Аннотация:
This research aims to develop lanthanide-based metal-organic frameworks (MOFs) with
aggregation-induced emission (AIE) ligands to achieve direct sensitization from the ligand to the
lanthanide ion. AIE ligands composed of AIE active cores and multiple carboxylic acid groups form
a contiguous structure with Ln ions and AIE luminophores to obtain direct sensitization in zerodistance.
The quantum cutting (QC) process is considered using Tb3+ as the sensitizer ion and Yb3+
as the activator ion. A solid-fluorescent ligand, dihydroxyterephthalic acid (DHTA), is used to
improve UV light absorption and transfer energy via coordination bonds to solve the concentration
quenching issue that reduces quantum cutting efficiency. The energy conversion efficiency of the
prepared MOFs is evaluated using intensive optical measurements. This study is novel as it employs
AIE or low concentration quenching fluorescent ligands, which is different from the conventional
fluorescent ligands for Ln-MOF, and addresses the concentration quenching issue. The research
contributes to the development of energy downconversion materials made of lanthanide metalorganic
frameworks with AIE ligands, with potential applications in solar energy conversion. The
results of photoluminescence (PL) spectroscopy analysis of Ln-AIE MOFs with the DHTA and
TPA ligands at different Tb concentrations (8%, 12%, and 15%) show that the AIE ligand
sensitization is successfully demonstrated. The emission peaks of Yb3+ in the near-infrared range
correspond to the transitions 2F5/2 → 2F7/2 as a result of QC. Quantum resonance energy transfer
from Tb3+ to Yb3+ is observed only when the AIE ligand is incorporated in the MOF structure,
which is a characteristic of quantum cutting. The AIE ligand sensitized Ln-MOF have a strong
potential to improve solar energy conversion efficiency of single hetero-junction solar cell.