Ultrafast Optical Nanoscopy of Carrier Dynamics in Silicon Nanowires

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.

Automated summary

The distribution and dynamics of carriers in semiconductor materials play a crucial role in their physical properties and performance in industrial applications. As electronic and photonic devices continue to shrink in size, there is a need for tools to study carrier behavior at picosecond time and nanometer length scales. In this study, we present pump-probe optical nanoscopy to investigate carrier dynamics in silicon nanostructures. By combining experiments with the point-dipole model, we are able to determine the size-dependent lifetime of photoexcited carriers in individual silicon nanowires. Additionally, we demonstrate the mapping of local carrier decay time in silicon nanostructures with sub-50 nm spatial resolution. This study enables the nanoimaging of ultrafast carrier kinetics and has promising applications in the design of various electronic, photonic, and optoelectronic devices.