PbS quantum dot retinomorphic sensors for event-based shortwave infrared imagers

Retinomorphic sensors imitate retinal processing by responding to changes in light intensity while suppressing steady photocurrent, enabling event-based imaging with reduced data volume. However, the material and architecture design of existing devices limit detectivity in the shortwave infrared (SWIR). The device integration with readout integrated circuits (ROICs) is still lacking. Here, we present zero-bias SWIR retinomorphic sensors based on solution-processed PbS quantum dot and ZnO nanoparticle layers stacked with SiO 2 or high-κ HfO 2 to form photosensitive capacitors (PCs). Light onset and offset charge and discharge the capacitor, producing transient spikes via a built-in potential that separates photocarriers. We correlate spike characteristics with carrier type, device architecture, and illumination. Integrated with a silicon ROIC array, these sensors realize SWIR event-driven imaging of moving objects with static-background suppression, achieving ∼30 Hz operation and ∼80% data reduction versus cameras using photodiodes. This work advances PC device architecture designs, elucidates their mechanisms, and achieves large-area retinomorphic imagers.