Preparation and wide band emission characteristics of Eu2+/Eu3+ co-doped Ba3P4O13 phosphors

A series of phosphors Ba3P4O13:xEu(2+/3+) (x = 0-0.1) were synthesized in a CO reduction atmosphere at a relatively low temperature (1113 K) by the solid-phase method. Crystallization and optical properties were investigated by using powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and fluorescence spectrophotometry (PL/PLE), respectively. Under the excitation of 394 nm, the emission spectrum of the phosphor presents a broad spectrum band of Eu2+ and characteristic peaks of Eu3+ in the range of 400-750 nm, indicating the coexistence of Eu2+ and Eu3+ in the system. The occupation of Eu2+ and Eu3+ in the Ba3P4O13 matrix position was discussed by Gaussian fitting and PL spectra. The existence of energy transfer between Eu2+ -> Eu3+ in the system can be found through PL spectra under excitation of 251 nm. The emission color of the phosphor can be adjusted by changing the Eu ion doping concentration, resulting in the CIE color coordinates changing from (0.213, 0.215) blue to (0.249, 0.261) light bluish white. The results show that Ba3P4O13:Eu2+/3+ phosphors can be used as a potential single-doped single-host white light-emitting material.