Formation of nano-wire and ring-like microstructures in LC media via self-assembly of NiO quantum dots and investigation of their optoelectronic properties

Abstract

Nickel oxide nano-dot wire and ring like structures were synthesized via self-assembly of nickel-oxide quantum dots in the presence of liquid crystal media. The sizes of the ring-like microstructures extend up-to a few tens of microns. After doping NiO QDs in 4-(trans-4-n-hexylcyclohexyl) isothiocyanatobenzoate (6CHBT), we characterize the LC and quantum dot hybrid system using optical microscopy, fluorescence, UV–vis-nir, FTIR, FESEM-EDX and Raman spectroscopy methods. The sizes of the synthesized NiO QDs are observed in the range of 5.38 nm–10.17 nm. Our FTIR data confirms for the purity as well as the nonbonding interactions of NiO NPs and LC molecules with each other. We have used theoretical models based on nanoscale principles to further validate our experimental findings. The predictive theoretical model match with the experimentally obtained particle size data and the corresponding band gap values for the case of spherical NiO nanoparticles very well. The band gap value of the hybrid system corresponds to spherical nanoparticle clusters of sizes 25 nm. This allows us to estimate the effective size of the nanoclusters of NiO QDs in the hybrid system. We have correlated the findings of fluorescence, Raman and optical microscopy to verify the formation of nanodot wires and nanodot-ring like microstructures in LC media. FESEM images further confirm for the formation of NiO nanodot-wire-like structures and presence of LC molecules anchoring over nano-dot hierarchical structures. Elemental analysis done using EDX, confirm for the presence of LC molecules and NiO.