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 PEA0.2FA0.8SnI3 films with 2-aminopyrimidine exhibited a high responsivity of 0.4 A W-1 and a detectivity of 1.16 x 10(12 )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.