Optoplasmonic Effects in Highly Curved Surfaces for Catalysis, Photothermal Heating, and SERS

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Surface curvature influences light focusing and optical processes.
• Optoplasmonic properties are key for applications like SERS, photocatalysis, and photothermal conversion.
• Understanding the role of geometry in plasmonic enhancement is critical for device optimization.

Purpose of the Study:

• To investigate the effect of surface curvature on optoplasmonic properties.
• To determine the optimal curvature for enhanced plasmonic performance.
• To explore the potential of curved substrates for SERS, photocatalysis, and photothermal applications.

Main Methods:

• Fabrication of curved substrates (spheres, cylinders, cones) with radii around 5 micrometers.
• Functionalization of substrates with gold nanoparticles (Au NP) and specific reporter molecules (4-MBA, 4-NBT, FPIC).
• Characterization of optoplasmonic properties including SERS, photocatalysis, and photothermal effects.

Main Results:

• Curved surfaces, particularly spheres with a ~5 micrometer radius, significantly enhance optoplasmonic properties.
• Observed up to a 10-fold increase in SERS response and a 5-fold increase in photocatalytic conversion.
• Photonic nanojets generated by curved surfaces focus light and improve SERS collection efficiency.

Conclusions:

• Surface curvature is a critical factor in enhancing optoplasmonic performance.
• Optimal enhancement is achieved with spherical objects around a few micrometers in diameter.
• These findings enable the development of next-generation sensors, plasmonic photocatalysts, and photothermal devices.