Phase Contraction, fluorescence quenching and formation of topological defects in chiral smectic C matrix by Cd0.15Zn0.85S/ZnS core/shell quantum dots dispersion: Faster electro-optic response for gadget displays. Issue 11 (1st September 2020)

• Record Type: Journal Article
• Authors: Singh, D. P.; Duponchel, B.; Kondratenko, K.; Boussoualem, Y.; Pujar, G. H.; Inamdar, S. R.; Douali, R.; Daoudi, A.
• Is Part Of: Liquid crystals. Volume 47:Issue 11(2020)
• Page Start: 1638
• Page End: 1654
• Publication Date: 2020-09-01
• Subjects: Ferroelectric liquid crystal -- quantum dots -- electro-optical response -- fluorescence quenching -- dsc -- polarised optical microscopy; Liquid crystals -- Periodicals; 548.905
• DOI: 10.1080/02678292.2020.1754939
• Languages: English
• ISSNs: 0267-8292

Abstract

ABSTRACT: Cd0.15 Zn0.85 S/ZnS core/shell quantum dots (CSQDs) of size 7.54 ± 0.99 nm in diameter were prepared via gram-scale one-pot synthesis method and dispersed in a ferroelectric liquid crystalline (FLC) material into two different concentrations. Spectroscopic, electro-optical (E-O) and morphological characterisations of aforementioned composites have been carried out. CSQDs cause a significant contraction in the width of chiral smectic C (SmC*) mesophase that has also been theoretically verified. Diffusion–controlled processes are responsible for the fluorescence quenching in the FLC/CSQDs composites which has been explained by using the Stern–Volmer quenching equation. The mesomorphic investigation has revealed that helical deformation takes place in the FLC/CSQDs composites, due to which the temperature-dependent gradual growth of ferroelectric domains is noticed. The perturbed helical geometry evinces a new structure-property correlation having a molecular switching time of 135 μ s that is 51% faster response as compared to the pristine system. Resultant spontaneous polarisation in the matrix of FLC/CSQDs composites is diminished because of the induced homeotropic and flexoelectric contributions. The faster E-O response and optical imaging are the fascinating features of the FLC/CSQDs composites that can probably be utilised in gadget displays. Graphical abstract: uf0001