Structures and luminescent properties of single-phase La5.90-xBa4+x(SiO4)6-x(PO4)xF2:0.10Ce3+ phosphors

A series of blue-emitting La5.90-xBa4+x(SiO4)(6-x)(PO4)(x)F-2:0.10Ce(3+) (x=0, 1, 2, and 3) phosphors with apatite structure were synthesized by a solid-state reaction. The crystal structure and the photoluminescence properties were investigated in detail. The crystallographic occupancy of Ce3+ in La2.90Ce0.10Ba7(SiO4)(3)(PO4)(3)F-2 and La5.90Ce0.10Ba4(SiO4)(6)F-2 were studied based on Rietveld refinements results and the crystal chemistry rules. La5.90-xBa4+x(SiO4)(6-x)(PO4)(x)F-2:0.10Ce(3+) exhibited strong blue light emission in the range of 407-414 nm with high thermal stability upon excitation at 276 nm. Besides, the activation energy E of La5.90Ce0.10Ba4(SiO4)(6)F-2 and La2.90Ce0.10Ba7(SiO4)(3)(PO4)(3)F-2 phosphors were calculated to be 0.152 and 0.177 eV. These results suggest that La5.90-xBa4+x(SiO4)(6-x)(PO4)(x)F-2:0.10Ce(3+) is a potential blue phosphor candidate for near-UV-pumped w-LEDs. (C) 2015 Elsevier B.V. All rights reserved.