye doped system in comparison to the pure system. Excitation wavelength, emission wavelength and quantum yield have been determined for all the mixtures from the fluorescence study. Quantum yield shows the probability of excited state being deactivated by fluorescence rather than non-radiative mechanism.