Highly sensitive all-silicon plasmonic metasurface for CO₂ detection applications

Area of Science:

• Nanotechnology
• Materials Science
• Sensor Technology

Background:

• Accurate carbon dioxide (CO2) detection is crucial across clinical, environmental, biological, and industrial fields.
• Surface plasmon polariton (SPP) resonant sensors are valuable for nanoscale biosensing.
• SPP dispersion is limited by metal characteristics, necessitating new sensor designs.

Purpose of the Study:

• To introduce a highly sensitive silicon (Si) grating-based plasmonic sensor for CO2 gas detection.
• To design a sensor utilizing a metal-air interface and a metal-dielectric-metal (MDM) structure.
• To leverage silicon's CMOS compatibility and fabrication ease for practical applications.

Main Methods:

• Proposed a silicon grating sensor with doped silicon (D-Si) metallic layers and Si/Si3N4 dielectric layers.
• Operated the sensor at a metal-air interface within the infrared (IR) range (12-14 µm).
• Employed finite difference time domain (FDTD) simulations to analyze resonant reflection spectra and non-Hermitian eigenmode space.

Main Results:

• The proposed metasurface plasmonic sensor demonstrated high sensitivity for detecting minute changes in refractive index.
• The sensor structure exhibited high sensitivity in the 12-14 µm IR wavelength range.
• Simulations confirmed the sensor's capability for gas detection applications.

Conclusions:

• The developed silicon-based metasurface plasmonic sensor offers a promising platform for accurate CO2 gas detection.
• The sensor's design leverages silicon's advantages for potential integration into existing technologies.
• This research contributes to advancements in gas sensing technologies for various critical applications.