Single-phase and warm white-light-emitting phosphors CaLa_2−x−y(MoO₄)₄: xDy³⁺, yEu³⁺: Synthesis, luminescence and energy transfer

详细信息    查看全文

• 作者：Li Han ; Guixia Liu ; ^{liuguixia22@163.com" class="auth_mail" title="E-mail the corresponding author} ; Xiangting Dong ; Jinxian Wang ; Wensheng Yu
• 关键词：Sol&ndash ; gel method ; Phosphors ; Photoluminescence ; Energy transfer
• 刊名：Journal of Luminescence
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：178
• 期：Complete
• 页码：61-67
• 全文大小：2758 K

文摘

A series of single-phase warm white light emitting CaLa_2−x−y(MoO₄)₄: xDy³⁺, yEu³⁺ phosphors were synthesized by a typical sol–gel method. X-ray diffraction (XRD) analysis reveals that the crystal structures of the samples are matched well with the tetragonal CaMoO₄. Upon ultraviolet (UV) light radiation, the Dy³⁺ or Eu³⁺ ions singly activated CaLa₂(MoO₄)₄ phosphors exhibit corresponding emissions originated from the f–f transitions of Dy³⁺ or Eu³⁺ ions. Under near ultraviolet (n-UV) light excitation, in the Dy³⁺ and Eu³⁺ ions co-doped samples, the energy transfer (ET) phenomenon from Dy³⁺ to Eu³⁺ ions can be observed and has been demonstrated to be a quadrupole–quadrupole interaction mechanism. The emission color of CaLa_1.98−y(MoO₄)₄: 0.02Dy³⁺, yEu³⁺ samples can be tuned from cool to warm white light by adjusting the concentration of Eu³⁺ ions. In addition, it can be found that CaLa_1.974(MoO₄)₄: 0.02Dy³⁺, 0.006Eu³⁺ samples emit bright white light with the CIE coordinate of (0.348, 0.313) and the color temperature of 5087 K, which is very close to the standard white light. All the results demonstrate that the as-synthesized phosphors have great potential applications in the field of n-UV white light emitting diodes (WLEDs).