Stable and Lead‐Free Perovskite Hemispherical Photodetector for Vivid Fourier Imaging

Abstract The filterless single‐pixel imaging technology is anticipated to hold tremendous competitiveness in diverse imaging applications. Nevertheless, achieving single‐pixel color imaging without a filter remains a formidable challenge. Here a lead‐free perovskite hemispherical photodetector is reported for filterless single‐pixel color imaging. Through passivating the active vacancy and antisite defects with functional chemical groups, the trap density of the perovskite film can be dramatically reduced to half of the pristine one, which results in a stable device with 0.69 nA standard deviation (SD) of the current fluctuations for over 10 000 s. The exceptional stability and remarkable low light response capability of passivated lead‐free perovskite devices ensure reliable and repeated distinguishment to high‐frequency color information of Fourier patterns. High‐resolution color imaging with 256 × 256 pixels can be achieved by integrating the Bayer template with Fourier patterns and designing a corresponding color restoration algorithm. Notably, its imaging quality surpasses commercial silicon photomultiplier tubes (SiPMs) under low light intensities or high‐temperature conditions as demonstrated by the larger signal‐to‐noise ratio (SNR). This work presents a novel approach for applying perovskite photodetectors in single‐pixel color imaging, propelling the advancement of filterless color imaging technology.