Nitrogen-Dopant-Induced Organic–Inorganic Hybrid Perovskite Crystal Growth on Carbon Nanotubes

Interfacial engineering of organic–inorganic halide perovskites in conjunction with different functional materials is anticipated to offer novel heterojunction structures with unique functionalities. Unfortunately, complex material compositions and structures of the organic–inorganic hybrid materials make it difficult to tailor a desirable intermolecular interaction at the interface. Spontaneous and highly specific nucleation of perovskite crystals, that is, methylammonium lead iodide perovskite (CH₃NH₃PbI₃, MAPbI₃) at nitrogen-doped carbon nanotube (NCNT) surfaces for the self-assembly of MAPbI₃/NCNT hybrids is reported. It is demonstrated that the lone-pair electrons of pyridinic nitrogen-dopant sites at NCNTs mediate specific interactions with the cationic component in the perovskite structure and serve as the nucleation sites via coordinate bonding formation, as supported by X-ray photoelectron spectroscopy and density functional theory calculation. The potential suitability of MAPbI₃/NCNT hybrids is presented for highly sensitive and selective NO₂ sensing layer. This work suggests a reliable self-assembly route to the molecular level hybridization of organic–inorganic halide perovskites by employing the substitutional dopant sites at graphene-based nanomaterials.