Advanced SnO₂ Thin Films: Stability and Sensitivity in CO Detection.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Semiconductor sensors are crucial for detecting toxic gases like carbon monoxide (CO).
• Tin dioxide (SnO2) based sensors are widely used but often suffer from stability issues.
• Modifying SnO2 films with specific dopants and catalysts can enhance their performance and durability.

Purpose of the Study:

• To investigate the characteristics of SnO2-based semiconductor sensors modified with antimony (Sb), dysprosium (Dy), and silver (Ag) impurities.
• To evaluate the effect of dispersed Platinum/Palladium (Pt/Pd) catalysts on sensor performance for carbon monoxide (CO) detection.
• To understand the impact of film composition on sensor stability during prolonged CO exposure.

Main Methods:

• Synthesis of Sn-Sb-O, Sn-Sb-Dy-O, and Sn-Sb-Dy-Ag-O powders via sol-gel method.
• Fabrication of thin films using RF magnetron sputtering from synthesized targets.
• Characterization of film morphology, elemental/chemical composition, and electrical/gas-sensitive properties.
• Analysis of sensor degradation mechanisms under prolonged CO exposure.

Main Results:

• Film composition significantly influenced nanocrystallite size, distribution, porosity, and defects.
• Pt/Pd/SnO2:0.5 at.% Sb film exhibited enhanced stability and CO sensing.
• The optimized film showed a response of G1/G0 = 2-2.5 to 100 ppm CO.

Conclusions:

• Optimized doping and catalyst deposition on SnO2 films can significantly improve CO sensor stability and performance.
• Understanding degradation mechanisms is key to developing robust gas sensors.
• The developed Pt/Pd/SnO2:Sb sensor demonstrates potential for reliable CO monitoring.