Radioluminescence and photoluminescence characterization of Eu and Tb doped barium stannate phosphor ceramics

Abstract In this paper, we report on structural and optical properties of terbium and europium doped barium stannate phosphors (BaSnO 3 ) synthesised by conventional solid state reaction method. We have studied those materials by using X-ray diffraction (XRD), radioluminescence (RL) and photoluminescence (PL) techniques. XRD patterns confirm that the BaSnO 3 sintered at 1400 °C exhibit orthorhombic structure and that the Tb 3+ and Eu 3+ substitution of Ba 2+ does not change the structure of the BaSnO 3 host. The optical emission spectrum is characterized a broad band centered at 897 nm (1.38 eV), with a high-energy tail approximately 750 nm from the host lattice. Other emission signals that are characteristic of the 3 + oxidation state of rare earth elements were generated by Eu and Tb doping. Luminescence measurements show that the series of emission states 5 D 4  →  7 F 6 , 5 D 4  →  7 F 5 , 5 D 4  →  7 F 4 and 5 D 4  →  7 F 3 corresponding to the typical 4f → 4f infra-configuration forbidden transitions of Tb 3+ are appeared and the major emission peak at 540 nm is due to 5 D 4  →  7 F 5 transitions of Tb 3+ . On the other hand, the emission spectrum of Eu doped BaSnO 3 phosphor exhibits a series of emission bands, which are attributed to the 5 D 0  →  7 F j ( j  = 0–4) transitions of Eu 3+ ions. The dominant emission of Eu 3+  corresponding to the electric dipole transition  5 D 0  →  7 F 2  is located at 613 nm. The sharp emission properties exhibited demonstrate that the BaSnO 3 is a suitable host for rare-earth ion doped phosphor material. This work clearly confirms the unusual near infrared (NIR) PL discovered by H. Mizoguchi et al. in BaSnO 3 at room temperature.