Long afterglow yellow luminescence from Pr^(3+) doped SrSc_(2)O_(4)

A yellow emitting long afterglow luminescence material SrSc_(2)O_(4):Pr^(3+)was successfully prepared by solid state reaction method.SrSc_(2)O_(4):Pr^(3+)phosphor shows a long afterglow luminescence peak at about 495,545,621,630 and 657 nm,respectively,corresponding to the f–f transitions of Pr^(3+).The afterglow chromaticity coordinates of SrSc_(2)O_(4):1 at%Pr^(3+)were calculated to be(0.35,0.41),indicating that the afterglow emission is close to the light of yellow region.And,the afterglow luminescence of the optimal sample doped by 1 at%Pr^(3+)can persist for over 3 h.The thermoluminescence results suggest that there are three types of traps with depth of 0.61,0.69 and 0.78 eV exiting for all the samples,which are produced by the addition of Pr^(3+)ions.The trap density of SrSc_(2)O_(4):1 at%Pr^(3+)is the maximum when the incorporation of Pr^(3+)ions reaches 1 at%,which thus results in the longest afterglow luminescence.All the results indicate that SrSc_(2)O_(4):Pr^(3+)can be a potential candidate of novel long afterglow phosphors.

Luminescent properties of Mg_(1.99)SnO_(4):0.01Mn^(2+)phosphors dopedwith Zn^(2+)

n this work,a series of Zn_(x)Mg_(1.99-x)SnO_(4):0.01Mn^(2+)(x=0,0.01,0.02,0.03,0.04)green long afterglow phosphors are prepared by high-temperature solid-phase reaction.The photoluminescence and long afterglow performance of host material doped with Zn^(2+)are investigated.The results show that the emission peak of Mn^(2+)is red-shifted by 5 nm with increasing Zn^(2+)concentration.Zn_(0.03)Mg_(1.96)SnO_(4):0.01Mn^(2+)phosphor has the strongest green luminescence intensity with the chroma-ticity coordinates of(0.0857,0.6083)under 270 nm,and Zn_(0.01)Mg_(1.98)SnO_(4):0.01Mn^(2+)phosphor has su-perior long afterglow performance with average lifetime of 102.41s.The afterglow decay and thermoluminescence curve of phosphor are used to explain the mechanism of long afterglow lumines-cence.Meanwhile,the afterglow intensity distribution of each pixel in Zn_(0.01)Mg_(1.98)SnO_(4):0.01Mn^(2+)coating samples is carried out by hyperspectral imaging,and the optimal luminescence intensity and uniformity of the sample are obtained at a phosphor/epoxy mass ratio of 0.0025.Therefore,Zn_(0.01)Mg_(1.98)SnO_(4):0.01Mn^(2+)can be a potential candidate of novel long afterglow phosphors,and hyperspectral imaging also provides new research approaches for the rational proportioning of luminescent materials.