Synthesis process and luminescence properties of Tm3+ in AWO4 (A = Ca, Sr, Ba) blue phosphors

AWO(4):Tm3+ (A = Ca, Sr and Ba) blue phosphors were prepared via a mild and facile hydrothermal route. X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence excitation and emission spectra and decay curve were used to characterize the AWO(4):Tm3+ phosphors. By analyzing the excitation and emission spectra of AWO(4):Tm and undoped AWO(4) samples, the result indicates that there exists the energy transfer from the WO42- group to the Tm3+ ion only in CaWO4:Tm phosphor. The luminescence decay curves from the D-1(2) state of Tm3+ in AWO(4) phosphors show bi-exponential characteristics when excited directly to the D-1(2) state, implying that there exist two luminescence centers in AWO(4):Tm phosphors. Because AWO(4):Tm3+ phosphors exhibit intensive blue emission and high color purity under UV excitation, it is considered to be a new promising blue phosphor for field emission display application. (C) 2009 Elsevier B.V. All rights reserved.