High-Detectivity Near-infrared Tin-Lead Perovskite Photodetectors for Beacon Light Detection

Mixed tin-lead perovskite is regarded as prospective candidates for next-generation near-infrared photodetectors due to its low cost and wide spectral response. However, Sn²⁺-induced oxidation and rapid crystallization exacerbate non-radiative recombination. Herein, multifunctional 2-Aminoacetamide hydrochloride has been introduced to achieve crystallization regulation and buried interface passivation in tin-lead perovskite device. It passivates the uncoordinated Pb²⁺/Sn²⁺ and reduces trap states at the buried interface. The synergistic effects of 2-Aminoacetamide hydrochloride lowers noise current in the device, realizing responsivity of 0.56 A/W and high specific detectivity of 8.9×10¹² Jones at 910 nm. With the large field-of-view degree, the 2-Aminoacetamide hydrochloride-treated photodetector is firstly applied in the 850nm beacon light system, achieving a communication rate of 23.05 Mbps, and enabling accurate signal restoration at low transmit power. This work expands the application of high-detectivity tin-lead perovskite photodetectors in the free space optical communication.