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 Gy_air^–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.