Low-temperature preparation of monodispersed Eu-doped CaTiO3 LED phosphors with controllable morphologies

Abstract

A novel solvothermal route has been developed to synthesize mondispersed and different mophologies of Eu-doped CaTiO₃ phosphors including magic-column spherical, magic-cube spherical and polyhedral shaped, using a mixture of ethylene glycol (EG) and ethylenediamine (EDA). By tuning the solvent ratio, the method exhibited excellent control over the morphology of CaTiO₃:Eu³⁺, and magic-column spherical phosphors have higher luminous intensities than magic-cube spherical and polyhedral shaped phosphors. The synthesized phosphors had higher luminous intensity and better packing properties than those obtained by a solid-state method. The phosphors showed strong red emissions, corresponding to the ⁵D₀ → ⁷F₂ (617.6 nm) transition of Eu³⁺ under near-ultraviolet excitation (398.4 nm). X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescent (PL) analyses were used to characterize the structure, morphology and luminous performance of CaTiO₃:Eu³⁺ phosphors.