Fast, Economical, and Reproducible Sensing from a 2D Si Wire Array: Accurate Characterization by Single Wire...

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Silicon (Si) is a promising material for field enhancement due to its abundance, low toxicity, and high refractive index.
• Field enhancement effects improve light-matter interactions, benefiting photocatalysis, solar cells, and sensors.
• Scalable fabrication of field enhancement materials requires cost-effectiveness, speed, reproducibility, and high enhancement factors (EF).

Purpose of the Study:

• To develop an economical and efficient fabrication method for a large-area two-dimensional silicon wire array (2D-SiWA) as a field enhancement substrate.
• To demonstrate the 2D-SiWA substrate's performance as a highly sensitive fluorescence sensor.
• To assess the reproducibility of the sensor's sensitivity across the fabricated array.

Main Methods:

• Fabrication of a two-dimensional silicon wire array (2D-SiWA) using an economical and efficient method.
• Demonstration of the 2D-SiWA as a fluorescence sensor.
• Utilization of single wire spectroscopy to evaluate sensor sensitivity and reproducibility.

Main Results:

• The 2D-SiWA substrate achieved a high fluorescence sensor sensitivity with an enhancement factor (EF) greater than 200.
• The sensor was fabricated over a large area (6.0 mm²).
• High reproducibility of sensor sensitivity was observed in both regular (97%) and mixed (87%) regions of the 2D-SiWA.

Conclusions:

• The developed fabrication method for large-area 2D-SiWA is cost-effective and rapid.
• The 2D-SiWA serves as a highly sensitive and reproducible fluorescence sensor.
• This approach offers significant advantages over traditional methods like electron beam lithography, being 50× less expensive, 20× faster, and producing 60,000× larger areas.