Uniform square-like BaFBr:Eu²⁺ microplates: Controlled synthesis and photoluminescence properties

Uniform square-like BaFBr:Eu²⁺ microplates were successfully fabricated via a simple water/oil emulsion method. Various characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Scanning electron microscopy (SEM) and Transition electron microscopy (TEM) were employed to examine the phase, size, morphology, and structure of the products. It was found that the morphology and size of products were strongly dependent on the reaction parameters, such as the ratio of reactants, the reaction time and the reaction temperature. The length and thickness of these square-like BaFBr:Eu²⁺ microplates can be tuned by adjusting the reaction time and temperature. Well-dispersed cuboctahedron and corner cut cuboid-like BaFBr:Eu²⁺ particles were produced when the reaction temperature was increased above 60 °C. A possible formation mechanism of the products was discussed based on the time and temperature-dependent experimental results. The optical properties were characterized by photoluminescence (PL) spectroscopy as well as kinetic decay. Eu²⁺-doped dependent luminescent intensity was investigated in detail. The prepared BaFBr:Eu²⁺ phosphors are considered promising materials for fluorescent applications.