Eu^2＋在Sr4Al14O25基磷光体中能量传递行为的研究

Studies on Energy Transfer of Eu2+ Ions in the Sr4Al14O25-Based Phosohor

摘要:

合成了3种不同Eu掺杂量的Sr4Al14O25，Dy^3 发光粉体，发现当Eu掺杂量低于0．012mol时，发射光谱中存在2个主发射峰，分别位于407nm和494nm。随着Eu掺杂浓度增加，407nm发射峰逐渐消失，而494nm主发射峰增强。结合Sr4Al14O25，晶体结构和激发．发射光谱，建立了2种Eu发光中心之间的能量传递模型，对实验现象进行了合理的解释。余辉衰减曲线测试结果表明，3种磷光体试样均具有长余辉性能，尤其Sr4Al14O25：Eu0.0l2，Dy0.024试样，其余辉时间在人眼可视亮度水平可持续20h以上。

Abstract:

Three kinds of Long afterglow Sr4Al14O25: Eu2+, Dy3+ phosphor samples with various Eu2+ contents were synthesized. When the concentration of doped Eu2+ in the host was less than 0.012 mol, the emission spectra of Sr4Al14O25: Eu2+, Dy3+ has two peaks at 407 nm and 494 nm respectively, which is ascribed to two types of Eu2+ sites existing in Sr4Al14O25 matrices crystal. But the 407nm emission peak disappeared slowly with the concentration of doped Eu2+ increasing. Based on the Sr4Al14O25 crystal structure, excitation and emission spectra, the energy transfer model has been established, and a reasonable explanation was given for the experimental phenomena. In addition, the decay curves indicate that these Sr4Al14O25: Eu2+, Dy3+ phosphors have obviously a long afterglow. Especially in phosphor, the afterglow can last over 20 h in the light perception of the human eye.