Mg2+、Al3+离子增强SrTiO3:Pr3+荧光体发光性能的研究

采用溶胶凝胶法成功制备了SrTiO3:Pr3+、SrTiO3:Pr3+, Mg2+及SrTiO3:Pr3+,Al3+荧光粉.通过XRD、PL谱及第一性原理计算对样品的晶体结构、光谱特性及发光增强机制进行了研究.研究结果表明:共掺杂后,SrTiO3:Pr3+荧光粉为单一组成的SrTiO3立方相,主发射锋位于617 nm,对应于Pr3+离子的1D2→3H4跃迁发射.SrTiO3:Pr3+,Mg2+ 及SrTiO3:Pr3+, Al3+荧光粉的发光强度分别是SrTiO3:Pr3+荧光粉发光强度的7倍和2倍,但主要发光机制没有改变.Mulliken布局分析表明,Mg2+、Al3+离子的掺入使SrTiO3:Pr3+荧光粉中Ti-O及Pr-O键的化学键增强、键长变短,SrTiO3:Pr3+基质向Pr3+离子发光中心的能量传递效率提高,导致SrTiO3:Pr3+,Mg2+ 及SrTiO3:Pr3+,Al3+荧光粉的发光效率提高.

Enhanced Luminescence for SrTiO3:Pr3+ Phosphors with the Addition of Mg2+ and Al3+ Ions

Al~(3+) and Mg~(2+)-doped SrTiO_3:Pr~(3+) phosphors are synthesized by a new sol-gel method and the mechanism on the enhancement of red luminescence intensity of SrTiO_3:Pr~(3+) by Al~(3+) and Mg~(2+) additions are investigated. From the photoluminescence (PL) spectra, X-ray diffraction patterns and Mulliken population analysis, it is speculated that one of the origins of the enhancement is the intensified Pr-O and Ti-O bonds by addition of Al~(3+) and Mg~(2+) in SrTiO_3:Pr~(3+). Because the Pr-O and Ti-O bonds are intensified and the corresponding bond lengths are reduced by addition of Al~(3+) and Mg~(2+) in SrTiO_3:Pr~(3+), the host to activator energy transfer efficiency is improved, leading to the enhancement of luminescence efficiency of SrTiO_3:Pr~(3+). And the fundamental excited mechanism in SrTiO_3:Pr~(3+) is not changed by addition of Al~(3+) and Mg~(2+).