Analysis of physical parameters and collective dielectric relaxations in core/shell quantum dot ferroelectric liquid crystal composite

摘要

The effect of doping of Cd1-xZnxS/ZnS core/shell quantum dots (QDs) on the physical parameters and dielectric relaxations of ferroelectric liquid crystal (FLC) with the variation of dopant concentration, temperature and frequency has been examined in the present study. Fourier transformed infrared spectroscopy reveals that the QDs interact with FLC molecules and affect their molecular dynamics. The UV absorbance of pure FLC material has diminished in the presence of QDs according to the dopant concentration in FLC. A substantial change has been observed in tilt angle, spontaneous polarization and relative permittivity with the addition of QDs. A faster optical response for FLC, when doped with 0.25 wt% quantum dots, is one of the interesting finding of the present study. In the SmC*phase, a low frequency relaxation mode at 20 Hz along with the characteristic Goldstone mode has been observed. The occurrence of new low frequency relaxation mode is accredited to the ionization-recombination assisted diffusion of slow ions present in the FLC material. These results would certainly be helpful in the fabrication of low charge consumable and faster liquid crystal systems. (C) 2015 Elsevier B.V. All rights reserved.