Impurity-trapped excitons and electron traps in CaF${}_2$:Yb${}^{2+}$ and SrF${}_2$:Yb${}^{2+}$ probed by transient photoluminescence enhancement

Abstract

CaF${}_2$:Yb${}^{2+}$ and SrF${}_2$:Yb${}^{2+}$ crystals have been investigated by a two-color UV + IR transient photoluminescence enhancement technique. The enhancement gives information about both changes in internal energy levels of the excitons and liberation of electrons from traps in the crystals.

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