文献类型：期刊文献

英文题名：Hot-node controlled facile synthesis of 3D rare earth micro-networks with symmetry deviation induced high luminescence

作者：Chen, Bin-Bin[1];Lv, Jian[1];Chang, Shuai[1];Wang, Xiao-Yuan[1];Qian, Ruo-Can[1];Li, Da-Wei[1]

机构：[1]East China Univ Sci & Technol, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Sch Chem & Mol Engn,Key Lab Adv Mat, Shanghai 200237, Peoples R China

年份：2020

卷号：8

期号：34

起止页码：11962

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY C

收录：;EI(收录号：20203709177353);WOS:【SCI-EXPANDED(收录号:WOS:000565865500029)】；

基金：We would like to thank Prof. He Tian (East China University of Science and Technology) for his valuable instructions and suggestions. This research was supported by the National Natural Science Foundation of China (21788102, 21977031), the National Science and Technology Major Project of China (2018ZX10302205), the Shanghai Science and Technology Committee (17520750100 and 19ZR1472300) and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Ions - Binary alloys - Ligands - Luminescence

摘要：Controlled self-assembly is a powerful strategy for building mesoscopic superstructures. However, the construction of high luminescence, millimeter-sized and spatially well-defined 3D rare earth (RE) material assemblies is a challenging objective. Apart from ligand sensitized luminescence of RE(3+)ions, improving their luminescence efficiency by changing the symmetry of the coordination environment of RE(3+)ions is a promising approach. In this work, we propose a facile "hot-node" growth strategy for the preparation of millimeter-sized high luminescence 3D RE micro-networks (RE-MNs) using citric acid (CA) as a ligand with weak absorption and mismatched energy levels of RE(3+)ions. A unique assembly mechanism for RE-MNs is revealed, mainly including RE3+/CA coordination, high temperature-promoted disordered aggregation, "hot-node" formation, and the "hot-node" controlled production of MNs. Surprisingly, the luminescence efficiency of RE-MN assemblies is similar to 10(2)times stronger than that of RE3+/CA complex precursors. Based on detailed photoluminescence (PL) spectra analysis, the significantly enhanced PL is directly attributed to the symmetry deviation induced transition (SDIT) effect. The formation of RE-MN assemblies results in the decrease of symmetry of the coordination environment of RE(3+)ions and leads to the deviation of RE(3+)from the center of inversion, which directly changes the originally Laporte-forbidden f-f transition to an allowed transition. Such facile and gram-scale synthesis technology enables the formation of high luminescence RE-MN assemblies with narrow bandwidth emission with promise for application in light emitting diodes (LEDs).