This research project, supported in the Analytical and Surface Chemistry Program, will address the lifetimes and energy transfer mechanisms of vibrationally excited molecular adsorbates on semiconductor and metallic surfaces. Well-defined adsorbate-surface systems will be prepared and characterized in ultra high vacuum and in solution, and selected vibrations of the adsorbates will be excited by ultrashort IR laser pulses. Evolution of the vibrational excitation will be monitored with coherent time-resolved laser surface spectroscopy methods. Mechanisms of inter-adsorbate, vibration-phonon, and vibration-electronic energy transfer will be explored. The work will concentrate initially on the study of energy transfer in the H/Si(111) and (100) adsorbate systems, as well as on molecular CO adsorbed at electrochemical interfaces. %%% The dynamics of energy transfer between adsorbed molecules and solid surfaces controls reactivity in surface chemistry. This research project will explore the details of adsorbate-surface energy transfer, with the goal of developing an understanding of this process and its relevance to semiconductor processing, electrochemical systems, and heterogeneous catalysis. Powerful laser spectroscopic methods will be used to study molecular adsorbates on well-characterized semiconductor and metallic surfaces.
