کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1259953 | 971706 | 2015 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Photoluminescence properties of an orange-red LaSr2AlO5:Sm3+ phosphor prepared by the Pechini-type sol-gel process Photoluminescence properties of an orange-red LaSr2AlO5:Sm3+ phosphor prepared by the Pechini-type sol-gel process](/preview/png/1259953.png)
LaSr2AlO5:Sm3+ phosphors were synthesized by the Pechini-type sol-gel process. The X-ray diffraction pattern revealed that a pure LaSr2AlO5 phase was obtained with a sintering temperature of 1200 °C. Microstructure characterization showed that the particles were spherical in shape with a mean size of 2.93 µm. Being a candidate orange/red emitting phosphor for orange and white light emitting diodes, LaSr2AlO5:Sm3+ could be effectively excited by both near-ultraviolet (NUV) and blue lights with typical f-f transitions of Sm3+ ions. The most intense emission corresponding to 4G5/2→6H7/2 (604 nm) could be achieved at the same Sm3+ concentration of 4 mol.%. The chromaticity coordinates of La0.96Sr2AlO5:0.04Sm3+ phosphor under the excitation of 407 and 458 nm were (0.57, 0.43) and (0.59, 0.38), respectively. Further study was carried out using Van Uitert's and Dexter's models. A consistent result was obtained that electric dipole-dipole interaction was dominant for the energy transfer among Sm3+ ions. The critical distance for energy transfer among Sm3+ ions in LaSr2AlO5 was calculated to be ca. 1.843 nm.
Graphical AbstractPL spectra of the La1–xSr2AlO5:xSm3+ (x=0.005–0.15) phosphors excited at 407 nm (a) and at 458 nm (b)Figure optionsDownload as PowerPoint slide
Journal: Journal of Rare Earths - Volume 33, Issue 9, September 2015, Pages 954–960