Understanding Metal-Semiconductor Plasmonic Resonance Coupling through Surface-Enhanced Raman Scattering

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Previous research on plasmon-induced charge transfer (PICT) in metal/semiconductor heterostructures primarily focused on noble metal surface plasmon resonance (SPR).
• Limited understanding exists regarding the synergistic effects of plasmonic coupling between noble metals and semiconductors.

Purpose of the Study:

• To investigate the plasmonic coupling between noble metal (Ag) and semiconductor (W18O49) nanostructures.
• To explore the resulting coupled-plasmon-induced charge transfer (CPCT) mechanism.
• To demonstrate the enhancement of charge transfer (CT) and surface-enhanced Raman scattering (SERS) signals.

Main Methods:

• Fabrication of W18O49/Ag heterostructures.
• Characterization of surface plasmon resonance (SPR) absorption.
• Utilizing surface-enhanced Raman scattering (SERS) to probe interfacial interactions and charge transfer.

Main Results:

• Observed broad and strong SPR absorption in the visible range due to coupled SPR of Ag nanoparticles (NPs) and W18O49 nanowires (NWs).
• Demonstrated that coupled SPR significantly enhances internal charge transfer (CT) within the heterostructure.
• Showcased enhanced SERS signals attributed to the CPCT mechanism.

Conclusions:

• Established a novel coupled-plasmon-induced charge transfer mechanism.
• Highlighted the importance of plasmonic coupling between noble metals and semiconductors for enhanced CT and SERS.
• Provided new insights into plasmonic effects and interfacial charge transfer in heterostructures.