Two-Dimensional Indium Selenide for Sulphur Vapour Sensing Applications

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Two-dimensional (2D) materials possess a high surface-to-volume ratio, making them sensitive to surface interactions.
• Indium selenide (InSe) is a 2D material with potential applications in sensing due to its unique electronic and optical properties.

Purpose of the Study:

• To investigate the potential of micromechanically exfoliated 2D InSe nanosheets as an optical vapor sensor.
• To demonstrate the sensing capability of InSe using 2-mercaptoethanol as a model analyte.

Main Methods:

• Micromechanical exfoliation of 2D InSe nanosheets.
• Photoluminescence (PL) spectroscopy to monitor InSe before and after vapor exposure.
• Exposure of InSe to 2-mercaptoethanol vapor at varying concentrations and durations.

Main Results:

• Photoluminescence enhancement observed for short vapor exposure times, attributed to surface defect passivation.
• Photoluminescence quenching observed for longer exposure times or higher concentrations, linked to molecule diffusion into the nanosheets.
• Demonstrated the correlation between PL changes and analyte concentration/exposure time.

Conclusions:

• 2D InSe nanosheets function as effective photoluminescent vapor sensors.
• The sensing mechanism relies on surface passivation and molecule diffusion effects within the InSe nanosheets.
• InSe offers a promising platform for developing sensitive optical chemical sensors.