Highly responsive and selective ozone sensor based on Ga doped ZnS-ZnO composite sprayed films.

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Ozone gas poses significant risks to human health, safety, and the environment.
• Developing highly sensitive and selective ozone detection materials is critical for monitoring and mitigation efforts.

Purpose of the Study:

• To synthesize and investigate gallium-doped zinc sulfide (ZnS) and ZnS-ZnO films for ozone sensing applications.
• To optimize gallium doping concentration for enhanced ozone detection performance.

Main Methods:

• Thin films of Ga-doped ZnS and ZnS-ZnO were prepared using the spray pyrolysis technique.
• Films were annealed at 400 °C for two hours.
• Ozone sensing properties were evaluated by measuring sensor resistance across various ozone concentrations (30-120 ppb) at elevated temperatures.

Main Results:

• Ozone sensor performance demonstrated a clear dependence on gallium doping concentration.
• The optimal gallium doping level was found to be 4%.
• The optimized sensor exhibited a sensitivity of 4.5 ppb⁻¹ at 260 °C, with a response of 150 to 30 ppb ozone, alongside good selectivity and rapid response times.

Conclusions:

• Gallium-doped ZnS films are promising materials for developing highly sensitive and efficient ozone gas sensors.
• The spray pyrolysis method is effective for fabricating such sensing materials.
• Further research into optimizing these materials could lead to improved environmental and health monitoring systems.