摘要
CaWO4 phosphor activated by the Tm^3+/Yb^3+, Er^3+/Yb^3+ and Ho^3+/Yb^3+ ions were synthesized by a traditional high-temperature solid-state method. The crystal structures and morphologies of the products were characterized by X-ray powders diffraction method (XRD), infrared spectra (FT-IR) and scanning electron microscopy (SEM). The samples were found to show up-conversion luminescence properties. CaWO4 doped with Tm^3+/Yb^3+ showed blue luminescence characteristic of Tm(Ⅲ) ion in the range of 460-485 urn, corresponding to the ^1G4→^3H6 electronic transition. CaWO4 doped with Er^3+/Yb^3+ showed strong green luminescence at 510-565 nm (^2H11/2, ^4S3/2→^4I15/2) and weak red luminescence at 640-685 nm (^4F9/2→^4I15/2) of Er(Ⅲ) ion. CaWO4 doped with Ho^3+/Yb^3+ phosphor emitted green luminescence at 525-560 nm (5S2, 5F4→518) and red luminescence at 6304i70 um (SFs→518) and at 730-770 nm (^5S2, ^5F4→^5I7), which is the characteristic of Ho(Ⅲ) ion.
CaWO4 phosphor activated by the Tm^3+/Yb^3+, Er^3+/Yb^3+ and Ho^3+/Yb^3+ ions were synthesized by a traditional high-temperature solid-state method. The crystal structures and morphologies of the products were characterized by X-ray powders diffraction method (XRD), infrared spectra (FT-IR) and scanning electron microscopy (SEM). The samples were found to show up-conversion luminescence properties. CaWO4 doped with Tm^3+/Yb^3+ showed blue luminescence characteristic of Tm(Ⅲ) ion in the range of 460-485 urn, corresponding to the ^1G4→^3H6 electronic transition. CaWO4 doped with Er^3+/Yb^3+ showed strong green luminescence at 510-565 nm (^2H11/2, ^4S3/2→^4I15/2) and weak red luminescence at 640-685 nm (^4F9/2→^4I15/2) of Er(Ⅲ) ion. CaWO4 doped with Ho^3+/Yb^3+ phosphor emitted green luminescence at 525-560 nm (5S2, 5F4→518) and red luminescence at 6304i70 um (SFs→518) and at 730-770 nm (^5S2, ^5F4→^5I7), which is the characteristic of Ho(Ⅲ) ion.