کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1523928 | 1511829 | 2011 | 7 صفحه PDF | دانلود رایگان |

Nanocrystalline yttrium pyrosilicate Y2Si2O7 (YPS) doped with Er3+(YPS:Er) or Yb3+/Er3+(YPS:Yb,Er) was obtained by the reaction of nanostructured Y2O3 and colloidal SiO2. X-ray diffraction analysis confirmed the crystallization of a single phase of α-YPS at 1150 °C and β-YPS at 1250 °C. The luminescence and upconversion spectra of Yb3+/Er3+ codoped phosphors are reported. After direct excitation at 488 nm the samples emitted mostly green radiation. Excitation at 980 nm produced green and red upconversion luminescence both from Er3+ doped and Yb3+ co-doped samples. Using 804 nm wavelength the green and red upconversion luminescences were observed for Yb3+ co-doped samples while Er3+ doped samples emitted exclusively in the green region. It was found that the Er3+ upconversion luminescence is more intense in β-YPS than in α-YPS. The dependence of upconversion luminescence intensity on the excitation power allows upconversion mechanisms for the investigated samples to be proposed.
► The synthesis of single phase of β polymorph of yttrium pyrosilicate (β-Y2Si2O7) nanoparticles at 1250 °C is reported for the first time.
► In nanocrystalline β-Y2Si2O7 doped with Er3+ and codoped with Yb3+ an efficient green and red upconversion luminescence was observed.
► The superiority of the β-Y2Si2O7:Yb3+/Er3+ upconversion phosphor over the α-Y2Si2O7:Yb3+/Er3+ phosphor was shown and discussed.
► The mechanism of upconversion processes in β-Y2Si2O7:Yb3+/Er3+ phosphor was proposed.
Journal: Materials Chemistry and Physics - Volume 131, Issues 1–2, 15 December 2011, Pages 306–312