Monolithically and in situ integrated PbS infrared imagers

Image sensors are critical components in artificial intelligence^1-3, yet conventional approaches bond detector arrays to readout integrated circuits (ROICs), a process that increases complexity and cost⁴. The ideal alternative-growing the detector directly on the ROIC from solution using raw materials-has remained elusive owing to the difficulty in achieving electronic-grade films through a ROIC-compatible process^5,6. Here, inspired by biomineralization principles⁷, we demonstrate monolithic in situ integration (MISI) of high-performance lead sulfide (PbS) photodetectors on ROICs by means of a room-temperature aqueous process. By regulating Pb-OH complexation and suppressing environmental perturbations, we achieve quasi-single-crystalline PbS films with excellent electronic properties (carrier density approximately 2 × 10¹⁵ cm^-3, mobility 124 cm² V^-1 s^-1) and wafer-scale, pixel-level uniformity. Through antimony doping, the resulting photodiodes exhibit a record specific detectivity of 4.4 × 10¹¹ Jones at 2.5 µm, surpassing commercial InGaAs detectors⁸. We further fabricate a 640 × 512-pixel focal-plane array that captures clear infrared images and also integrate devices directly onto flexible ROICs. This solution-based MISI approach offers a scalable and transformative route for advanced optoelectronics and sensors.