Theoretical predictions for hot-carrier generation from surface plasmon decay

Area of Science:

• Physics
• Materials Science
• Chemistry

Background:

• Surface plasmon decay into hot carriers is key for photocatalysis, energy conversion, and photodetection.
• A complete theoretical understanding of hot-carrier generation in real materials is lacking.

Purpose of the Study:

• To theoretically predict hot electron and hole distributions from plasmon decay before relaxation.
• To investigate the influence of electronic band structure on carrier properties.

Main Methods:

• Utilized a quantized plasmon model incorporating detailed electronic structure.
• Calculated prompt energy and momentum-direction distributions of excited carriers.

Main Results:

• Carrier energy distributions depend on the metal's band structure: Au and Cu yield hotter holes, while Ag and Al show more balanced distributions.
• Hot carrier momentum distributions are anisotropic, influenced by plasmon polarization (Al) or crystal orientation (noble metals).
• Intraband transitions in thin films can affect carrier distributions (e.g., hotter electrons in Au), but interband transitions remain dominant.

Conclusions:

• The electronic band structure critically dictates hot carrier generation from plasmon decay.
• Anisotropic momentum distributions offer pathways for directional control in plasmonic applications.
• Understanding these distributions is vital for advancing plasmon-enhanced technologies.