Eco-friendly MA₃Bi₂I₉perovskite thin films based ammonia sensor

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Organic-inorganic perovskite halides (OIPH) show promise for toxic gas detection.
• Lead toxicity in current perovskite sensors is a significant environmental concern.
• Development of lead-free, cost-effective alternatives is crucial for practical gas sensing.

Purpose of the Study:

• To synthesize and characterize methylammonium bismuth iodide (MABI) perovskite thin films for ammonia (NH3) gas sensing.
• To evaluate the performance of MABI-based sensors regarding responsivity, reversibility, response/recovery times, and stability.
• To demonstrate the feasibility of using environmentally friendly bismuth-based OIPH materials in high-performance gas sensors.

Main Methods:

• Antisolvent-assisted one-step spin coating was employed for MABI thin-film synthesis.
• Ammonia (NH3) gas sensing performance was tested at various concentrations.
• Sensor responsivity, reversibility, response/recovery times, and ambient stability were systematically analyzed.

Main Results:

• The MABI sensor demonstrated a linear relationship between responsivity and NH3 concentration.
• A maximum gas response of 24% with excellent reversibility was observed at 6 ppm NH3.
• The sensor exhibited short response (0.14 s) and recovery (8.15 s) times, along with good humidity and ambient stability over months.

Conclusions:

• Methylammonium bismuth iodide (MABI) is a viable lead-free material for high-performance ammonia gas sensors.
• The antisolvent-assisted spin coating method is effective for fabricating MABI thin films for gas sensing.
• Environmentally friendly Bi-based OIPH materials offer a promising alternative for developing sustainable and effective gas sensing technologies.