Abstract: Series of Er~(3+)/Yb~(3+) co-doped fluoro-oxide powder samples with the same composition were prepared at different sintering temperatures. One red up-converted emission band centered at 658 nm and two green up-converted emission bands centered at 539 nm,523 nm were observed under the excitation of an 980 nm semiconductor laser, which corresponded to Er~(3+) ions transitions of ~4F_(9/2)→~4I_(15/2) and ~4S_(3/2),~2H_(11/2)→~4I_(15/2), respectively. And the intensity of red emission is stronger than the green ones. It is concluded by comparing each spectra that, the shape of spectra is similar, but the intisity of emission band is obviously different from each other. The sample sintering at 800 ℃ emits the most intensive luminescence. The ratio of the intensity of red emission(658 nm) to green emission(539 nm) increases monotonously with sintering temperature changing from 600 ℃ to 1100 ℃. XRD data show that the oxidation degree of ZnF_2 has been enhanced by increasing sintering temperature, which changed the microstructure of samples. And then the microstructure influenced up-converted fluorescence properties. The relationship between upconversion intensity and pump power of samples were weasured, and the concerned upconversion processes were discussed in this paper.

Key words: up-conversion;sintering temperature;Er~(3+)/Yb~(3+);XRD