LAUSR

Abstract Sm3+ ions doped Na4CaSi3O9 and Sm3+-Eu3+ co-doped Na4CaSi3O9 novel phosphors were prepared via conventional solid-state reaction method. The structure, photoluminescence (PL) properties and thermostability of samples were investigated in detail. Rietveld refinement and XRD patterns are in good agreement with the structure of Na4CaSi3O9. The phosphors can be effectively excited by 405 nm irradiation to produce light emission. Under the excitation of 405 nm irradiation, the Na4CaSi3O9: Sm3+ phosphors show three broadband emission centered at about 564 nm, 603 nm and 650 nm due to the 4G5/2→6HJ (J = 5/2,7/2,9/2) forbidden transition of Sm3+ ions and the Sm3+-Eu3+ co-doped Na4CaSi3O9 phosphors show yellow broadband emission centered at about 564 nm and an orange-red emission band at 592 nm and 613 nm, due to the 4G5/2 → 6H5/2 transition of Sm3+ ions and the 5D0→7F1, 5D0→7F2 transition of Eu3+ ions, respectively. The energy transfer mechanism between Sm3+ and Eu3+ ions is electric dipole-electric dipole interaction. The temperature-dependent luminescent properties of Na4CaSi3O9:Sm3+, Eu3+ ions are measures from 30 °C to 210 °C, and the results show that the luminous intensity of sample at 150 °C is up to 80% of that at room temperature, which indicate that the phosphor has good thermal stability. The above results show that this series of phosphors will have potential applications in near-UV excited white LEDs.