Synthesis and down-conversion luminescence investigation of CaF<inf>2</inf>:Yb:Ce powders for photonics

Abstract

© 2019 Elsevier B.V. Single-phase solid solutions based on calcium fluoride doped with ytterbium and cerium trivalent ions were synthesized by co-precipitation from aqueous solutions. According to scanning electron microscopy, the average particle size was 225 nm. Luminescence kinetics analysis has shown significant energy transfer from Ce3+ to Yb3+ under excitation at 266 nm. The lifetime of the Yb3+ luminescence in the Ce/Yb doped samples was higher in comparison to the samples having Pr/Yb double activation. At the same time, we have not been able to detect Ce3+ luminescence. Direct measurements of down-conversion Yb3+ luminescence quantum yield have been performed using an integrating sphere. The maximum quantum yield (5.6%) of ytterbium luminescence, upon 266 nm pumping, was recorded for the CaF2:Ce(0.1 mol%):Yb (10 mol%) sample.