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Ba0.65Sr0.35TiO3(BST) nanocrystals doped with different concentrations of Er3+ 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 Er3+ 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 Er3+ 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 Er3+ ions, and discussed the mechanism underlying the process.
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 Er3 + 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 each of 2H9 / 2, 4I15 / 2, 2H11 / 2, 4I15 / 2, and 4S3 / 2, 4I15 / 2 transitions of Er3 + . 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 E r3 + ions, and discussed the mechanism underlying the process.