Stable and Bright Commercial CsPbBr₃ Quantum Dot-Resin Layers for Apparent X-ray Imaging Screen

CsPbBr₃ quantum dots (QDs) have recently gained much interest due to their excellent optical and scintillation properties and their potential for X-ray imaging applications. In this study, we blended CsPbBr₃ QDs with resin at different QD concentrations to achieve thick films and to protect the CsPbBr₃ QDs from environmental moisture. Then, their scintillation properties are investigated and compared to the traditional commercial scintillators, CsI:Tl microcolumns, and Gadox layers. The CsPbBr₃ QD-resin sheets show a high light yield of up to 21 500 photons/MeV at room temperature and a relatively small variation in light yield across a wide temperature range. In addition, the CsPbBr₃ QD-resin sheets feature a small scintillation afterglow. The CsPbBr₃ QD-resin sheets show a negligible trap density for the concentration below 50% weight, indicating that traps might arise from the aggregation of the QDs. The CsPbBr₃ QD-resin sheets are also very stable at low irradiation intensities and relatively stable at higher intensities, with higher CsPbBr₃ QD concentrations being more stable. Gamma-ray-excited-time-resolved emission measurements at 662 keV showed that the CsPbBr₃ QD-resin sheets have an average scintillation decay time between 108 and 176 ns, which are still 10 000 and 6000 times faster than CsI:Tl and Gadox, respectively. Imaging tests show that the CsPbBr₃ QD-resin sheets have a mean transfer function of 50% at 2 lp/mm and 20% at 4 lp/mm, comparable to that of commercial Gadox layers. This feature makes CsPbBr₃ QD-resin sheets a good candidate for the low-cost, flexible X-ray imaging screens and γ-ray applications.