Photoluminescence properties and thermal stability of blue-emitting Ba5 − xCl(PO4)3:xEu2 + (0.004 ≤ x ≤ 0.016) phosphors

Abstract A series of blue-emitting Ba 5 −  x Cl(PO 4 ) 3 : x Eu 2 + (0.004 ≤  x  ≤ 0.016) phosphors were synthesized by conventional high-temperature solid state reaction. The structure and photoluminescence (PL) properties of the phosphors were investigated. The as-prepared phosphors exhibit broad excitation band ranging from 250 to 420 nm, and strong asymmetric blue emission band peaking at 436 nm. The optimum concentration of Eu 2 + in the Ba 5 Cl(PO 4 ) 3 :Eu 2 + phosphor is x  = 0.01, and the concentration quenching mechanism is verified to be the combined actions of dipole-dipole interaction and radiation re-absorption mechanism. The thermal stability of Ba 5 Cl(PO 4 ) 3 :Eu 2 + was evaluated by temperature-dependent PL spectra. Compared with that of commercial BaMgAl 10 O 17 :Eu 2 + (BAM) phosphor, the Ba 5 −  x Cl(PO 4 ) 3 : x Eu 2 + phosphors exhibit similarly excellent thermal quenching property. In addition, the CIE chromaticity coordinates of Ba 5 −  x Cl(PO 4 ) 3 : x Eu 2 + (0.004 ≤  x  ≤ 0.016) were calculated to evaluate the color quality. All the results indicate that Ba 5 Cl(PO 4 ) 3 :Eu 2 + is a promising candidate phosphor for near-ultraviolet (n-UV) pumped LED.