Synthesis and quantum yield investigations of the Sr$_{1-x-y}$Pr$_x$Yb$_y$F$_{2+x+y}$ luminophores for photonics

Single-phase praseodymium- and ytterbium-doped strontium fluoride solid solutions were prepared by co-precipitation from aqueous nitrate solutions followed by annealing at 600$^\circ$C. Based on EDX analysis, the content of rare-earth elements in solid phase is slightly higher rather than in initial aqueous solution. All the characteristic praseodymium and ytterbium luminescent bands were present. The most intense luminescence in 800–1100 nm range was registered in SrF$_2$: Pr (0.1 mol.%):Yb (10.0 mol.%) solid solution. Using the integrating sphere, the values of the quantum yield were estimated. The maximum quantum yield was 1.1 % for Sr$_{0.9495}$Pr$_{0.0005}$Yb$_{0.05}$F$_{2.0505}$ solid solution.