Photoluminescence properties of a novel orange red emitting Sr₄Al₁₄O₂₅:Sm³⁺ phosphor and PL enhancement by Bi³⁺ co-doping

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• 作者：Hom Nath Luitel ; ^{mehomnath@yahoo.com} ; Takanori Watari ; ^{watarit@cc.saga-u.ac.jp} ; Rumi Chand ; Toshio Torikai ; Mitsunori Yada
• 关键词：Phosphors ; Sr4Al14O25 ; Sm3+ ; Orange-red ; Optical properties ; Bi3+ activation
• 刊名：Optical Materials
• 出版年：2012
• 出版时间：June, 2012
• 年：2012
• 卷：34
• 期：8
• 页码：1375-1380
• 全文大小：2924 K

文摘

A novel orange red emitting Sr₄Al₁₄O₂₅:Sm³⁺ and Sr₄Al₁₄O₂₅:Sm³⁺, M³⁺ (M = Bi, Dy, Nd) phosphors were synthesized by high temperature solid state reaction method. The phosphor samples were characterized by X-ray diffraction and Scanning Electron Microscopy. UV-visible absorption, photoluminescence emission and excitation spectra were investigated for the phosphor with various doped concentrations of Sm³⁺ and Bi³⁺ ions and different amount of H₃BO₃ as a flux. The emission intensity of Sm³⁺ ions in the Sr₄Al₁₄O₂₅ host largely enhanced with the amount of flux, concentration of activator (Sm³⁺) ion and co-activator (Bi³⁺) ion. The maximum intensity was observed in the phosphor prepared using 40 mol % H₃BO₃ as a flux and 2 at. % Sm³⁺ ions as an activator sintered at 1350 ¡ãC. Addition of 2 at. % Bi³⁺ ion drastically enhanced the emission intensity; the increase by Dy³⁺ ion was not so pronounced but Nd³⁺ ion largely suppressed the emission intensity. The increase of emission intensity by Bi³⁺ ion addition was explained on the basis of higher absorption of excitation energy by Bi³⁺ ions and efficient energy transfer from Bi³⁺ to Sm³⁺ emission center.