Interferometric Near-field Fano Spectroscopy of Single Halide Perovskite Nanoparticles.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39609946.
- Also identified by DOI 10.1021/acs.nanolett.4c04491 and PMC identifier 11638946.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Semiconducting halide perovskite nanoparticles support Mie-type resonances that confine light on the nanoscale in localized modes with well-defined spatial field profiles yet unknown near-field dynamics. We introduce an interferometric scattering-type near-field microscopy technique to probe the local electric field dynamics at the surface of a single MAPbI<sub>3</sub> nanoparticle. The amplitude and phase of the coherent light scattering from such modes are probed in a broad spectral range and with high spatial resolution. In the spectral domain, we uncover a Fano resonance with a 2π phase jump. In the near-field dynamics, this Fano resonance gives rise to a destructive interference dip after a few femtoseconds. Mie theory suggests that the interference between electric quadrupole and magnetic dipole modes of the particle, with spectra affected by resonant interband absorption of MAPbI<sub>3</sub>, lies at the origin of this effect. Our results open up a new approach for probing local near-field dynamics of single nanoparticles.