Approaches for deep-ultraviolet surface plasmon resonance sensors

Area of Science:

• Optoelectronics
• Materials Science
• Nanotechnology

Background:

• Aluminum is a common material for deep-ultraviolet (DUV) surface plasmon resonance (SPR) sensors.
• The native oxide layer on aluminum degrades DUV-SPR sensor performance.
• Improving DUV-SPR sensor sensitivity and dynamic range is crucial for advanced applications.

Purpose of the Study:

• To investigate alternative plasmonic materials to aluminum for DUV-SPR sensors.
• To explore the use of gold and graphene overlayers to enhance DUV-SPR sensor performance.
• To mitigate the negative impact of native oxide layers on DUV-SPR sensing.

Main Methods:

• Simulation and analysis of DUV-SPR sensor performance with various plasmonic materials (Cr, In, Ni, Pt) and overlayers (Au, graphene).
• Comparison of sensor performance metrics such as sensitivity and dynamic range.
• Optimization of overlayer thickness and number of graphene layers.

Main Results:

• Indium-based DUV-SPR sensors demonstrated superior performance compared to other alternative metals.
• Ultrathin gold overlayers on aluminum or indium significantly improved sensitivity.
• Graphene overlayers enhanced DUV-SPR sensor characteristics, with performance dependent on the number of layers.
• Both gold and graphene overlayers expanded the refractive index sensing dynamic range, particularly for indium.

Conclusions:

• Indium is a promising alternative plasmonic material for DUV-SPR sensors.
• Gold and graphene overlayers effectively enhance DUV-SPR sensor performance and expand dynamic range.
• These strategies offer solutions to overcome the limitations of native oxide layers in DUV-SPR sensing.