Materials design of vertically coupled plasmonic arrays.

Area of Science:

• Plasmonics and Nanophotonics
• Materials Science
• Optics and Photonics

Background:

• Plasmonic metasurfaces offer significant potential in life science, optics, and catalysis.
• Industrial adoption is hindered by high-throughput nanofabrication challenges.
• Block copolymer templating presents a viable solution for creating nanoscale patterns.

Purpose of the Study:

• Investigate the optical properties of quasi-Babinet complementary plasmonic metasurfaces.
• Explore the impact of geometric dimensions, materials, and substrate refractive index.
• Assess the suitability of these structures for plasmon-enhanced photocatalysis.

Main Methods:

• Finite-difference time-domain (FDTD) simulations were employed.
• Analysis of quasi-Babinet complementary arrays with nanopillar supports and metal disks.
• Systematic variation of critical geometric parameters, metals (Au, Ag, Cu, Al, Ni, Pd), and substrate refractive index (n=1.4–3.4).

Main Results:

• Demonstrated strong vertical plasmonic coupling in structures with small separation distances.
• Observed tunable extraordinary optical transmission.
• Achieved large electric near-field enhancements, highly dependent on material and geometry.
• Identified tunable optical properties and significant near-field enhancements.

Conclusions:

• Quasi-Babinet complementary plasmonic metasurfaces exhibit tunable optical properties and strong near-field enhancements.
• These structures are promising for applications in catalysis and advanced optical devices.
• The simulated designs offer a pathway towards scalable nanofabrication for industrial use.