An Efficient Europium(III) Organic Complex as Red Phosphor Applied in LED

Abstract

An efficient red-emitting europium(III) organic complex Eu(ECTFBD)3phen was designed and synthesized, where ECTFBD was 1-(9-ethyl-9H-carbazol-3-yl)-4,4,4-trifluorobutane-1,3-dione and phen was 1,10-phenanthroline. Eu(ECTFBD)3phen exhibits a high thermal stability and excellent photoluminescence properties. The photoluminescence mechanism of the complex was proposed as a ligand-sensitized luminescence process (antenna effect). A bright red light-emitting diode (LED) was fabricated by coating the complex phosphor onto an ∼395nm -emitting InGaN chip, whose CIE chromaticity coordinates (x=0.65,y=0.320) are close to the National Television Standard Committee standard values for red. All the results indicate that Eu(ECTFBD)3phen is a good candidate as a red component in the fabrication of white LEDs with a high color-rendering index.

Group 3 Elements and Lanthanide Metals

“…New bioapplications in medical and biological analysis, like monitoring drug delivery [176][177][178][179], have attracted attention as luminescent lanthanide coordination compounds like -diketonates can be used in time-resolved luminescent (TRL) immunoassays and Ln-MOFs for various imaging techniques including magnetic resonance imaging (MRI) [180][181][182]. Lanthanide coordination and framework compounds have also started to influence lighting in OLED technologies [183][184][185][186][187]. Furthermore, luminescent MOFs have initiated a revolutionary development of luminescent porous materials for sensing of chemical species, ranging from gases via liquids to ions based on changes of the luminescence; accordingly, there is no review report on the luminescence of MOFs without a strong emphasis on lanthanide participation [10, 13-16, 19, 20, 34, 179].…”

New multinuclear europium(III) complexes as phosphors applied in fabrication of near UV-based light-emitting diodes

“…There are several strong points for the organic complexes: (1) high color purity with narrow half-peak widths (5-10 nm); (2) the inner quantum yields can reach 100% in theory; (3) emissive wavelengths due to the f-f transitions of lanthanide ion rarely change after ligand modification [9,10]. To obtain a high efficient luminescent europium complex applied in LED, an organic ligand must meet three requirements, including having an appropriately expanded p-conjugated system in molecule to shift excitation band red till beyond $400 nm, keeping good coordination capacity to europium(III) ion, exhibiting high thermal stabilities and NUV irradiation resistance for the complex.…”

“…White light can be generated by incorporation of tri-color phosphors (blue, green and red) with UV-InGaN chips or phosphors (green and red) with blue GaN chips [5][6][7]. However, the current tri-color phosphors for near UV LEDs are mainly some traditional phosphors, such as BaMgAl 10 O 17 :Eu 2+ for blue, ZnS:(Cu + , Al 3+ ) for green, and Y 2 O 2 S:Eu 3+ for red. These phosphors show lower excitation efficiency, especially the red phosphor Y 2 O 2 S:Eu 3+ with low efficiency results in low color-rendering index, low color reproducibility and low luminous efficient of WLED [8].…”

“…The europium(III) complexes were synthesized with a method analogous to our earlier work [9,10]. The synthesis routine is shown in Fig.…”

A luminescent quadruple stranded dinuclear Eu(III) complex based on 2,8-bis(4′,4′,4′-trifluoro-1′,3′-dioxobutyl)-dibenzothiophene for light-emitting diodes

“…Europium(III) b-diketonate complex has long been known to give bright red emission under NUV irradiation because of the efficient energy transfer from the b-diketonate ligand to the central europium(III) ions. In our previous research, some europium(III) b-diketonate complexes were employed as red phosphors to fabricate red LEDs with NUV-emitting chips [6][7][8][9].…”