Hydrothermal synthesis of SrF₂:Yb³⁺/Er³⁺ micro-/nanocrystals with multiform morphologies and upconversion properties

【摘要】 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.更多还原

【Abstract】 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.更多还原