Date of Completion

4-27-2019

Embargo Period

4-25-2020

Keywords

Gold nanoparticles, Plasmon, Plasmonic Cavity, Quantum Dot, Plasmon-exciton coupling, Purcell effect, Assembly, Heterogeneous

Major Advisor

Jing Zhao

Associate Advisor

Jie He

Associate Advisor

Xudong Yao

Field of Study

Chemistry

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

Metallic nanoparticles can generate collective oscillation of conduction electrons when excited by incident light. This unique light-matter interaction is termed as localized surface plasmon resonance (LSPR) and offers the possibility of manipulating light well below the diffraction limit. This extreme concentration of light also greatly influences the absorption and decay processes of the nearby Quantum Dots (QD). When plasmon-exciton interaction enters strong coupling regime, the energy coherently oscillates between the QD and the plasmonic cavity. Optical studies at the single particle level of hybrid Au-QD structures with strong-coupling can help us understand the origin of this phenomena as well as open up the possibility of designing new optoelectronic devices. The ultimate goal of this thesis is to colloidally assemble the Au-QD structure with controlled coupling strength. Along the journey, we firstly studied how to synthesize the Au nanoparticle with desired plasmonic properties. Next, we developed a method to create Au-silica nanostructures of varying morphology and studied the mechanism how these morphologies were formed. The Au-silica nanostructures then served as building blocks for QDs to attach on. The strong plasmon-exciton coupling was finally achieved with an Au-QD-Au sandwich structure. In this structure, the plasmon-exciton coupling strength was controlled by the size of QDs, which determines the size of the gap in the Au dimer. Our results offer guidance of synthesizing hybrid materials and shed light on the design principle of new optoelectronic devices.

Available for download on Saturday, April 25, 2020

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