Plasmonic nanoparticles have very large absorption cross sections and can concentrate the local density of photon states on the nano scale. When they are coupled to molecules or semiconductor nanocrystals and form different hybrid nanostructures, various light-matter interaction processes can be significantly enhanced or manipulated, including optical responses like fluorescence and Raman scattering, photochemical reactions, energy transfer processes, etc. In this dissertation, several different plasmonic hybrid nanostructures were studied to explore in detail the plasmonic effect in various light-matter interaction processes, which can lead to potential novel applications in spectroscopy, photochemistry, and quantum optics.Chapter 1 provides an introduction and theory background to the projects in this thesis. In Chapter 2 we studied a plasmon-driven electron transfer reaction between gold nanoparticles and electron acceptor molecules, monitored by surface-enhanced Raman spectroscopy (SERS). We demonstrate that the hot electrons generated by plasmon decay from both the interband and intraband transitions in gold nanoparticles can trigger the electron transfer reaction through an indirect electron transfer mechanism. Chapter 3 describes a local-environment-engineering strategy of coating semiconductor nanocrystals with a plasmonic nanoshell structure to suppress spectral diffusion at the single particle level. The main mechanism is the Purcell enhancement of radiative decay rate of the semiconductor nanocrystals. In Chapter 4, a strongly coupled hybrid system composed of silver nanoprisms and a dye J-aggregates is constructed. The surface-enhanced Raman excitation spectroscopy not only reveals the plasmonic/molecular characteristics of the two hybrid polariton states, but also indicates the existence of a large manifold of dark states in the strong coupling regime.

Creator

• Wu, Yue

DOI

• https://doi.org/10.21985/n2-29e8-a776

Subject

• Physical chemistry
• Materials Science

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:15861
• etdadmin_upload_862992

Keyword

• plasmon
• nanostructures
• surface-enhanced Raman spectroscopy

Date created

• 2021-01-01

Resource type

• Dissertation

Rights statement

• In Copyright