Preparation And Investigation Of Rare Earth Ions Doped Long Persistent Luminescence Materials

In the past decade, much research attention has been paid to the rare earth luminescent materials. This material has a stable luminous performance, high brightness, high efficiency, non-radioactive, good weather resistance and other characteristics. In the experiments, we have obtained sulfide and cuprate phosphors via high temperature solid state reaction method. The crystal structures and luminescence properties were analyzed. We also discuss the potential application value of the phosphors.(1)A series of Sr1-xCaxS: 2% Yb2+ phosphors were prepared via solid state reaction method under the H2 reduce atmosphere. The X-ray diffraction spectra of Sr1-xCaxS:2% Yb2+ were investigated, and the excitation and emission spectra as well as Afterglow decay curves were obtained. We have described the Luminescent mechanism of Yb2+.in lattice. The pictures of afterglow and emission color under 365 nm excitation have been taken by SLR digital cameras. Finally we have analyzed the law of development.of afterglow and the causes.(2)A series of Ba1-xCaxS: 2% Yb2+ phosphors were prepared via solid state reaction method under the H2 reduce atmosphere. The X-ray diffraction spectra of Ba1-xCaxS: 2% Yb2+ were investigated, and the excitation and emission spectra as well as Afterglow decay curves were obtained. We have described the Luminescent mechanism of Yb2+.in lattice and compared the change of emission, meanwhlie give a further discussion of afterglow.(3)Ba Gd2 Cu O5: x Er3+, y Yb3+(x=3, y=9 mol%) upconversion phosphors were prepared via solid state reaction method. The XRD shows the matrix is pure phase. Rietveld refinements were accomplished in order to obtain the detailed crystal information. Different luminescence intensities have been obtained when the sample was excited by increasing excitation power. By calculating we can confirm the involvement of 2 photons for the red and green emissions. Fixing excitation power, We can get Different luminescence spectra in different temperature. The sensor sensitivity can be calculated by fluorescence intensity ratio(FIR).