Hydrothermal growth and characterization of large Rb2SnBr6 double perovskite crystals: a promising semiconductor material for photocatalysis and optoelectronics

Abstract

In this study, we present the growth of large (millimeter- and centimeter-scale) crystals of Rb₂SnBr₆ double perovskite via a hydrothermal process. The crystals and powders were successfully synthesized, yielding light-yellow products, and subjected to comprehensive characterization using powder and single crystal X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS) point analysis, and UV-Vis diffuse reflectance spectroscopy. Previously, methods such as solution growth, evaporation, and gel techniques have been employed to synthesize Rb₂SnBr₆. However, none of these approaches have successfully yielded large crystals on the millimeter- or centimeter-scale. Our experimental results reveal that Rb₂SnBr₆ is a semiconductor with a bandgap of 2.97 eV. This wide bandgap not only suggests high stability and low defect levels but also positions Rb₂SnBr₆ as a highly promising candidate for advanced applications in photocatalysis, photovoltaics, and optoelectronics. The ability to grow large-sized crystals with such favorable electronic properties highlights the material's potential for integration into scalable technologies, paving the way for further research and development in energy conversion and optoelectronic devices.