Organic electroluminescence device

Details Organic electroluminescence device Organic electroluminescence device

2002-09-16

2004-11-16

Garrett, Dawn (Department: 1774)

Stock material or miscellaneous articles

Composite

Of inorganic material

C428S917000, C313S504000, C313S506000, C252S301160

Reexamination Certificate

active

06818327

ABSTRACT:

TECHNICAL FIELD
The present invention relates to an organic electroluminescence device which is used as a light source such as a planar light emitting member of televisions and a back light of displays, exhibits an excellent purity of color and a high efficiency of light emission, has a long life and emits reddish light and to a novel compound having these characteristics.
BACKGROUND ART
Electroluminescence (referred to as EL, hereinafter) devices using organic compounds are expected to be used for inexpensive full color display devices of the solid light emission type which can display a large area and development thereof has been actively conducted. In general, an EL device is constituted with a light emitting layer and a pair of electrodes faced to each other at both sides of the light emitting layer. When a voltage is applied between the electrodes, electrons are injected at the side of the cathode and holes are injected at the side of the anode. The electrons are combined with the holes in the light emitting layer and an excited state is formed. When the excited state returns to the normal state, the energy is emitted as light.
Although the practical application of organic EL devices has started recently, devices for full color displays are still under development. In particular, a material for organic EL devices which exhibits an excellent purity of color and a high efficiency of light emission, has a long life and emits reddish light has been desired.
In an attempt to satisfy the above desire, a device emitting red light in which a derivative of naphthacene or pentacene is added to a light emitting layer is disclosed in Japanese Patent Application Laid-Open No. Heisei 8(1996)-311442. Although this device exhibits an excellent purity of red light, the device exhibits an efficiency of light emission as low as 0.7 lm/W and has an insufficient average life which is shorter than 150 hours. An average life of at least several thousand hours is necessary for practical applications. A device in which a compound derived from dicyanomethylene (DCM) is added to a light emitting layer is disclosed in Japanese Patent Application Laid-Open No. Heisei 3(1991)-162481. However, this device exhibits an insufficient purity of red light. In Japanese Patent Application Laid-Open Nos. Heisei 10(1998)-340782 and Heisei 11(1999)-40360, organic EL devices using fluoranthene compounds are disclosed. However, the devices using the compounds disclosed in the above patent applications do not emit yellow to red light. The efficiency of light emission is as small as 4 cd/A or smaller and insufficient.
DISCLOSURE OF THE INVENTION
The present invention has been made to overcome the above problems and has an object of providing an organic EL device which exhibits an excellent purity of color and a high efficiency of light emission, has a long life and emits reddish light and a novel compound having these characteristics.
As the result of extensive studies by the present inventors to develop an organic electroluminescence device (referred to as an organic EL device, hereinafter) having the above advantageous properties, it was found that the object can be achieved by using a compound having a fluoranthene skeleton structure substituted at least with an amine group or an alkenyl group as the light emitting material.
The organic electroluminescence device of the present invention comprises an organic layer disposed between at least one pair of electrodes, wherein the organic layer comprises a compound having a fluoranthene skeleton structure substituted at least with an amine group or an alkenyl group.
It is preferable that the above compound is a compound selected from compounds represented by the following general formulae [1] to [18]:
wherein X
1
to X
20
each independently represents hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon groups, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylalkylamino group having 7 to 30 carbon atoms or a substituted or unsubstituted alkenyl groups having 8 to 30 carbon atoms; a pair of adjacent groups represented by X
1
to X
20
and a pair of adjacent substituents to groups represented by X
1
to X
20
may form a cyclic structure in combination; when a pair of adjacent substituents are aryl groups, the pair of substituents may be a single group; and at least one of substituents represented by X
1
to X
i
, i representing a number of 12 to 20, comprises an amine group or an alkenyl group;
wherein R
1
to R
4
each independently represent an alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; in one or both of a pair of groups represented by R
1
and R
2
and a pair of groups represented by R
3
and R
4
, the groups forming the pair may be bonded through —O— or —S—; R
5
to R
16
represents hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon groups, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylalkylamino group having 7 to 30 carbon atoms or a substituted or unsubstituted alkenyl groups having 8 to 30 carbon atoms; a pair of adjacent groups represented by R
5
to R
16
and a pair of adjacent substituents to groups represented by R
5
to R
16
may form a cyclic structure in combination; and at least one of substituents represented by R
5
to R
16
comprises an amine group or an alkenyl group.
The novel compound of the present invention is a compound represented by any of the above general formulae [1] to [18].


REFERENCES:
patent: 6127516 (2000-10-01), Bard et al.
patent: 10-125467 (1998-05-01), None
patent: 10-168445 (1998-06-01), None
patent: 10189248 (1998-07-01), None
patent: 10-294177 (1998-11-01), None
patent: 10-340782 (1998-12-01), None
patent: 10-340783 (1998-12-01), None
patent: 11-040360 (1999-02-01), None
patent: 11-168445 (1999-06-01), None
patent: 11-176575 (1999-07-01), None
patent: 2000-026324 (2000-01-01), None
Matsuda, Masanori et al., Chemistry Letters (2), pp. 157-158, (1996).*
“Properties and Infrared Spectra in the Potassium Bromide Region of 8-quinolinol and Its Metal Chelates”, Tackett et al., Inorganic Chemistry, May 1964, vol. 3, No. 5, pp. 692-696.

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