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Nowadays, high performance (stability, spatial resolution, and optical yield) and multi‐functional application (low‐cost, large‐area, and flexible) are urgently needed for X‐ray detectors in national defense and medical treatment et al. Herein, self‐organizing pixelated zero‐dimensional metal halide Cs4PbBr6 based micro‐disks for low‐cost (0.0238 $ cm−2, 1/37 of CsI(Tl)), large‐area and ultra‐flexible scintillator plates are designed, prepared and applied. The theoretical model describes that the micro‐disks‐based structure being separated from others by air can reduce the transverse optical diffusion within the scintillator, especially when the optical boundary of "pixel" surface is changed by metal coating. Meanwhile, such structure also inhibits the stress generation in the crystal when bent. Further characterization points out that the fabricated scintillator plate possesses high spatial resolution (≈15.9 lp mm−1) and light yield (≈19000 ph Me V−1). Especially, the device shows excellent stability and almost no deterioration of spatial resolution after aging in various extreme environments and in extreme bending tests (folding, keeping bending for a long time). Finally, the good suitability to couple with various photoelectric devices and successful imaging demonstrations of nondestructive measurement are exhibited. It is believed that these findings provide a low‐cost and flexible scintillator preparation scheme and demonstrate a pre‐eminent design paradigm. [ABSTRACT FROM AUTHOR]

The use of metal halides promotes the development of X‐ray detectors (XDs) owing to their excellent X‐ray absorbance, electrically benign defects, and large mobility−lifetime (µτ) product. Yet the severe baseline drift, size limitation, large dark current, and mediocre stability are still waiting to be solved. Herein, high density size‐scalable Cs4PbBr6 wafer‐based XD is constructed by the hot isostatic‐pressed method for the first time. Meanwhile, different Br− vacancy (VBr) concentration‐based Cs4PbBr6 is realized. The role of VBr in electrical structure and charge transport is highlighted by density functional theory and experimental measurement. Moreover, the further study points the 0D structure endows Cs4PbBr6 with high activation energy for ionic transport (1044 meV) and bandgap (3.88 eV), which finally results in an ultra‐stable baseline and thermal stability. On the basis of efficient response (7068 µC Gyair−1 cm−2), reliable current output, ultra‐low detection limit (1.75 nGyair s−1), high spatial resolution (5.2 lp mm−1 at modulation transfer function = 0.2), fast response speed and radiation stabilities (>1000 Gyair), the high‐resolution X‐ray images under broad energy range (20–160 keV) are realized on both single‐pixel and linear scanning mode, thus holding huge potential for medical diagnosis, safety inspection, and outer space detection. [ABSTRACT FROM AUTHOR]

Zero‐dimensional Cs3Cu2Cl5 exhibits intriguing optical properties, which can meet the basic requirements of ideal scintillator application. Here, green emitter Cs3Cu2Cl5 nanosheets are successfully synthesized, and by doping with 2% potassium (K+), their photoluminescence quantum yield (70.23% to 81.39%), radioluminescence intensity, and stability are improved. Further experimental and theoretical studies point out that: (1) K+ brings the neighboring [Cu2Cl5]3− dimers groups closer, leading to lattice shrinkage and lower lattice constants; (2) such compact crystal structure results in stronger exciton–photon coupling and reduced phonon–electron coupling strength, which is beneficial to form self‐trapped excitons and enhanced luminescence; (3) lower lattice constants also induce decreased bandgap (2.58 to 2.51 eV) and increased Stokes shift (217 to 223 nm), for less self‐absorption and higher quantum efficiency. Finally, area‐controllable uniform flexible Cs3Cu2Cl5:2%K+–polystyrene film is successfully achieved with excellent X‐ray sensibility. Such flexible film shows low cost (2.8223 $/g), broadband response (20–160 keV), and high spatial resolution (5 lp mm−1) that is comparable to commercial CsI:Tl wafer. Moreover, it fits well with nonplanar surfaces for high‐quality medical and industrial flexible images applications. It is believed that this work can provide a viable tactic to enhance X‐ray detection in metal halide scintillators. [ABSTRACT FROM AUTHOR]