Patterning RGB Perovskite Pixels via Sequential Vapor-Solution Process for Integrated Wavelength-Selective Photodetectors.

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 (PbX2, X = I, Br, or I-Br) with solution-processed methylammonium halides (MAX, X = Br-Cl), enabling precise control of MAPbX3 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.