Facile hydrothermal synthesis of rare earth hydroxycarbonate phosphors for high-performance warm white LEDs

The traditional synthesis of inorganic phosphors often requires complex procedures, including precursor preparation and high-temperature treatment. In contrast, this study introduces a simplified hydrothermal precipitation approach for fabricating europium/terbium hydroxycarbonates (Eu₂(OH)_x(CO₃)_y(NO₃)_(6−x−2y)·nH₂O and analogous Tb compound). The synthesized materials demonstrate high thermal stability, with high quenching activation energies (E_a(Eu) = 0.283 eV, E_a(Tb) = 0.221 eV). When applied in white LED devices, these phosphors demonstrate warm white light emission with a color rendering index (CRI) reaching R_a = 84.0 and correlated color temperature (CCT) of 3865 K, making them promising for lighting applications.