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*

Al3+ and Mg2+-doped SrTiO3∶Pr3+ phosphors are synthesized by a new sol-gel method and the mechanism on the enhancement of red luminescence intensity of SrTiO3∶Pr3+ by Al3+ and Mg2+ 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 Al3+ and Mg2+ in SrTiO3∶Pr3+. Because the Pr-O and Ti-O bonds are intensified and the corresponding bond lengths are reduced by addition of Al3+ and Mg2+ in SrTiO3∶Pr3+, the host to activator energy transfer efficiency is improved, leading to the enhancement of luminescence efficiency of SrTiO3∶Pr3+. And the fundamental excited mechanism in SrTiO3∶Pr3+ is not changed by addition of Al3+ and Mg2+.