Enhanced Photoluminescence Quantum Yield of Metal Halide Perovskite Microcrystals for Multiple Optoelectronic Applications

Abstract Recently, metal 1halide perovskites have shown compelling optoelectronic properties for both light‐emitting devices and scintillation of ionizing radiation. However, conventional lead‐based metal halide perovskites are still suffering from poor material stability and relatively low X‐ray light yield. This work reports cadmium‐based all‐inorganic metal halides and systematically investigates the influence of the metal ion incorporation on the optoelectronic properties. This work introduces the bi‐metal ion incorporation strategy and successfully enhances the photoluminescence quantum yield (98.9%), improves thermal stability, and extends the photoluminescence spectra, which show great potential for white light emission. In addition, the photoluminescent decay is also modulated with single metal ion incorporation, the charge carrier lifetime is successfully reduced to less than 1 µs, and the high luminescent efficiency and X‐ray light yield (41 000 photons MeV −1 ) are maintained. Then, these fast scintillators are demonstrated for high‐speed light communication and sensitive X‐ray detection and imaging.