Micro-and nanocrystals cubic-phase SrF2:Yb3+/Er3+ upconversion luminescence phosphors were synthesized via a facile hydro-thermal route in the presence of different surfactants.The samples were characterized with X-ra...Micro-and nanocrystals cubic-phase SrF2:Yb3+/Er3+ upconversion luminescence phosphors were synthesized via a facile hydro-thermal route in the presence of different surfactants.The samples were characterized with X-ray diffraction (XRD),Fourier transform infra-red spectra (FT-IR),scanning electron microscopy (SEM),transmission electron microscopy (TEM),and upconversion emission spectra.As-prepared products showed a variety of morphologies,such as cubic-shaped microcrystal,hierarchical structure microspheres,spheri-cal-shaped nanocrystals and nanosheets.The intrinsic structural feature of cubic-phase SrF2 and two important external factors,namely,the surfactants in the reaction solution and fluoride sources,were responsible for shape determination of SrF2:Yb3+/Er3+.The possible formation mechanisms for products with various architectures were presented.A systematic study on the photoluminescence of Yb3+/Er3+-doped SrF2 samples with cubic shape,microspheres,spherical and nanosheets shapes showed that the optical properties of these products were strongly dependent on their morphologies and size.展开更多
Nearly monodisperse,regular-shaped and well oil-dispersible tetragonal BaYF5:0.2Yb3+/0.02Er3+ nanocrystals(NCs) were synthesized in water-ethanol-oleic acid-sodium oleate system.The as-obtained NCs exhibited bright up...Nearly monodisperse,regular-shaped and well oil-dispersible tetragonal BaYF5:0.2Yb3+/0.02Er3+ nanocrystals(NCs) were synthesized in water-ethanol-oleic acid-sodium oleate system.The as-obtained NCs exhibited bright upconversion(UC) fluorescence under the 980 nm excitation.Blue(2H9/2-4I15/2),green((2H11/2,4S3/2)-4I15/2) and red(4F9/2-4I15/2) transitions were observed.The results indicated that the relative intensity of green to red increased gradually with increasing power density,which were seldom in the previous work.Therefore,the UC properties and mechanism were studied in detail.展开更多
基金Project supported by the National Natural Science Foundations of China (20876002,20976002)Natural Science Foundation of Beijing (2082009,2091002)Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality
文摘Micro-and nanocrystals cubic-phase SrF2:Yb3+/Er3+ upconversion luminescence phosphors were synthesized via a facile hydro-thermal route in the presence of different surfactants.The samples were characterized with X-ray diffraction (XRD),Fourier transform infra-red spectra (FT-IR),scanning electron microscopy (SEM),transmission electron microscopy (TEM),and upconversion emission spectra.As-prepared products showed a variety of morphologies,such as cubic-shaped microcrystal,hierarchical structure microspheres,spheri-cal-shaped nanocrystals and nanosheets.The intrinsic structural feature of cubic-phase SrF2 and two important external factors,namely,the surfactants in the reaction solution and fluoride sources,were responsible for shape determination of SrF2:Yb3+/Er3+.The possible formation mechanisms for products with various architectures were presented.A systematic study on the photoluminescence of Yb3+/Er3+-doped SrF2 samples with cubic shape,microspheres,spherical and nanosheets shapes showed that the optical properties of these products were strongly dependent on their morphologies and size.
基金Project supported by the National Natural Science Foundations of China (20876002,20976002)Natural Science Foundation of Beijing (2082009,2091002)Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality
文摘Nearly monodisperse,regular-shaped and well oil-dispersible tetragonal BaYF5:0.2Yb3+/0.02Er3+ nanocrystals(NCs) were synthesized in water-ethanol-oleic acid-sodium oleate system.The as-obtained NCs exhibited bright upconversion(UC) fluorescence under the 980 nm excitation.Blue(2H9/2-4I15/2),green((2H11/2,4S3/2)-4I15/2) and red(4F9/2-4I15/2) transitions were observed.The results indicated that the relative intensity of green to red increased gradually with increasing power density,which were seldom in the previous work.Therefore,the UC properties and mechanism were studied in detail.
