High Resolution Imaging of Excited State Dynamics in Nanomaterials

Who: Martin Gruebele, University of Illinois Urbana-Champaign
When: 
Friday, April 1, 2022 - 1:00pm
Where: 
Chevron 154

A Pitt Chem Seminar

Abstract: Two topics will be covered in the general area of tunneling microscopy: looking at surface dynamics of glasses on a millisecond to hour scale, and excited state dynamics of nanomaterials on the sub-picosecond to nanosecond scale, both with sub-nm resolution. The technique of “SMA-STM” works by shining modulated light on a sample and detecting the resulting change in electron density with an STM tip, which also enhances the evanescent light wave that excites the sample. I’ll show that we can build energy landscapes of glass surfaces and characterize the collective units that underly glassy dynamics. I’ll also discuss results on excited state dynamics of nanomaterials such as quantum dots, carbon dots and carbon nanotubes, including recent results to look at energy and charge migration with sub-picosecond time resolution.