Effect of Eu3+ contents on structure and luminescence properties of Na3Bi2-x(PO4)3:xEu3+ and Na3Bi1-x(PO4)2:xEu3+ phosphors

A series of Na3Bi2-x(PO4)(3):xEu(3+) and Na3Bi1-x(PO4)(2):xEu(3+) phosphors were successfully synthesized by solid-state method. The structure and luminescence properties were carefully investigated. The excitation spectra presented an obvious excitation band, and the peak was located at 396 nm, which matched well with the popular emissions from near-UV light-emitting diode chips. With the phase of Na3Bi2-x(PO4)(3):xEu(3+) changing to that of Na3Bi1-x(PO4)(2):xEu(3+), the intensity of magnetic dipole transition (D-5(0) -> F-1) at 598 nm became stronger than that of electric dipole transition (D-5(0) -> F-7(2)) at 621 nm. Under 396 nm excitation, the chromaticity coordinates and the decay curves of the entitled phosphors were also investigated. Based on all experiments without concentration quenching, we could control the luminescence intensity of the material by adjusting the doping amount of the active ions. All results indicated that Na3Bi2-x(PO4)(3):xEu(3+) and Na3Bi1-x(PO4)(2):xEu(3+) phosphors have potential application as red phosphors in near UV chip-based white light emitting diodes.