Structure and tunable luminescence in Sm3+/Er3+ doped host-sensitized LaNbO4 phosphor by energy transfer

The pure Sm3+/Er3+ doped host-sensitized LaNbO4 phosphors were synthesized and characterized. By virtue of the Rietveld Method, crystal structure of LaNbO4:Sm3+/Er3+ were refined, with the occupation of dopants determined. The luminescence properties of Sm3+/Er3+ doped LaNbO4 phosphors were carefully measured and analyzed by diffuse reflectance spectra, ultraviolet and cathodoluminescence (CL). The energy transfer was recognized between host and doped Sm3+/Er3+ ions based on the luminescence spectra and decay lifetimes, which is dominated by electric multipolar interaction. Further, the calculated critical distance is 23.71 and 23.08 Å for Sm3+ and Er3+ doped, respectively. Moreover, the temperature sensitivity of Sm3+/Er3+ doped LaNbO4 was evaluated at the temperature ranging from 23 K to 298 K. By adjusting the concentration of Sm3+/Er3+ ions, the emission colors of LaNbO4:Sm3+ and LaNbO4:Er3+ are varied from blue to pink and from blue to cyan. These results indicate that LaNbO4:Sm3+/Er3+ phosphors can be applied in the plasma display panels (PDP) and general lighting.