Li Ting, Li Panlai, Wang Zhijun, Xu Shuchao, Bai Qiongyu, Yang Zhiping
College of Physics Science & Technology, Hebei Key Lab of Optic-Electronic Information and Materials, Hebei University, Baoding 071002, China.
Phys Chem Chem Phys. 2017 Feb 1;19(5):4131-4138. doi: 10.1039/c6cp07494d.
Ce/Eu-doped LiBaBO (LBB) samples were prepared via conventional high temperature solid state reactions. The XRD patterns, crystal structures, luminescence properties, and decay times were investigated systematically. Ce ions exist in LBB:xCe that were synthesized in a reducing atmosphere and in an air atmosphere. However, we observed Eu ions in LBB:yEu in a reducing atmosphere and Eu ions in LBB:zEu in an air atmosphere. LBB:0.05Ce,yEu phosphors synthesized in a reducing atmosphere only possess Ce and Eu and exhibit a broad excitation band ranging from 350 to 425 nm. A reduction phenomenon of Eu → Eu and coexistence of Ce, Ce, Eu and Eu were observed when LBB:0.05Ce,wEu phosphors were synthesized in an air atmosphere. There are three processes in LBB:0.05Ce,wEu, i.e., energy transfers from Ce to Eu and from Eu to Eu, and metal-metal charge transfer (MMCT) between Ce and Eu. Moreover, the MMCT process is dominant in LBB:0.05Ce,wEu due to less efficient energy transfer from Ce to Eu. Moreover, the CIE coordinates of LBB:0.05Ce,wEu vary systematically from light blue (0.313, 0.129) to red (0.589, 0.315) for LBB:0.05Ce,wEu synthesized in air with the changes in Eu ion concentration. Thus, we can control the color by controlling the synthesis atmospheres.
通过传统高温固态反应制备了铈/铕掺杂的锂钡硼酸盐（LBB）样品。系统研究了其X射线衍射图谱、晶体结构、发光性能和衰减时间。在还原气氛和空气气氛中合成的LBB:xCe中存在铈离子。然而，我们在还原气氛中的LBB:yEu中观察到铕离子，在空气气氛中的LBB:zEu中也观察到铕离子。在还原气氛中合成的LBB:0.05Ce,yEu荧光粉仅含有铈和铕，呈现出350至425nm的宽激发带。当在空气气氛中合成LBB:0.05Ce,wEu荧光粉时，观察到Eu→Eu的还原现象以及Ce、Ce、Eu和Eu的共存。LBB:0.05Ce,wEu中有三个过程，即从Ce到Eu以及从Eu到Eu的能量转移，以及Ce和Eu之间的金属-金属电荷转移（MMCT）。此外，由于从Ce到Eu的能量转移效率较低，MMCT过程在LBB:0.05Ce,wEu中占主导。而且，随着在空气中合成的LBB:0.05Ce,wEu中铕离子浓度的变化，其CIE坐标从浅蓝色（0.313，0.129）系统地变化到红色（0.589，0.315）。因此，我们可以通过控制合成气氛来控制颜色。
