InSe-Based Sensors and Related Sensing Systems for NO₂ Gas/Temperature Monitoring

Area of Science:

• Materials Science
• Nanoscience
• Environmental Science

Background:

• High-sensitivity, multiparameter sensing is crucial for environmental monitoring and electronics.
• Current sensing platforms face challenges in integrating precise, rapid, and stable detection of hazardous gases and temperature in a single miniaturized device.
• Need for advanced sensors capable of detecting pollutants like nitrogen dioxide (NO2) at parts per billion levels.

Purpose of the Study:

• To develop a novel, miniaturized sensor for simultaneous, high-sensitivity detection of hazardous gases and temperature.
• To investigate the sensing mechanism of two-dimensional (2D) indium selenide (InSe) for nitrogen dioxide (NO2) detection.
• To integrate the developed sensor into a portable intelligent monitoring system for practical applications.

Main Methods:

• Fabrication of a novel sensor utilizing two-dimensional (2D) indium selenide (InSe).
• First-principles density functional theory (DFT) calculations to elucidate the layer-dependent NO2 adsorption mechanism on InSe.
• Experimental validation of the sensor's dual-mode performance for NO2 gas and temperature sensing.
• Integration of the sensor into a portable intelligent monitoring system with signal acquisition, processing, and alarm functionalities.

Main Results:

• The 2D InSe sensor demonstrated exceptional dual-mode performance.
• Achieved a 103.40% response to 2 parts per million (ppm) of NO2 with high sensitivity.
• Successfully detected temperature over a broad range (25-150 °C) with high sensitivity.
• The integrated portable system provided reliable signal acquisition, processing, and alarm functions.

Conclusions:

• The developed 2D InSe sensor offers a promising platform for high-sensitivity, multiparameter sensing.
• The sensor effectively detects both NO2 gas and temperature, addressing limitations of existing technologies.
• The integrated bifunctional platform represents a significant advancement in miniaturized sensing for environmental monitoring and electronics.