WO2012039241A1 - Élément électroluminescent organique et procédé de fabrication d'un élément électroluminescent organique - Google Patents

Élément électroluminescent organique et procédé de fabrication d'un élément électroluminescent organique Download PDF

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WO2012039241A1
WO2012039241A1 PCT/JP2011/069543 JP2011069543W WO2012039241A1 WO 2012039241 A1 WO2012039241 A1 WO 2012039241A1 JP 2011069543 W JP2011069543 W JP 2011069543W WO 2012039241 A1 WO2012039241 A1 WO 2012039241A1
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light emitting
emitting layer
organic
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敦 今村
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コニカミノルタホールディングス株式会社
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2101/00—Properties of the organic materials covered by group H10K85/00
    • H10K2101/10—Triplet emission
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K85/00—Organic materials used in the body or electrodes of devices covered by this subclass
    • H10K85/30—Coordination compounds
    • H10K85/341—Transition metal complexes, e.g. Ru(II)polypyridine complexes
    • H10K85/342—Transition metal complexes, e.g. Ru(II)polypyridine complexes comprising iridium

Definitions

  • the present invention relates to an organic electroluminescence element and a method for producing the organic electroluminescence element. Specifically, the present invention relates to an organic electroluminescent element that can be manufactured by a simple process and has improved light emission efficiency and lifetime, and a method for manufacturing the organic electroluminescent element.
  • ELD electroluminescence display
  • an inorganic electroluminescence element hereinafter also referred to as an inorganic EL element
  • an organic electroluminescence element hereinafter also referred to as an organic EL element
  • Inorganic EL elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.
  • an organic electroluminescence device has a structure in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and excitons (excitons) by injecting electrons and holes into the light emitting layer and recombining them.
  • a device that emits light using the emission of light (fluorescence / phosphorescence) when this exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Since it is a type, it has a wide viewing angle, high visibility, and since it is a thin-film type completely solid element, it has attracted attention from the viewpoints of space saving, portability, and the like.
  • the organic electroluminescence element is also a major feature that it is a surface light source, unlike the main light sources that have been used in the past, such as light-emitting diodes and cold-cathode tubes.
  • Applications that can effectively utilize this characteristic include illumination light sources and various display backlights.
  • it is also suitable to be used as a backlight of a liquid crystal full color display whose demand has been increasing in recent years.
  • Improvements in light emission efficiency and lifetime are examples of problems for using an organic electroluminescence device as such a light source for illumination or a backlight of a display.
  • a so-called host / guest structure in which a part of the organic functional layer constituting the organic electroluminescence element is configured by mixing a plurality of materials having different functions. It is becoming common.
  • a combination of a host material / a light emitting dopant in the light emitting layer may be mentioned. It shows that the lifetime is improved by the ratio of the light emitting dopant to the light emitting host in the light emitting layer continuously changing in the light emitting layer.
  • control of the deposition rate in the vacuum deposition method is cited in the dry process (see, for example, Patent Documents 1 and 2), while in the wet process, between two adjacent layers.
  • Means for continuously mixing the components is disclosed (for example, see Patent Documents 3 and 4). In this case, the difference in solubility between adjacent two layers of materials is used, and there is a problem that it cannot be applied as a means for continuously changing the dopant concentration in a single layer using the same material.
  • Patent Document 5 it is disclosed that the emission lifetime is improved by gradually reducing the emission dopant concentration from the hole transport layer side to the electron transport layer side (see, for example, Patent Document 5).
  • the dopant of the light emitting layer is evaluated only with a single color (green), and when a plurality of dopants having different wavelengths are used, the chromaticity stability with respect to the luminance change is difficult.
  • the life under the room temperature environment is improved, the life performance under the high temperature environment is still insufficient, and improvement has been demanded.
  • the present invention solves the above-described problems, and provides an organic electroluminescence device having high luminous efficiency, a lifetime under a room temperature / high temperature environment, and excellent color stability, and a method for producing the organic electroluminescence device can do.
  • an organic electroluminescence device having a pair of electrodes and an organic functional layer including a light emitting layer on a substrate
  • the light emitting layer contains a host compound, a blue phosphorescent dopant compound, and a phosphorescent dopant compound of a color other than blue.
  • the blue phosphorescent dopant compound in the light emitting layer forms a concentration gradient in the thickness direction, and the dopant compound concentration at the anode side interface of the light emitting layer is 15% by mass or more and 40% by mass.
  • An organic electroluminescence device wherein the dopant compound concentration at the cathode side interface of the light emitting layer is 5 mass% or less lower than the dopant compound concentration at the anode side interface.
  • the dopant compound concentration at the anode side interface of the light emitting layer is from 20% by mass to 35% by mass, and the dopant compound concentration at the cathode side interface of the light emitting layer is from 5% by mass to 20% by mass. 2.
  • the organic electroluminescence device as described in 1 above.
  • the concentration gradient in the thickness direction is such that the slope a of the concentration difference (mass%) at both interfaces with respect to the thickness (nm) from the cathode side interface to the anode side interface of the light emitting layer satisfies the following formula. 4.
  • the organic electroluminescence device as described in any one of 1 to 3 above.
  • a method for manufacturing an organic electroluminescence device in which a dopant compound in a light emitting layer forms a concentration gradient in the thickness direction, and two or more coating liquids having different dopant compound concentrations are discharged from two or more discharge ports with a time difference.
  • a method for producing an organic electroluminescence element characterized by being formed by laminating.
  • an organic electroluminescence device having high luminous efficiency, a long lifetime at both normal temperature and high temperature, excellent color stability, and capable of being stably produced by a dry process or a wet process, and the organic electroluminescence device A method for manufacturing a luminescence element can be provided.
  • the present invention relates to an organic electroluminescence device having a pair of electrodes and an organic functional layer including a light emitting layer on a substrate, wherein the light emitting layer comprises a host compound, a blue dopant compound, and a phosphorescent dopant compound of a color other than blue. And the blue dopant compound in the light emitting layer forms a concentration gradient in the thickness direction, and the dopant compound concentration at the anode side interface of the light emitting layer is 15% by mass or more and 40% by mass
  • the organic electroluminescence device is characterized in that the dopant compound concentration at the cathode side interface of the light emitting layer is 5 mass% or less lower than the dopant compound concentration at the anode side interface.
  • the dopant compound concentration at the anode side interface of the light emitting layer is preferably 20% by mass or more and 35% by mass or less, and the dopant compound concentration at the cathode side interface is preferably 5% by mass or more and 20% by mass or less.
  • the slope a of the concentration difference (mass%) at both interfaces with respect to the thickness (nm) from the cathode side interface to the anode side interface of the light emitting layer satisfies the following formula. It is preferable.
  • the light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface
  • the thickness of the light emitting layer is not particularly limited, but it is 2 to 2 from the viewpoint of the uniformity of the film to be formed and the application of unnecessary high voltage during light emission, and the improvement of the stability of the emission color with respect to the driving current. It is preferable to adjust to a range of 200 nm, more preferably to a range of 5 nm or more and 100 nm or less.
  • the light emitting layer of the organic electroluminescence device of the present invention can be formed by either a dry process or a wet process, but is preferably formed by a wet process.
  • Known wet process coating methods include die coating, spin coating, casting, ink jet, spraying, printing, etc., but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. From the viewpoint, in the present invention, film formation by a coating method such as a die coating method, an ink jet method, or a spray method is preferable.
  • the light emitting layer of the organic electroluminescence device of the present invention contains at least one of a light emitting host and a light emitting dopant, and the concentration of the light emitting dopant in the light emitting layer is continuously changed from the anode side to the cathode side.
  • the following means are used as means for continuously changing the concentration.
  • a light emitting dopant material and a light emitting host material of the light emitting layer are co-evaporated, and a concentration gradient in the film thickness direction is created by controlling the deposition rate.
  • the rate is gradually lowered during the deposition.
  • two or more coating liquids having two or more different dopant compound concentrations in the light emitting layer are prepared, and these are discharged from two or more discharge ports with time lag, applied in layers, and emitted from the light emitting host during drying.
  • the concentration of the light-emitting dopant from the anode side toward the cathode side the light-emitting dopant / light-emitting host ratio of the solution to be applied to the anode side is the highest when two or more types of light-emitting layer solutions having different light-emitting dopant concentrations are applied. What is necessary is just to make it higher than the light emission dopant / light emission host ratio of the solution apply
  • a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.
  • the light emitting host a known light emitting host may be used alone, or a plurality of kinds may be used in combination. By using a plurality of types of light-emitting hosts, the movement of charges can be adjusted, and the organic EL element can be made highly efficient. In addition, by using a plurality of kinds of light emitting materials described later, it is possible to mix different light emission, thereby obtaining an arbitrary light emission color.
  • the light emitting host used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (deposition polymerization property). Light emitting host).
  • the known light-emitting host that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of longer wavelengths, and has a high Tg (glass transition temperature) is preferable.
  • the glass transition point (Tg) is a value determined by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).
  • the host compound used in the present invention is preferably a carbazole derivative, more preferably a carbazole derivative, and more preferably a dibenzofuran compound.
  • Luminescent dopant As the light-emitting dopant according to the present invention, a phosphorescent dopant is used.
  • the phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed.
  • the phosphorescent dopant is a compound that emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., a preferable phosphorescence quantum yield is 0.1 or more.
  • the phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of the Fourth Edition Experimental Chemistry Course 7. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.
  • phosphorescent dopants There are two types of emission of phosphorescent dopants in principle. One is the recombination of carriers on the light-emitting host on which carriers are transported to generate the excited state of the light-emitting host, and this energy is transferred to the phosphorescent dopant. Energy transfer type to obtain light emission from the phosphorescent dopant, another is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant is obtained Although it is a carrier trap type, in any case, it is a condition that the excited state energy of the phosphorescent dopant is lower than the excited state energy of the light emitting host.
  • the phosphorescent dopant can be appropriately selected from known ones used in the light emitting layer of the organic EL device, but in the present invention, at least one blue phosphorescent dopant compound and at least one other than blue phosphorescent compound are used. Contains phosphorescent dopant compounds of other colors.
  • the blue dopant is a dopant having an emission maximum wavelength at 520 nm or less, and the other color dopants other than blue are dopants having an emission maximum wavelength at 520 nm or more.
  • a phosphorescent dopant represented by the following general formula (1) as the blue dopant.
  • R 1 represents a substituent.
  • Z represents a nonmetallic atom group necessary for forming a 5- to 7-membered ring.
  • n1 represents an integer of 0 to 5.
  • B 1 to B 5 represent a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and at least one of B 1 to B 5 represents a nitrogen atom.
  • M 1 represents a group 8 to group 10 metal in the periodic table.
  • X 1 and X 2 represent a carbon atom, a nitrogen atom, or an oxygen atom, and L 1 represents an atomic group that forms a bidentate ligand together with X 1 and X 2 .
  • m1 represents an integer of 1, 2 or 3
  • m2 represents an integer of 0, 1 or 2
  • m1 + m2 is 2 or 3.
  • examples of the substituent represented by R 1 include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, octyl group).
  • alkyl group for example, methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, octyl group).
  • Z represents a nonmetallic atom group necessary for forming a 5- to 7-membered ring.
  • the 5- to 7-membered ring formed by Z include a benzene ring, naphthalene ring, pyridine ring, pyrimidine ring, pyrrole ring, thiophene ring, pyrazole ring, imidazole ring, oxazole ring and thiazole ring. Of these, a benzene ring is preferred.
  • B 1 to B 5 represent a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and at least one represents a nitrogen atom.
  • the aromatic nitrogen-containing heterocycle formed by these five atoms is preferably a monocycle. Examples thereof include a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a tetrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an oxadiazole ring, and a thiadiazole ring.
  • a pyrazole ring and an imidazole ring are preferable, and an imidazole ring is more preferable.
  • These rings may be further substituted with the above substituents.
  • Preferred as the substituent are an alkyl group and an aryl group, and more preferably an aryl group.
  • L 1 represents an atomic group forming a bidentate ligand together with X 1 and X 2 .
  • Specific examples of the bidentate ligand represented by X 1 -L 1 -X 2 include, for example, substituted or unsubstituted phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, picolinic acid And acetylacetone. These groups may be further substituted with the above substituents.
  • M1 represents an integer of 1, 2 or 3
  • m2 represents an integer of 0, 1 or 2
  • m1 + m2 is 2 or 3.
  • m2 is 0 is preferable.
  • a transition metal element of Group 8 to Group 10 (also referred to simply as a transition metal) in the periodic table of elements is used, among which iridium and platinum are preferable, and iridium is more preferable.
  • the light-emitting dopant represented by the general formula (1) according to the present invention may or may not have a polymerizable group or a reactive group.
  • Injection layer electron injection layer, hole injection layer >> The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.
  • An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance.
  • Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).
  • anode buffer layer hole injection layer
  • copper phthalocyanine is used.
  • examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.
  • cathode buffer layer (electron injection layer) The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc.
  • Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc.
  • the buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 ⁇ m, although it depends on the material.
  • ⁇ Blocking layer hole blocking layer, electron blocking layer>
  • the blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL elements and the forefront of industrialization (published by NTT Corporation on November 30, 1998)” on page 237. There is a hole blocking (hole blocking) layer.
  • the hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.
  • the hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.
  • the hole blocking layer contains the carbazole derivative mentioned as the light emitting host.
  • the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers.
  • 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the light emitting host of the shortest wave emitting layer.
  • the ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by, for example, the following method.
  • Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA, is used as a keyword.
  • the ionization potential can be obtained as a value obtained by rounding off the second decimal place of a value (eV unit converted value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.
  • the ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy.
  • a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd. or a method known as ultraviolet photoelectron spectroscopy can be suitably used.
  • the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed.
  • the film thickness of the hole blocking layer and the electron transporting layer according to the present invention is preferably 3 to 100 nm, more preferably 5 to 30 nm.
  • the hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer.
  • the hole transport layer can be provided as a single layer or a plurality of layers.
  • the hole transport material has either hole injection or transport or electron barrier properties, and may be either organic or inorganic.
  • triazole derivatives oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives
  • Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.
  • the above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.
  • aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminoph
  • No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ′, 4 ′′ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.
  • NPD 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl
  • JP-A-4-308 4,4 ′, 4 ′′ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the
  • a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.
  • inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.
  • JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used.
  • these materials are preferably used because a light-emitting element with higher efficiency can be obtained.
  • the hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can.
  • the thickness of the hole transport layer is not particularly limited, but is usually about 5 nm to 5 ⁇ m, preferably 5 to 200 nm.
  • the hole transport layer may have a single layer structure composed of one or more of the above materials.
  • a hole transport layer having a high p property doped with impurities examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.
  • a hole transport layer having such a high p property because a device with lower power consumption can be produced.
  • the electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer.
  • the electron transport layer can be provided as a single layer or a plurality of layers.
  • an electron transport material also serving as a hole blocking material used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode.
  • any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like.
  • a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material.
  • a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.
  • metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.
  • metal-free or metal phthalocyanine or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material.
  • the distyrylpyrazine derivative exemplified as the material for the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.
  • the electron transport layer is formed by thinning the electron transport material by a known method such as a vacuum deposition method, a die coating method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Can do.
  • the thickness of the electron transport layer is not particularly limited, but is usually about 5 nm to 5 ⁇ m, preferably 5 to 200 nm.
  • the electron transport layer may have a single layer structure composed of one or more of the above materials.
  • an electron transport layer having a high n property doped with impurities may be used.
  • examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.
  • an electron transport layer having such a high n property because an element with lower power consumption can be produced.
  • an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used.
  • electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO 2 , and ZnO.
  • conductive transparent materials such as CuI, indium tin oxide (ITO), SnO 2 , and ZnO.
  • an amorphous material such as IDIXO (In 2 O 3 —ZnO) capable of forming a transparent conductive film may be used.
  • these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 ⁇ m or more)
  • a pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.
  • wet film-forming methods such as a printing system and a coating system, can also be used.
  • the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred ⁇ / ⁇ or less.
  • the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.
  • cathode a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used.
  • electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al 2 O 3 ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.
  • a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al 2 O 3 ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.
  • the cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.
  • the sheet resistance as the cathode is preferably several hundred ⁇ / ⁇ or less, and the film thickness is usually selected in the range of 10 nm to 5 ⁇ m, preferably 50 to 200 nm.
  • the light emission luminance is improved, which is convenient.
  • a transparent or semi-transparent cathode can be produced by producing the conductive transparent material mentioned in the description of the anode on the cathode after producing the metal with a film thickness of 1 to 20 nm. By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.
  • substrate As a substrate (hereinafter also referred to as a substrate, a support substrate, a substrate, a support, etc.) that can be used in the organic EL element of the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the substrate side, the substrate is preferably transparent. Examples of the transparent substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable substrate is a resin film that can easily give flexibility to the organic EL element.
  • polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfone , Polyetherimide, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, acrylic or polyarylates, and cycloolefin resins such as ARTON (manufactured by J
  • An inorganic or organic film or a hybrid film of both may be formed on the surface of the resin film, and a barrier film having a water vapor permeability of 0.01 g / m 2 / day ⁇ atm or less is preferable. Further, a high barrier film having an oxygen permeability of 10 ⁇ 3 g / m 2 / day or less and a water vapor permeability of 10 ⁇ 5 g / m 2 / day or less is preferable.
  • the material for forming the barrier film may be any material that has a function of suppressing the intrusion of elements that cause deterioration of elements such as moisture and oxygen.
  • silicon oxide, silicon dioxide, silicon nitride, or the like can be used.
  • the method for forming the barrier film is not particularly limited.
  • vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma polymerization A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.
  • the opaque substrate examples include metal plates such as aluminum and stainless steel, films, opaque resin substrates, ceramic substrates, and the like.
  • the external extraction quantum efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more.
  • the external extraction quantum efficiency (%) the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element ⁇ 100.
  • a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination.
  • the ⁇ max of light emission of the organic EL element is preferably 480 nm or less.
  • a sealing means used for this invention the method of adhere
  • a sealing member it should just be arrange
  • Specific examples include a glass plate, a polymer plate / film, and a metal plate / film.
  • the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
  • the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.
  • the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.
  • a polymer film and a metal film can be preferably used because the element can be thinned.
  • the polymer film oxygen permeability measured by the method based on JIS K 7126-1987 is 1 ⁇ 10 -3 ml / m 2 / 24h or less, as measured by the method based on JIS K 7129-1992, water vapor permeability (25 ⁇ 0.5 ° C., relative humidity (90 ⁇ 2)%) is preferably that of 1 ⁇ 10 -3 g / (m 2 / 24h) or less.
  • sealing member For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.
  • the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups of acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to.
  • hot-melt type polyamide, polyester, and polyolefin can be mentioned.
  • a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.
  • an organic EL element may deteriorate by heat processing, what can be adhesively cured from room temperature to 80 ° C. is preferable.
  • a desiccant may be dispersed in the adhesive.
  • coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.
  • an inorganic or organic layer as a sealing film by covering the electrode and the organic layer on the outer side of the electrode facing the substrate with the organic layer interposed therebetween, and in contact with the substrate.
  • the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen.
  • silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.
  • the method for forming these films is not particularly limited.
  • vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.
  • an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase.
  • a vacuum can also be used.
  • a hygroscopic compound can also be enclosed inside.
  • hygroscopic compound examples include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate).
  • metal oxides for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide
  • sulfates for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate.
  • metal halides eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.
  • perchloric acids eg perchloric acid Barium, magnesium perchlorate, and the like
  • anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.
  • a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the substrate with the organic layer interposed therebetween or on the sealing film.
  • the mechanical strength is not necessarily high. Therefore, it is preferable to provide such a protective film and a protective plate.
  • the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used. It is preferable to use a film.
  • the organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because the light incident on the interface (interface between the transparent substrate and air) at an angle ⁇ greater than the critical angle causes total reflection and cannot be taken out of the element, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the side surface direction of the element.
  • a method of improving the light extraction efficiency for example, a method of forming irregularities on the surface of the transparent substrate and preventing total reflection at the transparent substrate and the air interface (US Pat. No. 4,774,435), A method for improving efficiency by giving light condensing property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on the side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from the substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No.
  • these methods can be used in combination with the organic EL device of the present invention.
  • a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.
  • the low refractive index layer examples include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.
  • the thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.
  • the method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency.
  • This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction.
  • Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.
  • the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.
  • the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.
  • the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.
  • the arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.
  • the organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface.
  • a specific direction for example, the device light emitting surface.
  • quadrangular pyramids having a side of 30 ⁇ m and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate.
  • One side is preferably 10 to 100 ⁇ m. If it becomes smaller than this, the effect of diffraction will generate
  • the condensing sheet it is possible to use, for example, a sheet that has been put to practical use in an LED backlight of a liquid crystal display device.
  • a sheet for example, Sumitomo 3M brightness enhancement film (BEF) can be used.
  • BEF Sumitomo 3M brightness enhancement film
  • the base material may be formed with a triangle stripe having a vertex angle of 90 degrees and a pitch of 50 ⁇ m, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.
  • a light diffusion plate / film may be used in combination with the light collecting sheet.
  • a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.
  • a desired electrode material for example, a thin film made of an anode material is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 ⁇ m or less, preferably 10 to 200 nm, thereby producing an anode.
  • the light emitting layer of the organic EL device of the present invention is preferably formed by a wet process. Since the dopant compound in the light emitting layer forms a concentration gradient in the thickness direction, as described above, two or more coating liquids having different dopant compound concentrations are ejected and laminated from two or more ejection ports with a time difference. It is preferable. In addition, a drying process may be introduced after each discharge during the plurality of discharges. Further, it is preferable that ejection and lamination are performed on a substrate that is continuously conveyed.
  • a method for forming an organic layer other than the light emitting layer there are a vapor deposition method, a wet process (a die coating method, a spin coating method, a casting method, an ink jet method, a spray method, a printing method), etc., but a homogeneous film is easily obtained. Further, in the present invention, film formation by a coating method such as a die coating method, a spin coating method, an ink jet method, a spray method, a printing method, or the like is preferable for part or all of the organic layer from the viewpoint that pinholes are hardly generated.
  • liquid medium for dissolving or dispersing the organic EL material according to the present invention examples include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene.
  • Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used.
  • a dispersion method it can disperse
  • a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 ⁇ m or less, preferably in the range of 50 to 200 nm, and a cathode is provided.
  • a desired organic EL element can be obtained.
  • a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode.
  • An alternating voltage may be applied.
  • the alternating current waveform to be applied may be arbitrary.
  • Example 1 [Production of Organic EL Element 118] After patterning on a support of PEN (polyethylene naphthalate) formed with 100 nm of ITO (indium tin oxide) as an anode, the substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol and dried nitrogen After drying with gas, UV ozone cleaning was performed for 5 minutes.
  • PEN polyethylene naphthalate
  • ITO indium tin oxide
  • a poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, manufactured by Bayer, Baytron P Al 4083) diluted to 70% with pure water was formed by die coating, It dried at 130 degreeC for 1 hour, and provided the positive hole transport layer with a film thickness of 70 nm.
  • this substrate was moved to a nitrogen atmosphere, and the following light emitting layer composition 1 was formed by die coating so that the wet film thickness was 4 ⁇ m.
  • the substrate was dried by applying an infrared heater at 600 w for 7 seconds to form a light emitting layer (first layer).
  • Light emitting layer composition 1 Host: HA 0.74 mass% Blue dopant: (1) -79 0.25% by mass Green dopant: DA 0.005 mass% Red dopant: 0.005% by mass of DB The total amount was 100% by mass using isopropyl acetate.
  • the following light emitting layer composition 2 was formed on the light emitting layer (first layer) by die coating so that the wet film thickness was 4 ⁇ m. Immediately after the film formation, it was dried by applying it at 600 W for 7 seconds with an infrared heater to form a light emitting layer (lamination).
  • Light emitting layer composition 2 Host: HA 0.86% by mass Blue dopant: (1) -79 0.13 mass% Green dopant: DA 0.005 mass% Red dopant: 0.005% by mass of DB The total amount was 100% by mass using isopropyl acetate.
  • This substrate was fixed to a substrate holder of a vacuum deposition apparatus, while 200 mg of the following ET-A was placed in a molybdenum resistance heating boat, and 100 mg of CsF was placed in another molybdenum resistance heating boat and attached to the vacuum deposition apparatus.
  • the vacuum chamber was depressurized to 4 ⁇ 10 ⁇ 4 Pa, and then heated by energizing the heating boat containing ET-A and CsF, and the light emitting layer was deposited at a deposition rate of 0.2 nm / second and 0.03 nm / second, respectively.
  • An electron transport layer having a film thickness of 40 nm was further provided.
  • 110 nm of aluminum was deposited to form a cathode, and an organic EL element 118 was produced.
  • the concentration distribution of the light-emitting dopant contained in the light-emitting layer of the obtained organic EL element is detected by analyzing the Ir distribution in the film thickness direction by TOF-SIMS (time-of-flight secondary ion mass spectrometry). Can do.
  • TOF-SIMS performs sputtering by irradiating a sample surface with an ion beam called primary ions under a high vacuum of about 10 ⁇ 8 Pa.
  • Primary ions include Ga + , In + , Au + , Bi 3 ++ , and sputtered ions include Cs + . This is a method of analyzing elements present on the surface by mass spectrometry of secondary ions released thereby.
  • a TRIFT2 manufactured by Physical Electronics is used, the primary ion species is Ga + , and the sputter ions are Cs +, and the depth in the organic EL device is 25 kV and 3 kV, respectively.
  • the distribution amount of Ir element in the vertical direction was measured.
  • Fig. 1 shows the result of analyzing the Ir distribution in the film thickness direction by TOF-SIMS from the sample surface using the prepared sample as a coated sample.
  • FIG. 1 shows that the organic EL device of the present invention was able to continuously change the luminescent dopant concentration in the luminescent layer.
  • Table 1 shows the results of conversion of the Ir and cathode interface Ir concentrations from the Ir ion intensity at the cathode and cathode interface. Similarly, the Ir distribution of each organic EL element was analyzed, and the result of calculating the concentration difference (mass%) with respect to the film thickness as the slope a is shown in Table 1.
  • External quantum efficiency (%) was measured when a 2.5 mA / cm 2 constant current was applied to the produced organic EL element.
  • a spectral radiance meter CS-1000 manufactured by Konica Minolta Sensing was used.
  • the external extraction quantum efficiencies of the organic EL elements 112 to 129 are expressed as relative values with the measured value of the organic EL element 111 (comparative) being 100.
  • the produced organic EL element was continuously driven at room temperature (25 ° C.) by applying a current with a front luminance of 3000 cd / m 2 .
  • the time required for the front luminance to reach the initial half value (1500 cd / m 2 ) is obtained, and the light emission lifetime of the organic EL elements 112 to 129 is a relative value with the measured value of the organic EL element 111 (comparative) as 100. expressed.
  • the produced organic EL element was continuously driven by applying an electric current with a front luminance of 3000 cd / m 2 at an external temperature of 60 ° C.
  • the time required for the front luminance to reach the initial half value (1500 cd / m 2 ) is obtained, and the light emission lifetime of the organic EL elements 112 to 129 is a relative value with the measured value of the organic EL element 111 (comparative) as 100. expressed.
  • the produced organic EL element emits light, and the color coordinates when the front luminance is 300 cd / m 2 are (x, y), the color coordinates when the front luminance is 1500 cd / m 2 are (X, Y), and the chromaticity Distribution ⁇ E xy was defined as follows.
  • ⁇ E xy (( xy ) 2 + (XY) 2 ) 1/2
  • the color stability of the organic EL elements 111 to 129 is represented by an absolute value of ⁇ E xy .
  • Example 2 [Production of organic EL elements 130 to 140]
  • a light emitting layer was formed by vapor deposition.
  • the substrate after forming the hole transport layer was fixed to a substrate holder of a vacuum deposition apparatus, and 150 mg of each of the four light emitting layer compositions except isopropyl acetate was placed in a molybdenum resistance heating boat, and vacuum deposition was performed. Attached to the device. After reducing the pressure in the vacuum chamber to 4 ⁇ 10 ⁇ 4 Pa, the heating boat was energized and heated to co-evaporate 4 types of HA, DA, DB, and (1) -79.
  • FIG. 2 shows the result of analyzing the Ir distribution in the film thickness direction by TOF-SIMS from the sample surface in the same manner as in Example 1.
  • Example 1 and 2 show that the organic EL device of the present invention was able to continuously change the light-emitting dopant concentration in the light-emitting layer in both the wet process and the dry process.
  • Table 2 shows the result of converting the Ir concentration at the anode and cathode interfaces from the Ir ion intensity at the anode and cathode interfaces.
  • the Ir distribution of each organic EL element was analyzed, and the results of calculating the concentration difference (mass%) relative to the film thickness as the slope a are shown in Table 2.
  • Example 3 [Preparation of organic EL elements 141 to 144] Organic EL elements 141 to 144 were similarly manufactured except that the red dopant concentration was changed as shown in Table 3 in the preparation of the organic EL element 135 of Example 2.
  • Table 3 shows the results of converting the Ir concentration at the anode and cathode interface and the result of calculating the concentration difference (mass%) from the Ir ion intensity at the anode and cathode interface.
  • the organic EL device of the present invention has improved external extraction quantum efficiency and emission lifetime, as well as improved lifetime under high temperature environment and color stability with different luminance. .

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

L'invention concerne un élément électroluminescent organique qui offre une efficacité lumineuse élevée tout en assurant une excellente stabilité des couleurs et une bonne durée de vie dans des environnements à température ambiante et à haute température. Plus spécifiquement, l'invention concerne un élément électroluminescent organique qui comprend, sur un substrat, une paire d'électrodes et une couche fonctionnelle organique comprenant une couche d'émission lumineuse et qui est caractérisé en ce que : la couche d'émission lumineuse comprend un composé hôte, un composé dopant phosphorescent bleu et un composé dopant phosphorescent d'une couleur autre que le bleu ; le composé dopant phosphorescent bleu, dans la couche d'émission lumineuse, présente un gradient de concentration dans la direction de l'épaisseur ; la concentration du composé dopant au niveau de l'interface de la couche d'émission lumineuse avec l'électrode positive est de 15 - 40 % en masse (valeurs incluses) ; et la concentration du composé dopant à l'interface de la couche d'émission lumineuse avec l'électrode négative est inférieure, par rapport à la concentration du composé dopant à l'interface avec l'électrode positive, de 5 % en masse ou plus.
PCT/JP2011/069543 2010-09-24 2011-08-30 Élément électroluminescent organique et procédé de fabrication d'un élément électroluminescent organique WO2012039241A1 (fr)

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CN104716265A (zh) * 2015-03-30 2015-06-17 京东方科技集团股份有限公司 蓝光有机电致发光器件及制备方法、显示面板和显示装置
US10411199B2 (en) 2012-12-12 2019-09-10 Samsung Electronics Co., Ltd. Organometallic complexes, and organic electroluminescent device and display using the same
EP2887417B1 (fr) * 2013-12-17 2020-03-25 The Regents Of The University Of Michigan Durée de vie opérationnelle OLED étendue par profil de dopant phosphorescent

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WO2009084413A1 (fr) * 2007-12-28 2009-07-09 Konica Minolta Holdings, Inc. Dispositif électroluminescent organique et procédé de fabrication de dispositif électroluminescent organique
JP2010515255A (ja) * 2006-12-28 2010-05-06 ユニバーサル ディスプレイ コーポレイション 長寿命リン光発光有機発光デバイス（ｏｌｅｄ）構造
WO2010150694A1 (fr) * 2009-06-25 2010-12-29 コニカミノルタホールディングス株式会社 Élément électroluminescent organique émettant de la lumière blanche

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JP2010515255A (ja) * 2006-12-28 2010-05-06 ユニバーサル ディスプレイ コーポレイション 長寿命リン光発光有機発光デバイス（ｏｌｅｄ）構造
WO2009084413A1 (fr) * 2007-12-28 2009-07-09 Konica Minolta Holdings, Inc. Dispositif électroluminescent organique et procédé de fabrication de dispositif électroluminescent organique
WO2010150694A1 (fr) * 2009-06-25 2010-12-29 コニカミノルタホールディングス株式会社 Élément électroluminescent organique émettant de la lumière blanche

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Publication number Priority date Publication date Assignee Title
US10411199B2 (en) 2012-12-12 2019-09-10 Samsung Electronics Co., Ltd. Organometallic complexes, and organic electroluminescent device and display using the same
EP2887417B1 (fr) * 2013-12-17 2020-03-25 The Regents Of The University Of Michigan Durée de vie opérationnelle OLED étendue par profil de dopant phosphorescent
EP3690972A1 (fr) * 2013-12-17 2020-08-05 The Regents Of The University Of Michigan Durée de vie opérationnelle delo étendue par gestion de profil de dopant phosphorescent
CN104716265A (zh) * 2015-03-30 2015-06-17 京东方科技集团股份有限公司 蓝光有机电致发光器件及制备方法、显示面板和显示装置
US9954192B2 (en) 2015-03-30 2018-04-24 Boe Technology Group Co., Ltd. Blue organic electroluminescent device and preparation method thereof, display panel and display apparatus

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