Improvement in molecular alignment of ferroelectric liquid crystal by Co-ZnO/ZnO core/shell quantum dots

ABSTRACT

The ferroelectric liquid crystal (FLC) shows improvement in electro-optical properties on incorporation of Co-ZnO/ZnO core/shell (CZZ) quantum dots (QDs), which is a manifestation of better alignment for FLC molecules. A suitable amount of core/shell QDs was added into pure FLC and studied using polarising optical microscope, ferroelectric, photoluminescence (PL) and dielectric measurements. Significant increase in the order parameters (θ, P_S) and PL intensity with reduced light leakage centres and dielectric loss factor are the consequences of enhanced molecular ordering of FLC molecules dispersed with CZZ QDs. FLC composites with luminescent core/shell QDs are a step forward for the improvement of low power operated highly photoluminescent FLC-based display devices. Such emissive liquid crystal displays would exhibit improved brightness, better contrast, wide viewing angle and lower operating power.

Graphical abstract

KEYWORDS:

• Core/shell quantum dots
• chiral smectic C phase
• photoluminescence
• tilt angle
• molecular ordering

Acknowledgments

SD acknowledges UGC-UPE (India) for the financial support. Authors are grateful Dr. A. M. Biradar and Mr. Lokesh Gangwar of CSIR-National Physical Laboratory (CSIR-NPL), New Delhi (India) for helpful discussion and experiments regarding dielectric and rotational viscosity measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary materials

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