Tin (Sn)-lead (Pb) mixed halide perovskites have attracted widespread interest due to their wider response wavelength and lower toxicity than lead halide perovskites. Among the preparation methods, the two-step method more easily controls the crystallization rate and is suitable for preparing large-area perovskite devices. However, the residual low-conductivity iodide layer in the two-step method can affect carrier transport and device stability, and the different crystallization rates of Sn- and Pb-based perovskites may result in poor film quality. Therefore, Sn-Pb mixed perovskites are mainly prepared by a one-step method. Herein, a MAPb_0.5Sn_0.5I₃-based self-powered photodetector without a hole transport layer is fabricated by a two-step method. By adjusting the concentration of the ascorbic acid (AA) additive, the final perovskite film exhibited a pure phase without residues, and the optimal device exhibited a high responsivity (0.276 A W⁻¹), large specific detectivity (2.38 × 10¹² Jones), and enhanced stability. This enhancement is mainly attributed to the inhibition of Sn²⁺ oxidation, the control of crystal growth, and the sufficient reaction between organic ammonium salts and bottom halides due to the AA-induced pore structure.

锡（Sn）-铅（Pb）混合卤化物钙钛矿由于其比卤化铅钙钛矿更宽的响应波长和更低的毒性而引起了广泛的兴趣。其中，两步法更容易控制结晶速率，适合制备大面积钙钛矿器件。然而，两步法中残留的低电导率碘化物层会影响载流子传输和器件稳定性，并且Sn基和Pb基钙钛矿的不同结晶速率可能导致薄膜质量较差。因此，Sn-Pb混合钙钛矿主要采用一步法制备。本文中，通过两步法制造了基于MAPb _0.5 Sn _0.5 I ₃ 的无空穴传输层的自供电光电探测器。通过调节抗坏血酸（AA）添加剂的浓度，最终的钙钛矿薄膜呈现出无残留的纯相，并且最佳器件表现出高响应度（0.276 A W ⁻¹ ）、大比探测率（2.38 × 10 ¹² Jones），并增强了稳定性。这种增强主要归因于抑制Sn ²⁺ 氧化、控制晶体生长以及由于AA诱导的孔结构而使有机铵盐和底部卤化物之间充分反应。