Theoretical spectra identification and fluorescent properties of reddish orange Sm-doped BaTiO 3 phosphors

Abstract The reddish orange Sm3+-doped tetragonal perovskite BaTiO3 (BTO) phosphors for white LEDs were synthesized by the simple solid state reaction method. These phosphors, which can be effectively excited by the near ultraviolet light 409 nm (6P3/2 (Γ7) → 6H5/2 (Γ7)), produces the emitted reddish orange light peaks locate at about 561 nm, 595 nm and 643 nm originated from the transitions of 4G5/2 (Γ7) → 6H5/2 (Γ7), 4G5/2 (Γ7) → 6H7/2 (Γ7) and 4G5/2 (Γ7) → 6H9/2 (Γ7). Moreover, in order to calculate the fluorescent spectra of these phosphors, the complete 2002 × 2002 energy matrix was successfully constructed by an effective operator Hamiltonian including the free ion and crystal field interactions. Sixteen experimental fluorescent spectra in visible light range for Sm3+ ion at the tetragonal (C4v) Ba2+ site of BTO crystal, firstly, were accurately and quantitatively indentified from a complete diagonalization (of energy matrix) method (CDM) through only five crystal field parameters. The fitting values are very close to the experimental results, evidently proving the capability of CDM to investigate the luminescent phosphors alike in kind for w-LEDs.