Excited-state absorption ofEu2+-doped materials

Abstract

We have investigated the excited-state absorption spectra of four ${\mathrm{Eu}}^{2+}$-doped materials: ${\mathrm{CaF}}_2$, ${\mathrm{SrF}}_2$, ${\mathrm{SrCl}}_2$, and ${\mathrm{LiCaAlF}}_6$. The excited-state absorption in the emission region of each material is similar in nature to that previously observed for ${\mathrm{CaF}}_2$, and is suggested to arise from a 5d→ (conduction band) transition. An electrostatic model for the onset of this type of transition is successful in predicting trends among different hosts.