Organic–Inorganic Gas Sensor Based on a Perovskite Nanocrystal–Conductive Polymer Hybrid

We present a novel approach for fabricating organic-inorganic hybrid gas sensors by blending perovskite nanocrystals with a conductive polymer matrix. Organic semiconductors (OSCs) hold considerable potential as sensing materials for printed organic gas sensors. However, they face challenges in terms of limited sensitivity and poor stability under ambient conditions, which hinder their development compared to inorganic-based gas sensors. To overcome these limitations, we have incorporated functional nanomaterials into the organic semiconductors. In this study, we introduce a perovskite-structured material, specifically CsPbBr₃, into the conductive polymer matrix, resulting in a significant enhancement of the gas-sensing performance of the sensors while retaining their high responsivity and response rates. Moreover, we have employed a zwitterionic polymer surface modification with a hydration treatment to further improve the adsorption of target gas molecules on the perovskite surface. Our results demonstrate that the amide group of the encapsulation polymer exhibits a strong affinity towards NO₂ gas molecules, and this affinity is enhanced upon hydration of the polymer. Additionally, the presence of perovskite materials within the semiconducting polymer layer acts as a protective barrier, effectively shielding the polymer thin film against oxidation during extended storage under ambient conditions, owing to the perovskite crystals' ability to adsorb oxidizing molecules. This approach addresses the limitations of OSCs, resulting in improved gas-sensing performance, enhanced responsivity, and increased stability, thus paving the way for practical applications in gas sensing and detection.