Top-Seed Solution-Based Growth of Perovskite Cs3Bi2I9 Single Crystal for High Performance X-ray Detection

X-ray detection is widely used in medical imaging, safety inspection, scientific research, and so on, in which the Cs3Bi2I9 perovskite single crystal (SC) material has attracted increasing attentions for its excellent intrinsic properties (high X-ray absorption coefficient, low toxicity, high resistivity, etc.). However, existing methods for this SC growth enable low quality and high preparation cost, thus resulted in the defects of limit sensitivity, detectable dose rate, and large-scale application of the Cs3Bi2I9-based device. In this work, high-quality Cs3Bi2I9 perovskite SCs were successfully grown by the novel top-seed solution (TSS) method, which contains the advantages of constant growth rate, simple system and high yield. Due to the high quality of TSS-based Cs3Bi2I9 SC, the X-ray detector exhibited high sensitivity of 4382 μC·Gyair–1 cm–2 at 20 V mm–1 bias. Under 7.93 nGyair s–1 X-ray irradiation, the signal-to-noise ratio reached 27.9. This work presents a new strategy for the low-cost growth of high-quality Cs3Bi2I9 perovskite SC.