Strengthening the Interactions Between Metal and Semiconductor Heterostructures via Microwave Synthesis for...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Metal-semiconductor core-shell nanostructures are promising for chemiresistor applications.
• Strong metal-semiconductor interactions (SMSIs) are crucial for enhancing device performance.

Purpose of the Study:

• To develop an effective hydrogen (H2) gas sensor using Au-In2O3 core-shell nanostructures.
• To investigate the role of SMSIs in the gas-sensing properties of these nanostructures.

Main Methods:

• Synthesis of Au-In2O3 core-shell nanostructures via a short-time microwave hydrothermal process.
• Fabrication and testing of a chemiresistor device based on the synthesized nanostructures.
• Evaluation of gas-sensing performance, including sensitivity, selectivity, and stability towards H2 gas.

Main Results:

• The Au-In2O3 sensor exhibited a high sensitivity of ~42 towards 100 ppm H2 gas at 375 °C, five times greater than In2O3 alone.
• The sensor demonstrated enhanced selectivity and long-term stability for H2 detection.
• Synergistic effects between the Au core and In2O3 shell, including Schottky heterojunctions and SMSIs, were identified as key factors.

Conclusions:

• Facile synthesis of Au-In2O3 core-shell nanoparticles with synergistic properties is achieved.
• Strong metal-semiconductor interactions significantly enhance H2 gas-sensing performance.
• This work provides insights for designing high-performance gas sensors based on core-shell nanostructures.