Preparation And Research Of Silicate Afterglow Luminescence Material

Luminescent material has long been a hot research field because of its extensiveapplication. As high performance long afterglow phosphors, silicate phosphors madeby cheap and abundance raw material SiO₂, has more chemical and thermal stability,lower sintering temperature and better compatibility to ceramics, so it is doomed tohave wide application in the near future.The paper prepares and investigates two kinds of silicate phosphors: whitelong-lasting phosphor Sr₂SiO₄: Pr and red afterglow phosphor BaMg₂Si₂O₇: Pr, Mn.They all characterized by X-ray diffract meter (XRD),scanning electron microscopy(SEM),fluorescence spectrophotometer and thermo luminescence (TL) meter. On thebasis of the results, it is reasonable to ascertain the best synthetic condition,bestconcentration of the doped ions and best quantity of the fluxing agent.The white-emitting phosphor Sr₂SiO₄: Pr³⁺ was synthesized through asolid-state reaction, and Pr³⁺ ions were the luminescence centre. It can emit whitelight under UV irradiation. Its emission spectra is composed of bluish purple (peakingat 390 nm),green (peaking at 535 nm) and red (peaking at 604 nm)light emission.They originate from the transitions of 4f→5d,³P₀→³H₅ and ¹D₂→³H₄ of Pr³⁺. Theafterglow emission spectrum is similar to the emission spectra. And the afterglow canlast over 40 minutes in darkness.The red-emitting phosphor BaMg₂Si₂O₇: Pr, Mn was synthesized through asolid-state reaction, and Mn²⁺ ions were the luminescence centre, while Pr³⁺ ions werethe co-activation. Its red-emitting originates from the transition of ⁴T₁ (⁴G)→⁶A₁(⁶S)peaking at 606nm. After UV irradiated for several minutes, the afterglow can lastmore than 50 minutes in darkness. On base of the characterization results, thefluorescence intensity and afterglow performance were improved for Pr³⁺→Mn²⁺energy transition in the BaMg₂Si₂O₇: Pr, Mn.