Thin-film formation for promoting the potential of luminescent lanthanide coordination complexes

Molecular thin films that are periodically layered and core-shell type nanoparticles with interfacial coordination are observed in lanthanide complexes via organic photo-antennae. The layer structures of Eu complexes induced the linearly polarized luminescence (LPL) of ff-transitions by using the Langmuir-Blodgett technique. The aforementioned was achieved due to the independent existence of Eu and the interpretation of the transition dipole moment localized on chromophores in the layers. The chain structure of the complexes was sequentially deposited on the substrates, but exhibited no LPL due to the formation of dome-like chain aggregates. The interfacial coordination can adopt various combinations of nanoparticles (e.g., SiO2, TiO2, and Ln(2)O(3)) with different lanthanides and various types of organic shells to induce upconversion even with low-power light or efficient photomultiplying photodetection. The divalent Eu ion demonstrated high stability. (C) 2020 Elsevier B.V. All rights reserved.