Design Strategy of Lanthanide Complexes for Effective Photosensitized Emission

Abstract

Highly luminescent compounds with high color purity are becoming increasingly important in the development of display and sensing materials. Among the various luminophores, trivalent lanthanide (Ln(III)) complexes (especially Eu(III) and Tb(III) complexes) are promising candidates for achieving pure color luminescence owing to their 4f–4f transition. The brightness of Ln(III) emission is determined by the product of the light-absorption coefficient of organic ligands and the emission quantum yield due to the excitation of organic ligands. Thus, controlling the electronic structure of ligands is crucial for developing luminescent Ln(III) complexes with high brightness. Herein, a design strategy based on the triplet-state control of ligands toward the development of highly luminescent Ln(III) complexes is demonstrated.