Achieving high response of perovskite-based (MAPbI3) ammonia gas sensors at room temperature via light enhancement

Abstract

In this study, we fabricated metal halide perovskite MAPbI₃-based resistive gas sensors and investigated their performance for NH₃ gas detection under exposure to light with different wavelengths. Under light illumination, the MAPbI₃ film generates a significant number of electron–hole pairs, increasing free carriers and enhancing NH₃ gas sensing. Additionally, light illumination allows the MAPbI₃-based sensor to detect low concentrations of NH₃ and operate effectively at room temperature. The gas sensing performance under 380 nm illumination at an intensity of 100 W cm⁻² demonstrated a maximum response of 3.99 for 10 ppm of NH₃, which is 324% higher than that of the sensor without light exposure. The remarkable enhancement in sensitivity is reproducible. These findings suggest that the light-assisted MAPbI₃-based gas sensor has strong potential for gas detection at room temperature.