(669f) Quantum Dot Doped Lead Halide Perovskites for Ionizing Radiation Detection

High performance scintillators are essential in the fields of medical imaging, security, high energy physics, and many others. Lead halide perovskites are attractive materials for ionizing radiation detection due to their high X-ray absorption, intrinsic defect tolerance, and high charge carrier mobility. Current scintillator technologies are expensive, typically grown as single crystals at high temperatures, whereas lead halide perovskites are solution processible at low temperatures and are capable of being manufactured as large-area devices via scalable, low-cost fabrication methods. Using solution-based techniques, we synthesize infrared-bandgap PbS quantum dot doped MAPbBr₃ scintillators that leverage the exceptional optoelectronic properties of lead halide perovskites and the high radiative efficiency of quantum dots for radiation detection. The perovskite matrix attenuates all X-rays with energies up to 40 keV within 2mm of material followed by efficient transfer of carriers to quantum dot nanomaterials for NIR emission. The large Stokes shift of the composite material prevents reabsorption of scintillated photons to intensify light output. The dependence of scintillation light output on QD loading (0.01% to 1.0%) is demonstrated, and we achieve a maximum light yield of 37,000 ph/MeV at room temperature. Emission wavelength was tuned from 1100 nm to 1350 nm by varying QD size and loading. Using scalable methods that can accommodate large photon absorption lengths of ionizing radiation, our work provides a significant step toward the implementation of lead halide perovskite technology as cost-effective and efficient scintillators.