Control of quantum dot emission by colloidal plasmonic pyramids in a liquid crystal.

Haridas Mundoor,Enid M Cruz-Colón,Sungoh Park,Qingkun Liu,Ivan I Smalyukh,Jao Van De Lagemaat

doi:10.1364/oe.383672

Haridas Mundoor, Enid M Cruz-Colón + Show 4 more

Open Access

https://doi.org/10.1364/oe.383672

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Abstract

We study the plasmon-enhanced fluorescence of a single semiconducting quantum dot near the apex of a colloidal gold pyramid spatially localized by the elastic forces of the liquid crystal host. The gold pyramid particles were manipulated within the liquid crystal medium by laser tweezers, enabling the self-assembly of a semiconducting quantum dot dispersed in the medium near the apex of the gold pyramid, allowing us to probe the plasmon-exciton interactions. We demonstrate the effect of plasmon coupling on the fluorescence lifetime and the blinking properties of the quantum dot. Our results demonstrate that topological defects around colloidal particles in liquid crystal combined with laser tweezers provide a platform for plasmon exciton interaction studies and potentially could be extended to the scale of composite materials for nanophotonic applications.

Highlights

Emission control of single-particle fluorescence using metal nanoparticle is a topic of rapidly increasing scientific importance and technological relevance [1,2,3,4,5,6]
By analyzing the emission characteristics of the quantum dot (QD) trapped at the apex of the gold micro pyramid (GMP) with the help of time-resolved spectroscopy techniques, we demonstrate strong plasmon-exciton coupling and discuss how the combination of colloidal selfassembly and plasmon-exciton interactions can be useful for the preparation of next-generation photonic materials and devices utilizing metal and semiconductor nanoparticles
We have demonstrated the use of topological boojum defects nearby a colloidal particle dispersed in a liquid crystal (LC) to study the nanoscale optical interaction between a GMP and a single QD particle

Summary

Introduction

Emission control of single-particle fluorescence using metal nanoparticle is a topic of rapidly increasing scientific importance and technological relevance [1,2,3,4,5,6]. We demonstrate how colloidal particles can self-assemble within the bulk of a nematic LC to provide a toolkit for probing plasmon-exciton interactions This self-assembly is driven by the minimization of the free energy of the LC host, allowing for the spontaneous well-defined relative arrangement of particles needed to probe the effect of the plasmonic enhancement on the physical behavior of a single fluorescent QD particle. By analyzing the emission characteristics of the QD trapped at the apex of the GMP with the help of time-resolved spectroscopy techniques, we demonstrate strong plasmon-exciton coupling and discuss how the combination of colloidal selfassembly and plasmon-exciton interactions can be useful for the preparation of next-generation photonic materials and devices utilizing metal and semiconductor nanoparticles

Preparations of GMPs and LC colloids

Optical measurements methods and materials

Numerical simulations

Results and discussion

Conclusions

Disclosures