Probing Materials at the Nanoscale: a Journey in Tip-Enhanced Spectroscopy.
François Lagugné-Labarthet
Professor, Department of Chemistry
Western University
Tuesday, March 25, 2025
11:00 a.m.
C2-361 (reading room)
Abstract:
The past two decades have been very active in the development of tip-enhanced spectroscopy and of its application to a variety of materials and biomaterials with intricate properties at a nanoscale level. We present here our journey in this dynamic field applied to the study of nanomaterials and what knowledge it has brought to the field, its promises, its limitation and its challenges. In particular, we will focus on our most recent work applied to the study of 2D materials and how combination of Tip-enhanced Raman spectroscopy (TERS) and atomic force microscope (AFM) modes can be utilized jointly to decipher the optical and mechanical properties of 2D flakes of transition metal dichalcogenides with thickness of less than 1 nm. The presence of surface defects, growth of additional layers and surface functionalization are examples of nm features that can be revealed optically and mechanically from the combination of an Atomic Force Microscope and a confocal microscope. Current developments in machine-learning methods are also interesting tools that can be applied to analyse thousands of spectra collected a typical confocal or TERS mapping. We will present few examples on how such methods can be applied to spectroscopy measurements.
Figure 1: (A) TERS map of substructures in WS2 flakes (B) deep learning analysis of a TERS map of multiple carbon nanotubes.
Citations
[1] "The Hidden Flower in WS2 Flakes: A Combined Nano-Mechanical and Tip-Enhanced Raman Exploration”, J. Jelken, M. O. Avilés, F.Lagugné-Labarthet, ACS Nano, 2022, 16, 12352.
[2] "Molybdenum Disulfide Flakes as Platforms for the Photoconversion of 4-Nitrothiophenol”, C. Lambin, M. O. Avilés, J. Jelken, and F.Lagugné-Labarthet, J. Phys. Chem. C, 2023, 127, 24281.
[3] "Tuning the Bandgap of MoS2 Single Layer with Aryl Diazonium Salts", C. Lambin, M. McCarvell, P. Cheng, S. Lau-Thruong, P. Decorse, C. Mangeney, N. Felidj, and F. Lagugné- Labarthet*, J. Phys. Chem. C, 2025, (10.1021/acs.jpcc.4c08755).
Biography: François Lagugné-Labarthet is a Professor of Chemistry at Western University. His research themes encompass the study of the optical properties of nanoscale materials using a variety of original combinations of microscopy and optical techniques yielding nanoscale information with unprecedented sensitivity and spatial resolution. As the scientific director of the Western Nanofabrication facility, his mission is to maintain the state-of-the-art instrumentation for the fabrication and characterization of nanoscale devices, enable new fabrication techniques with better specifications and promote the open-user access to the Western Nanofabrication Facility, Ontario’ first open-user nanofabrication facility opened in 2004, to a variety of users from academia and industry. F.Lagugné-Labarthet has been the Chair of the board of directors of NanoOntario [2018-2024], representing the interests of members from academic, government, industrial, and financial sectors in the development of nanotechnologies in Ontario. Supported by Health Canada , F.Lagugne and industry partner SCATR Inc, are currently running a network of connected spectrometers powered by machine learning algorithms located at supervised consumption sites across Ontario to fight Canada’s current opioid crisis.
Learn more about Dr. Lagugné-Labarthet and his work at the FFL group website
Location Information
200 University Avenue West
Waterloo, ON, CA N2L 3G1
