[3Ea01-05] Photo-related scanning probe microscopy: MHz to X-ray: Probe Microscopy Division's Session

[3Ea03] Probing local carrier and exciton dynamics in spatially confined nanomaterials with infrared nano-spectroscopy

*Jun Nishida¹ (1. Institute for Molecular Science)

We demonstrate the application of infrared scattering scanning near-field optical microscopy (IR s-SNOM) and its time-resolved extension of ultrafast IR s-SNOM with high sensitivity to address the impact of spatial confinement on nanomaterials. In the application of IR s-SNOM to vanadium dioxide nanoparticles (VO₂ NPs), we identify characteristic size effects and stochasticity in the insulator-to-metal transitions, both highlighting the metastable nature of superheated VO₂ NPs. By employing interferometric ultrafast IR s-SNOM, we find highly heterogeneous exciton dynamics in carbon nanotubes at both the inter-tube and intra-tube levels. These findings establish tip-based infrared nano-spectroscopy as a valuable tool for characterizing nanoconfined materials, with implications for nanomaterials and nanodevices.