Efficient blue luminescence of Mg3(BO3)F3:Eu2+ phosphor with peculiar 4f65d1→4f7(8S7/2) transition

Eu2+-doped Mg3(BO3)F3 phosphors were synthesized by solid-state reaction. The structural refinement, the luminescence and decay curves were investigated. The phosphor presents a broad emission band assigned to 4f65d→4f7(8S7/2) transitions in blue range, which was overlapped with the peculiar 4f7(6P7/2)→4f7(8S7/2) transitions even at room temperature. In addition, the 4f7(6P7/2)→4f7(8S7/2) transition presents extremely strong intensity compared with the peculiar 4f7(6P7/2)→4f7(8S7/2) transitions. The decay properties and the thermal activation energy (ΔE) were reported. It shows high activation energy of 0.71 eV on temperature quenching. The maximum absolute quantum efficiency (QE) was measured to be 83% under UV light. The phosphor could deserve further investigations because of its peculiar spectral characteristics for basic studies and excellent application performances.