Quenching of photoluminescence and enhanced contrast of ferroelectric liquid crystal dispersed with Cd1−XZnXS/ZnS core/shell nanocrystals

We report the dispersion of Cd1−xZnxS/ZnS core/shell nanocrystals (NCs) in ferroelectric liquid crystal (FLC) into different concentrations. Absorbance of white light, photoluminescence (PL), contrast, polarizing optical microscopy and Fourier transformed infrared spectroscopy (FTIR) have been performed to disclose the nature of FLC/NCs composite. The presence of NCs, in different concentration, quenches the PL of FLC material. The mechanism of quenching is explained by the modified Stern-Volmer quenching equation. The maximum contrast for FLC/NCs was found at 0.25 wt% of dopant concentration which is the optimized concentration of NCs in FLC from application point of view. Contrast was further supported by polarizing optical micrographs (POMs). The change in POM also indicates the change in molecular alignment of FLC owing to concentration of NCs which also affect the optical properties of composites. FTIR spectra reveal that the NCs strongly interact with FLC molecules and changes their molecular dynamics associated with the central core and aliphatic chain. The present FLC/NCs composite has potential application in ultraviolet to visible light conversion, ultraviolet light storage applications and high contrast PL displays.