Synthesis, Structure, and Luminescence Properties of K2Ba7Si16O40:Eu2+ for White Light Emitting Diodes

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• 作者：Wenzhen Lv ; Yongchao Jia ; Qi Zhao ; Wei L眉 ; Mengmeng Jiao ; Baiqi Shao ; Hongpeng You
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：March 6, 2014
• 年：2014
• 卷：118
• 期：9
• 页码：4649-4655
• 全文大小：455K
• 年卷期：v.118,no.9(March 6, 2014)
• ISSN：1932-7455

文摘

In this paper, a novel divalent europium-doped green emitting blue convertible K₂Ba₇Si₁₆O₄₀:Eu²⁺ phosphor has been synthesized successfully via high-temperature solid-state reaction. The structure of K₂Ba₇Si₁₆O₄₀:Eu²⁺ has been refined on the basis of X-ray powder diffraction by Rietveld refinement method, which consists of two infinite dimensional layers of corner-sharing [SiO₄] tetrahedral parallel to (201) linked together through eight-coordinate K and seven- and nine-coordinate Ba atoms. Under excitation of blue light, the K₂Ba₇Si₁₆O₄₀:Eu²⁺ phosphor emits a strong green emission band peaking at 500 nm. The concentration quenching mechanism of the Eu²⁺ ion was discussed and the critical distance was calculated. Furthermore, the phosphor exhibits high quantum efficiency and good thermal stability, indicating that the K₂Ba₇Si₁₆O₄₀:Eu²⁺ phosphor can serve as an effective green emitting candidate for blue light down-conversion white light emitting diodes.