Affiliation:
1. Institute of Microstructure Technology Karlsruhe Institute of Technology Hermann‐von‐Helmholtz‐Platz 1 76344 Eggenstein‐Leopoldshafen Germany
2. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology (NCNST) ZhongGuanCun BeiYiTiao 11 Beijing 100190 P. R. China
3. Light Technology Institute Karlsruhe Institute of Technology Engesserstrasse 13 76131 Karlsruhe Germany
Abstract
AbstractMetal–organic frameworks (MOFs) have emerged as promising hosts for lanthanide ions owing to their ability to sensitize the lanthanides and provide a rigid topology while still permitting interactions with guest species. Among these lanthanide MOFs, MOF‐76 is a noteworthy example composed of 1,3,5‐benzenetricarboxylic acid (H3BTC) and lanthanide ions. In this study, a high photoluminescence quantum yield (ΦPL) of 91% for Tb‐based MOF‐76 (Tb‐MOF) is reported, while the efficiency of Eu‐based MOF‐76 (Eu‐MOF) is over five times lower. A potential circumvention of the poor performance of Eu3+ is energy transfer from Tb3+ to Eu3+, but it is found that although energy transfer is efficient the ΦPL of the Eu3+ remains low. The study investigates the cause of the lower quantum yield in Eu‐MOF by ruling out possible factors such as crystal size, guest solvent molecules, and energy transfer from or back to the linker. None of these are significant loss mechanisms, leading to conclude that the MOF‐76 ligand unfortunately leads to fast non‐radiative deactivation of the Eu3+ excited state. The results suggest that MOF‐76 is an excellent host for Tb3+ ions, but exploration is required for MOF linkers to simply access the potentially excellent emission efficiency of Eu3+ ions.
Funder
National Natural Science Foundation of China
Helmholtz Association