Photophysical properties of highly green luminescent Tb(III) complexes

This article reports four Tb(III) green luminescent complexes based on the ligand 4-oxochromene-3-carbaldehyde and other synergistic ligands. Sharp peaks in the X-ray diffractogram confirms the crystalline property of the complexes. Four characteristic emission peaks of Tb(III) ion at ~499 nm, 545 nm, 586 nm, and 621 nm, assignable to 5D4→7F6,5,4,3 transitions, respectively, were obtained in photoluminescence spectra when irradiated at 345 nm. Bright green emission by the complexes was due to the dominant 5D4→7F5 peak at 545 nm. Ternary complexes exhibited improved thermal stability, emission intensities, quantum yield, and lifetime compared to the binary complex. Our investigations demonstrated that the prepared complexes might be practically useful in display devices, lighting systems, OLEDs, and liquid lasers due to their fascinating photometric properties.