Transparent zinc oxide（ZnO） thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations（0.3-1.2 M） using zinc acetate dehydrate [Zn（CH_3COO）_2&...Transparent zinc oxide（ZnO） thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations（0.3-1.2 M） using zinc acetate dehydrate [Zn（CH_3COO）_2·2H_2O] as precursor and isopropanol and monoethanolamine（MEA） as solvent and stabilizer, respectively. The molar ratio of zinc acetate dehydrate to MEA is 1.0. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of solution concentration on the structural and optical properties of the ZnO thin films. The obtained results of all thin films are discussed in detail and are compared with other experimental data.展开更多
CaMoO_4：Pr^（3＋）/Yb^（3＋） powder was successfully synthesized by a facile hydrothermal method. X-ray diffraction（XRD） patterns of samples confirmed tetragonal structure and morphology and sizes were confirmed b...CaMoO_4：Pr^（3＋）/Yb^（3＋） powder was successfully synthesized by a facile hydrothermal method. X-ray diffraction（XRD） patterns of samples confirmed tetragonal structure and morphology and sizes were confirmed by scanning electron microscopy（SEM） analyses. Particles consisted of regular micro-spheres with uniform sizes, the diameter of each sphere lay in the range of 3 to 4 μm. The up-conversion photoluminescence emission and its concentration dependence were investigated under infrared excitation at 980 nm. All the UC micro-particles exhibited the typical blue, green and red emissions. Dominant blue emissions originated from ~3P_0→~3H_4 and intense red emissions originated from ~3P0→~3F_2 transitions, and they both belonged to two-photon excitation processes in CaMoO_4： Yb^（3＋）/Pr^（3＋） powder. The optimum doping concentrations of Pr^（3＋） and Yb^（3＋） for the highest UC luminescence were 0.1 mol.% and 16 mol.%, respectively. The possible up-conversion mechanisms were discussed in detail. It was found that the UC emission could be well controlled from blue to green to white color by adjusting the concentration of Pr^（3＋） ions in CaMoO_4：Pr^（3＋）/Yb^（3＋） microcrystal. So it is a candidate material for solid-state lasers, biological imaging, solar cells, and optical communications.展开更多
文摘Transparent zinc oxide（ZnO） thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations（0.3-1.2 M） using zinc acetate dehydrate [Zn（CH_3COO）_2·2H_2O] as precursor and isopropanol and monoethanolamine（MEA） as solvent and stabilizer, respectively. The molar ratio of zinc acetate dehydrate to MEA is 1.0. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of solution concentration on the structural and optical properties of the ZnO thin films. The obtained results of all thin films are discussed in detail and are compared with other experimental data.
基金Project supported by the National Science Foundation of China(11574190)the Fundamental Research Funds for the Central Universities(GK201503024)
文摘CaMoO_4：Pr^（3＋）/Yb^（3＋） powder was successfully synthesized by a facile hydrothermal method. X-ray diffraction（XRD） patterns of samples confirmed tetragonal structure and morphology and sizes were confirmed by scanning electron microscopy（SEM） analyses. Particles consisted of regular micro-spheres with uniform sizes, the diameter of each sphere lay in the range of 3 to 4 μm. The up-conversion photoluminescence emission and its concentration dependence were investigated under infrared excitation at 980 nm. All the UC micro-particles exhibited the typical blue, green and red emissions. Dominant blue emissions originated from ~3P_0→~3H_4 and intense red emissions originated from ~3P0→~3F_2 transitions, and they both belonged to two-photon excitation processes in CaMoO_4： Yb^（3＋）/Pr^（3＋） powder. The optimum doping concentrations of Pr^（3＋） and Yb^（3＋） for the highest UC luminescence were 0.1 mol.% and 16 mol.%, respectively. The possible up-conversion mechanisms were discussed in detail. It was found that the UC emission could be well controlled from blue to green to white color by adjusting the concentration of Pr^（3＋） ions in CaMoO_4：Pr^（3＋）/Yb^（3＋） microcrystal. So it is a candidate material for solid-state lasers, biological imaging, solar cells, and optical communications.
