The King group investigates condensed phase and interface dynamics using the tools of ultrafast spectroscopy, surface science, and materials science. The group focuses on understanding the ultrafast dynamics of non-equilibrium excited electronic states on 10s of femtosecond to picosecond timescales in order to determine the mechanisms of energy transfer in polycrystalline and heterogeneous materials and across interfaces.
Interfaces and boundaries between materials, phases, and structural motifs are ubiquitous in our natural and manufactured world. Changes in the atomic and electronic structure of materials and molecules at interfaces and material boundaries lead to unique properties such as modified excited state lifetimes, charge transport mechanisms, and interfacial states. In materials, boundaries and interfaces can create unique electronic states that improve charge transfer or produce trap states, facilitating charge recombination. This influences material suitability for applications such as photovoltaics or light emitting diodes. Relevant to environmental science and catalysis, unique interfacial electronic states can fundamentally change chemical reactivity at surfaces, altering pollutant reactivity and catalysis mechanisms.
In order to address these critical questions, the group develops and uses various ultrafast spectroscopic techniques, including electron microscopy and optical spectroscopy, to selectively investigate heterogeneous and polycrystalline materials, surfaces, and interfaces. By combining ultrafast spectroscopy with a wide range of materials and chemical characterization tools, we link the ultrafast processes occurring in a material or at an interface with the relevant macroscopic properties. Our understanding of these complex systems will help to guide new material development, provide fundamental insight into interfacial chemical reactivity, and inform catalytic and energy science applications.
