Ultrafast Self-powered Near-infrared Photodetectors and Imaging Array Based on Tin-lead Mixed Perovskites

Tin-lead（Sn-Pb）mixed perovskites are extensively investigated in near-infrared（NIR）photodetectors （PDs）owing to their excellent photoelectric performance. However，achieving high-performance Sn-Pb mixed PDs remains challenging，primarily because of the rapid crystallization and the susceptibility of Sn²⁺ to oxidation. To ad⁃ dress these issues，this study introduces the multifunctional molecules 2，3-difluorobenzenamine（DBM）to modulate the crystallization of Sn-Pb mixed perovskites and retard the oxidation of Sn²⁺，thereby significantly enhancing film quality. Compared with the pristine film，Sn-Pb mixed perovskite films modulated by DBM molecules exhibit a high⁃ ly homogeneous morphology，reduced roughness and defect density. The self-powered NIR PDs fabricated with the improved films have a spectral response range from 300 nm to 1 100 nm，a peak responsivity of 0. 51 A·W⁻¹，a spe⁃ cific detectivity as high as 2. 46 × 10¹¹ Jones within the NIR region（780 nm to 1 100 nm），a linear dynamic range ex⁃ ceeding 152 dB，and ultrafast rise/fall time of 123/464 ns. Thanks to the outstanding performance of PDs，the fabri⁃ cated 5 × 5 PDs array demonstrates superior imaging ability in the NIR region up to 980 nm. This work advances the development of Sn-Pb mixed perovskites for NIR detection and paves the way for their commercialization.