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Sensors

Breakthrough in Nanotechnology: Porous Silicon Gas Sensor Detects Nitrogen Dioxide at ppm Levels

Strategic Insights

— 1 min read

Researchers from the Indian Institute of Technology Roorkee (IITR) have made a significant discovery in the field of nanotechnology, developing a highly selective and recoverable gas sensor for nitrogen dioxide (NO2) at room temperature. The sensor, based on a molybdenum diselenide (MoSe2) and tungsten disulfide (WS2) nanocomposite co-sputtered over a porous silicon substrate, demonstrates exceptional sensing properties, including a fast response/recovery time and excellent stability over 100 days.

Key Takeaways:

  • The WS2-MoSe2/PSi gas sensor exhibits a superior sensor response of 34.14 % towards 50 ppb NO2 gas at room temperature, with a fast response/recovery time of 17.67 s/41.05 s.
  • The sensor maintains its original response towards 50 ppb NO2 under high relative humidity (80 % RH) with a retention of 92.44 % of its original response.
  • The developed WS2-MoSe2/PSi sensor demonstrates a significant improvement over its pristine counterparts, with a superior sensor response and faster recovery time.
  • The porous silicon substrate substantially boosts the sensor's characteristics by providing a large surface area for the growth of nanostructured sensing film and making the sensor's surface highly hydrophobic.
  • The sensor demonstrates excellent selectivity and commendable stability, making it an ideal candidate for sensing applications in harsh and humid atmospheres.

Statistics:

  • 34.14 %: Superior sensor response of the WS2-MoSe2/PSi gas sensor towards 50 ppb NO2 gas at room temperature.
  • 17.67 s/41.05 s: Fast response/recovery time of the WS2-MoSe2/PSi gas sensor towards 50 ppb NO2 gas at room temperature.
  • 90.9 %: Retention of the sensor's original response towards 50 ppb NO2 gas over 100 days with a retention of 90.9 % at room temperature.
  • 92.44 %: Retention of the sensor's original response towards 50 ppb NO2 under high relative humidity (80 % RH).
  • 80 % RH: High relative humidity at which the sensor maintains its original response.

Sources:

  • Synergistically Integrated Ws 2 -mose 2 Nanowires Cosputtered Over Porous Silicon Towards Ppb Level No 2 Detection. Sensors and Actuators B: Chemical, 2025;441.
  • Elsevier Science Sa, PO Box 564, 1001 Lausanne, Switzerland. (Elsevier - www.elsevier.com; Sensors and Actuators B: Chemical - www.journals.elsevier.com/sensors-and-actuators-b-chemical/)
  • Ramesh Chandra, Indian Inst Technol Roorkee Iit Roorkee, Institute Instrumentation Center, Thin Film Laboratory, Roorkee 247667, India.

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