Flux assisted low-temperature synthesis of YAG:Yb3+,Er3+ and its optical property

Abstract

Yb3+/Er3+ co-doped polycrsytalline yttrium-aluminum garnet (YAG : Yb3+,Er3+) powders were synthesized by a flux (BaF2) assisted solid-state reaction method at low-temperature. The optimum condition of flux concentration and calcination temperature was investigated by the XRD analysis. Crystal structure and upconversion luminescent property of the synthesized YAG : Yb3+,Er3+ powder was analyzed as a function of Yb3+ concentration when concentration of Er3+ was fixed at 25.0 mol%. Under 980 nm excitation, YAG : Yb3+,Er3+ powder exhibited weak red emissions near 660 and 670 nm, and strong green UC emissions at 530 and 550 nm corresponding to the intra 4f transitions of Er3+ (F-4(9/2), H-2(11/2), S-4(3/2)) -˃ Er3+ (I-4(15/2). The Yb3+ 15 mol% doped YAG : Yb3+,Er3+ powder sample exhibited strongly shiny green emission. A possible UC mechanism for YAG : Yb3+,Er3+ depending was discussed in detail.