Time evolution photoluminescence studies of quantum dot doped ferroelectric liquid crystals

Abstract

Time evolution photoluminescence (PL) studies of ferroelectric liquid crystal (FLC) mixtures doped with different concentrations of ZnS and CdS quantum dots (QDs) are carried out. Remarkable enhancement in the PL intensity and a significant shift in the emission band of FLC materials are observed by doping with a suitable amount of QDs. The modifications in the PL behaviour of the QD/FLC composites are found to depend strongly on time, and also on the QD/FLC mixtures themselves. The enhancement in the PL intensity of the FLC materials is attributed to the additive combination of the emissions from FLCs and QDs and the highly scattering phase of the FLC materials used. The shifting of the emission band and reduction in the PL intensity of the QD/FLC composites could be attributed to the oxidation of QDs. The observed results would be helpful in selecting QD/FLC composites to observe stable and enhanced PL from composites.