Seeded growth and optical properties of large-size perovskite Cs3Cu2I5 crystals

All-inorganic lead-free Cs 3 Cu 2 I 5 crystals exhibit remarkable structural stability and have shown significant potential for applications in scintillators and luminescent materials. In this study, Cs 3 Cu 2 I 5 single crystal at the centimeter scale has been successfully grown with the hydroiodic acid (HI) solution by the bottom seeded solution growth (BSSG) method. The X-ray diffraction (XRD) and TG-DSC results have confirmed its excellent environmental stability. The crystal has shown prominent UV absorption peaks at 270 nm and 352 nm, with a bandgap of 2.49 eV. The as-grown crystal exhibits blue luminescence under ultraviolet irradiation, with the main PL spectral peak positioned at 452 nm and corresponding CIE color coordinates of (0.15, 0.11). Overall, the growth of large-size Cs 3 Cu 2 I 5 crystals, coupled with their optical properties, suggests potential applications in the field of luminescent materials.