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

TL;DR

This study uses a two-color UV + IR transient photoluminescence technique to investigate impurity-trapped excitons and electron traps in CaF$_2$:Yb$^{2+}$ and SrF$_2$:Yb$^{2+}$ crystals, revealing insights into their internal energy levels and trap liberation.

Contribution

It introduces a novel application of transient photoluminescence enhancement to probe excitons and electron traps in fluoride crystals doped with ytterbium.

Findings

Identified changes in exciton energy levels.

Demonstrated electron trap liberation upon IR excitation.

Provided detailed insights into impurity-trapped excitons.

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.