Dual-site hydrogen bonding in 3D hybrid halide perovskitoids towards stable and sensitive ultraviolet light detection

Abstract

Three-dimensional (3D) organic–inorganic hybrid perovskites (OIHPs) are known for excellent charge transport and large light absorption coefficients, making them promising materials for ultraviolet (UV) photodetection. However, the traditional 3D ABX₃ perovskite structure is constrained by the tolerance factor, limiting its capacity to accommodate larger A-site cations. Therefore, it is necessary to explore novel 3D perovskitoids that can incorporate larger organic cations for UV photodetection. Herein, we introduced the diamine 3-methylaminopropylamine (3-MAPA) cation into the lead-iodide framework and successfully synthesized a 3D perovskitoid compound (3-MAPA)Pb₂I₆ (MPI). By forming an extensive network of hydrogen bonds between the 3-MAPA²⁺ cations and the inorganic framework, MPI effectively suppresses ion migration, thereby achieving an ultralow dark-current drift of 8.184 × 10⁻⁸ nA cm⁻¹ s⁻¹ V⁻¹. Owing to its 3D inorganic lattice, MPI exhibits a high carrier mobility–lifetime product (μτ) of 2.613 × 10⁻³ cm² V⁻¹. These synergistic effects of extensive hydrogen bonding and the 3D lead-halide framework collectively enable stable UV photodetection under periodic 377 nm illumination with high responsivity (R ≈ 464.42 mA W⁻¹) and detectivity (D* ≈ 4.05 × 10¹² Jones). This work establishes stable UV photodetection via 3D perovskitoid compounds, expanding the candidate materials.