Energy transfer, luminescence properties, and thermal stability of color tunable barium pyrophosphate phosphors*

Abstract

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 Å 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.