Ba1.3Ca0.7SiO4:Eu2+,Mn2+: A Promising Single-Phase, Color-Tunable Phosphor for Near-Ultraviolet White-Light-Emitting Diodes

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• 作者：Wenzhen Lv ; Mengmeng Jiao ; Qi Zhao ; Baiqi Shao ; Wei L眉 ; Hongpeng You
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：October 20, 2014
• 年：2014
• 卷：53
• 期：20
• 页码：11007-11014
• 全文大小：563K
• ISSN：1520-510X

文摘

In this paper, Eu²⁺-doped and Eu²⁺/Mn²⁺-codoped Ba_1.3Ca_0.7SiO₄ phosphors were synthesized by means of a conventional solid-state reaction process. The single-phase purity was checked by means of X-ray diffraction and the Rietveld method. Under excitation at 390 nm, the emission spectra of the Eu²⁺-doped phosphors exhibit a broad-band emission centered at 500 nm caused by the electric dipole allowed transition of the Eu²⁺ ions. The emission spectra of codoped phosphors show one more broad emission centered at 600 nm attributable to the transitions from the ⁴T₁(⁴G) 鈫?⁶A₁(⁶S) of Mn²⁺ ions. The luminescent color of the codoped phosphors can be easily adjusted from blue to red with variation of the Mn²⁺ content. The energy transfer mechanism from the Eu²⁺ to Mn²⁺ ions in Ba_1.3Ca_0.7SiO₄ phosphors has been confirmed to be the resonant type via dipole鈥搎uadrupole interaction, and the critical distance has been calculated quantitatively. All these results demonstrate that the Eu²⁺/Mn²⁺-codoped Ba_1.3Ca_0.7SiO₄ phosphors can be a promising single-phase, color-tunable phosphor for near-UV white-light-emitting diodes after a further optimization process. Additionally, a great red shift from 593 to 620 nm has been observed following the increase of Mn²⁺ content, and the phenomenon has been discussed in relation to the changes in the crystal field surrounding the Mn²⁺ ions and the exchange interactions caused by the formation of Mn²⁺ pairs.