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A series of barium pyrophosphate Ba2P2O7 (BPO) phosphors doped with Ce3+ or Tb3+ ions is synthesized via a co-precipitation method under reducing atmosphere. The phase structures, photoluminescence (PL) properties, and thermal stabilities of the samples are characterized by using powder x-ray diffraction (PXRD) and PL spectra. The emission colors of samples can be tuned from blue (0.1544, 0.0310) to green (0.2302, 0.4229) by changing the doping concentrations of Tb3+ under ultraviolet excitation. The energy transfer mechanism between Ce3+ and Tb3+ in the BPO is dipole–dipole interaction with a critical distance of 25.86 Ĺ and an energy transfer efficiency of about 85%, which are determined through the PL spectrum and the decay curve. Moreover, the Ce3+/Tb3+ co-doped sample has good thermal stability for temperature quenching, and the emission intensity at 423 K is maintained at 95% measured at 298 K. The above results show that the BPO:Ce3+, Tb3+ can serve as a promising candidate of green emitting phosphor for solid-state lighting. [ABSTRACT FROM AUTHOR]

Uniform orange-to-red spherical phosphors of Sr2 P2 O7: Ce3+, Mn2+ have been synthesized by the co-precipitation method and characterized by X-ray powder diffraction, scanning electron microscopy, and photoluminescence spectroscopy. The results indicate that the morphology, size, and photoluminescence properties of Sr2 P2 O7: Ce3+, Mn2+ phosphors can be effectively controlled by the reaction and the sintering temperatures. Energy transfer from Ce3+ to Mn2+ in Sr2 P2 O7 phosphor was observed from photoluminescence spectra of Sr2 P2 O7: Ce3+, Sr2 P2 O7: Mn2+, and Sr2 P2 O7: Ce3+, Mn2+. Moreover, based on a self-assembly process, a possible formation mechanism for the spherical phosphors is proposed. The uniform phosphor spheres obtained in this work exhibit great potential for high-resolution display devices such as light emitting diodes. [ABSTRACT FROM AUTHOR]