Photoluminescence-based gas sensing with MoS₂ monolayers.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Two-dimensional transition metal dichalcogenides (TMDs) offer strong light-matter interactions and high surface-to-volume ratios, making them suitable for sensing applications.
• Scalable on-chip photonic nanodevices can be developed by growing TMDs on various substrates and waveguide geometries.

Purpose of the Study:

• To develop a versatile technique for remote optical gas sensing utilizing two-dimensional TMDs.
• To investigate the potential of molybdenum disulfide (MoS2) monolayers for detecting specific gas molecules.

Main Methods:

• Gas sensing based on charge-transfer-induced photoluminescence variation upon gas molecule adsorption on monolayer TMDs.
• Utilizing inert gas purging (N2) for desorption at room temperature.
• Monitoring photoluminescence from semiconducting MoS2 monolayers grown on SiO2/Si chips for gas detection.

Main Results:

• Demonstrated detection of carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2) at 10 ppm levels.
• Achieved fast response times for gas detection.
• Density functional theory (DFT) calculations supported significant interactions between detected gases and MoS2 monolayers.

Conclusions:

• The developed technique shows promise for remote optical gas sensing applications.
• Findings suggest potential advancements in surface-sensitive bioanalytics and lab-on-a-chip sensors.
• MoS2 monolayers are effective for sensitive and rapid gas detection.