Speaker: Ivan Pechenezhskiy, University of California, Berkeley
Abstract: Vibrational spectroscopy of molecules on surfaces provides valuable insights into their surface behavior, including molecule-surface and molecule-molecule interactions, self-assembly, as well as chemical and structural properties. Traditionally this information is obtained via infrared spectroscopic techniques that contain little or no real-space information. Combining this type of optical vibrational spectroscopy with atom-scale microscopy would be extremely useful for better understanding microscopic phenomena. In this talk I will present a new technique whereby a scanning tunneling microscope can be used to perform vibrational spectroscopy of molecular adsorbates at the submonolayer coverage through the use of a tunable infrared laser source. Using this technique, infrared absorption spectra of several diamondoid molecules deposited on a Au(111) surface were obtained. I will discuss the performance of the new technique and the physical insights that were deduced from the measurements, as well as the feasibility of achieving single molecule resolution in the future.