Mark Ratner of Northwestern University is supported by an award from the Chemical Theory, Models and Computational Methods program to carry out research on the development of theoretical methods for the study of electron transfer (ET) in molecular systems. There are three major thrusts for the work: 1). Investigation of ET in hybrid materials constructed of polymers with redox-available sites suspended within them, or with semiconductor or metal quantum dots. The central challenge is relating the dynamics of the polymeric host with the overall transport. 2). Extension of the scheme for describing local inter-atomic contributions to the overall electron currents within the molecule to deal with inelastic behavior, with polaron formation, with vibrational and photonic effects, and with decoherence in general. 3). Development of analytic forms for self-energies for tight-binding metals in 1, 2 and 3 dimensions. The PI and his coworkers try to understand how differing geometries of molecules between electrodes result in different conduction patterns. For example, does current always go through a single molecule, or does it pass between molecules before exiting at the anode?
The work has broad impact on our understanding of a number of situations involving electron transfer (ET) including photochemical and electronic systems. Given the dominant significance of ET, applications to devices for solar energy capture and storage and to environmental stability will follow directly from this work. Ratner is involved in a number of outreach and educational activities, including codirecting the Initiative for Sustainability and Energy at Northwestern (www.isen.northwestern.edu/). He is also planning new approaches both to teaching first-year chemistry courses and to giving community outreach talks, based on the importance and interest of energy within the society.
