Ultrafast Optical Control over Hot Electron Dynamics in Nanoplasmonic Systems

Nanoscale metal systems support strong light-matter interactions known as plasmons, which generate high densities of high-energy (“hot”) electrons. These hot electrons can be harvested by surrounding molecules or semiconductors, or emitted into free space, with each possibility representing a broad set of applications, including next-generation solar energy conversion and storage, novel biological therapies, and ultrafast nanoscale electronics. The full realization and optimization of many of these applications, however, will require a de-tailed understanding of where hot electrons are excited, how fast and far they travel, and what directions they travel in—i.e. their spatial, temporal, and momentum distributions. In this thesis, new methods are introduced for measuring, modeling, and even optically con-trolling nanoplasmonic hot electron distributions on femtosecond timescales, using a unique single-particle, angle-resolved nonlinear photoemission spectroscopy technique with a highly-tunable ultrafast visible laser system. These experiments are both complemented and driven by the parallel development of a simple new theoretical framework for predictively mod-eling nanoplasmonic hot electron distributions and dynamics. A variety of nanoparticle geometries are investigated to reveal an equally wide variety of behaviors, from the simple directional photoemission properties of complex defects to the strikingly complex and often counter-intuitive photoemission properties of simple nanorods and spherical nanoparticles.
Year of Publication
Academic Department
Department of Physics
Number of Pages
Date Published
University of Colorado Boulder
JILA PI Advisors
Advisors - Other
Gordana Dukovic
Publication Status