Patterning RGB Perovskite Pixels via Sequential Vapor–Solution Process for Integrated Wavelength‐Selective Photodetectors

ABSTRACT The patterning of multi‐wavelength pixel arrays remains a critical challenge as conventional solvent‐based approaches often suffer from chemical degradation, cross‐contamination, and process incompatibilities. Halide perovskites, with their high absorption coefficients, long carrier diffusion lengths, and tunable bandgaps, are promising candidates for the next‐generation high‐resolution optoelectronics if precise and damage‐free patterning can be achieved. Here, we report a two‐step hybrid patterning strategy that combines vapor‐deposited lead halides (PbX ₂ , X = I, Br, or I‐Br) with solution‐processed methylammonium halides (MAX, X = Br‐Cl), enabling precise control of MAPbX ₃ bandgaps from 1.77 to 2.48 eV without structural damage or chamber contamination. The resulting RGB perovskite pixel array exhibits sharp edges, uniform thickness (∼220 nm), and high crystallinity. Photodetectors (PDs) integrated on the array demonstrate wavelength‐selective photo responses, achieving peak external quantum efficiencies of 65%, 61%, and 50% at 658, 520, and 450 nm, respectively. Moreover, a 5 × 5 image sensor array successfully performs direct RGB imaging without the need of digital filtering, validating the intrinsic wavelength selectivity of the patterned pixels. This scalable patterning strategy provides a versatile platform for multi‐wavelength optoelectronic applications, including color‐resolved photodetectors, integrated image sensors, and neuromorphic vision systems.