Au double nanopillars with nanogap for plasmonic sensor

Area of Science:

• Plasmonics
• Nanotechnology
• Materials Science

Background:

• Plasmonic nanostructures are crucial for sensing applications.
• Achieving precise control over nanogap size is challenging but vital for enhancing optical properties.

Purpose of the Study:

• To develop a simple, precise, and wafer-scale fabrication technique for gold double nanopillar (DNP) arrays.
• To investigate the plasmonic properties and refractive index sensitivity (RIS) of these DNP arrays, particularly focusing on the effect of nanogaps.

Main Methods:

• Fabrication of Au DNP arrays through alternate lamination of gold and polymer layers on a template, followed by selective layer removal.
• Characterization of DNP arrays and measurement of their refractive index sensitivity (RIS).

Main Results:

• Successful fabrication of Au DNP arrays with controllable nanogaps (e.g., 33 nm).
• Achieved a high RIS of 1075 nm RIU(-1) for DNP arrays with 33 nm gaps.
• Demonstrated a higher sensor figure of merit compared to structures lacking nanogaps but with similar surface areas, attributed to the enhanced plasmon electromagnetic field.

Conclusions:

• The proposed fabrication technique enables precise and scalable production of Au DNP arrays.
• The nanogap structure significantly enhances plasmonic properties, leading to superior sensor performance.
• These findings offer valuable insights for developing advanced plasmonic sensors and nanogap-based applications.