Photostimulated luminescence in BaFBr:Eu2+, AM(AM=Li+, Na+, K+, Cs+) phosphors

BaFBr:Eu2+, AM(AM=Li+, Na+, K+, Cs+) phosphors co-doped with Eu2+ and alkali metal ions (AM=Li+, Na+, K+, Cs+) as an activator were prepared, and the effect of kind and concentration of the alkali metal ions on the spectra and the relative intensity of the photostimulated luminescence(PSL) of the prepared phosphors have been studied. The PSL intensity is increased by doping Na+, K+, or Cs+ ions in BaFBr:Eu2+, but the PSL intensity is decreased by doping Li+ ion. The optimal concentration of activator were 0.5 mol% EuF3, 4.0 mol% NaF, 1.5 mol% KF and 7.0 mol% CsF. The PSL intensity of BaFBr:Eu2+, Li+, BaFBr:Eu2+, Na+, BaFBr:Eu2+, K+ and BaFBr:Eu2+, Cs+ phosphors was about 0.5, 1.7, 1.8 and 2.3 times stronger than that of the BaFBr:Eu2+, respectively. The emission spectra of PSL of BaFBr:Eu2+, AM and BaFBr:Eu2+ phosphors are located in the range of 360∼430 nm, peaking at 390 nm, and the emission spectra of photoluminescence(PL) of these samples were identical to that of PSL. The PSL in these samples is belived to be the 4f65d → 4f7 transition of Eu2+ in the phosphors. The dose dependence of the phosphors was shown linear in the range of 0.5 mGy ∼ 10 Gy. Fading characteristics of the phosphors tend to decline by doped alkali metal ions