Fundamental studies of reactive processes at plasma-surface interfaces.

Schatz will have 1.5 postdocs and two graduate students on the project to perform computational and theoretical studies of plasma-surface interactions, and for work related to quantum cutting effects in semiconductor nanoparticles. The primary theory tools to be used in this work are: (1) ab initio molecular dynamics (for atoms, ions, metastables and molecules interacting with solid surfaces), including for transitions between multiple electronic states using trajectory surface hopping, (2) scattering theory methods (for electrons interacting with solids or molecules) using R-matrix theory, and (3) electronic structure methods for characterizing structures and energies, (4) coarse-grained models including kinetic Monte Carlo and effective transmission models to describe larger scale effects and the effect of multiple species interactions such as occur in plasmas. The quantum cutting project will involve the development of Forster-based and electronic structure methods to calculate photoabsorption cross sections of two exciton generation in semiconductor nanoparticles. The dynamics methods mentioned above will be used to perform studies of projects in all five components of the proposal as follows: I. Scattering and reaction of atomic and molecular ions: D+, D2+, O+, O2+, OH+, and CH3+: This work will also involve ab initio molecular dynamics calculations and trajectory-surface hopping calculations. II. Scattering and reaction of atomic and molecular radicals: H, D, and CH3, and scattering of metastable atoms: This concerns ab initio molecular dynamics calculations and trajectory surface hopping calculations, including calculations that are embedded in QM/MM calculations. III. Inelastic electron scattering and ionization for electron impact on solid surfaces: This involves a combination of R-matrix theory calculations coupled to an electron escape model. IV. Surface modification and plasma-surface interactions using a UHV-compatible plasma source: He we will develop kinetic Monte Carlo methods, and coarse-grained simulations. V. In-situ measurements of plasma-surface interactions and plasma properties in a microplasma discharge: This involves the same models as in section IV, but for different surface compositions and substantially different fluxes of ions, electrons and neutrals.