Zhang Mao-feng, Meng Jian-xin, Liu Ying-liang, Man Shi-qing
Department of Chemistry, Institute of Nano-Chemistry, Jinan University, Guangzhou 510632, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Feb;27(2):232-5.
Green-emitting LaF3:Ce, Tb phosphor nanoparticles were synthesized by a simple hydrothermal method and characterized by XRD, TEM and fluorescence spectra. The prepared samples had a hexagonal shape, fine size (30 nm), and high brightness under ultraviolet, and the structure of LaF3 remained unchanged after being doped with Ce3+ and Tb3+ ions. The blue Ce3+ emission centered at 261 nm is efficiently quenched in the samples of LaF3:Ce, Tb, in which the dominant emission is in the green at 544 nm, originating from the doped Tb3+ ions' transition of (5)D4 to (7)F5. Excitation spectra of the LaF3:Ce, Tb, observed at 544 nm, consist of both contributions from Ce3+ and Tb3+ ions. There is energy transfer of Ce3+ --> Tb3+ in this system. The energy transfer mechanism was discussed. Above all, the phosphor nanoparticles have high photoluminescence intensity even without any calcination, about twice that of bulk materials prepared by high temperature solid synthesis, and the intensity is also stronger than calcined phosphor nanoparticles.
通过简单的水热法合成了发射绿色光的LaF3:Ce,Tb荧光粉纳米颗粒，并通过X射线衍射、透射电子显微镜和荧光光谱对其进行了表征。制备的样品呈六边形，尺寸细小（30nm），在紫外光下具有高亮度，并且在掺杂Ce3+和Tb3+离子后LaF3的结构保持不变。在LaF3:Ce,Tb样品中，以261nm为中心的蓝色Ce3+发射被有效猝灭，其中主要发射为544nm处的绿色光，源于掺杂的Tb3+离子从(5)D4到(7)F5的跃迁。在544nm处观察到的LaF3:Ce,Tb的激发光谱由Ce3+和Tb3+离子的贡献组成。该体系中存在Ce3+→Tb3+的能量转移。对能量转移机制进行了讨论。最重要的是，即使没有任何煅烧，荧光粉纳米颗粒也具有高光致发光强度，约为高温固相合成制备的块状材料的两倍，并且其强度也比煅烧后的荧光粉纳米颗粒更强。
