Luminescence enhancement of (Sr_1-xM_x)₂SiO₄:Eu²⁺ phosphors with M (Ca²⁺/Zn²⁺) partial substitution for white light-emitting diodes

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• 作者：Yulong Wang ; Wentao Zhang ; Yang Gao ; Jianping Long and Junfeng Li
• 刊名：Luminescence
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：32
• 期：1
• 页码：119-124
• 全文大小：449K
• ISSN：1522-7243

文摘

Eu²⁺-doped Sr₂SiO₄ phosphor with Ca²⁺/Zn²⁺ substitution, (Sr_1–xM_x)₂SiO₄:Eu²⁺ (M = Ca, Zn), was prepared using a high-temperature solid-state reaction method. The structure and luminescence properties of Ca²⁺/Zn²⁺ partially substituted Sr₂SiO₄:Eu²⁺ phosphors were investigated in detail. With Ca²⁺ or Zn²⁺ added to the silicate host, the crystal phase could be transformed between the α-form and the β-form of the Sr₂SiO₄ structure. Under UV excitation at 367 nm, all samples exhibit a broad band emission from 420 to 680 nm due to the 4f⁶5d¹ → 4f⁷ transition of Eu²⁺ ions. The broad emission band consists of two peaks at 482 and 547 nm, which correspond to Eu²⁺ ions occupying the ten-fold oxygen-coordinated Sr.(I) site and the nine-fold oxygen-coordinated Sr.(II) site, respectively. The luminescence properties, including the intensity and lifetime of Sr₂SiO₄:Eu²⁺ phosphors, improved remarkably on Ca²⁺/Zn²⁺ addition, and promote its application in white light-emitting diodes. Copyright