Liu Jie, Li Gen, Guo Haijie, Liu Dongwei, Feng Peng, Wang Yuhua
Department of Materials Science, School of Physical Science and Technology, Lanzhou University Lanzhou 730000 PR China
Key Laboratory for Special Function Materials and Structural Design of the Ministry of Education, Lanzhou University Lanzhou 730000 China.
RSC Adv. 2018 Mar 13;8(19):10246-10254. doi: 10.1039/c8ra00842f.
Through drawing upon a solid-state reaction, a newly proposed long-lasting phosphor BaLuSiO:Eu, Nd is presented and prepared in this work. The thermoluminescence properties of the phosphor are substantially extended, and the long-lasting phosphorescence behavior is markedly intensified by virtue of the consolidation of Nd ions which serve as trap centers. In line with density functional theory calculations, the conduction band is mostly composed of Lu 5d states while the Ba 5d states only have a tiny contribution. We analyzed the relationship between the phosphor's electronic structure and its optical properties. The photoluminescence emission spectrum shows a blue emitting band with a wide asymmetric property and an extremum of 426 nm, arising from the 5d-4f transitions of the Eu ions which occupy the Ba and Lu sites. It is asserted that the long-lasting phosphorescence of the Eu ions which take up both Ba and Lu sites stems from the special form of conduction band and the occupying environment of the emission center. Yet, they have different contributions and induce an interesting phenomenon in which the blue emitting phosphor shows a bluish-green phosphorescence. The long-lasting phosphorescence can last in excess of 6 h at the recognized intensity level (0.32 mcd m) after excitation for 10 min. This work provides a new way of thinking for the development of multicolored LLP materials. This work analyzes and sheds light on the specific courses and provides a likely mechanism for the process.
通过利用固态反应，本文提出并制备了一种新型长效荧光粉BaLuSiO:Eu, Nd。由于作为陷阱中心的Nd离子的强化作用，该荧光粉的热释光性能得到显著扩展，长效磷光行为也明显增强。根据密度泛函理论计算，导带主要由Lu的5d态组成，而Ba的5d态贡献极小。我们分析了该荧光粉的电子结构与其光学性能之间的关系。光致发光发射光谱显示出一个具有宽不对称特性且极值为426 nm的蓝色发射带，这是由占据Ba和Lu位点的Eu离子的5d-4f跃迁引起的。据认为，占据Ba和Lu位点的Eu离子的长效磷光源于导带的特殊形式和发射中心的占据环境。然而，它们的贡献不同，导致出现了一种有趣的现象，即蓝色发射荧光粉呈现出蓝绿色磷光。在10分钟激发后，长效磷光在公认的强度水平（0.32 mcd m）下可持续超过6小时。这项工作为多色长效磷光材料的开发提供了一种新的思路。这项工作分析并阐明了具体过程，并为该过程提供了一种可能的机制。
