Broadband Detection of X‐ray, Ultraviolet, and Near‐Infrared Photons using Solution‐Processed Perovskite–Lanthanide Nanotransducers

Solution‐processed metal‐halide perovskites hold great promise in developing next‐generation low‐cost, high‐performance photodetectors. However, the weak absorption of perovskites beyond the near‐infrared spectral region posts a stringent limitation on their use for broadband photodetectors. Here, the rational design and synthesis of an upconversion nanoparticles (UCNPs)–perovskite nanotransducer are presented, namely UCNPs@mSiO2@MAPbX3 (X = Cl, Br, or I), for broadband photon detection spanning from X‐rays, UV, to NIR. It is demonstrated that, by in situ crystallization and deliberately tuning the material composition in the lanthanide core and perovskites, the nanotransducers allow for a high stability and show a wide linear response to X‐rays of various dose rates, as well as UV/NIR photons of various power densities. The findings provide an opportunity to explore the next‐generation broadband photodetectors in the field of high‐quality imaging and optoelectronic devices.