Preparation and Long Persistence Red Luminescence of M_(0.2)Ca_(0.8)TiO_3:Pr~(3+)(M=Mg~(2+), Sr~(2+), Ba~(2+), Zn~(2+))

摘要

M_(0.2)Ca_(0.8)TiO_3:Pr~(3+)(M=Mg~(2+), Sr~(2+), Ba~(2+), Zn~(2+)) long persistence red phosphors were prepared by solid state reaction. The influence of the partially replacing Ca~(2+) in CaTiO_3 with Mg~(2+), Sr~(2+), Ba~(2+), Zn~(2+) on the excitation spectra, the emission spectra unit the long persistence properties were studied. The results suggest that certain quantity of Mg~(2+), Sr~(2+), Ba~(2+), Zn~(2+) which partially replace Ca~(2+) can enhance the luminescent intensity and prolong the afterglow persistence of the samples . The intensity of M_(0.2)Ca_(0.8)TiO_3:Pr~(3+) is above ail of the samples. Take M_(0.2)Ca_(0.8)TiO_3:Pr~(3+) as the basic sample the influence of Pr~(3+) concentrations (C ( Pr~(3+))) on the long afterglow properties were also studied The results suggest that when the C(Pr~(3+)) is 0.10 percent (mol fraction) the intensity of the sample is the highest. The excitation spectra of all these samples show broad band spectra ranging from 300 approx 500 nm peaking at about 342 nm. The emission spectra also exhibit a broad band peaking at 613 nm (CaTiO_3: Pr~(3+) is 612 nm) . XRD research indicates that the crystalline phases change due to the replacement of divalent metal ions. The research on the thermoluminescence spectra of M_(0.2)Ca_(0.8)TiO_3:Pr~(3+) indicates that the peak is at 107.35 deg C and the depth of the trap energy is about 0.852 eV.