Dielectric and electro-optical studies of Au/SnO₂ core/shell nanocrystals incorporated ferroelectric liquid crystal

ABSTRACT

We study the effect of Au/SnO₂ core/shell nanocrystals (NCs) on dielectric and electro-optical parameters of a ferroelectric liquid crystal (FLC) material, namely KCFLC 7S. The FLC composites are characterised through polarising optical microscope (POM), photoluminescence (PL) spectroscopy and dielectric spectroscopy. Incorporation of Au/SnO₂ NCs enhances the optical contrast, optical tilt angle, PL intensity and reduces saturation voltage of a FLC mixture. This modification in electrical and optical properties is attributed to change in dynamics of FLC molecules in presence of the NCs. Dielectric measurement shows that chiral Smectic C (SmC*) phase of FLC is dominated by an applied oscillating field dependent partially unwound helical mode (p-UHM) process in FLC composite with Au/SnO₂ NCs. These results would be useful to fabricate power efficient and highly luminescent NCs-FLC-based electro-optical devices.

GRAPHICAL ABSTRACT

KEYWORDS:

• Chiral smectic C phase
• metal/metal oxide core/shell
• dielectric properties
• p-UHM
• helix

Acknowledgements

S.D. acknowledges University Grants Commission (UGC), India (Grant reference number: UPE 262 (A) 3) for the financial support. Dr. A. M. Biradar from CSIR-National Physical Laboratory (CSIR-NPL), New Delhi, India, is kindly acknowledged for helpful discussion and experiments regarding dielectric measurements. The authors would also like to thank Department of Physics, S. P. Pune University, India for the characterization techniques.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the University Grants Commission [UPE 262 (A) 3].