A highly sensitive self-powered photodetector based on pinhole-free PEA_0.2FA_0.8SnI₃ films with aminopyrimidine

Tin-based perovskite halides have emerged as promising lead-free perovskite photodetectors. However, achieving high performance is hampered by poor stability and a high density of intrinsic defects. In this study, we developed an efficient tin-based perovskite photodetector that is sensitive to visible and near-infrared light through the incorporation of 2-aminopyrimidine as an additive. Our results demonstrated that the inclusion of 2-aminopyrimidine significantly improves film morphology, reduces roughness, passivates defect states, and suppresses the oxidation of Sn²⁺. The PEA_0.2FA_0.8SnI₃ films with 2-aminopyrimidine exhibited a high responsivity of 0.4 A W^-1 and a detectivity of 1.16 × 10¹² Jones, a fast response time of 0.93 ms, and excellent operation stability after 10⁴ on/off cycles. The findings highlight the significant potential of tin-based perovskite in the development of advanced photodetectors. © 2024 The Royal Society of Chemistry.