Martin Gruebele

Department of Chemistry
University of Illinois
Thursday, May. 6, 2021
Zoom Webinar
Annabella Selloni
Add to Calendar2021-05-06 16:00:002021-05-06 16:00:00Annabella SelloniZoom Webinar15YYYY-MM-DD

Excited state structure and dynamics of nanomaterials via STM-imaged absorption spectroscopy

Unlike small molecules, which can be synthesized with atomic precision, very large molecules from DNA to carbon nanotubes have unavoidable defects The interesting properties of such materials usually involve energy or charge migration in the excited state, and such dynamics is affected, and sometimes even controlled, by defects. For this reason, the interpretation of spectra is more difficult, and it can be nice to have not just time- and energy-information about the system, but also about its wavefunction, at least in the form of excited state electron density of the system. I will discuss how single molecule absorption scanning tunneling microscopy (SMA-STM) can provide such information, allowing the visualization of excited states by sub-nanometer resolution, tomography of excited state orbital structure for individual particles, and even femtosecond time evolution of the electron density of a nanoparticle to be visualized, to make a direct connection with nanomaterials structure.