Synthesis and photophysical properties of europium(iii)–β-diketonate complexes applied in LEDs

Abstract

Six β-diketonate ligands were used to prepare the corresponding antenna europium(III) ternary complexes using 1,10-phenanthroline as an ancillary ligand. All the complexes exhibited high decomposition temperatures. Photophysical properties such as FT-IR spectra, UV-Vis absorption spectra, excitation and emission spectra, relative luminescent intensity ratios, luminescence decay curves and quantum yields based on the complexes were systematically studied and compared with each other. The energy-transfer mechanism was proposed as a ligand-sensitized luminescence process. Bright red light-emitting diodes (LEDs) were then fabricated by coating the complexes onto 395 nm-emitting InGaN chips. The light emission from the InGaN chips could be completely absorbed in the spectra of LEDs. The Commission International de I'Eclairage (CIE) chromaticity coordinates are close to the National Television Standard Committee (NTSC) standard value for the red color. All these findings indicate that these Eu(III) complexes are promising red phosphors for fabrication of near UV-based white LEDs.

Stimuli‐Responsive Properties of Aggregation‐Induced‐Emission Compounds Containing a 9,10‐Distyrylanthracene Moiety

“…On the basis of the reported HOMO level of spiro‐OMeTAD (−5.22 eV), the HOMO levels of JX01 and JX02 are −5.45 and −5.73 eV, respectively. Δ E g was calculated from the onset wavelength of the UV absorption (515 nm, 2.40 eV for JX01 and 483 nm, 2.56 eV for JX02 ; Figures S24 and S25 in the Supporting Information) . LUMO energy levels were obtained from the HOMO energy and Δ E g and calculated to be −3.05 and −3.17 eV, respectively (Table ).…”

Luminescent Eu(III) coordination polymer cross-linked with Zn(II) complexes

“…The photophysical properties were estimated using the emission spectra, the emission lifetimes, and the emission quantum yields. The emission quantum yields are larger then that of precursor Eu(hfa) 3 (H 2 O) 2 . The emission quantum yield of Eu-Zn was found to be 59%.…”

“…The 4f-4f transitions of lanthanide complexes lead to narrow emission bands (FWHM < 10 nm) and long emission lifetime (τ > 1 μs), resulting in formation of remarkable luminescent materials such as display devices and bio-imaging applications [1,2]. The strong and characteristic luminescence of lanthanide complexes including Eu 3+ , Tb 3+ , Sm 3+ , Yb 3+ and Pr 3+ ions have been reported [3][4][5].…”

Synthesis and Luminescence Properties of a Novel Eu3+‐Containing Polysiloxane Copolymer

“…Compared with inorganic phosphors, organic phosphors are attracting increasing attention owing to their easily tunable light color by introducing desired light via chemical reaction . Recently, Eu(III)‐complex has been widely used as a red phosphor to produce red light component in white‐LED because of its excellent red emission properties . However, the Eu(III)‐complexes suffers easily crystallization, poor thermal stability and mechanical properties as well as inferior processability .…”