Diffusion doping route to plasmonic Si/SiO nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Semiconductor nanoparticles (SNPs) are crucial for functional materials.
• Engineering SNP electronic structure requires advanced doping techniques.
• Post-synthetic doping methods like diffusion offer controlled impurity introduction.

Purpose of the Study:

• To report on the doping of silicon/silicon dioxide (Si/SiO2) SNPs using phosphorus diffusion.
• To investigate the control over impurity incorporation and distribution.
• To confirm the electrical activity and efficiency of the doping process.

Main Methods:

• Annealing Si/SiO2 SNPs in gaseous phosphorus.
• High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction for structural analysis.
• Elemental analysis (e.g., EDX) and thermopower measurements for doping characterization.

Main Results:

• Achieved doping levels up to 10% with controlled impurity incorporation via precursor vapor pressure.
• Confirmed retention of nanocrystallinity and uniform phosphorus distribution within silicon cores.
• Demonstrated electrical activity of phosphorus, with impurity activation efficiencies up to 34%.

Conclusions:

• Diffusion doping of Si/SiO2 SNPs with phosphorus is an effective post-synthetic method.
• The technique allows for precise control over doping levels and impurity distribution.
• High impurity activation efficiencies highlight the potential of this method for advanced nanosilicon-based functional materials.