Ba0.65Sr0.35TiO3（BST） nanocrystals doped with different concentrations of Er^3＋ ion were fabricated using sol-gel method. The structure and morphology of these BST nanocrystals were studied using X-ray diffraction...Ba0.65Sr0.35TiO3（BST） nanocrystals doped with different concentrations of Er^3＋ ion were fabricated using sol-gel method. The structure and morphology of these BST nanocrystals were studied using X-ray diffraction（XRD）, field emission scanning electron microscopy（FESEM） and transmission electron microscopy（TEM）. The X-ray diffraction patterns of all the nanocrystals prepared in the study correspond to polycrystalline perovskite BST structure. The blue and green upconversion luminescence properties of Er^3＋ doped BST nanocrystals were investigated under excitation by a 785-nm laser. The upconversion emission bands centered at 407, 523, and 547 nm can be attributed to ^2H9/2, ^4I15/2, ^2H11/2, ^4I15/2, and ^4S3/2, 4I15/2 transitions of Er^3＋ ion, respectively. The upconversion mechanism was studied in detail, based on the laser power dependence of the upconverted emissions. In addition, we examined the dependence of the intensity of green upconverted luminescence on the doping concentration of Er^3＋ ions, and discussed the mechanism underlying the process.展开更多
基金Funded by the National Natural Science Foundation of China(No.51302075 and 11174071)the Natural Science Foundation of Hubei Province(No.2012FFB01902)the Scientifi c Research Foundation for Doctoral Program of Hubei Unviersity of Arts and Science
文摘Ba0.65Sr0.35TiO3（BST） nanocrystals doped with different concentrations of Er^3＋ ion were fabricated using sol-gel method. The structure and morphology of these BST nanocrystals were studied using X-ray diffraction（XRD）, field emission scanning electron microscopy（FESEM） and transmission electron microscopy（TEM）. The X-ray diffraction patterns of all the nanocrystals prepared in the study correspond to polycrystalline perovskite BST structure. The blue and green upconversion luminescence properties of Er^3＋ doped BST nanocrystals were investigated under excitation by a 785-nm laser. The upconversion emission bands centered at 407, 523, and 547 nm can be attributed to ^2H9/2, ^4I15/2, ^2H11/2, ^4I15/2, and ^4S3/2, 4I15/2 transitions of Er^3＋ ion, respectively. The upconversion mechanism was studied in detail, based on the laser power dependence of the upconverted emissions. In addition, we examined the dependence of the intensity of green upconverted luminescence on the doping concentration of Er^3＋ ions, and discussed the mechanism underlying the process.
