A luminescent Eu(III) complex based on 2-(4′, 4′, 4′-trifluoro-1′, 3′-dioxobutyl)-dibenzothiophene for light-emitting diodes

Complex Eu(dbt)3(phen) (Hdbt = 2-(4′, 4′, 4′-trifluoro-1′, 3′-dioxobutyl)-dibenzothiophene, phen = 1,10-phenanthroline) was synthesized. The complex emits red luminescence, characteristic of the 5D0 → 7FJ (J = 0–4) emission bands of Eu3+ under near ultraviolet. A red conversion light-emitting diode (LED) device was fabricated by coating complex onto InGaN-based-LED chip that emits 395 nm ultraviolet light. When the mass ratio of the red phosphor to the silicone is 1:25, the LED device's CIE chromaticity coordinates are x = 0.5835, y = 0.2857, and the luminescence efficiency is 1.29 lm/w. All the results show that this europium complex may act as a red component in fabrication of white LEDs with high color-rendering index.