Effect of the doping of Al3+ ions on up-conversion luminescent performance of ZnGa2O4:Yb3+,Er3+ Phosphors

Abstract

Al3+ doped ZnGa2O4:Yb3+,Er3+ powder phosphors with different Al3+ doping content were synthesized by solid-state method with subsequent thermal treatment at 1300 ℃. The morphology, structural characterization and up-conversion luminescent properties of as-prepared samples were investigated by scanning electron microscope (SEM), x-ray diffraction (XRD) and LSP920 spectrofluorometer under the excitation of a 980 nm laser with different power density. In brief, all samples have good crystallinity and consist of long rods with width of 600–900 nm and length of 1–3 µm. Under the 980 nm excitation, all phosphors can generate strong green emission at 524 nm, 549 nm (attributed to 2H11/2→ 4I15/2 transition, 4S3/2→4I15/2 transition of Er3+), red emission at 659 nm (corresponding to 4F9/2→4I15/2 transition of Er3+) and slight blue emission at 410 nm (attributed to 2H9/2→4I15/2 transition of Er3+). By contrast, the up-conversion efficiency and intensity raises with the doping of Al3+ ions. Accordingly, the doping of Al3+ ions has no effect on up-conversion emission peaks, but improve the up-conversion efficiency and intensity of phosphors.