Experimental Studies of the Vibrational Dynamics of Adsorbates

这项研究项目得到了分析和表面化学计划的支持，将研究半导体和金属表面上振动激发的分子吸附的寿命和能量转移机制。我们将在超高真空和溶液中制备和表征定义良好的吸附表面体系，并用超短红外激光脉冲激发选定的吸附表面振动。振动激发的演化将用相干时间分辨激光表面光谱学方法来监测。探讨了吸附间、振动-声子和振动-电子能量传递的机理。这项工作将首先集中在H/Si(111)和(100)吸附体系中的能量转移，以及在电化学界面上吸附的分子CO。在表面化学反应中，吸附分子和固体表面之间的能量传递动力学控制着反应性。本研究项目将探索吸附-表面能量转移的细节，目的是了解这一过程及其与半导体加工、电化学系统和多相催化的相关性。强大的激光光谱方法将被用来研究分子在表征良好的半导体和金属表面上的吸附。

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.