Growth and characterization of CsCu2I3 single crystal for X-ray detection with a modified Bridgman method

Lead-free copper halide CsCu 2 I 3 crystal is a potential detector material for high-energy rays because of its wide band gap (3.54 eV), large relative molecular mass , strong absorption of high-energy rays, and low hygroscopicity in the air environment. In this study, a single crystal of CsCu 2 I 3 with 27 mm in diameter and 55 mm in length, the largest reported size, was successfully grown using a modified Bridgman method . It has a high degree of transparency and the transmittance is more than 90 % in the range of 4∼22 μm. An Au/CsCu 2 I 3 SC/Au detector was fabricated and tested, showing a resistivity of 1.08 × 10 11 Ω cm. The X-ray responsivity of CsCu 2 I 3 single crystals was investigated using a corresponding high-energy ray detector. The device exhibited a fast response time (<0.1 s), a high switching ratio (180), and a response sensitivity of 77.61 μC·Gy air −1 ·cm −1 under an electric field strength of 10 V mm −1 . The successful growth of such a large CsCu 2 I 3 single crystal demonstrates the potential for producing high-quality single crystals, which are essential for practical applications. CsCu 2 I 3 single crystal, grown to a record size using a modified Bridgman method , shows high transparency and excellent X-ray detection performance, highlighting its potential as a high-energy ray detector material. • Largest reported size of CsCu 2 I 3 crystal grown by the modified Bridgman method. • Confirmed excellent transmittance of the grown CsCu 2 I 3 single crystal. • Demonstrated strong stability of the grown CsCu 2 I 3 single crystal. • X-ray response sensitivity is comparable to crystals grown by the solution method.