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摘要
Tb3+ and Eu3+ ion co-doped LaBWO6 phosphors with tunable color emissions were synthesized by a conventional high-temperature solid-state reaction technique and were characterized by powder X-ray diffraction, scanning electron microscope, emission and excitation spectra, and decay lifetimes. Under 380 rim near-ultraviolet excitation, the characteristic visible emissions, which originate from the f-f transitions of Tb3+ and Eu3+ ions, were observed in the emission spectra. By increasing of the Eu3+/Tb3+ concentration ratio, the LaBWO6:Tb3+,Eu3+ phosphors were capable of generating color tamability from green to yellow, then to red. The energy transfer process between Tb3+ and Eu3+ was demonstrated to be a resonant type via a dipole-dipole mechanism, and the critical distance calculated by the concentration quenching method was determined to be 11.1 angstrom. Moreover, the temperature-dependent emission spectra showed that the as-prepared phosphors possessed good thermal stability with an activation energy of 0.263 eV. These LaBWO6:Tb3+,Eu3+ phosphors with tunable emissions may have potential applications in near-ultraviolet-pumped white light-emitting diodes.
