Effect of La³⁺ ion doping on the performance of Eu²⁺ ions in novel Sr₃CeNa(PO₄)₂SiO₄ phosphors

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>We synthesized and investigated the effect of La<SUP>3+</SUP> ion doping in a novel phosphor-silicate apatite Sr<SUB>2.99</SUB>CeNa(PO<SUB>4</SUB>)<SUB>2</SUB>SiO<SUB>4</SUB>:0.01Eu<SUP>2+</SUP> phosphor. X-ray diffraction, GSAS Rietveld refinement, X-ray photoelectron spectroscopy, luminescent spectra, decay curves, and thermal quenching were applied to investigate the phase, structure, luminescence, and thermal stability properties of the obtained phosphor. It is noteworthy that the Eu<SUP>2+</SUP>-activated Sr<SUB>3</SUB>CeNa(PO<SUB>4</SUB>)<SUB>2</SUB>SiO<SUB>4</SUB> phosphor can match well with commercial near-UV chips, suggesting its promising application in phosphor-converted white LEDs. Interestingly, by incorporating La<SUP>3+</SUP> ions in Sr<SUB>2.99</SUB>CeNa(PO<SUB>4</SUB>)<SUB>2</SUB>SiO<SUB>4</SUB>: 0.01Eu<SUP>2+</SUP>, the regulation of Eu<SUP>2+</SUP> luminescence intensities in two centers was achieved via two methods: one is to increase the La<SUP>3+</SUP> concentration from 0 to 0.9 mol and the other is to adjust the excitation wavelength from 300 to 390 nm. More specifically, the luminescence dynamic process and internal quantum efficiency were also changed by La<SUP>3+</SUP> ion doping in Sr<SUB>2.99</SUB>CeNa(PO<SUB>4</SUB>)<SUB>2</SUB>SiO<SUB>4</SUB>:0.01Eu<SUP>2+</SUP>. Therefore, these phenomena illustrate that incorporating La<SUP>3+</SUP> ions in Sr<SUB>2.99</SUB>CeNa(PO<SUB>4</SUB>)<SUB>2</SUB>SiO<SUB>4</SUB>: 0.01Eu<SUP>2+</SUP> can affect the performance and characteristics of Eu<SUP>2+</SUP> ions. Furthermore, our work also encourages research on the luminous effect of site occupancy and the local environment of luminescence centers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> By doping La<SUP>3+</SUP>, the performance and characteristics of Eu<SUP>2+</SUP> were changed. </LI> <LI> The internal quantum efficiency of SCNPS:0.01Eu<SUP>2+</SUP>,0.1La<SUP>3+</SUP> is 64.82%. </LI> <LI> These solid solutions can be properly excited by UV/near–UV LED chip. </LI> <LI> Two methods of adjusting Eu<SUP>2+</SUP> luminescence in two centers. </LI> <LI> Energy transfer from host (Ce<SUP>3+</SUP> ions) to two kinds of Eu<SUP>2+</SUP> ions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>