First-principles computational visualization of localized surface plasmon resonance in gold nanoclusters

Area of Science:

• Computational physics
• Materials science
• Nanotechnology

Background:

• Localized surface plasmon resonance (LSPR) is a key optical property of metallic nanostructures.
• Understanding LSPR in gold nanoclusters is crucial for applications in optics and electronics.
• Previous first-principles calculations were limited to smaller nanocluster sizes.

Purpose of the Study:

• To investigate the cluster-size dependence of LSPR in gold nanoclusters (Aun, n = 54–1414).
• To explore photoinduced electron dynamics and optical response in unprecedentedly large gold nanoclusters.
• To elucidate the role of electron screening in LSPR phenomena.

Main Methods:

• Utilized a newly developed computational program for first-principles calculations.
• Simulated photoinduced electron dynamics in gold nanoclusters of varying sizes (up to Au1414, 3.9 nm diameter).
• Analyzed electron charge distributions and LSPR peak shifts.

Main Results:

• Demonstrated a gradual growth of LSPR with increasing gold nanocluster size.
• Observed a red shift in LSPR peaks as cluster size increased.
• Visualized collective oscillations of electron charge distributions on the nanocluster surface.
• Identified screening of conduction-like s-electron oscillations by core d-electrons.

Conclusions:

• LSPR in gold nanoclusters is strongly dependent on cluster size.
• The observed red shift and growth of LSPR are attributed to collective electron behavior.
• Core d-electrons play a significant role in screening surface plasmon oscillations.