Laminar Flow-Optimized Confined Geometry Assistant Solution Growth of Large-Sized CsPbBr₃ Single Crystals for High-Sensitivity X-ray Detection

The CsPbBr3 crystal grown by the solution method is regarded as an attractive and cost-effective material for radiation detection. However, approaching large-size, high-quality CsPbBr3 single crystals is restricted by mass nucleation and an unstable growth interface. Here, the confined geometry assisted solution method is employed to obtain high-quality CsPbBr3 single crystals with dimensions up to 17 × 17 × 2 mm3. High yield growth of CsPbBr3 seed crystals is achieved by adopting 2-bromopropionic acid (2-BPA) in the precursor, which expands the metastable zone twice and reduces nucleation. The crystal growth environment, simulated with a specific laminar flow model, reveals the uniform concentration distribution is realized by suitable forced convection velocity, thereby substantially enhancing the stability of the crystal growth interface. The resulting CsPbBr3 single crystal exhibits low trap density states of 2.27 × 109 cm–3, leading to a high hole mobility of 377.63 cm2 V–1 s–1. Finally, a high sensitivity of 1.6 × 105 μC Gyair–1 cm–2 is realized under 50 kVp X-rays at 500 V cm–1. These results promote the application of large-sized CsPbBr3 single crystals in X-ray radiation detection as well as the reference and guidance for the growth of other perovskite single crystals.