Abstract : In article number 2001534, Liang Shen and co‐workers demonstrate a sensitive and stable Sn‐Pb perovskite photodetector, employing phenethylammonium iodide to complete defects passivation aiming the top and bottom of films. The double‐sided surface passivation engineering can promote the grain growth, reduce the density of trap states and improve surface hydrophobicity. Finally, it realizes infrared up‐conversion application for visualization.