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 (5)D(0)-->(7)F(J) (J=0-4) emission bands of Eu(3+) under near ultraviolet. A red conversion light-emitting diode (LED) device was fabricated by coating complex onto InGaN-based-LED chip that emits 395nm 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.