Plasmon-induced hot carriers in metallic nanoparticles

Area of Science:

• Plasmonics
• Nanotechnology
• Materials Science
• Quantum Mechanics

Background:

• Plasmon-induced hot carrier generation is crucial for photocatalysis, photodetection, and solar energy harvesting.
• A comprehensive theoretical model for hot carrier generation is currently lacking despite experimental interest.

Purpose of the Study:

• To develop a theoretical model for plasmon-induced hot carrier generation.
• To apply the model to spherical silver nanoparticles and nanoshells.
• To understand the factors influencing hot carrier production and energy distribution.

Main Methods:

• Developed a theoretical model describing conduction electrons as free particles in a finite spherical potential well.
• Calculated hot carrier production using Fermi's golden rule.
• Investigated the influence of many-body interactions, particle size, and hot carrier lifetime.

Main Results:

• Hot carrier generation rate closely follows the plasmon's spectral profile.
• Particle size and hot carrier lifetime are key determinants of production rate and energy distribution.
• Larger sizes and shorter lifetimes yield higher rates but lower energies; vice versa for smaller sizes and longer lifetimes.

Conclusions:

• The theoretical model provides fundamental insights into plasmon-induced hot carrier generation.
• Results offer guidance for optimizing hot carrier generation efficiency in plasmonic nanostructures.
• Introduced a figure of merit to quantify the efficiency of high-energy carrier generation per plasmon.