An efficient 2-linked carbazolyl β-diketonate europium(III) complex as red phosphor applied in LED

Abstract

An efficient 2-linked carbazolyl β-diketonate europium(III) complex Eu(ETFMCTFBD)3phen was designed and synthesized, where ETFMCTFBD was 1-(9-ethyl-7-(trifluoromethyl)-9H-carbazol-2-yl)-4,4,4-trifluorobutane-1,3-dione and phen was 1,10-phenanthroline. Eu(ETFMCTFBD)3phen exhibits high thermal stability and excellent photoluminescence properties. The CIE chromaticity coordinates (x=0.668, y=0.331) are close to the National Television Standard Committee (NTSC) standard values for red. The lowest triplet energy was measured and suggests the photoluminescence process as a ligand-sensitized luminescence process (antenna effect). A bright red light-emitting diode was fabricated by coating the complex phosphor onto a ∼395 nm-emitting InGaN chip. All the results indicate that Eu(ETFMCTFBD)3phen is a good candidate as a red component in the fabrication of white LEDs with a high color-rendering index.