Stock material or miscellaneous articles – Composite – Of inorganic material
Reexamination Certificate
2001-02-12
2003-05-20
Yamnitzky, Marie (Department: 1774)
Stock material or miscellaneous articles
Composite
Of inorganic material
C428S917000, C313S504000, C313S506000
Reexamination Certificate
active
06565994
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a material used for light emitting devices capable of light-emitting through conversion of electric energy into light, and a light emitting device using such a material. In particular, the invention is concerned with a light emitting device suitably used in various areas of indicators, displays, backlight, electrophotography, illumination sources, recording light sources, exposure illuminants, reading light sources, beacons, signboards, interiors and optical communication device.
BACKGROUND OF THE INVENTION
Recently animated researches and developments on various display devices have been made. Of such devices, the organic electroluminescence (EL) devices are receiving particular attention as promising display devices nowadays, because they can emit light of high intensity under low voltage. For instance, the EL devices having organic thin films formed by vapor deposition of organic compounds are known (
Applied Physics Letters,
51, p.913 (1987)). The organic EL devices described in the literature cited above employ tris(8-hydroxyquinolinato)aluminum complex (Alq) as an electron transporting material, and they are each structured so to superimpose a layer of positive hole transporting material (an amine compound) on the layer of electron transporting material. By taking such a double-layer structure, those devices have substantial improvements in their light emitting characteristics over conventional single-layer devices.
In recent years, the application of organic EL devices to full-color displays has been examined actively. For development of high-performance color displays, it is necessary to improve characteristics of blue, green and red light emitting devices respectively.
As a means of improving characteristics of light emitting devices, the green light emitting device utilizing the luminescence from tris-ortho-metalated complex of iridium(III) with 2-phenylpyridine (Ir(ppy)
3
) is proposed in
Applied Physics Letters,
75, 4 (1999). Such a device has an external quantum yield coming up to 8%, and it surpasses hitherto known devices in external quantum yield because the external quantum yields of conventional devices are supposed to have the limit of 5%. However, that device confines its luminescence to green color, so its applicability as display is limited. Such being the case, development of light emitting device materials capable of light-emitting the other colors with high efficiency has been required.
On the other hand, the organic light emitting devices that have achieved luminescence of high luminance are devices comprising organic materials laminated by vacuum evaporation. In manufacturing devices, the use of coating methods have advantages over that of vacuum evaporation methods from the viewpoints of simplicity of the manufacturing process, workability and ease in achievement of large-area luminescence. However, the devices manufactured according to conventional coating methods are inferior to those manufactured using vapor deposition methods in luminous efficiency (light emitting efficiency). Therefore, the development of novel light emitting materials has been awaited.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a light emitting device having excellent luminous characteristics and a material enabling a light emitting device to have such characteristics.
This object is attained with the following Embodiments (1) to (3) of the invention.
(1) A light emitting device material comprising an iridium complex having a partial structure represented by the following formula (1) or a tautomer thereof:
wherein Q
1
and Q
2
each independently represent an atomic group for completing a nitrogen-containing hetero ring, and Q
1
and Q
2
may be combined to form a condensed ring.
(2) A light emitting device comprising a pair of electrodes between which a light emitting layer or at least two thin layers of organic compounds, inclusive of a light emitting layer, are sandwiched, wherein at least one layer is a layer containing at least one light emitting device material as described in Embodiment (1).
(3) A light emitting device as described in Embodiment (2), wherein the layer containing at least one light emitting device material as described in Embodiment (1) is a layer formed by a coating process.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described below in detail.
First Q
1
and Q
2
in formula (1) are illustrated. Q
1
and Q
2
each represent an atomic group for completing a nitrogen-containing hetero ring. Q
1
and Q
2
may further be combined to form a condensed ring (e.g., a phenanthroline ring). Examples of a nitrogen-containing hetero ring completed by Q
1
and Q
2
each include a pyridine ring, a pyrazine ring, a pyrimidine ring, a quinoline ring, a quinoxaline ring, a naphthyridine ring, a quinazoline ring, a cinnoline ring, a pteridine ring, phenanthridine ring, benzazole rings (e.g., benzoxazole, benzothiazole, benzimidazole), a pyrazole ring, an imidazole ring, a triazole ring, a thiazole ring, an oxazole ring, an oxadiazole ring and a thiadiazole ring. These rings each may have a substituent group.
Examples of a substituent group which may be present on Q
1
and Q
2
each include alkyl groups (containing preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl and cyclopentyl groups), alkenyl groups (containing preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as vinyl, allyl, 2-butenyl and 3-pentenyl groups), alkynyl groups (containing preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl and 3-pentynyl groups), aryl groups (containing preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl and anthranyl groups), amino groups (containing preferably 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 10 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino and ditolylamino groups), alkoxy groups (containing preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy and 2-ethylhexyloxy groups), aryloxy groups (containing preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 1-naphthyloxy and 2-naphthyloxy groups), heteroaryloxy groups (containing preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridyloxy, prazyloxy, pyrimidyloxy and quinolyloxy groups), acyl groups (containing preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferablty 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl and pivaroyl groups), alkoxycarbonyl groups (containing preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl and ethoxycarbonyl groups), aryloxycarbonyl groups (containing preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonyl group), acyloxy groups (containing preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetoxy and benzoyloxy groups), acylamino groups (containing preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetylamino and benzoylamino groups), alkoxycarbonylamino groups (containing preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 1
Fuji Photo Film Co. , Ltd.
Yamnitzky Marie
LandOfFree
Light emitting device material comprising iridium complex... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Light emitting device material comprising iridium complex..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Light emitting device material comprising iridium complex... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3069997