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On the phosphorescence mechanism in SrAl2O4:Eu2+ and its codoped derivatives

2007; Elsevier BV; Volume: 9; Issue: 7 Linguagem: Inglês

10.1016/j.solidstatesciences.2007.03.020

1873-3085

Frédéric Clabau, Xavier Rocquefelte, Stéphane Jobic, Philippe Deniard, Myung‐Hwan Whangbo, A. Manas Garcia, Thierry Le Mercier,

Microwave Dielectric Ceramics Synthesis

The mechanism of phosphorescence in SrAl2O4:Eu,Dy material is discussed on the basis of a thermo-activated release of electrons trapped at oxygen vacancy sites. The depths and concentration of the electron traps are strongly affected by codoping with trivalent lanthanide cations Ln3+. This finding is rationalized by comparing the ionization potentials of the dopant cation Eu2+, the codopant cation Ln3+ and the substituted cation Sr2+. Such a use of ionization potentials provides a practical guide with which the variation of the phosphorescent decay time in the codoped derivatives of SrAl2O4:Eu is predicted.