Exploring the electro-optical properties of nematic liquid crystal through incorporation of ZnCuGaS2 core/shell quantum dots

Abstract

ABSTRACT The current study focuses on elucidating the interaction mechanisms between ZnCuGaS2 quantum dots (QDs) and nematic liquid crystals (NLCs) (5CB), intending to comprehend how this interaction leads to the alteration of electro-optical properties of the host material. Various concentrations of QDs were incorporated into NLCs and investigated to examine their emission and transmittance characteristics. Remarkably, an enhancement (~68%) in photoluminescence was observed for the concentration of 0.04 wt. %, adding an intriguing aspect to the findings. A notable decrease in the threshold voltage, from 1.5 V (in pure NLC) to 0.5 V, was observed for the optimised concentration (0.04 wt. %) calculated using transmittance-voltage measurement. This sample exhibited a noteworthy improvement in optical transmission, showing an increase by 2.7 times compared to pure NLC. Fundamentally, the introduction of QDs leads to a reduction in light leakage centres and ionic impurities, consequently enhancing radiative recombination. Moreover, the memory effect of the sample was evident in the capacitance-voltage data, revealing that the NLC with QDs significantly increased the capacitance value from 290 pF to 466 pF when compared to the pure NLC. The objective of the present research is to examine the impact of QDs on NLC concerning key parameters such as mentioned above.