(633a) First-Principles Characterization of Electronic Structure and Transport of e-/h+ Polaron Defects in Oxides: Application to TiO2

In this presentation we will review our first-principles approach to the characterization of the structure, dynamics, and reactivity of e^-/h⁺ polaron defects in metal oxides with illustration on TiO₂. In this approach we combined a Marcus/Holstein two-state model of polaron hopping with a DFT +U level of theory to characterize the polaron transport in bulk and across interfaces. The approach has proven highly succcessful. We extended the approach to the characterization of the structure and reactivity of excess electrons in defected TiO₂ surfaces to create a framework for understanding their role with regards to the reactivity of surface absorbates and for other photochemical processes. We will also discuss ideas for new methodological developments  for the ab initio characterization of polaron dynamics.

This work is supported by the Division of Chemical Sciences, Geosciences, and Biosciences of the Office of Basic Energy Sciences of U.S. Department of Energy. Battelle operates Pacific Northwest National Laboratory for the DOE.