Synthesis, characteristics and luminescent properties of a new Tb(III) ternary complex applied in near UV-based LED

• Tb(p-BBA)3UA complex can match with 365 nm UV chip.
• Tb(p-BBA)3UA complex exhibits excellent Tb(III) characteristic emissions.
• Tb(p-BBA)3UA complex has longer fluorescence lifetime and higher quantum yield.
• Tb(p-BBA)3UA complex has high thermal stability.
• Tb(p-BBA)3UA complex can be used as an efficient green phosphor in WLEDs.

A novel Tb(III) ternary complex, Tb(p-BBA)3UA, was synthesized with 4-benzoylbenzoic acid (p-BBA) as primary ligand and undecylenic acid (UA) as reactive ligand. Tb(III) complex exhibits high thermal stability and wide and strong excitation bands from 310 nm to 400 nm when monitored at 543 nm, which matches well with the 365 nm UV chip. The complex displays Tb(III) characteristic peaks at 488, 543, 584 and 619 nm under the excitation of 365 nm UV-light. The intramolecular energy transfer process was also discussed. Meanwhile, the complex has longer fluorescence lifetime (1.317 ms) and higher quantum yield (44.8%). When used in LED with 365 nm UV chip (power efficiency is 17.3 lm/W), the complex still maintained its qualified luminescent performance. All the results indicate that Tb(p-BBA)3UA can be applied as a green component for fabrication of near UV-based white LED.