Bionic Detectors Based on Low‐Bandgap Inorganic Perovskite for Selective NIR‐I Photon Detection and Imaging

Fluorescence imaging with photodetectors (PDs) toward near‐infrared I (NIR‐I) photons (700–900 nm), the so‐called “optical window” in organisms, has provided an important path for tracing biological processes in vivo. With both excitation photons and fluorescence photons in this narrow range, a stringent requirement arises that the fluorescence signal should be efficiently differentiated for effective sensing, which cannot be fulfilled by common PDs with a broadband response such as Si‐based PDs. In this work, delicate optical microcavities are designed to develop a series of bionic PDs with selective response to NIR‐I photons, the merits of a narrowband response with a full width at half maximum (FWHM) of