November 2, 2021

Presenter: Dr. Andrey Krayev, North America AFM-Raman manager for Horiba Scientific

Note: If you'd like to use this tool at MRL, you can find more info about it and who to contact for training here:  https://mrl.illinois.edu/facilities/equipment/horiba-xplora-nano-ters-tepl

First we’ll discuss how useful HORIBA SmartSPM can be for characterization of diverse materials from molecular layers to polymers and 2D materials.

After a brief introduction of the tip enhanced spectroscopy (TERS) technique and instrumentation, We’ll talk about recent advances in TERS and TEPL (tip enhanced photoluminescence) characterization of 2D semiconductors, in particular their lateral and vertical heterostructures.

We’ll demonstrate how novel, contamination-free technique of dry transfer of 2D semiconductor crystals grown on Si/SiO2 or sapphire to metallic (gold and silver) substrates opens new possibilities in nanoscale Raman and PL characterization of lateral and complex vertical/lateral heterostructures. I’ll further demonstrate that comprehensive Raman characterization with several excitation wavelengths, both resonant and below-the-bandgap non-resonant, is crucial for understanding the composition of the heterostructures and the nature of observed Raman modes.