CdSe quantum dots in chiral smectic C matrix: experimental evidence of smectic layer distortion by small and wide angle X-ray scattering and subsequent effect on electro-optical parameters

ABSTRACT

CdSe quantum dots (QDs) dispersed ferroelectric liquid crystal (FLC) has been subjected to small and wide-angle X-ray scattering and atomic force microscopy to understand the molecular organization in chiral smectic C (SmC*) phase. SAXS indicates that the presence of QDs causes enhancement in the smectic layer separation. The smectic order parameter for neat FLC and FLC–QDs mixtures is obtained in the range of 0.6 to 0.85. Both smectic order parameter and structural tilt are found to be lesser for FLC–QDs mixtures as compared to neat FLC. The insertion of QDs in SmC* matrix causes localized smectic layer distortion in such a way that spontaneous polarization remains almost the same but the electro-optic switching of molecules becomes faster. We have outlined the superiority of FLC–QDs mixtures for electrical energy storage and their suitability in electronic devices.

Graphical Abstract

KEYWORDS:

• Ferroelectric liquid crystal
• quantum dots
• small and wide angle X-ray scattering

Acknowledgments

Prof. A. H. Sahraoui, Director UDSMM is gratefully acknowledged for his kind support and interest in our work. We are sincerely thankful to Prof. Jan P. F. Lagerwall for providing the help in estimating the order parameter by SAXS. We are also thankful to Dr. A. Segovia-Mera and Mr. Amaury Kasprowiak for his help in performing some experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed here.

Additional information

Funding

DPS is thankful to UDSMM, ULCO for the financial support. SAXS/WAXS studies in this work were supported by the Soft Materials Research Center under NSF MRSEC Grant No. [DMR-1420736].