The characterization and mechanism of energy transfer in Na2Mg(SO4)2: Ce phosphor co-doped by Dy, Mn and Tb

The phase formation of the compound Na2Mg(SO4)(2) Prepared by a wet chemical method was confirmed by the X-ray powder diffraction (XRD) pattern. Photoluminescence (PL) of Na2Mg(SO4)(2): Ce3+ shows strong emission at 322 nm, and this phosphor is also efficient for Ce3+ -> Dy3+ and Ce3+ -> Mn2+ energy transfers. The Dy3+ emission by Ce3+ -> Dy3+ under UV wavelength is peaking at 475 nm and 572 nm for an excitation of 254 nm due to F-4(9/2) -> H-6(15/2) and H-6(13/2) transitions, whereas Ce3+ -> Mn2+ is peaking at 515 nm due to T-4(1) -> (6)A(1) transitions. The Tb3+ emission by Ce3+ -> Tb3+ under UV wavelength is peaking at 490, 529, 546 nm, (with a small peak at 586 nm) for the excitation of 352 nm due to D-5(4) -> F-7(J) (J=4, 5,6) transitions. The purpose of the present study is to develop and understand the photoluminescence and effect of Dy3+, Mn2+ or Tb3+ co-doping in Na2Mg(SO4)(2):Ce3+ new luminescent materials, which can be the green phosphor in many applications such as lamp phosphors. (C) 2012 Elsevier B.V. All rights reserved.