Gas Sensing Properties of a Novel Indium Oxide Monolayer: A First-Principles Study

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Gas sensors are crucial for environmental monitoring and safety.
• Two-dimensional (2D) materials offer unique properties for advanced sensor applications.
• Indium Oxide (In₂O₃) is a promising semiconductor material for gas sensing.

Purpose of the Study:

• To investigate the gas sensing capabilities of a novel 2D In₂O₃ monolayer.
• To evaluate its performance for detecting hazardous and atmospheric gases.
• To explore the effect of mechanical strain on sensing properties.

Main Methods:

• First-principles investigation using density functional theory (DFT) calculations.
• Evaluation of interactions with ten hazardous gases (NH₃, NO, NO₂, SO₂, CS₂, H₂S, HCN, CCl₂O, CH₂O, CO).
• Analysis of interactions with atmospheric gases (O₂, CO₂, H₂O).
• Assessment of resistive-type and work-function-based detection mechanisms.
• Study of biaxial mechanical strain (tensile and compressive).

Main Results:

• 2D In₂O₃ monolayer shows significant conductivity modulation and work-function shifts for NO and H₂S.
• NH₃ and HCN are detected via substantial work-function alteration.
• Biaxial tensile strain enhances sensing capabilities and enables detection of NO₂, CS₂, CCl₂O, and CO.
• Compressive strain facilitates CH₂O detection through work-function modulation.

Conclusions:

• 2D In₂O₃ is a highly promising and tunable platform for next-generation gas sensors.
• The material demonstrates potential for miniaturized sensors in environmental monitoring and safety-critical applications.
• Mechanical strain offers a viable strategy to broaden the sensing range and improve selectivity.