Synthesis and photoluminescence properties of Ln3+ (Ln3+= Sm3+/Eu3+) doped Na2NbAlO5 phosphors

摘要： A series of Ln3+ (Ln3+=Sm3+/Eu3+) ions doped Na2NbAlO5 phosphors have been synthesized by solid-state method. Sm3+ and Eu3+ ion doped phosphors are characterized by SEM, XRD, EDX, photoluminescence, decay and thermal stability profiles. The Ln3+-doped samples are consistent with the pure Na2NbAlO5 phase which were analyzed by the X-ray diffraction result. SEM results showed the homogeneous aggregates and particles size of Sm3+ (0.6-0.9μm) and Eu3+ (0.2-0.3μm) doped Na2NbAlO5. From EDX diagram, the samples are consisted of Na, Nb, Al, O and Sm ,or Eu elements.With the introduction of Eu3+ ions, the decay curves of Sm3+ decreases monotonically, which supports the occurrence of the energy transfer from Sm3+ to Eu3+ in Na2NbAlO5 host. The fluorescence lifetime decreases with increasing temperature . The energy transfer mechanisms of Sm3+ and Eu3+ doped Na2NbAlO5 have been investigated and can be derived to be electric dipole-dipole and diopole-quadrupole interactions, respectively. In addition, the temperature-dependent emission spectra of Sm3+/Eu3+ doped Na2NbAlO5 phosphors possess superior thermal stability. Under the ultraviolet light, the prepared Na2-xNbAlO5: xLn3+ (Ln3+= Sm3+/Eu3+) phosphors show the characteristic orange (Sm3+), red (Eu3+) emissions respectively. The obtained results suggest that the new Na2NbAlO5:xLn3+ (Ln3+= Sm3+/Eu3+) phosphors are promising candidates for white light-emitting diodes.