Ultrafast optical nanoscopy of carrier dynamics in silicon nanowires

TL;DR

This paper introduces a pump-probe optical nanoscopy technique capable of imaging ultrafast carrier dynamics in silicon nanowires with nanometer spatial and picosecond temporal resolution, advancing nanoscale semiconductor characterization.

Contribution

It develops a novel optical nanoscopy method combining experiments with a point-dipole model to resolve size-dependent carrier lifetimes and map decay times at sub-50 nm resolution.

Findings

Resolved size-dependent carrier lifetimes in silicon nanowires

Achieved sub-50 nm spatial resolution in carrier decay mapping

Enabled ultrafast carrier kinetics imaging at the nanoscale

Abstract

Carrier distribution and dynamics in semiconductor materials often govern their physical properties that are critical to functionalities and performance in industrial applications. The continued miniaturization of electronic and photonic devices calls for tools to probe carrier behavior in semiconductors simultaneously at the picosecond time and nanometer length scales. Here, we report pump-probe optical nanoscopy in the visible-near-infrared spectral region to characterize the carrier dynamics in silicon nanostructures. By coupling experiments with the point-dipole model, we resolve the size-dependent photoexcited carrier lifetime in individual silicon nanowires. We further demonstrate local carrier decay time mapping in silicon nanostructures with a sub-50 nm spatial resolution. Our study enables the nanoimaging of ultrafast carrier kinetics, which will find promising applications in the future design of a broad range of electronic, photonic, and optoelectronic devices.