利用高温固相法合成Na2CaSiO4:Sm3+,Eu3+系列荧光粉末,研究了Sm3+和Eu3+掺杂对Na2CaSiO4晶体结构的影响、材料发光特性以及存在的能量传递现象.X射线衍射结果表明Sm3+和Eu3+单掺及共掺样品均为单相的Na2CaSiO4结构,晶体结构没有改变.Na2CaSiO4:Sm3+荧光样品在404 nm激发波长下呈现峰峰值为602 nm的橙红色荧光,来源于4G5/2→6H7/2跃迁.Na2CaSiO4:Eu3+荧光样品在395 nm激发波长下发射出峰峰值为613 nm的红色荧光.对光谱和荧光寿命的测试和分析结果表明Sm3+与Eu3+之间存在能量传递,通过理论计算得到Sm3+和Eu3+之间的能量传递临界距离为1.36 nm,相互作用形式为电四极-电四极相互作用.随着Eu3+掺杂浓度的增加,能量传递效率也逐渐提高至20.6%.%A series of Na2CaSiO4:Sm3+, Eu3+ phosphors is prepared by the high-temperature solid-state reaction method at 1150 ℃, and their crystal structures, luminescent properties and energy transfer phenomenon influenced by Sm3+ and Eu3+ are studied. The X-ray diffraction results indicate that the samples single- and co-doped with Sm3+ and Eu3+keep single-phase and no impurity phases are observed. At the excitation wavelength of 404 nm, the Na2CaSiO4:Sm3+samples emit narrow-band spectral fluorescence with lines composed of peak-to-peak values of 565, 602, 650, 713 nm, which correspond to the electronic transitions of Sm3+ from the ground state level 4G5/2 to 6H5/2, 6H7/2, 6H9/2, and 6H11/2. On the other hand, the Na2CaSiO4:Eu3+ sample exhibits red emission with a peak-to-peak value of 613 nm at the excitation wavelength of 395 nm. The analyses of the spectrum and lifetime of fluorescence show that with the increase of Eu3+ content, the emission intensity of Sm3+ decreases and the emission intensity of Eu3+ increases. Moreover, the lifetime corresponding to Sm3+ at 602 nm decreases gradually. It is indicated that the energy transfers from Sm3+ to Eu3+. The critical distance of energy transfer is 1.36 nm, which is calculated by the concentration quenching method. The energy transfer mechanism is ascribed to the quadrupole-quadrupole interaction. As the Eu3+ doping concentration increases, the transfer efficiency increases to 20.6%. In conclusion, the Na2CaSiO4:Sm3+, Eu3+ phosphors may be used as a red component for white light-emitting diodes.
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