Gas Sensing Properties of Perovskite Decorated Graphene at Room Temperature

This paper explores the gas sensing properties of graphene nanolayers decorated with lead halide perovskite (CH₃NH₃PbBr₃) nanocrystals to detect toxic gases such as ammonia (NH₃) and nitrogen dioxide (NO₂). A chemical-sensitive semiconductor film based on graphene has been achieved, being decorated with CH₃NH₃PbBr₃ perovskite (MAPbBr₃) nanocrystals (NCs) synthesized, and characterized by several techniques, such as field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Reversible responses were obtained towards NO₂ and NH₃ at room temperature, demonstrating an enhanced sensitivity when the graphene is decorated by MAPbBr₃ NCs. Furthermore, the effect of ambient moisture was extensively studied, showing that the use of perovskite NCs in gas sensors can become a promising alternative to other gas sensitive materials, due to the protective character of graphene, resulting from its high hydrophobicity. Besides, a gas sensing mechanism is proposed to understand the effects of MAPbBr₃ sensing properties.