Abstract High‐performance semiconductor devices capable of multiple functions are pivotal in meeting the challenges of miniaturization and integration in advanced technologies. Despite the inherent difficulties of incorporating dual functionality within a single device, a high‐performance, dual‐mode device is reported. This device integrates an ultra‐thin Al 2 O 3 passivation layer with a PbS/Si hybrid heterojunction, which can simultaneously enable optoelectronic detection and neuromorphic operation. In mode 1, the device efficiently separates photo‐generated electron‐hole pairs, exhibiting an ultra‐wide spectral response from ultraviolet (265 nm) to near‐infrared (1650 nm) wavelengths. It also reproduces high‐quality images of 256 × 256 pixels, achieving a Q ‐value as low as 0.00437 µW cm − 2 at a light intensity of 8.58 µW cm − 2 . Meanwhile, when in mode 2, the as‐assembled device with typical persistent photoconductivity (PPC) behavior can act as a neuromorphic device, which can achieve 96.5% accuracy in classifying standard digits underscoring its efficacy in temporal information processing. It is believed that the present dual‐function devices potentially advance the multifunctionality and miniaturization of chips for intelligence applications.