Evolution of Nanoscale Film Morphology

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ABSTRACTThe goal of this research project is to conduct a multi-scale computational and theoretical investigation of the evolution of thin film morphology on metal and semi-conductor surfaces. This research involves several nanoscale modeling strategies: (1) ab inito electronic structure calculations for small-scale systems using density functional theory and quantum chemistry approaches for energetics, electronic effects, diffusion paths, and selected adsorbate vibrational modes; (2) development of robust model potentials from parameterization of results from the proposed ab initio calculations and experimental data; (3) application of recently developed accelerated MD code to examine novel cluster diffusion process which may appear when simulations are performed for micro-mili seconds; (4) determination, successively, of the vibrational dynamics, thermodynamics, diffusion prefactors and rates for small Ag clusters on proposed substrates; (5) calculation of energy barriers and diffusion paths for Ag clusters on proposed substrates using the model potentials; (6) modeling of epitaxial growth for realistic system sizes (microns) using the calculated diffusion rates an energetics in kinetic Monte Carlo technique; (7) continuum modeling of nanostructure relaxation using information from all of the above. An added strategy is to work in tandem with on-going experiments to provide constant feedback.This is a collaborative effort by researchers in chemical engineering, physics, chemistry and mathematics. Together with industrial collaboration, the project will allow them to determine the characteristics of the systems for length and time scales that are several orders of magnitude larger than the atomic scales for which the information is initially collected.