Ultrafast Processes in Nanophotonic Structures

Speaker: 

Gary Wiederrecht

Description: 

Understanding ultrafast photoprocesses in nanostructures is important for realizing new opportunities related to technologies such as solar energy conversion and single photon emission for quantum optics applications. In this talk I discuss our center’s work in characterizing several ultrafast optical phenomena that are specifically enhanced in nanoscale structures. Examples include the ultrafast decay of plasmons into hot “nonthermal” plasmonic carriers and their potential importance to increasing efficiencies of photovoltaic and photocatalytic processes. We seek to spectroscopically characterize hot electrons on an ultrafast timescale, as well as to design new nanostructures to create hot electrons in greater numbers. Physical insights into how to extract the hot carriers before loss of energy to thermalization is given. 

A second set of examples includes the design of new biomimetic nanostructures for light harvesting, which offer unique opportunities for tuning structure and the resultant energy transport properties. This work focuses on exploring light harvesting in both metal-organic-frameworks using porphyrin building blocks as well as the use of chromophore-doped peptide amphiphiles to create varied and potentially self-healing structures for transporting energy. 

A third set of examples includes the ultrafast processes that can occur in colloidal quantum well-like nanostructures to produce correlated photon emission for quantum optics applications. Finally, an overview is provided of the Center for Nanoscale Materials (CNM) user science program, which enables free access (for work intended to be published, e.g. not proprietary) to a wide variety of fabrication, synthesis, characterization, and theory capabilities at the CNM.