A series of tunable emission phosphors of Sm3+, Eu3+ and Mn2+ doped Ba3Tb(PO4)3: luminescence and energy transfer†
Abstract
A series of activator Sm3+, Eu3+, Mn2+ ion doped Ba3Tb(PO4)3 phosphors with tunable emitting color were synthesized via the high temperature solid state method. X-ray diffraction, luminescence and fluorescent decay curves were used to characterize the phosphors. The obtained powder crystallizes as a cubic unit cell with the space group Ī43d. Under 377 nm excitation of Tb3+, Ba3Tb(PO4)3:Sm3+ not only presents 5D4–7F6–3 of Tb3+ emission lines but also 4G5/2–6H5/2–9/2 of Sm3+ orange emission lines, Ba3Tb(PO4)3:Eu3+ contains the emission lines of Tb3+ and Eu3+ (5D0–7F1–4), and Ba3Tb(PO4)3:Mn2+ exhibits the emission lines of Tb3+ and 4T1–6A1 orange emission band of Mn2+. In addition, the intensities of the red or orange-red emission can be enhanced by tuning the Sm3+, Eu3+ and Mn2+ contents. The intense emission intensities of Sm3+, Eu3+ and Mn2+ ions are attributed to the efficient energy transfer from Tb3+ to Sm3+, Eu3+ and Mn2+ ions, respectively, which have been justified through the luminescence spectra and fluorescence decay dynamics. The energy transfer mechanism was demonstrated to be the electric dipole–dipole interaction. For Ba3Tb(PO4)3:Sm3+, Ba3Tb(PO4)3:Eu3+ and Ba3Tb(PO4)3:Mn2+, the best quantum efficiencies are 41.6%, 70.3% and 49.8%, respectively. The properties of the phosphors indicate that they may have potential application in UV-pumped white light emitting diodes.