Low-temperature solvent evaporation-induced growth of CsPbBr 3 single crystals for high-sensitivity X-ray detection

All-inorganic CsPbBr3 single crystals have emerged as promising candidates for high-energy radiation detectors owing to their exceptional X-ray absorption capabilities, charge transport properties, and high stability. This study uses first-principles calculations to analyze the structure, band structure, and density of states of different CsPbBr3 phases, demonstrating that the orthorhombic phase of CsPbBr3 single crystals is more suitable for X-ray detector fabrication. A low-temperature solvent evaporation-induced crystallization method was used to fabricate single crystals to prevent defect introduction during phase transitions. After the introduction of NH4SCN additives, the crystalline quality of the CsPbBr3–NH4SCN single crystals was significantly enhanced, with the μτ value and bulk resistivity increasing to 1.3 × 10−2 cm2·V−1 and 6.8 × 1010 Ω·cm, respectively. The ultimately fabricated CsPbBr3–NH4SCN single-crystal X-ray detector achieved a sensitivity level of 2,360.1 μC·Gyair−1·cm−2 and a detection limit as low as 424.1 nGyair·s−1 under an electric field of 20 V·mm−1. Overall, the experimental results provide new insights into the future fabrication of CsPbBr3 single-crystal X-ray detectors.