Electroluminescent properties of a Eu-complex doped in phosphorescent materials

• Published in: Journal of luminescence Vol. 81; no. 3; pp. 159 - 164
• Main Authors: Miyamoto, Yasuo, Uekawa, Masahiro, Ikeda, Hitoshi, Kaifu, Katsuaki
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.1999; Elsevier
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electroluminescence; Electronics; Electrophosphorescence; Eu complexes; Exact sciences and technology; Light-emitting devices; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optoelectronic devices; Organic electroluminescence; Other luminescence and radiative recombination; Photoluminescence; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solid organic materials; Triplet excited states; 78.66.Qn; 85.60.Jb; Electrophosphorescence; 78.60.Fi; 71.20.Eh; Eu complexes; Organic electroluminescence; Triplet excited states; Thin films; Benzophenone derivatives; Acetophenone derivatives; Electroluminescent devices; Photoluminescence; Doped materials; Electroluminescence; Experimental study; Europium complexes; Organic compounds
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/S0022-2313(98)00173-2

Electroluminescent spectra of thin films in which a Eu(III)-β-diketonate complex is doped into a phosphorescent layer have been investigated. At low temperatures (77 K), the spectra consist of emissions both from the triplet excited levels of the phosphorescent material and from the 5 D 0 and 5 D 1 levels of the Eu 3+ ion. In contrast, electroluminescent spectra from the Eu complex at room temperature and photoluminescent spectra from the Eu complex consist predominantly of emissions from the 5 D 0 level. Furthermore, the electroluminescent spectra at room temperature depend on the host materials. Energy transfer from triplet states of the phosphorescent materials to the ligand triplet state of the Eu complex and emission saturation of the Eu 3+ ion at a higher level of current-injection are discussed.