Synthesis and Luminescence Properties of Dy3+/Eu3+Co-Doped CaLaGa3O7 Color Tunable Phosphors
A series of Eu3+singly-and Dy3+/Eu3+co-doped CaLaGa3O7 single matrix phosphors were successfully prepared by high-temperature solid-phase method.The phase and luminescence properties of the samples were characterized by X-ray diffraction(XRD)and photoluminescence spectra.The XRD patterns show that all the prepared samples have a tetragonal structure consistent with the matrix crystal,indicating the successful synthesis of that Eu3+singly-and Dy3+/Eu3+co-doped CaLaGa3O7 phosphors.Under excitation of 393 nm,Eu3+∶CaLaGa3O7 exhibits characteristic red emission of Eu3+(5D0→7F2),and the luminescence purity is as high as 100％.After introducing Dy3+,Dy3+/Eu3+co-doped CaLaGa3O7 phosphors could be excited not only by 393 nm light but also by 348 nm.Regardless of the excitation wavelength,the emission spectra of Dy3+/Eu3+∶CaLaGa3O7 include both the characteristic red emission of Eu3+and the yellow emission of Dy3+(4F9/2→6H13/2).By analyzing the emission spectra and fluorescence lifetime,it is confirmed that there exists effective energy transfer process between Dy3+and Eu3+in the co-doped phosphors.Further,the corresponding chromaticity coordinates and CCT values were calculated.The results show that the overall chromaticity coordinates shift from the yellow-green region to the yellow-orange region when the excitation wavelength is changed from 348 nm to 393 nm.Therefore,the Dy3+/Eu3+∶CaLaGa3O7 is a tunable luminescent material with good application prospects in displays and solid-state lighting.
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