Colloquium Prof. Latha Venkataraman, Columbia University

Speaker: Prof. Latha Venkataraman, Columbia University

Title: “Charge Transfer at the Nano Scale - Single Molecule and X-ray Photoemission Spectroscopy Measurements”

Abstract: Understanding and controlling electron transfer across metal/organic interfaces is of critical importance to the field of organic electronics and photovoltaics. Single molecule devices offer an ideal test bed for probing charge transfer and mechanics at these interfaces, while x-ray photoemission measurements enable a probing of femtosecond dynamics of charge transfer across interfaces. In this talk, I will review the scanning tunneling microscope break-junction technique we use to measure conductance through single molecule junctions1 and illustrate how it can be used to determine key parameters that control transport, namely the alignment of the molecular levels to the metal electrode and their electronic coupling. I will then compare these results with those from resonant x-ray photoemission spectroscopy measurements to illustrate how the dynamics of charge transfer can provide insights into these transport parameters.

Bio: Prof. Venkataraman is a world leader in measuring charge and energy transport in individual nanostructures. Her group has pioneered the use of the so-called junction techniques for measuring electronic and mechanical properties such as forces, current, rectification, and thermopower with atomic precision. Her work seeks to understand the interplay of physics, chemistry, and engineering impacting functional devices at the nanometer scale.