Na4Ca3(AlO2)10∶Eu2+,Mn2+荧光粉的发光特性

采用高温固相法,制得一种新型荧光粉Na₄Ca₃(AlO₂)₁₀∶Eu²⁺,Mn²⁺。样品的结构和发光性质分别由X射线衍射谱和荧光光谱来表征。在Na₄Ca₃(AlO₂)₁₀∶Eu²⁺的激发光谱中出现了Eu²⁺的f-d跃迁吸收带;在发射光谱中,出现蓝光发射,峰值位于441 nm。当在Na₄Ca₃(AlO₂)₁₀∶Eu²⁺中掺杂Mn²⁺时,发生了Eu²⁺→Mn²⁺的能量传递,在542 nm处出现了Mn²⁺的发射峰。在Na₄Ca₃(AlO₂)₁₀∶Eu²⁺,Mn²⁺中,随着Mn²⁺浓度的增加,Eu²⁺粒子的发射强度减弱,而Mn²⁺粒子的发射强度增强,且Eu²⁺离子发射的衰减时间缩短,同时色度由蓝光移向白光。

Photoluminescence Characteristics of Na4Ca3（AlO2）10∶Eu2+,Mn2+

A novel phosphor Na₄Ca₃(AlO₂)₁₀∶Eu²⁺ was prepared by solid state reaction method in a thermal-carbon reducing atmosphere. The photoluminescence(PL) properties were investigated in this paper. The excitation spectrum of Na₄Ca₃(AlO₂)₁₀∶Eu²⁺ showed two absorption bands centered at 262 nm and 320 nm respectively. The photoluminescence spectrum of Na₄Ca₃(AlO₂)₁₀∶Eu²⁺ exhibited a single emission peak centered at 441 nm, which could be attributed to 5d-4f transition of Eu²⁺. The excitation spectrum of Na₄Ca₃-(AlO₂)₁₀∶Mn²⁺ showed absorption peak at about 440 nm monitoring at 542 nm, which shows spectral overlap between emission spectrum of Na₄Ca₃(AlO₂)₁₀∶Eu²⁺. Co-doped Mn²⁺ with Eu²⁺, the photoluminescence spectra of Na₄Ca₃(AlO₂)₁₀∶Eu²⁺,Mn²⁺ were observed two peaks centered at 441 nm and 542 nm correspon-ding to the 5d-4f transition of Eu²⁺ and the d-d transition of Mn²⁺, respectively. With increasing the concentration of Mn²⁺, the emission intensity of 5d-4f transition of Eu²⁺ at 441 nm was significantly decreased, whereas the d-d transition of Mn²⁺ at 542 nm was found to increase. The decay lifetime for Eu²⁺ was found to decrease with increasing Mn²⁺ dopant content, which was strong evidence for the energy transfer from Eu²⁺ to Mn²⁺. We were also interested in investigating the energy transfer efficiency η_T of Eu²⁺→Mn²⁺. With increasing Mn²⁺ dopant content, the energy transfer efficiency η_T was found to increase gradually. According to the Dexter's energy transfer formula of multipolar interaction, it was demonstrated that the energy transfer from Eu²⁺ to Mn²⁺ was due to the electric quadripole-quadripole interaction of the resonance transfer. According to the CIE chromaticity coordinates of Na₄Ca₃(AlO₂)₁₀∶Eu²⁺,xMn²⁺, it was clearly observed that the CIE chromaticity coordinates with the increase of Mn content shifted from blue region to white region.