Interferometric Near-field Fano Spectroscopy of Single Halide Perovskite Nanoparticles

Area of Science:

• Nanophotonics
• Materials Science
• Quantum Optics

Background:

• Semiconducting halide perovskite nanoparticles exhibit Mie resonances, confining light into localized modes with defined spatial profiles.
• The near-field dynamics of these localized modes remain poorly understood, hindering further applications.

Purpose of the Study:

• To investigate the local electric field dynamics at the surface of single methylammonium lead iodide (MAPbI₃) nanoparticles.
• To probe the amplitude and phase of coherent light scattering from Mie-type resonances in a broad spectral range with high spatial resolution.

Main Methods:

• Development and application of an interferometric scattering-type near-field microscopy technique.
• Analysis of coherent light scattering from single MAPbI₃ nanoparticles across a wide spectrum.

Main Results:

• Observation of a Fano resonance with a 2π phase jump in the spectral domain.
• Discovery of a destructive interference dip in near-field dynamics occurring within femtoseconds.
• Mie theory analysis suggests interference between electric quadrupole and magnetic dipole modes, influenced by MAPbI₃ interband absorption.

Conclusions:

• The study reveals complex near-field dynamics in perovskite nanoparticles, driven by Fano resonances.
• This work establishes a novel approach for investigating local near-field dynamics in single nanoparticles.
• Findings contribute to understanding light-matter interactions at the nanoscale in perovskite materials.