Real-time visualization of plasmonic nanoparticle growth dynamics by high-speed atomic force microscopy.

Area of Science:

• Nanophotonics and Plasmonics
• Materials Science
• Surface Science

Background:

• Plasmonic nanoparticles are crucial in nanophotonics due to their light-field enhancement properties.
• Understanding nanoparticle growth dynamics is key for controlling their optical properties and geometry.
• Conventional imaging techniques cannot capture rapid nanoparticle growth.

Purpose of the Study:

• To demonstrate in situ real-time observation of silver nanoparticle (AgNP) growth dynamics at the single-particle level.
• To establish high-speed atomic force microscopy (HS-AFM) as a platform for visualizing plasmonic nanoparticle growth.
• To investigate the influence of laser intensity on AgNP nucleation and growth.

Main Methods:

• Utilized a photoreduction method for controlled AgNP formation via laser irradiation.
• Integrated a stand-alone tip-scan HS-AFM with an optical setup for simultaneous photoreduction and imaging.
• Captured real-time movies of AgNP nucleation and growth at the single-particle level.

Main Results:

• Successfully visualized the nucleation and growth dynamics of AgNPs in real-time at the single-particle level.
• Quantitative analysis revealed significant particle-to-particle variations in growth dynamics.
• Observed intensity-dependent growth rates and the interplay between nucleation and growth at different laser intensities.

Conclusions:

• HS-AFM provides a novel platform for in situ visualization of plasmonic nanoparticle growth.
• This technique offers unprecedented insights into nanoparticle growth mechanisms and control.
• The findings will advance research in plasmonics, nanophotonics, and materials science.