Lead-Free Perovskite Photodetectors for Fast Fourier Single-Detector Imaging

In the pursuit of high-resolution imaging, the expense of conventional silicon photodiode arrays poses a significant challenge. To address this issue, we present a novel imaging approach using a single-detector camera based on a fast Fourier transform (FFT) technique. Our system uses an optimized single Cs3Bi2Br9 photodetector (PD) as a light receiver, achieving a high-resolution 256 × 256-pixel image within 130 s with a low sampling rate of 3.8% and surpassing that of other perovskite imagers. By double-side interfacial engineering, an optimized CuxO/Cs3Bi2Br9/PCBM/BCP (CCPB) PD exhibits significant enhancement in the response speed and on/off ratio by 9333 and 503 times, respectively. These improvements are attributed to the synergistic effects of the ultrathin CuOx interfacial layer and the spin-coated BCP layer, which form well-matched energy-band alignments with perovskites. Our findings suggest that the double-sided interface engineering strategy can be extended to other high-exciton binding energy Bi-based perovskites and their applications, potentially revolutionizing the field of digital imaging by providing a cost-effective alternative to traditional high-resolution sensors.