Research Interests
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.
Selected Publications
P. P. Joshi, R. Li, J. L. Spellberg, L. Liang, and S. B. King, "Nanoimaging of the Edge-Dependent Optical Polarization Anisotropy of Black Phosphorus." Nano Letters 22, 3180-3186 (2022)
S. B. King, K. Broch, A. Demling, and J. Stähler, “Multistep and multiscale electron transfer and localization dynamics at a model electrolyte/metal interface.” J. Chem. Phys. 150, 041702 (2019)
S. B. King, D. Wegkamp, C. Richter, M. Wolf, and J. Stähler, “Trapped Electrons at the Amorphous Solid Water/Vacuum Interface as Possible Reactants in a Water Splitting Reaction.” J. Phys. Chem. C 121, 7379-7386 (2017)
A. B. Stephansen, S. B. King, Y. Yokoi, Y. Minoshima, W. Li, A. Kunin, T. Takayanagi and D. M. Neumark, “Dynamics of dipole- and valence-bound anions in iodide-adenine binary complexes: A time-resolved photoelectron imaging and quantum mechanical investigation.” J. Chem. Phys. 143, 104308 (2015)
S. B. King, A. B. Stephansen, Y. Yokoi, M. A. Yandell, A. Kunin, T. Takayanagi and D. M. Neumark, “Electron accommodation dynamics in the DNA base thymine.” J. Chem. Phys. 143, 024312 (2015)
S. B. King, M. A. Yandell, A. B. Stephansen and D. M. Neumark, “Time-resolved radiation chemistry: dynamics of electron attachment to uracil following UV excitation of iodide-uracil complexes.” J. Chem. Phys. 141, 224310 (2014)
M. A. Yandell, S. B. King and D. M. Neumark, “Decay dynamics of nascent acetonitrile and nitromethane dipole-bound anions produced by intracluster charge-transfer.” J. Chem. Phys. 140, 184317 (2014)
S. B. King, M. A. Yandell and D. M. Neumark, “Time-resolved imaging of the iodide-thymine and iodide-uracil binary cluster systems.” Farad. Disc. 163, 59 (2013)
M. A. Yandell, S. B. King and D. M. Neumark, “Time-Resolved Radiation Chemistry: Photoelectron Imaging of Transient Negative Ions of Nucleobases.” J. Am. Chem. Soc. 135, 2128 (2013)