Tip-Enhanced Optical Spectroscopy and Imaging at the Angstrom Scale
Prof. Nan Jiang, University of Illinois Chicago
Abstract
This video will introduce and review methods that couple optical spectroscopy and imaging with the scanning tunneling microscope (STM) for researchers from diverse scientific backgrounds. The first technique, tip-enhanced Raman spectroscopy, uses photons for both excitation and detection. It introduces light into the STM tip-sample junction and monitors the inelastic scattering of photons by molecules and materials, resulting in unique and sensitive vibrational fingerprints. The second technique, STM-induced luminescence, uses tunneling electrons for excitation and photons for detection. It examines the intrinsic luminescence of single molecules and their charge transfer processes with their surroundings. Both techniques not only maintain STM high spatial resolution (angstrom scale) but also provide new chemical and physical insights into individual molecular adsorbates, surface-supported molecular assemblies, and two-dimensional materials.
Biosketch
Nan Jiang is an Associate Professor of Chemistry at the University of Illinois at Chicago. He received his Ph.D. in Condensed Matter Physics from Chinese Academy of Sciences in 2010, under the advisement of Hongjun Gao. He was also a joint Ph.D. student at Max Planck Institute for Solid State Research, under the advisement of Klaus Kern. His postdoctoral research at Northwestern University was under the supervision of Richard P. Van Duyne. His research group at the University of Illinois at Chicago was founded in 2015, and he was the recipient of an NSF CAREER award in 2020. His research group is developing a hybrid technique by combining scanning probe microscopy with optical spectroscopy to understand and predict the single-molecule processes, including photoabsorption, photoemission, chemical bond breaking and bond formation at the angstrom scale.