CN102201543A - Organic electric field luminous element and organic electric field luminescent display using the same - Google Patents

Abstract

The invention provides an organic electric field luminous element, comprising a first electrode, a luminous layer, a semi-transmitting second electrode, a middle layer, a semi-transmitting layer and a light-transmitting layer in order. The organic electric field luminous element also comprises a first resonator structure which resonates and ejects light ejecting from the luminescent layer between the first electrode and the second electrode, and a second resonator structure which resonates and ejects the light between the first electrode and the semi-transmitting layer. One fourth of peak value wavelength of light ejecting from the luminescent layer is set as t, and the refractive index of the light-transmitting layer is set as n. the thickness of the light-transmitting layer is set above 0.9*t/n and below 1.1*t/n.

Description

Organic electric-field light-emitting element and use its organic electric field luminescence display

Technical field

The present invention relates to have organic electric-field light-emitting element (following be called sometimes " organic EL " of multiple resonant structure.) and the organic electric field luminescence display that uses it.

Background technology

Organic electric-field light-emitting element is the display unit of emissive type, is used in the purposes of display or illumination.The organic electric field luminescence display is compared with in the past CRT or LCD, has the identification height, does not have the advantage of the display performance of angle of visual field dependence and so on.In addition, also having can be with the advantage of display lighting, thin layerization.In addition, organic EL illumination in addition can be by the illumination of the shape using flexible base, board to realize can't to realize up to now except the such advantage of lighting, thin layerization.

Said, organic electric-field light-emitting element has excellent feature, yet in general, comprises luminescent layer, constitutes the refractive index ratio air height of each layer of display unit.For example, in organic electric-field light-emitting element, the refractive index of organic thin film layers such as luminescent layer is 1.6～2.1.Thus, total reflection takes place in light easily that sent at the interface, also have its light to take out the situation of efficient less than 20%, thereby lost most light.

For example, the organic electric field luminescence display part in the organic electric-field light-emitting element known to general constitutes at the organic compound layer that possesses on the substrate between the pair of electrode layers of being disposed at.This organic compound layer comprises luminescent layer, and organic electric-field light-emitting element makes the light that penetrates from this luminescent layer take out the face side from light and penetrates.

But, under this situation,, the total reflection composition that belongs to the above light of critical angle can't be taken out owing to take out in the interface of face or electrode layer and organic compound layer at light, therefore there is the inefficient problem of taking-up of light.

Based on this kind situation, take out efficient in order to improve light, for example proposed to have the organic electric-field light-emitting element (with reference to TOHKEMY 2006-140130 communique) of following micro-cavity structure, described microdischarge cavities structure have the optical resonance layer that makes the photoresonance of from light-emitting component, emitting and be clipped in optical resonance layer and light-emitting component between the intermediate layer.According to above-mentioned organic electric-field light-emitting element, to compare with the organic electric-field light-emitting element of non-micro-cavity structure, light takes out efficient and improves.

But, in the above-mentioned organic electric-field light-emitting element, owing to use the reflecting surface of transparent materials with different refractive index as light exit side, therefore can't obtain near the volume reflection of vertical incidence fully, exist the light that unlikely improves with respect to frontal to take out efficiency.In addition, because of resonance effects, also have color and observer to change the problem of (colourity variation) accordingly with respect to the position of organic electric-field light-emitting element.

In addition, about having the organic electric-field light-emitting element of micro-cavity structure, proposed to have doubly the organic electric-field light-emitting element (with reference to TOHKEMY 2003-123987 communique) of the multiple resonant structure of resonant structure.This organic electric-field light-emitting element possesses completely reflecting mirror, optionally reflects first semi-transparent semi-reflective layer, the second semi-transparent semi-reflective layer excessively of reflection second wavelength different with above-mentioned first wavelength optionally crossed of first wavelength, first resonance part and second resonance part that utilization is made of them are respectively with respect to different fundamental wavelength resonance.

Above-mentioned organic electric-field light-emitting element is synthetic with the different fundamental wavelength in second resonance part with first resonance part, for example will show blue (λ ₁) and orange (λ ₂) the light of fundamental wavelength carry out addition colour mixture and send white light.

But, above-mentioned organic electric-field light-emitting element is owing to utilize complementary colours to realize white, therefore for example when and when having used the color selecting mechanism of colour filter, just have the problem that produces the colourity variation with the observer with respect to the position of organic electric-field light-emitting element accordingly.

Said, for the organic electric-field light-emitting element with micro-cavity structure, realistic situation is that the inhibition effect that the raising of light taking-up efficient and colourity change is still abundant inadequately, expects further to improve.

Summary of the invention

The objective of the invention is to, provide not only to have organic electric-field light-emitting element that colourity that excellent light takes out efficient but also can suppress to produce accordingly with respect to the position of organic electric-field light-emitting element with the observer changes and the organic electric field luminescence display that uses this organic electric-field light-emitting element.

As the approach that is used to address the above problem, as follows.That is,

＜1〉a kind of organic electric-field light-emitting element, it is characterized in that, be the organic electric-field light-emitting element that has second electrode, intermediate layer, semitransmissive layer and the light-transmitting layer of first electrode, luminescent layer, half transmitting successively at least, and have: first resonator structure that makes the light that from described luminescent layer, penetrates between described first electrode and described second electrode, resonate and penetrate; And second resonator structure that makes described light between described first electrode and described semitransmissive layer, resonate and penetrate, wherein, 1/4 length at the peak wavelength of the light that will penetrate from described luminescent layer is made as t, when the refractive index of described light-transmitting layer was made as n, the thickness of described light-transmitting layer satisfied following formula: below the above 1.1 * t/n of 0.9 * t/n.

In above-mentioned＜1〉in the organic electric-field light-emitting element of record, electronics injects above-mentioned luminescent layer from above-mentioned first electrode, above-mentioned luminescent layer is injected from above-mentioned second electrode in the hole, in above-mentioned luminescent layer, collide in above-mentioned electronics and above-mentioned hole.In case above-mentioned electronics and the collision of above-mentioned hole, the luminescent material in the above-mentioned luminescent layer becomes excited state with regard to obtaining energy, penetrates light when getting back to ground state.The part of above-mentioned light interreflection and resonated and penetrate light between above-mentioned first electrode and above-mentioned second electrode penetrates to the outside through above-mentioned intermediate layer, above-mentioned semitransmissive layer and above-mentioned light-transmitting layer.

In addition, the other part of above-mentioned light interreflection and penetrated light by resonance ground between above-mentioned first electrode and above-mentioned semitransmissive layer penetrates to the outside through above-mentioned intermediate layer, above-mentioned semitransmissive layer and above-mentioned light-transmitting layer.When being made as this formation, light takes out efficient and just obtains improving.

Because the thickness of above-mentioned light-transmitting layer is 1/4th optical length thickness about equally with the peak wavelength of the light that penetrates from above-mentioned luminescent layer, therefore except constituting the light that brings and take out the raising of efficient, can also further improve light and take out efficient by above-mentioned.In addition, the colourity that produces accordingly with respect to the position of above-mentioned organic electric-field light-emitting element with the observer changes and has also obtained inhibition.

＜2〉according to above-mentioned＜1〉in the organic electric-field light-emitting element of record, wherein, light-transmitting layer and and the layer of this light-transmitting layer adjacency between the difference of refractive index be at least 0.1.

＜3〉according to above-mentioned＜1〉to＜2 in the organic electric-field light-emitting element of any record, wherein, the material of semitransmissive layer is a metal.

＜4〉according to above-mentioned＜3〉the middle organic electric-field light-emitting element of putting down in writing, wherein, metal is at least a metal that is selected from silver, magnesium-silver alloy and the aluminium.

＜5〉according to above-mentioned＜1〉to＜4 in the organic electric-field light-emitting element of any record, wherein, luminescent layer contains at least a phosphorescent material.

＜6〉according to above-mentioned＜1〉to＜5 in the organic electric-field light-emitting element of any record, wherein, organic electric-field light-emitting element is an end emission type.

＜7〉according to above-mentioned＜1〉to＜6 in the organic electric-field light-emitting element of any record, wherein, between second electrode and intermediate layer, also has light-transmitting layer, wherein, 1/4 length at the peak wavelength of the light that will penetrate from above-mentioned luminescent layer is made as t, when the refractive index of above-mentioned light-transmitting layer was made as n, the thickness of above-mentioned light-transmitting layer satisfied following formula: below the above 1.1 * t/n of 0.9 * t/n.

＜8〉according to above-mentioned＜1〉to＜7 in the organic electric-field light-emitting element of any record, wherein, in the luminescent spectrum of the luminescent material in luminescent layer, front resonant wavelength ratio is short from first peak wavelength of the short wavelength side number of luminescent spectrum, above-mentioned luminescent spectrum satisfies the relation with the Δ λ＜25nm of following mathematical expression 1 expression

＜mathematical expression 1 〉

Δλ＝λ(I0)-λ(0.2×I0)

Wherein, in the above-mentioned mathematical expression 1, λ (I0) expression front resonant wavelength, I0 represents the luminous intensity this wavelength under, λ (0.2 * I0) wavelength when representing to reach 0.2 times of luminous intensity of λ (I0) luminous intensity, λ (I0)＞λ (0.2 * I0).

＜9〉a kind of organic electric field luminescence display is characterized in that,

Have with above-mentioned＜1〉to＜8 in the organic electric-field light-emitting element of any record as the redness of sub-pixel, green, blue each single pixel.

According to the present invention, can solve above-mentioned variety of issue in the past, can reach above-mentioned purpose, can provide not only to have organic electric-field light-emitting element that colourity that excellent light takes out efficient but also can suppress to produce accordingly with respect to the position of organic electric-field light-emitting element with the observer changes and the organic electric field luminescence display that uses this organic electric-field light-emitting element.

Description of drawings

Fig. 1 is the summary section of an example of expression organic electric-field light-emitting element of the present invention.

Fig. 2 is another routine summary section of expression organic electric-field light-emitting element of the present invention.

Fig. 3 is the curve chart of one example of the shape of the luminescent spectrum of the light of transmission by the reflection of second electrode not in the middle of the light that penetrates from luminescent layer of expression.

Fig. 4 is another routine curve chart of the shape of the luminescent spectrum of the light of transmission by the reflection of second electrode not in the middle of the light that penetrates from luminescent layer of expression.

Fig. 5 is the summary section of an example of expression organic electric field luminescence display of the present invention.

Fig. 6 is the curve chart of an example of dependence of angle of the colourity of expression embodiment 1～3 and comparative example 1～comparative example 2.

Fig. 7 is the curve chart of an example of the relation between the expression Δ u ' v ' value and the angle of visual field.

Fig. 8 is the curve chart of the luminescent spectrum that depends on the angle of visual field of expression comparative example 1.

Fig. 9 is the curve chart of the luminescent spectrum that depends on the angle of visual field of expression embodiment 1.

Embodiment

(organic electric-field light-emitting element)

Organic electric-field light-emitting element of the present invention has second electrode, intermediate layer, semitransmissive layer and the light-transmitting layer of first electrode, luminescent layer, half transmitting successively at least, as required, also has the functional layer that is selected from hole injection layer, hole transporting layer, electron injecting layer and the electron supplying layer, in addition, as required, also have substrate, screen, other member etc.

Above-mentioned organic electric-field light-emitting element has first resonator structure and second resonator structure.

-the first electrode, second electrode-

Above-mentioned first electrode is made of reflecting electrode, and above-mentioned second electrode is made of the half transmitting electrode.

As above-mentioned first electrode, be to constitute as having the electrode that makes the light that from above-mentioned luminescent layer, penetrates take out the function of face lateral reflection to light.

Average thickness as above-mentioned first electrode is not particularly limited, and can suitably select according to purpose, yet be preferably more than the 50nm.

If above-mentioned average thickness less than 50nm, then has the situation that can't obtain enough light reflectivities.

Average thickness as above-mentioned second electrode is not particularly limited, and can suitably select according to purpose, yet be preferably more than the 10nm, more preferably more than the 20nm.

If above-mentioned average thickness less than 10nm, then has and makes from a part of transmission of the light of above-mentioned first electrode reflection and can't reflect the situation of the other part of above-mentioned each light.In addition, also can become high-resistance electrode, thereby have the situation that power consumption is risen.

As above-mentioned average thickness, for example use probe-type surface shape measuring device (Ulvac corporate system, Dektak etc.) or use electron microscope (Hitachi's system) photo of the cross section sample made from the FIB method of organic electric-field light-emitting element, measure above-mentioned first electrode of 10 points or the thickness of second electrode, its mean value is made as average thickness.

As above-mentioned first electrode and above-mentioned second electrode, can anode and negative electrode in any one form form, utilize each electrode, constitute the anode and the negative electrode of above-mentioned organic electric-field light-emitting element.

--anode-

Above-mentioned anode is a member of supplying with the hole to hole injection layer, hole transporting layer, luminescent layer etc., can use metal, alloy, metal oxide etc., and preferred work function is the above material of 4eV.

Material as forming above-mentioned anode is not particularly limited, and can suitably select according to purpose, for example can enumerate aluminium, gold, silver, chromium, nickel etc.

As the formation method of above-mentioned anode, can make according to above-mentioned material in all sorts of ways, for example can utilize methods such as electronic beam method, sputtering method, resistance heating vapour deposition method to form.

--negative electrode-

Above-mentioned negative electrode is a member of supplying with electronics to electron injecting layer, electron supplying layer, luminescent layer etc., can consideration with electron injecting layer, electron supplying layer, luminescent layer be equal to the negative electrode adjacency layer adaptation or ionization potential, stability wait and select.

As the material of above-mentioned negative electrode, can use metal, alloy, metal oxide etc., preferred work function is the following material of 4eV.

As above-mentioned material, be not particularly limited, can suitably select according to purpose, for example can enumerate alkali metal, alkaline-earth metal, rare earth metal, gold, silver, lead, aluminium, sodium-potassium-sodium alloy, lithium-aluminium alloy, magnesium-silver alloy, their hybrid metal etc.

As above-mentioned alkali metal, for example can enumerate lithium, sodium, potassium or their fluoride etc.

As above-mentioned alkaline-earth metal, for example can enumerate magnesium, calcium or their fluoride etc.

As above-mentioned rare earth metal, for example can enumerate indium, ytterbium etc.

As the formation method of above-mentioned negative electrode, can make according to material in all sorts of ways, for example can utilize methods such as electronic beam method, sputtering method, resistance heating vapour deposition method to form.

The sheet resistance of above-mentioned anode and negative electrode is low more good more, is preferably below hundreds of Ω/.

-luminescent layer-

Material as above-mentioned luminescent layer, be not particularly limited, can suitably select according to purpose, can use the material that can form following layer etc., promptly, having when applying electric field can be from anode or hole injection layer, hole transporting layer injected hole, and can inject the function of electronics from negative electrode or electron injecting layer, electron supplying layer; Or the function that the electric charge that injected is moved; Provide the hole to make it luminous function with the place that combines again of electronics.

Average thickness as above-mentioned luminescent layer is not particularly limited, and can suitably select according to purpose, is preferably 1nm～5 μ m, and more preferably 5nm～1 μ m is preferably 10nm～500nm especially.Here, above-mentioned average thickness for example can use the electron micrograph in cross section to measure the thickness of the above-mentioned luminescent layer of 10 points, and its mean value is made as average thickness.

As above-mentioned luminescent layer, contain luminescent material.As above-mentioned luminescent layer, both can only constitute by luminescent material, also can be that the mixed layer of material of main part and luminescent material (is called luminescent material " photism dopant " or " dopant " in the latter case, sometimes.)。

As above-mentioned luminescent material, no matter be fluorescence luminescent material or phosphorescent material can, also can mix more than 2 kinds, yet consider from obtaining high efficiency aspect, preferably use phosphorescent material.

As above-mentioned phosphorescent material, in general, can enumerate the complex compound that contains transition metal atoms or group of the lanthanides atom.

As this transition metal atoms, be not particularly limited, can suitably select according to purpose, for example can enumerate ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold, silver, copper, platinum etc., in the middle of them, more preferably rhenium, iridium, platinum, preferred especially iridium, platinum.

Dentate as above-mentioned complex compound, work such as G.Wilkinson for example, Comprehensive Coordination Chemistry, Pergamon Press company issued in 1987, the H.Yersin work, the dentate of putting down in writing in the distribution in 1987 of " Photochemistry and Photophysics of Coordination Compounds ", Springer-Verlag company, the bright husband's work in Yamamoto " organometallic chemistry-basis and application-" skirt China room company, the nineteen eighty-two distribution etc. etc.

Above-mentioned complex compound both can have 1 transition metal atoms in compound, also can be the polynuclear complex that has more than 2 in addition.Can also contain the different kinds of metals atom simultaneously.

In the middle of them, as the concrete example of above-mentioned phosphorescent material, for example can enumerate US6303238B1, US6097147, WO00/57676, WO00/70655, WO01/08230, WO01/39234A2, WO01/41512A1, WO02/02714A2, WO02/15645A1, WO02/44189A1, WO05/19373A2, WO2004/108857A1, WO2005/042444A2, WO2005/042550A1, TOHKEMY 2001-247859, TOHKEMY 2002-302671, TOHKEMY 2002-117978, TOHKEMY 2003-133074, TOHKEMY 2002-235076, TOHKEMY 2003-123982, TOHKEMY 2002-170684, EP1211257, TOHKEMY 2002-226495, TOHKEMY 2002-234894, TOHKEMY 2001-247859, TOHKEMY 2001-298470, TOHKEMY 2002-173674, TOHKEMY 2002-203678, TOHKEMY 2002-203679, TOHKEMY 2004-357791, TOHKEMY 2006-93542, TOHKEMY 2006-261623, TOHKEMY 2006-256999, TOHKEMY 2007-19462, TOHKEMY 2007-84635, phosphorescent compound of putting down in writing in each communique such as TOHKEMY 2007-96259 etc.In the middle of them, preferred Ir complex compound, the Pt complex compound, the Cu complex compound, the Re complex compound, the W complex compound, the Rh complex compound, the Ru complex compound, the Pd complex compound, the Os complex compound, the Eu complex compound, the Tb complex compound, the Gd complex compound, the Dy complex compound, the Ce complex compound, more preferably Ir complex compound, the Pt complex compound, the Re complex compound, further preferably contain the metal-carbon key, metal-nitrogen key, metal-oxygen key, the Ir complex compound of at least a coordination mode in the metal-sulfur key, the Pt complex compound, the Re complex compound, from luminous efficiency, drive durability, viewpoints such as colourity are considered, are especially preferably contained 3 and nibble the above Ir complex compound of nibbling dentate more, the Pt complex compound, the Re complex compound.

As the concrete example of operable phosphorescent material among the present invention, can enumerate following compound, yet be not limited to them.

Content as above-mentioned luminescent material, with respect to the total compound quality that in luminescent layer, in general forms luminescent layer, contain 0.1 quality %～50 quality %, yet consider from the viewpoint of durability, external quantum efficiency, preferably contain 1 quality %～50 quality %, more preferably contain 2 quality %～40 quality %.

As the aforementioned body material, can use the cavity conveying material of main part of cavity conveying excellence and the electron transport material of main part of electron transport excellence.

As above-mentioned cavity conveying material of main part, for example can enumerate pyrroles, indoles, carbazole, azaindole, azepine carbazole, triazole,

Azoles,

Diazole, pyrazoles, imidazoles, thiophene, the polyaryl alkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, the amino chalcone that replaces, the styryl anthracene, Fluorenone, hydrazone, Stilbene, silazane, aromatic uncle amine compound, the styryl amines, aromatic series two methine based compounds, the porphyrin based compound, the polysilane based compound, poly-(N-vinylcarbazole), the aniline based copolymer, thiophene oligomers, electrical conductance macromolecule oligomer such as polythiophene, organosilan, carbon film, or their derivative etc.In the middle of them, preferred indole derivatives, carbazole derivates, aromatic uncle amine compound, thiophene derivant more preferably have the compound of carbazyl in molecule, especially preferably have the compound of tert-butyl group substituted carbazole base.

As above-mentioned electron transport material of main part, consider that from the viewpoint that improves durability, reduction driving voltage electron affinity Ea is preferably below the above 3.5eV of 2.5eV, more preferably below the above 3.4eV of 2.6eV, is preferably especially below the above 3.3eV of 2.8eV.In addition, consider that from the viewpoint that improves durability, reduction driving voltage ionization potential Ip is preferably below the above 7.5eV of 5.7eV, more preferably below the above 7.0eV of 5.8eV, is preferably especially below the above 6.5eV of 5.9eV.

As above-mentioned electron transport material of main part, for example can enumerate pyridine, pyrimidine, triazine, imidazoles, pyrazoles, triazole,

Azoles,

Diazole, Fluorenone, anthraquinone bismethane, anthrone, two benzoquinones, thiapyran dioxide, carbodiimide, fluorenylidene methane, diphenylethyllene pyrazine, fluorine substituted aromatic compound, naphthalene and perylene condensed ring tetracarboxylic anhydride, phthalocyanine or their derivatives such as (naphthalene perylene) (also can form condensed ring) with other ring, with the metal complex of oxine derivatives such as BAlq or with metal phthalocyanine, benzo

Azoles or benzothiazole are various metal complexs of representative etc. as the metal complex of dentate.

As above-mentioned electron transport material of main part, preferable alloy complex compound, Zole derivatives (benzimidizole derivatives, imidazopyridine derivatives etc.), azine derivatives (pyridine derivate, pyrimidine derivatives, pyrrolotriazine derivatives etc.), wherein, consider from the aspect of durability, more preferably metal complex.Metal complex (A) preferably possesses the metal complex of any one dentate at least that has with nitrogen-atoms, oxygen atom and the sulphur atom of metal-complexing.

Metal ion in the metal complex is not particularly limited, and can suitably select according to purpose, for example can enumerate beryllium ion, magnesium ion, aluminium ion, gallium ion, zinc ion, indium ion, tin ion, platinum ion or palladium ion etc.In the middle of them, preferred beryllium ion, aluminium ion, gallium ion, zinc ion, platinum ion or palladium ion, more preferably aluminium ion, zinc ion or palladium ion.

As dentate contained in the above-mentioned metal complex, so long as various known dentates get final product, for example can enumerate the middle dentates of putting down in writing such as " Photochemistry and Photophysics of Coordination Compounds ", Springer-Verlag company, H.Yersin work, distribution in 1987, " organometallic chemistry-basis and application-", skirt China room company, the bright husband's work in Yamamoto, nineteen eighty-two distribution.

As above-mentioned dentate, more preferably nitrogen heterocyclic ring dentate (preferred carbon number is 1～30, and more preferably carbon number is 2～20, and preferred especially carbon number is 3～15).In addition, as above-mentioned dentate, both can be singly to nibble dentate, also can 2 nibble above dentate, be preferably 2 and nibble above 6 and nibble following dentate.In addition, also preferred 2 nibble the above 6 mixed ligand bases of nibbling following dentate and singly nibbling.

As above-mentioned dentate, for example can enumerate the azine dentate and (for example can enumerate pyridine coordination base, bipyridine dentate, terpyridyl dentate etc.), hydroxy phenyl azoles dentate (for example can enumerate hydroxy phenyl benzimidazole dentate, hydroxy phenyl benzo

Azoles dentate, hydroxy phenyl imidazoles dentate, hydroxy phenyl imidazopyridine dentate etc.), (for example can enumerate methoxyl group, ethyoxyl, butoxy, 2-ethyl hexyl oxy etc., preferred carbon number is 1～30 to the alkoxyl dentate, and more preferably carbon number is 1～20, and preferred especially carbon number is 1～10.), the aryloxy group dentate (for example can enumerate phenoxy group, 1-naphthoxy, 2-naphthoxy, 2,4,6-trimethyl phenoxy group, 4-xenyl oxygen base etc., preferred carbon number is 6～30, more preferably carbon number is 6～20, preferred especially carbon number is 6～12.), (for example can enumerate pyridine oxygen base, pyrazine oxygen base, 2-pyrimidinyl oxy, quinoline oxy etc., preferred carbon number is 1～30 to the heteroaryloxy dentate, and more preferably carbon number is 1～20, and preferred especially carbon number is 1～12.), (for example can enumerate methyl mercapto, ethylmercapto group etc., preferred carbon number is 1～30 to the alkylthio group dentate, and more preferably carbon number is 1～20, and preferred especially carbon number is 1～12.), (for example can enumerate thiophenyl etc., preferred carbon number is 6～30 to the arylthio dentate, and more preferably carbon number is 6～20, and preferred especially carbon number is 6～12.), the heteroarylthio dentate (for example can enumerate pyridine sulfenyl, 2-benzimidazole sulfenyl, 2-benzo

Azoles sulfenyl, 2-[4-morpholinodithio sulfenyl etc., preferred carbon number is 1～30, and more preferably carbon number is 1～20, and preferred especially carbon number is 1～12.), (for example can enumerate triphenyl siloxy, triethoxysilyl, triisopropyl siloxy etc., preferred carbon number is 1～30 to the siloxy dentate, and more preferably carbon number is 3～25, and preferred especially carbon number is 6～20.), (for example can enumerate phenyl anion, naphthyl anion and anthryl anion etc., preferred carbon number is 6～30 to aromatic hydrocarbon anion binding base, and more preferably carbon number is 6～25, and preferred especially carbon number is 6～20.), heteroaromatic anion binding base (for example can enumerate pyrroles's anion, pyrazoles anion, pyrazoles anion, triazole anion,

Azoles anion, benzo

Azoles anion, thiazole anion, benzothiazole anion, thiophene anion and benzothiophene anion etc., preferred carbon number is 1～30, and more preferably carbon number is 2～25, and preferred especially carbon number is 2～20.), indoles anion binding base etc., preferred nitrogen heterocyclic ring dentate, aryloxy group dentate, heteroaryloxy dentate, siloxy dentate etc., more preferably nitrogen heterocyclic ring dentate, aryloxy group dentate, siloxy dentate, aromatic hydrocarbon anion binding base, heteroaromatic anion binding base etc.

As the example of above-mentioned metal complex electron transport main body, for example can enumerate the compound of putting down in writing in each communique such as TOHKEMY 2002-235076, TOHKEMY 2004-214179, TOHKEMY 2004-221062, TOHKEMY 2004-221065, TOHKEMY 2004-221068, TOHKEMY 2004-327313.

As the triplet lowest excited energy level (T1) of aforementioned body material, consider from the aspect of colour purity, luminous efficiency, driving durability, preferably be higher than the T1 of above-mentioned phosphorescent material.

Content as the aforementioned body material is not particularly limited, yet considers from the viewpoint of luminous efficiency, driving voltage, with respect to the total compound quality that forms luminescent layer, is preferably below the above 95 quality % of 15 quality %.

Formation method as above-mentioned luminescent layer is not particularly limited, and can suitably select according to purpose, for example can enumerate methods such as resistance heating evaporation, electron beam, sputter, molecule layered manner, cladding process, LB method.In the middle of them, preferred especially resistance heating evaporation, cladding process.

As above-mentioned cladding process, for example can enumerate spin-coating method, The tape casting, dip coating etc.

-hole injection layer, hole transporting layer-

Material as above-mentioned hole injection layer and hole transporting layer, so long as have function from the anode injected hole, carry the hole function, stop any one material from the function of negative electrode injected electrons, just be not particularly limited, can suitably select according to purpose.

As the material of above-mentioned hole injection layer and hole transporting layer, for example can enumerate carbazole derivates, triazole derivative,

Zole derivatives, Oxadiazole derivative, imdazole derivatives, polyaryl chain alkane derivatives, pyrazoline derivative, pyrazolone derivative, phenylenediamine derivative, the arylamine derivative, the amino chalcone derivative that replaces, the styryl anthracene derivant, fluorenone derivatives, hydazone derivative, stilbene derivative, the silazane derivative, aromatic uncle amine compound, the styryl amines, aromatic series two methine based compounds, the porphyrin based compound, the polysilane based compound, poly-(N-vinylcarbazole) derivative, the aniline based copolymer, thiophene oligomers, electroconductive polymer oligomer such as polythiophene etc.They both can be used alone or two or more kinds may be used.

As above-mentioned hole injection layer and hole transporting layer, both can be the single layer structure that constitutes more than a kind or 2 kinds by above-mentioned material, also can form or the different a plurality of layers of sandwich construction of forming that constitutes by same.

As the formation method of above-mentioned hole injection layer and hole transporting layer, for example can use vacuum vapour deposition, LB method, hole injectant and cavity conveying agent are dissolved or dispersed in the solvent and the method (spin-coating method, The tape casting, dip coating etc.) that applies.Under the situation of cladding process, can dissolve or disperse with resinous principle.

As above-mentioned resinous principle, be not particularly limited, can suitably select according to purpose, for example can enumerate Corvic, polycarbonate resin, polystyrene resin, plexiglass, the polybutylene terephthalate (PBT) resin, mylar, polysulfone resin, polyphenylene oxide resin, polybutadiene, poly-(N-vinylcarbazole) resin, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin, polyurethane resin, melamine resin, unsaturated polyester resin, alkyd resins, epoxy resin, silicone resin etc.They both can be used alone or two or more kinds may be used.

Thickness as above-mentioned hole injection layer and hole transporting layer is not particularly limited, and can suitably select according to purpose, for example is preferably 1nm～5 μ m, and more preferably 5nm～1 μ m is preferably 10nm～500nm especially.As above-mentioned average thickness, for example can use the electron micrograph in cross section to measure the above-mentioned hole injection layer of 10 points or the thickness of hole transporting layer, its mean value is made as average thickness.

-electron injecting layer, electron supplying layer-

Material as above-mentioned electron injecting layer and electron supplying layer, so long as have from negative electrode inject function, the conveying electronic of electronics function, stop any one material from the function of anode injected holes, just be not particularly limited, can suitably select according to purpose.

As the material of above-mentioned electron injecting layer and electron supplying layer, for example can enumerate triazole derivative,

Zole derivatives,

Condensed ring tetracarboxylic anhydrides such as oxadiazole derivative, fluorenone derivatives, anthraquinone bismethane derivative, anthracyclinone derivatives, two quinone derivatives, thiapyran dioxide derivative, carbodiimide derivative, fluorenylidene methane Derivatives, diphenylethyllene pyrazines derivatives, naphthalene perylene, phthalocyanine derivates, with the metal complex of oxine derivative or with metal phthalocyanine, benzo Azoles or benzothiazole are various metal complexs of representative etc. as the metal complex of dentate.They both can be used alone or two or more kinds may be used.

As above-mentioned electron injecting layer and electron supplying layer, both can be the single layer structure that constitutes more than a kind or 2 kinds by above-mentioned material, also can form or the different a plurality of layers of sandwich construction of forming that constitutes by same.

As the formation method of above-mentioned electron injecting layer and electron supplying layer, for example can use vacuum vapour deposition or LB method, electronics injectant and electron transporting agent are dissolved or dispersed in the solvent and the method (spin-coating method, The tape casting, dip coating etc.) that applies.Under the situation of cladding process, can dissolve or disperse with resinous principle.As above-mentioned resinous principle, for example can be applied in illustrated material under the situation of hole injection layer and hole transporting layer.

Thickness as above-mentioned electron injecting layer and electron supplying layer is not particularly limited, and can suitably select according to purpose, is preferably 1nm～5 μ m, and more preferably 5nm～1 μ m is preferably 10nm～500nm especially.As above-mentioned average thickness, for example can use the electron micrograph in cross section to measure the above-mentioned electron injecting layer of 10 points or the thickness of electron supplying layer, its mean value is made as average thickness.

-intermediate layer-

As above-mentioned intermediate layer, the light that is in above-mentioned second electrode takes out the face side, has the function of adjustment as the length of the light of advancing in this intermediate layer of the optical path length of the light of institute's incident.

As above-mentioned intermediate layer, so long as have the material of above-mentioned functions, just be not particularly limited, for example can enumerate following material etc., promptly, in first electrode and semitransmissive layer the phase difference of reflex time and when being the integral multiple of 2 π, after the peak luminous wavelength in the luminescent layer is made as λ, will be adjusted into the integral multiple of λ/2 to the optical path length of above-mentioned semitransmissive layer from above-mentioned first electrode.

As above-mentioned intermediate layer,, can suitably select according to purpose so long as this kind form then for shape, structure, size etc., just is not particularly limited.

Material as above-mentioned intermediate layer, so long as can not cause the material of tangible influence to incident light wavelength or luminous intensity, just be not particularly limited, optically transparent inorganic and organic various material can be enumerated, for example transparent resins such as polyacrylate, polymethyl methacrylate, polyimides can be enumerated.

Formation method as above-mentioned intermediate layer is not particularly limited, and can suitably select according to purpose, for example can enumerate methods such as electronic beam method, sputtering method, resistance heating vapour deposition method, spin-coating method, spraying process, ink-jet method.

Thickness as above-mentioned intermediate layer, be adjusted into and suppress the colourity that the angle by the light of the wavelength of observing regulation causes and change, specifically, according to following general formula (1) and general formula (2), by the refractive index that is held on the material between first electrode and the intermediate layer and form, decision such as thickness.

General formula (1)

Wherein, in the above-mentioned general formula (1), n represents the refractive index of each layer, d ₁Represent the distance between this luminescent layer side surface of the luminescent layer side surface of above-mentioned first electrode and above-mentioned second electrode, m represents number of times, φ ₀The reflected phase will side-play amount of representing the first electrode place, φ ₁The reflected phase will side-play amount of representing the second electrode place, φ ₂The reflected phase will side-play amount at expression semitransmissive layer place, the peak wavelength of the light that λ 1 expression is sent.

General formula (2)

Wherein, in the above-mentioned general formula (2), n represents the refractive index of each layer, d ₂Represent the distance between the surface of above-mentioned luminescent layer side in the luminescent layer side surface of above-mentioned first electrode and above-mentioned intermediate layer, m represents number of times, φ ₀The reflected phase will side-play amount of representing the first electrode place, φ ₁The reflected phase will side-play amount of representing the second electrode place, φ ₂The reflected phase will side-play amount at expression semitransmissive layer place, the peak wavelength of the light that λ 1 expression is sent.

Above-mentioned general formula (1) expression is observed the resonance condition of the light time of wavelength X 1 from frontal (θ=0 °).Above-mentioned so-called frontal is meant, draws vertical line from aforesaid substrate to above-mentioned luminescent layer, the direction the when angle of visual field of seeing from this direction (θ) is 0 °.

Above-mentioned general formula (2) expression is observed the resonance condition of the light time of wavelength X 1 from 45 ° of directions (θ=45 °).Above-mentioned so-called 45 ° of directions are meant, draw vertical line from aforesaid substrate to above-mentioned luminescent layer, when the angle of visual field (θ) of this direction is made as 0 °, and the direction the when angle of visual field (θ) is 45 °.

Satisfy the relation of above-mentioned general formula (1) and general formula (2) by the thickness that makes above-mentioned intermediate layer, even with the observer with respect to the position of organic electric-field light-emitting element to 45 ° (45 ° of angles of visual field) such high angle side migration (moving), utilization at from the observation of high angle apart from d ₂The effect of resonator length, also can continue to radiate the light of wavelength X 1 in the high angle side.

Though, take out and utilize apart from d at the frontal of aforesaid substrate ₁Resonator length obtain the wavelength X 1 of resonance effects, yet when the observer with respect to the position of organic electric-field light-emitting element when the high angle side is moved, resonant wavelength will move to short wavelength side.At this moment, because by distance d ₁The resonance effects of bringing diminishes, so luminous intensity diminishes.

But, in the face such high angle side of observer, in above-mentioned general formula (2), because apart from d with respect to the approaching above-mentioned organic electric-field light-emitting element in position of above-mentioned organic electric-field light-emitting element ₂Be in the relation of the resonator length that satisfies wavelength X 1, therefore utilize by distance d ₂The resonance effects of bringing is taken out wavelength X 1 light once more consumingly, so even change the position of observer with respect to organic electric-field light-emitting element, also can suppress the spectrum change amount.

But the peak value of spectrum or the angle variable quantity of colourity depend on the shape of the luminescent spectrum of luminescent material as providing shown in the example among Fig. 3 and Fig. 4.Resonant wavelength along with the angle of visual field becomes big, moves to the short wavelength for example as shown in Figure 8.Luminescent material is owing to also be luminous from short wavelength side, so the luminous intensity of short wavelength side will strengthen, and angle of visual field dependency characteristic (colourity corresponding with observer's position changes) changes.Thus, preferably make the front resonant wavelength with than the shorter consistent wavelength of first peak wavelength from the short wavelength side number of above-mentioned luminescent spectrum.The luminous intensity of the peak wavelength of luminescent material is made as 1, then can shows and be in the slope that reaches the short wavelength side of the above-mentioned luminescent spectrum till 0.2 than the short wavelength side of above-mentioned peak wavelength and luminous intensity with following mathematical expression 1.

＜mathematical expression 1 〉

Δλ＝λ(I0)-λ(0.2×I0)

Wherein, in the above-mentioned mathematical expression 1, λ (I0) expression front resonant wavelength, I0 represents the luminous intensity this wavelength under, λ (0.2 * I0) wavelength when representing to reach 0.2 times of luminous intensity of λ (I0) luminous intensity, λ (I0)＞λ (0.2 * I0).

And, be defined as luminous intensity reach Δ λ till 0.2 be because, if below 0.2, then the SN of luminous composition ratio will variation, it is many that noise becomes.

If the Δ λ of above-mentioned mathematical expression 1 is little, then can suppresses colourity and change.Δ λ represents the slope of the wavelength side shorter than the peak wavelength of luminescent spectrum as shown in Figure 3, Figure 4.λ is more little for Δ, and then as shown in Figure 3, steeper slopes is high and steep, and Δ λ is big more, and then as shown in Figure 4, slope is mild more.

If Δ λ is big, even, also have the luminous composition that much can resonate, therefore will strengthen in the short wavelength side luminous intensity then because the angle of visual field changes (observer is with respect to the change in location of organic electric-field light-emitting element), angle of visual field dependency characteristic changes.

Achievement according to the inventor's etc. further investigation obtains following opinion, that is, in organic electric-field light-emitting element of the present invention, if make Δ λ less than 25nm, then the variation of tone just obtains suppressing, and satisfies the performance as display.

Change as above-mentioned colourity, as shown in Figure 7, use Δ u ' v ' value.Change as above-mentioned colourity, the variable quantity of each angle that the u ' v ' value when using from positive (0 ° of the angle of visual field) is counted is represented.Known in display devices such as display, if in general Δ u ' v ' surpasses 0.02 then not ideal enough.

For example, for red (among Fig. 7, Δ λ=25nm (resonant wavelength is a short wavelength side)), if in Δ λ＜25nm, the index Δ u ' v ' so that the scope of 0 °～80 ° of the angles of visual field observes colourity change then can be suppressed at the colourity variable quantity below 0.02.In addition, as shown in Figure 7, for blue (among Fig. 7, Δ λ=20nm) or green (among Fig. 7, Δ λ=15nm), also can similarly obtain effect.And when resonant wavelength being set in than the longer wavelength side of the peak wavelength of luminescent spectrum, then as shown in Figure 7, Δ u ' v ' value can surpass 0.02.Like this,, Δ λ is made as less than 25nm, just can suppresses colourity and change by resonant wavelength being made as the wavelength side shorter than peak wavelength.

Specifically, as the average thickness in above-mentioned intermediate layer, can for example, under the situation of redness, determine according to the change color of the light that from above-mentioned luminescent layer, penetrates as followsly.

When the peak wavelength of the light that will take out to frontal is made as 620nm, total for the thickness of first resonator structure that comprises luminescent layer etc., according to general formula (1), be 324nm, be made as 1.8 o'clock in refractive index the intermediate layer, if ask the thickness of second resonator structure, then be 465nm according to general formula (2).

So the thickness that deducts the average thickness of second electrode from its difference is exactly the average thickness in intermediate layer, under this situation, 130nm is best.

In above-mentioned intermediate layer, because luminescent spectrum is wide, therefore ± be range of allowable error about 5nm.The angular regions that also inhibition can be depended on the peak wavelength migration of the angle of visual field is set at than 45 ° of angle sides that direction is low, if 40 ° of directions, then according to general formula (2), the average thickness in intermediate layer is 90nm.If further be made as low angle, then the peak wavelength migration will become big in the high angle side, thereby the problem of the tone of infringement high angle side occurs.

So under this situation, the thickness in intermediate layer is preferably 85～135nm, more preferably 125～135nm.

If above-mentioned average thickness is less than 85nm or surpass 135nm, then along with observer's position difference, colourity changes or color displacement will become greatly, and the raising of efficient tails off, thereby has the situation that can't obtain effect of the present invention.

Here,, for example can use the electron micrograph in cross section, measure the thickness in the above-mentioned intermediate layer of 10 points, its mean value is made as average thickness as above-mentioned average thickness.

In addition, under green and blue situation, also can utilize the principle identical to obtain average thickness with red situation.

-semitransmissive layer-

Above-mentioned semitransmissive layer is between above-mentioned intermediate layer and the above-mentioned light-transmitting layer, has to make the light that penetrates and from a part of transmission of the light of above-mentioned first electrode reflection and with other a part of function of reflecting of above-mentioned each light from above-mentioned luminescent layer.

Material as above-mentioned semitransmissive layer is not particularly limited, and can suitably select according to purpose, for example can enumerate metal etc.

As above-mentioned metal, for example can enumerate silver, magnesium-silver alloy, aluminium etc.

Formation method as above-mentioned semitransmissive layer is not particularly limited, and can suitably select according to purpose, for example can enumerate methods such as electronic beam method, sputtering method, resistance heating vapour deposition method.

Average thickness as above-mentioned semitransmissive layer is not particularly limited, and can suitably select according to purpose, for example is preferably 3nm～50nm, and more preferably 5nm～40nm is preferably 10nm～30nm especially.

If above-mentioned average thickness less than 3nm, then because reflectivity is low, therefore has the situation that can't obtain effect of the present invention,,, therefore have the situation that can't obtain effect of the present invention then because transmissivity is low if surpass 10nm.

Here,, for example can use the electron micrograph in cross section, measure the thickness of the above-mentioned semitransmissive layer of 10 points, its mean value is made as average thickness as above-mentioned average thickness.

In addition, as the average thickness of above-mentioned semitransmissive layer, in order to improve optical distance d ₁Resonance effects, preferably make average thickness thinner than above-mentioned second electrode.As the average thickness of above-mentioned semitransmissive layer and the ratio of the average thickness of above-mentioned second electrode (average thickness of the average thickness of semitransmissive layer/second electrode), be preferably 0.1～2, more preferably 0.2～1.5, be preferably 0.4～1 especially.

If the ratio of above-mentioned average thickness is less than 0.1, then reflectivity is abundant inadequately, have the situation that can't obtain effect of the present invention,, then have and to strengthen as the wavelength of target or can't obtain the situation that colourity when the high angle side is watched suppresses effect if surpass 2.

-light-transmitting layer-

Above-mentioned light-transmitting layer is between substrate and the above-mentioned semitransmissive layer at least, have following function, that is, and with the catoptrical phase cancellation of above-mentioned semitransmissive layer and substrate interface, increase the transmission amount of light to aforesaid substrate, the colourity that suppresses simultaneously to be caused by observed angle changes.

As above-mentioned light-transmitting layer, as long as have this kind function, then just be not particularly limited for shape, structure, size etc., can suitably select according to purpose.

Material as above-mentioned light-transmitting layer is not particularly limited, and can suitably select according to purpose, for example can enumerate magnesium fluoride, Alq, Cytop (Asahi Glass corporate system), SiNx etc.

As above-mentioned light-transmitting layer, for example,, also can between above-mentioned second electrode and above-mentioned intermediate layer, also have except between aforesaid substrate and the above-mentioned semitransmissive layer as providing among Fig. 2 shown in the example.By being made as this kind formation, just can improve the anti-reflection effect at the interface of second electrode, can further improve light and take out efficient.

As the average thickness of above-mentioned light-transmitting layer, be made as t in 1/4 length of the peak wavelength of the light that will from above-mentioned luminescent layer, penetrate, when the refractive index of above-mentioned light-transmitting layer is made as n, be preferably below the above 1.1 * t/n of 0.9 * t/n.

If above-mentioned average thickness, then has the light that can't obtain to be brought by effect of the present invention less than 0.9 * t/n and takes out the situation that efficient improves effect,, then can with good grounds material difference, absorption take out the situation that efficient reduces on the contrary because of making light if surpass 1.1 * t/n.

Specifically, for example peak wavelength being made as red 620nm, with MgF ₂Be made as under the situation of material, because MgF ₂Refractive index be 1.38, so 101nm～123.5nm is suitable.If consider the phase change that causes by reflection etc. as a whole structure come optimization, then can be compared to most the thin 10nm of 101nm～123.5nm, therefore be preferably 91nm～113.5nm.

In above-mentioned light-transmitting layer because luminescent spectrum is wide, therefore as the variation of thickness allow ± 5nm about.So, as the average thickness of light-transmitting layer, more preferably 86nm～118.5nm.

As above-mentioned average thickness, for example can use the electron micrograph in cross section, measure the thickness of the above-mentioned light-transmitting layer of 10 points, its mean value is made as average thickness.

As poor (the Δ n) of refractive index between the layer of above-mentioned light-transmitting layer and adjacency, if because (Δ n) is big, then the boundary reflection rate improves, so effect further emphasized, so be at least 0.1.

If above-mentioned refringence is less than 0.1, then reflectivity is low, therefore has the situation that can't obtain resonant structure required for the present invention.Here, the layer of above-mentioned so-called adjacency is meant substrate, semitransmissive layer in Fig. 1, is meant substrate, semitransmissive layer, intermediate layer and second electrode in Fig. 2.Above-mentioned refractive index can use ellipsometer (the hole field makes made) to measure.

-substrate-

As aforesaid substrate,, in general,, preferably tabular as the shape of substrate as long as suitably select its shape, structure, size etc.As the structure of substrate, both can be single layer structure, also can be stepped construction, in addition, both can form by solid memder, also can form by the member more than 2.

As aforesaid substrate, both can be water white, also can be colored transparent, yet aspects such as the light scattering of sending from luminescent layer or decay are considered, preferably water white.

Material as aforesaid substrate, be not particularly limited, can suitably select according to purpose, for example can enumerate inorganic material such as yttria-stabilized zirconia (YSZ), glass, pet resin, polybutylene terephthalate (PBT), PEN resin, mylar, polystyrene resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, polyimide resin, poly-cyclic olefin resins, norbornene resin, poly-(chlorotrifluoroethylene) resin etc.They both can be used alone or two or more kinds may be used.

Using under the situation of glass,,, preferably use alkali-free glass in order to reduce released ion from glass for its material as aforesaid substrate.In addition, under the situation of using soda-lime glass, the preferred glass (for example barrier layer substrate) that has applied barrier layers such as silicon dioxide that uses.Under the situation of organic material, preferred excellence aspect thermal endurance, dimensional stability, solvent resistance, electrical insulating property and processability.

State in the use under the situation of thermoplasticity substrate, also can as required hard conating, priming coat etc. be set also.

Also can be on aforesaid substrate, configuration makes the planarization layer of this upper shape planarization, disposes above-mentioned light-transmitting layer etc. on this planarization layer.

Material as this planarization layer is not particularly limited, and can suitably select according to purpose, for example can enumerate SiO ₂, SiON, polyimides etc.

Use Fig. 2 that one example of the execution mode of the organic electric-field light-emitting element of the present invention that constitutes is as described above described.

Above-mentioned organic electric-field light-emitting element 100 disposes first electrode 9, electron supplying layer 8, light-emitting component 7, hole transporting layer 6, second electrode 5, intermediate layer 4, semitransmissive layer 3, light-transmitting layer 2, substrate 1 successively.

In this organic electric-field light-emitting element 100, play a role as first resonator structure that constitutes by first electrode 9, electron supplying layer 8, luminescent layer 7, hole transporting layer 6 and second electrode 5, and play a role as second resonator structure that constitutes by first electrode 9, electron supplying layer 8, luminescent layer 7, hole transporting layer 6, second electrode 5, intermediate layer 4 and semitransmissive layer 3.

In the organic electric-field light-emitting element 100 that so constitutes,, penetrate by optical distance d in above-mentioned frontal (θ=0 °) ₁The light of the wavelength X 1 selected of resonator length.Different with it, become big direction in the observed angle of counting from optical axis direction, utilize at optical distance d from the observation of high angle ₂The effect of resonator length, also can continue to penetrate the light of wavelength X 1 in the high angle side.Consequently, can suppress to change with respect to the colourity that the position of organic electric-field light-emitting element produces accordingly with the observer.

As organic electric-field light-emitting element of the present invention, when considering large-area luminaire, consider from the electrical characteristics such as sheet resistance of transparency electrode, preferably be made as from the formation of the end emission type of aforesaid substrate 1 side-draw bright dipping.

(organic electric field luminescence display)

Organic electric field luminescence display of the present invention has above-mentioned organic electric-field light-emitting element, as required, can use other formation.As above-mentioned other formation, be not particularly limited, can suitably select according to purpose, as for the necessary item of display, can use all known mechanisms.

As above-mentioned organic electric field luminescence display, as providing among Fig. 5 shown in the example,, take out light of all kinds by making the varied in thickness with red (R), green (G), above-mentioned intermediate layer that blue (B) is corresponding.By being made as this kind formation, just can have excellent light and take out efficient, and power consumption is low, the colourity that can suppress to be caused by observed angle changes.

Embodiment

Below, embodiments of the invention are described, yet the present invention is not subjected to any qualification of these embodiment.And for the material refractive index among the embodiment, short of particularly pointing out is exactly the measured value by the analysis of polarized light determination method.The analysis of polarized light determination method is by the assay method of monochromatic source to polariscopic angle scanning, therefore records the refractive index under its optical source wavelength.Light source has used the He-Ne laser of wavelength 632.8nm.

(embodiment 1)

The making of＜organic electric-field light-emitting element 〉

Be on 1.51 the glass substrate,,, to utilize vacuum evaporation to form MgF in thick 0.7mm, refractive index according to making thickness reach the mode of 100nm as light-transmitting layer ₂Use ellipsometer to measure the refractive index of light-transmitting layer, consequently 1.38.

On light-transmitting layer,,, utilize vacuum evaporation to form silver (Ag) according to making thickness reach the mode of 12nm as semitransmissive layer.

On semitransmissive layer,,, utilize vacuum evaporation to form Alq (three (oxine) aluminium) according to making thickness reach the mode of 130nm as the intermediate layer.Use ellipsometer to measure the refractive index of Alq, consequently 1.74.

Then, on the intermediate layer,,, utilize vacuum evaporation to form silver (Ag), formed silverskin is contacted with electrode terminal according to making thickness reach the mode of 20nm as second electrode (anode).

On second electrode, as hole transporting layer, according to making thickness reach the mode of 235nm, utilize vacuum evaporation to be formed on 1.0% the F4-TCNQ (2; 3,5,6-tetrafluoro-7; 7,8,8-four cyano quinone bismethane) that mixed among the 2-TNATA (4,4 ', 4 "-three (2-naphthyl phenyl amino) triphenylamine); then, on hole transporting layer, according to making thickness reach the mode of 10nm; vacuum evaporation NPD (N, N '-diphenyl-N, N '-two (Alpha-Naphthyl)-benzidine).

Then, on NPD, will as the BAlq (aluminium (III) two (2-methyl-8-quinoline) 4-benzene substituting phenol base) of material of main part, as the luminescent material A that represents with following structural formula of luminescent material with 95: 5 ratio of mass ratio, according to making thickness reach the mode of 30nm, utilize vacuum evaporation altogether, form luminescent layer.And the ratio of the signal of the quartz crystal unit that will monitor out with CRTM9000 (Ulvac corporate system) is as mass ratio.

Then, on luminescent layer,,, utilize vacuum evaporation to form BAlq (aluminium (III) two (2-methyl-8-quinoline) 4-benzene substituting phenol base) according to making thickness reach the mode of 39nm as electron supplying layer.In order to make the electronics injection good, according to making thickness reach the mode of 1nm, vacuum evaporation BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) is then according to making thickness reach the mode of 1nm, vacuum evaporation LiF.

Then, by on LiF,,, utilize vacuum evaporation to form Al, and produce organic electric-field light-emitting element (1) according to making thickness reach the mode of 100nm as first electrode (negative electrode).

The organic electric-field light-emitting element of gained (1) has the micro-cavity structure of two dimension, the organic electric-field light-emitting element of made (1) be concerning red (about 620nm) luminous optimization element.

(embodiment 2)

The making of＜organic electric-field light-emitting element 〉

Except in embodiment 1, form beyond the light-transmitting layer as followsly, made organic electric-field light-emitting element (2) in the same manner with embodiment 1.

The formation of-light-transmitting layer-

On the glass substrate of thick 0.7mm, refractive index 1.51,,, utilize vacuum evaporation to form MgF according to making thickness reach the mode of 112nm as light-transmitting layer ₂Use ellipsometer to measure the refractive index of light-transmitting layer, consequently 1.38.

The organic electric-field light-emitting element of gained (2) has the micro-cavity structure of two dimension, the organic electric-field light-emitting element of made (2) be concerning red (about 620nm) luminous optimization element.

(embodiment 3)

The making of＜organic electric-field light-emitting element 〉

Except in embodiment 1, form beyond the intermediate layer as followsly, made organic electric-field light-emitting element (3) in the same manner with embodiment 1.

The formation in-intermediate layer-

On semitransmissive layer, as the intermediate layer, with the thickness evaporation of 30nm MgF ₂, next, utilize vacuum evaporation to form ITO according to making thickness reach the mode of 100nm.Use ellipsometer mensuration refractive index separately, consequently, MgF ₂Be 1.38, ITO is 1.98.

The organic electric-field light-emitting element of gained (3) has the micro-cavity structure of two dimension, the organic electric-field light-emitting element of made (3) be concerning red (about 620nm) luminous optimization element.

(comparative example 1)

The making of＜organic electric-field light-emitting element 〉

Except in embodiment 1, be made as and do not have light-transmitting layer, beyond the formation in semitransmissive layer and intermediate layer, made organic electric-field light-emitting element (4) in the same manner with embodiment 1.

(comparative example 2)

The making of＜organic electric-field light-emitting element 〉

Except in embodiment 1, be made as beyond the formation with light-transmitting layer, made organic electric-field light-emitting element (5) in the same manner with embodiment 1.

(evaluation)

Colourity variation and the light taking-up efficient corresponding with respect to the position of organic electric-field light-emitting element of each organic electric-field light-emitting element of made have been estimated with the observer as followsly.In addition, for embodiment 1 and comparative example 1, determine luminescent spectrum as followsly.

-with the observer with respect to the corresponding colourity in the position of organic electric-field light-emitting element change-

Each organic electric-field light-emitting element of made is erect configuration, according to the x that from spectrum, derives, y chromaticity coordinate, obtain each angle based on the standard of CIE1976 and (draw vertical line to above-mentioned luminescent layer from aforesaid substrate, to be made as 0 ° from the angle of visual field that this direction is seen, with above-mentioned vertical line be benchmark to the left and right direction every 5 ° of ground offset straight till ± 85 °) u ', the v ' of cie color coordinate.The results are shown among Fig. 6.

-light taking-up efficient-

Make each organic electric-field light-emitting element of made luminous, utilize quantometer (multichannel optical splitter, Oceanphotonics Co., Ltd. system) to determine its light quantity.Based on the light quantity that determines, calculate light and take out efficient.The results are shown in Table 1.

＜changed the mensuration of the luminescent spectrum of the angle of visual field 〉

To the embodiment 1 of made and the organic electric-field light-emitting element of comparative example 1, when in angle measurement platform (gonio stage), making the sample rotation, determine luminescent spectrum with beam split brightness photometer 2000 (Unica Minolta corporate system).The result of embodiment 1 is shown among Fig. 8, the result of comparative example 1 is shown among Fig. 9.

[table 1]

	Embodiment 1	Embodiment 2	Embodiment 3	Comparative example 1	Comparative example 2
						Efficient (cd/A)	18.08	18.11	18.26	14.83	17.28

Wherein, said efficient is represented 1000cd/m in the table 1 ²The time electric current briliancy efficient.

According to table 1 as can be known, embodiment 1～3 compares with comparative example 1～2, and light takes out efficient and improves.

In addition, according to Fig. 6 as can be known, the Δ u ' v ' value of embodiment 1～3 is 0.02, and in comparative example 1～comparative example 2, Δ u ' v ' is worth far away from more than 0.02.Hence one can see that, and among the embodiment 1～3, the colourity corresponding with respect to the position of organic electric-field light-emitting element with the observer changes the inhibition that obtains very greatly.

In addition, as shown in Figure 8, the luminescent spectrum of comparative example 1 is along with the angle of visual field becomes big as can be known, and the peak of spectrum moves to short wavelength side, and variation has also taken place the shape of spectrum.

In addition, as shown in Figure 9, the luminescent spectrum of embodiment 1 is compared with comparative example 1 as can be known, and the migration of the peak of spectrum is little, even the angle of visual field changes, also can form more identical shape.The change of shape of known spectra is relevant with the variation of tone, thereby the migration amount of peak, spectral shape all are that a side with low uncertainty is more excellent.That is, as can be known as the formation of embodiment 1 except colourity changes, also the effect because of light-transmitting layer improves the briliancy that light takes out.

Organic electric-field light-emitting element of the present invention has excellent light and takes out efficient, and can suppress the colourity variation corresponding with respect to the position of organic electric-field light-emitting element, therefore for example go for display, computer, Vehicular display device, open-air display, domestic appliance, business machine, household electrical appliances with in the various fields headed by machine, traffic related display, clock and watch display, calendar date display, phosphor screen, the sound machine etc. with the observer.

Claims (9)

1. an organic electric-field light-emitting element is characterized in that, is the organic electric-field light-emitting element that has second electrode, intermediate layer, semitransmissive layer and the light-transmitting layer of first electrode, luminescent layer, half transmitting successively at least, and has:

First resonator structure that makes the light that from described luminescent layer, penetrates between described first electrode and described second electrode, resonate and penetrate; With

Second resonator structure that makes described light between described first electrode and described semitransmissive layer, resonate and penetrate,

Wherein, be made as t in 1/4 length of the peak wavelength of the light that will penetrate from described luminescent layer, when the refractive index of described light-transmitting layer was made as n, the thickness of described light-transmitting layer satisfied following formula: below the above 1.1 * t/n of 0.9 * t/n.

2. organic electric-field light-emitting element according to claim 1 is characterized in that, light-transmitting layer and and the layer of this light-transmitting layer adjacency between the difference of refractive index be at least 0.1.

3. organic electric-field light-emitting element according to claim 1 is characterized in that, the material of semitransmissive layer is a metal.

4. organic electric-field light-emitting element according to claim 3 is characterized in that, metal is at least a metal that is selected from silver, magnesium-silver alloy and the aluminium.

5. organic electric-field light-emitting element according to claim 1 is characterized in that, luminescent layer contains at least a phosphorescent material.

6. organic electric-field light-emitting element according to claim 1 is characterized in that, organic electric-field light-emitting element is an end emission type.

7. organic electric-field light-emitting element according to claim 1 is characterized in that, also has light-transmitting layer between second electrode and intermediate layer,

Wherein, be made as t in 1/4 length of the peak wavelength of the light that will penetrate from described luminescent layer, when the refractive index of described light-transmitting layer was made as n, the thickness of described light-transmitting layer satisfied following formula: below the above 1.1 * t/n of 0.9 * t/n.

8. organic electric-field light-emitting element according to claim 1 is characterized in that,

In the luminescent spectrum of the luminescent material in luminescent layer, resonant wavelength ratio in front is short from first peak wavelength of the short wavelength side number of luminescent spectrum,

Described luminescent spectrum satisfies the relation with the Δ λ＜25nm of following mathematical expression 1 expression,

＜mathematical expression 1 〉

Δλ＝λ(I0)-λ(0.2×I0)

Wherein, in the described mathematical expression 1, λ (I0) expression front resonant wavelength, I0 represents the luminous intensity this wavelength under, λ (0.2 * I0) wavelength when representing to reach 0.2 times of luminous intensity of λ (I0) luminous intensity, λ (I0)＞λ (0.2 * I0).

9. an organic electric field luminescence display is characterized in that,

Have with following organic electric-field light-emitting element as the redness of sub-pixel, green, blue each single pixel,

Described organic electric-field light-emitting element is the organic electric-field light-emitting element that has second electrode, intermediate layer, semitransmissive layer and the light-transmitting layer of first electrode, luminescent layer, half transmitting successively at least, and has:

First resonator structure that makes the light that from described luminescent layer, penetrates between described first electrode and described second electrode, resonate and penetrate; And second resonator structure that makes described light between described first electrode and described semitransmissive layer, resonate and penetrate,

Wherein, be made as t in 1/4 length of the peak wavelength of the light that will penetrate from described luminescent layer, when the refractive index of described light-transmitting layer was made as n, the thickness of described light-transmitting layer satisfied following formula: below the above 1.1 * t/n of 0.9 * t/n.

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