Overview

In the Bragg lab we are interested in ultrafast processes that underlie the behaviors of light-responsive materials. An overarching goal of our work is to understand how structure or material architecture at the intra-, inter-, and supramolecular levels influence the properties and dynamics of transient excited and charge-separated states and thereby determine the nature, timescales, and efficiencies of processes initiated with light – such as bond formation, energy transfer, and charge separation. We aim to provide insights on the relationships between structure and dynamics to inform rational design of light-responsive chemical and material systems, thereby serving a critical role in a number of collaborative research efforts. An additional aspect of our work involves the development, application, and extension of spectroscopic probes for interrogating complex dynamics and chemical or material environments in order to chart molecular and material photoresponses comprehensively.

Over the last several years, specific photophysical and photochemical phenomena we have studied in our lab have included:

• Mechanisms and structural control of nonadiabatic photochemical bond formation and molecular switching mechanisms
• Transient Raman and polarized optical spectroscopies as probes of structure, dynamics, and properties of transient states in conjugated materials
• Intramolecular charge-transfer in hybrid inorganic-organic materials
• Intermolecular energy and charge transfer mechanisms in supramolecular assemblies
• Thermal-energy transfer in plasmonic metal nanoparticles