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用溶胶-凝胶法制备了不同Eu2+掺杂浓度的纳米铝酸锶长余辉发光粉体。着重研究了Eu2+对纳米发光粉体的晶体结构、基质晶格、发光特性和浓度猝灭的影响。研究发现,在SrAl2O4∶Eu,Dy发光粉体中Eu2+离子取代了Sr2+离子进入晶格,其发光是由Eu2+离子的4f65d1→4f7跃迁所产生的。确定了在SrAl2O4∶Eu,Dy发光粉体中,Eu2+离子占据两种Sr2+离子格位,形成两个发射中心(Eu1和Eu2)。两者的发射光谱由两个强度不同的发射带组成;随着Eu2+离子浓度增大,SrAl2O4∶Eu,Dy发光粉体的发射强度随之增强,直到Eu2+离子浓度超过0.03mol时,发生浓度猝灭,其发射强度开始减少。Eu2+离子在SrAl2O4∶Eu,Dy发光粉体中的浓度猝灭包括两个不同的浓度猝灭过程。随着Eu2+离子浓度增大,首先是中心Eu1向另一个中心Eu2传递能量而被猝灭,随后是发光中心Eu2发生自身的浓度猝灭;余辉衰减的测试结果证实了余辉衰减由初始的快衰减和其后的慢衰减两个过程所组成。Eu2+离子的掺杂对纳米SrAl2O4∶Eu,Dy发光体的余辉衰减时间并无太大影响,只是影响其初始发光强度。
Nanostructured strontium aluminate long afterglow luminescent powders with different Eu2 + doping concentrations were prepared by sol-gel method. The effects of Eu2 + on the crystal structure, lattice, luminescent properties and quenching of luminescence of nano-luminescent powders are emphatically studied. It is found that Sr2 + ions replace Sr2 + ions into the lattice in the SrAl2O4: Eu, Dy luminescent powders and their luminescence is caused by the 4f65d1 → 4f7 transition of Eu2 + ions. In the SrAl2O4: Eu, Dy luminescent powder, Eu2 + ions occupy two Sr2 + ion sites and form two emission centers (Eu1 and Eu2). The emission spectra of the two powders are composed of two emission bands with different intensities. With the increase of Eu2 + ion concentration, the emission intensity of SrAl2O4: Eu, Dy phosphor increases with the concentration of Eu2 + Off, its emission intensity began to decrease. The concentration quenching of Eu2 + ions in SrAl2O4: Eu, Dy luminescent powders includes two different quenching processes. With the increase of Eu2 + ion concentration, the first Eu1 energy is quenched by the energy transfer to the other Eu2, followed by the quenching of the Eu2 luminescence center concentration. The afterglow decay test results show that afterglow decays from the initial fast decay And the subsequent slow attenuation of the two processes. Eu2 + doping nano-SrAl2O4: Eu, Dy luminous body afterglow decay time does not have much effect, but affect the initial luminous intensity.