Synthesis and luminescence properties of apatite-type red-emitting Ba2La8(GeO4)6O2:Eu3+ phosphors

A new kind of apatite-type red-emitting Ba2La8(GeO4)(6)O-2:Eu3+ phosphor was prepared by high temperature solid-state method. The Rietveld analysis based on the powder diffraction data shows that Ba2La8(GeO4)(6)O-2:Eu3+ phosphors possess a pure apatite phase without any impurity. The emission spectrum of Ba2La8(GeO4)(6)O-2:Eu3+ phosphor consists of two bands, an orange emission band from 500 to 600 nm and a red emission band from 600 to 680 nm. By varying the amount of the doped europium ions from 0.02 to 0.14 mol, it is found that the luminescent properties of this rare earth phosphor are the best when the concentration of europium ion is 0.08 mol. The optimum concentration is eventually proved to be 0.08 mol. The Eu3+ doping dependent luminescence quenching can be further ascribed to dipole-quadrupole interactions. The quantum yield of Ba2La7.92(GeO4)(6)O-2:0.08Eu(3+) is 37.23%. The CIE analysis confirms a reddish emission in the near ultraviolet (n-UV) excitation. All these above properties of the phosphor can help in contribution of promoting white light-emitting diode. (C) 2021 The Authors. Published by Elsevier B.V.

Automated summary

A new red-emitting Ba2La8(GeO4)(6)O-2:Eu3+ phosphor was successfully prepared, showing pure apatite phase without impurities. The optimal luminescent properties were achieved with a doping concentration of 0.08 mol Eu3+ ions. The phosphor exhibited a reddish emission under near ultraviolet excitation, with a quantum yield of 37.23%.