Rodcast Quantitative morphology-property correlations in gold plasmonic nanoparticles

This thesis presents a comprehensive, quantitative framework for understanding and measuring the optical response of individual plasmonic nanoparticles, focusing on gold nanorods. It bridges electron scale plasmonic physics with experimentally observed single particle behaviour, encompassing static response, environmental effects, and non equilibrium structural dynamics. Central to the work is the integration of accurate electrodynamic simulations, experimentally validated three dimensional morphology, high signal to noise single particle spectroscopy, and in situ structural probing under pulsed excitation. Morphology is treated not as an assumed input, but as a measurable, dynamically evolving property with direct optical consequences.
The thesis first establishes the relevance of plasmonics to energy, catalysis, and sensing technologies, introducing the electrodynamics governing metallic resonances and their damping mechanisms. It then develops a validated simulation framework, demonstrating the necessity of fully retarded electrodynamics for realistic nanorod sizes and benchmarking numerical solvers against exact solutions. A dedicated tomography workflow is introduced to obtain simulation grade 3D geometries, showing how small morphological errors propagate into significant spectral shifts.
Experimentally, a quasi darkfield platform enables quantitative single particle spectroscopy directly on TEM grids, with careful calibration for meaningful comparison to simulations. This enables per particle extraction of effective dielectric environments and scalable morphology–property correlations. Finally, pulsed optical excitation inside a TEM reveals rich, history dependent reshaping dynamics driven by transient heating and surface diffusion.
Together, the thesis provides a unified experimental–computational methodology for quantitative single particle plasmonics, enabling precise structure–property analysis and insight into dynamically driven nanoparticle behaviour.