Electroluminescent devices based on rare-earth tetrakis beta-diketonate complexes


Autoria(s): QUIRINO, W. G.; LEGNANI, C.; SANTOS, R. M. B. dos; TEIXEIRA, K. C.; CREMONA, M.; GUEDES, M. A.; BRITO, H. F.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

20/10/2012

20/10/2012

2008

Resumo

In this paper the synthesis, photo luminescence and electroluminescence investigation of the novel tetrakis beta-diketonate of rare-earth complexes such as M[Eu(dbM)(4)] and M[Tb(acac)(4)] with a variety of cationic ligands, M=Li(+), Na(+) and K(+) have been investigated. The emission spectra of the Eu(3+) and Tb(3+) complexes displayed characteristic narrow bands arising from intraconfigurational transitions of trivalent rare-earth ions and exhibited red color emission for the Eu(3+) ion ((5)D(0) -> F(J), J=0-6) and green for the Tb(3+) ion ((5)D(4) -> (7)F(J), J = 6-0). The lack of the broaden emission bands arising from the ligands suggests the efficient intramolecular energy transfer from the dbm and acac ligands to Eu(3+) and Tb(3+) ions, respectively. In accordance to the expected, the values of PL quantum efficiency (eta) of the emitting (5)D(0) state of the tetrakis(beta-diketonate) complexes of Eu(3+) were higher compared with those tris-complexes. Therefore, organic electroluminescent (EL) devices were fabricated with the structure as follows: indium tin oxide (ITO)/hole transport layer (HTL) NPB or MTCD/emitter layer M[RE(beta-diketonate)(4)] complexes)/Aluminum (Al). All the films were deposited by thermal evaporation carried out in a high vacuum environment system. The OLED light emission was independent of driving voltage, indicating that the combination of charge carriers generates excitons within the M[RE(beta-diketonate)(4)] layers, and the energy is efficiently transferred to RE(3+) ion. As a best result, a pure red and green electroluminescent emission was observed from the Eu(3+) and Tb(3+) devices, confirmed by (X,Y) color coordinates. (C) 2008 Elsevier B.V. All rights reserved.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

CNPq

FAPERJ

FAPERJ

FAPESP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Brazilian Nanotechnology Network

Brazilian Nanotechnology Network

RENAMI

RENAMI

IM2C (Instituto do Milenio de Materiais Complexos)

IM2C (Instituto do Milenio de Materiais Complexos)

Identificador

THIN SOLID FILMS, v.517, n.3, p.1096-1100, 2008

0040-6090

http://producao.usp.br/handle/BDPI/31250

10.1016/j.tsf.2008.06.012

http://dx.doi.org/10.1016/j.tsf.2008.06.012

Idioma(s)

eng

Publicador

ELSEVIER SCIENCE SA

Relação

Thin Solid Films

Direitos

restrictedAccess

Copyright ELSEVIER SCIENCE SA

Palavras-Chave #OLED #Rare-earth ions #Photoluminescence #Electroluminescence #Tetrakis complexes #beta-diketonates #INTRAMOLECULAR ENERGY-TRANSFER #SPECTROSCOPIC PROPERTIES #EUROPIUM #Materials Science, Multidisciplinary #Materials Science, Coatings & Films #Physics, Applied #Physics, Condensed Matter
Tipo

article

original article

publishedVersion