Outstanding surface plasmon resonance performance enabled by templated oxide gratings.

Area of Science:

• Materials Science
• Nanotechnology
• Plasmonics

Background:

• Surface Plasmon Resonance (SPR) is a powerful optical sensing technique.
• Developing cost-effective and high-performance SPR substrates is crucial for widespread application.
• Existing fabrication methods can be complex and expensive.

Purpose of the Study:

• To develop a simple, scalable, and cost-effective method for fabricating plasmonic gratings.
• To investigate the impact of thermal annealing on the plasmonic properties of these gratings.
• To evaluate the potential of these gratings for sensing applications.

Main Methods:

• Soft-lithography-based templating using discarded DVDs.
• Fabrication of gold-covered titania and zirconia gratings.
• Systematic investigation using experimental techniques (SEM, XRD) and finite-difference time-domain (FDTD) simulations.
• Analysis of surface plasmon resonance (SPR) sensitivity and figure of merit (FOM).

Main Results:

• Achieved high SPR sensitivity (up to ~940 nm/RIU) and FOM (up to 62.5).
• Thermal annealing increased SPR sensitivity but slightly decreased FOM.
• Annealing led to larger oxide crystal domains and smoother surfaces, affecting SPR properties.
• FDTD simulations confirmed the influence of structural deformation on SPR characteristics.

Conclusions:

• The DVD-templated plasmonic gratings offer excellent SPR performance.
• Thermal annealing can tune SPR properties, with trade-offs in sensitivity and FOM.
• The high performance and thermal stability make these gratings promising for sensing, including in situ catalysis monitoring.