Alloying Bismuth‐Antimony Halide Photodiodes Enable Reconfigurable Logic Gates for Multifunctional Image Processing

Abstract The novel fundamental device unit is an effective solution to decrease the complexity and volume of imaging processing tasks, positioning it as a promising building block in optoelectronic logic circuits. However, there remains a lack of innovative strategies to enable multi‐logic operation within a single device. Herein, multifunctional logic gates are achieved within an individual Cs ₃ Bi _0.6 Sb _1.4 I ₉ single crystal‐based photodiode, enabling diverse image processing tasks on this platform. The optimized Cs ₃ Bi _2‐2x Sb _2x I ₉ (× = 0, 0.3, 0.7, and 1.0) single crystals exhibit high crystal quality, tunable bandgap, and sustained photoresponse. Sb doping significantly reduces defect density and improves contact interfaces, establishing stable carrier transport channels and low‐loss charge transfer bridges. Benefiting from these modifications, Cs ₃ Bi _0.6 Sb _1.4 I ₉ single crystal‐based photodiode shows exceptional optoelectronic performance, with a switch ratio up to 8665 and a 120‐fold improvement in responsivity. Subsequently, by adopting an optical control strategy, reconfigurable switching among OR, AND, NOR, and NAND gates is achieved, and multiple image processing pathways including shape union, mask composition, and color inversion, are devised by employing these logic functions. This work not only provides an effective fabrication strategy for photodiode‐based reconfigurable logic gates, but also demonstrates its potential image processing application.