Photoluminescence properties of novel red-emitting NaSrBO3:Eu3+ phosphor for near-UV light-emitting diodes

A series of NaSrBO3:xEu(3+) and NaSr1-2xBO3:xEu(3+), xM(+) (M=Li, Na, K) phosphors were synthesized by the solid state reaction. The crystal structure, photoluminescence properties and concentration quenching of NaSrBO3:Eu3+ phosphors were systematically investigated. The excitation spectra indicate that the phosphors can be efficiently excited by 394 nm, which is matched well with the emission wavelength of near-UV LED chip. All the samples show the characteristic red emission of Eu3+ ions (D-5(0)-> F-7(J), J=0, 1, 2, 3 and 4). The maximum intensity of luminescence is observed at the Eu3+ concentration around x=0.11. The concentration quenching of Eu3+ in NaSrBO3:Eu3+ phosphor can be mainly attributed to quadrupole-quadrupole interaction. The relative emission intensities of Eu3+ (D-5(0)-> F-7(2)) in NaSrBO3:Eu3+ phosphors with Li+, Na+ or K+ introduced as charge compensator are significantly enhanced, and the phosphors added with K ions show the strongest emission. The emission intensities of NaSr1-2xBO3:xEu(3+), xM(+) (M=Li, Na, K) are about 1.47, 1.64 and 2.08 times than that of commercial red phosphor Y2O2S:Eu3+. These results indicate that NaSr1-2xBO3:xEu(3+), xM(+) (M=Li, Na, K) phosphors exhibit potential applications in the field of near-UV LED as an efficient red-emitting phosphors. (C) 2012 Elsevier Ltd. All rights reserved.