Up-Conversion Photoluminescence Reconfiguration in Silicon by Inner Microstructure Control of Hybrid...

Area of Science:

• Nanophotonics
• Materials Science
• Optical Engineering

Background:

• Hybrid metal-semiconductor nanostructures offer unique optical properties by combining plasmonic and high-refractive-index materials.
• Understanding the structure-property relationship in these systems is crucial for applications but remains challenging.

Purpose of the Study:

• To investigate the influence of internal microstructure evolution on the up-conversion white-light photoluminescence of gold-silicon hybrid nanoparticles.
• To establish a link between microstructure changes and optical property modifications.

Main Methods:

• In situ tracking of microstructural evolution using HAADF and EDS STEM techniques during thermal treatment up to 500 °C.
• Numerical simulations to analyze the relationship between the surface-area-to-volume ratio and enhancement factor spectral width.
• Experimental characterization of photoluminescence spectra after thermal treatment and laser reconfiguration.

Main Results:

• Thermal treatment caused material redistribution and reduced silicon nanograin numbers without altering nanoparticle shape.
• A near-linear dependence was found between the enhancement factor spectral width and the plasmonic component's surface-area-to-volume ratio.
• Photoluminescence spectra shrinkage of up to 42% was observed after reconfiguration via laser exposure and thermal treatment.

Conclusions:

• The internal microstructure significantly impacts the optical properties of hybrid nanostructures.
• Microstructure rearrangement offers a pathway to control and tune the photoluminescence of these systems.
• Results pave the way for developing reconfigurable silicon-based up-conversion light nanosources for integrated optics and biophotonics.