Classifications

• • 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]
  • H10K50/17—Carrier injection layers
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/12—Light sources with substantially two-dimensional [2D] radiating surfaces
  • H05B33/22—Light sources with substantially two-dimensional [2D] radiating surfaces characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• • 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]
  • H10K50/17—Carrier injection layers
  • H10K50/171—Electron injection layers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/917—Electroluminescent

Definitions

• the present invention relates to an organic EL (Electro-Magnetic Luminescence) device, and more particularly, to an inorganic-organic organic junction structure used for a device that emits light by applying an electric field to a thin film of an organic compound.
• Organic EL Electro-Magnetic Luminescence
• Organic EL devices can be formed on glass in a large area, and research and development for display applications is underway.
• an organic EL device is formed by forming a transparent electrode such as ITO on a glass substrate, forming an organic amine-based hole transport layer on the transparent electrode, and forming an organic conductive material such as an A1q3 material exhibiting electronic conductivity and strong light emission.
• the light-emitting layer is laminated, and an electrode with a small work function such as MgAg is formed as a basic element.
• the device structure reported to date has a structure in which one or more organic compound layers are sandwiched between a hole injection electrode and an electron injection electrode. There is a structure or a three-layer structure.
• Examples of the two-layer structure include a structure in which a hole transport layer and a light emitting layer are formed between a hole injection electrode and an electron injection electrode, or a structure in which a light emitting layer and an electron transport layer are formed between a hole injection electrode and an electron injection electrode.
• As an example of the three-layer structure there is a structure in which a hole transport layer, a light emitting layer, and an electron transport layer are formed between a hole injection electrode and an electron injection electrode.
• single-layer structures in which a single layer has all the roles have been reported for polymers and mixed systems.
• FIGS. 3 and 4 show a typical structure of an organic EL device.
• a hole transport layer 14 and a light emitting layer 15 which are organic compounds are formed between a hole injection electrode 12 and an electron injection electrode 13 provided on a substrate 11.
• the light emitting layer 15 also functions as an electron transport layer.
• an organic compound, a hole transport layer 14, an emission layer 15, and an electron transport layer 16 are formed between a hole injection electrode 12 and an electron injection electrode 13 provided on a substrate 11. I have.
• the organic EL element has a hole injection electrode and an electron injection electrode in principle, and requires an organic layer for efficiently injecting and transporting holes and electrons from between these electrodes.
• these materials are susceptible to damage during manufacture and have a problem with their compatibility with electrodes. Further, there is a problem that the deterioration of the organic thin film is remarkably large as compared with the LED and the LD.
• Electroluminescent (EL) devices emit light under the influence of an electric field.
• the action in the semiconductor layer constituting such an EL is performed through radiative coupling of an electron-hole pair injected into the semiconductor from a pair of electrodes.
• One example is light emitting diodes based on G a P and similar III-V semiconductors.
• these devices are not only difficult but also economical to use in large area displays due to their very small size.
• Several alternative materials are known that can be used in large area displays. And among such inorganic semiconductors, ZnS is most useful. However, this system has practical disadvantages that cannot be ignored, first of all, its reliability is poor.
• An example of the mechanism related to ZnS is considered to be that, under a strong electric field, one type of carrier is accelerated through a semiconductor, thereby causing local excitation of the semiconductor to be alleviated by radiative emission.
• simple aromatic molecules such as anthracene, perylene, and coronene are known to exhibit electroluminescence.
• U.S. Pat. No. 4,672,265 describes an electroluminescent device having a two-layer structure as the light emitting layer.
• the substance proposed for the two-layer structure is an organic material having the above-mentioned disadvantages.
• JP-A-10-92576 discloses a semiconductor layer in the form of a thin dense polymer film made of at least one kind of conjugated polymer, a first contact layer in contact with a first surface of the semiconductor layer, and a semiconductor layer.
• An electroluminescent device comprising: a second contact layer in contact with a second surface of the semiconductor layer, wherein the polymer film of the semiconductor layer has a structure such that the second contact layer is positive with respect to the first contact layer.
• Conjugated polymers themselves are also known, for example their use in optical modulators is discussed in European Patent Application No. 0 294 061.
• polyacetylene is used as the active layer in the modulation structure between the first and second electrodes. It is necessary to provide an insulating layer between one of the electrodes and the active layer so as to form a space charge region in the active layer that produces an optical modulation effect.
• the presence of the space charge layer makes the formation of electron / hole pairs that emit light impossible due to its collapse. Therefore, such a structure cannot exhibit electroluminescence.
• the development of electroluminescence in European Patent Application No. 0 294 061 is completely undesirable because the optical modulation effect is thereby destroyed.
• An object of the present invention is to provide an organic EL device having both the advantages of an organic material and an inorganic material, high efficiency, long life, and low cost.
• the organic layer has a light emitting layer having a conjugated polymer
• An inorganic electron injecting and transporting layer is provided between the light emitting layer and the electron injecting electrode.
• An organic EL device containing silicon oxide and / or germanium oxide as a third component.
• each component is based on all components, the first component: 5 to 95 1%,
• Second component 5 to 95 mol%
• the electron injection electrode is one or more metal elements selected from AiAg, In, Ti, Cu, Au, Mo, W, Pt, Pd, and Ni.
• the organic EL device according to any one of the above (1) to (4).
• the conjugated polymer (Conju gated Polymer) used in the light emitting layer is preferably poly (p-phenylenevinylene).
• the polymer film has a uniform thickness in the range of approximately 1 Onm to 5 / zm, and the conjugated polymer has a semiconductor band gap in the range of 1 eV to 3.5 eV. Further, it is desirable that the ratio of the conjugated polymer in the electroluminescent region of the polymer film is sufficient to secure charge transfer in the conjugated polymer existing in the film.
• Conjugated polymer means a polymer having a non-polarized T-electron system along the main skeleton of the polymer. This depolarized ⁇ -electron system confers semiconductor properties to the polymer and also gives the polymer the ability to carry positive and negative charge carriers with high mobility along the polymer backbone. .
• At least one layer of the inorganic insulating hole injection / transport layer or the electron injection / transport layer controls the injection ratio of electrons to holes into the electroluminescent layer in addition to the charge injection material, and reduces radiation decay. It helps to ensure that the contact layer occurs away from the charge injection material.
• the conjugated polymer membrane is preferably composed of a single conjugated polymer or a single copolymer containing a segment of a conjugated polymer.
• the conjugated polymer film can be composed of a mixture of a conjugated polymer or copolymer and another suitable polymer.
• the polymer is stable to exposure to oxygen, humidity and high temperatures.
• the polymer film has good adhesion to the underlying layer, ability to resist cracking due to elevated temperature and pressure compression, and resistance to shrinkage, expansion, recrystallization or other morphological changes Having.
• the polymer film is resilient to the ion-atom transfer process due to, for example, high crystallinity and high melting point.
• FIG. 1 is a schematic sectional view showing a first basic configuration of the organic EL device of the present invention.
• FIG. 2 is a schematic sectional view showing a second basic configuration of the organic EL device of the present invention.
• FIG. 3 is a schematic cross-sectional view showing a configuration example of a conventional organic EL element.
• FIG. 4 is a schematic cross-sectional view showing another configuration example of the conventional organic EL element.
• An organic EL device includes a pair of a hole injection electrode and an electron injection electrode, and an organic layer involved in at least a light emitting function between the electrodes.
• the organic layer includes a light emitting layer having a conjugated polymer.
• An inorganic insulating electron injecting and transporting layer is provided between the light emitting layer and the electron injecting electrode.
• the negative electrode When the negative electrode is combined with the inorganic electron injecting and transporting layer described below, it is not necessary to have a low work function and electron injecting property, so that there is no particular limitation, and ordinary metals can be used.
• ordinary metals can be used.
• a 1, Ag, In, Ti, Cu, Au, Mo, W, Pt, Pd, and Ni are selected from the viewpoints of conductivity and ease of handling, especially A 1 and Ag.
• One or two metal elements are preferred.
• the thickness of these negative electrode thin films may be a certain thickness or more that can provide electrons to the inorganic electron injecting and transporting layer, and may be 50 nm or more, preferably 10 Onm or more. Although there is no particular upper limit, the film thickness is usually 50 to 5
• metal element such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Sn, Zn, Zr, etc., or those for improving stability.
• metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Sn, Zn, Zr, etc., or those for improving stability.
• two-component and three-component alloy systems such as Ag * Mg (Ag: 0.1 to 50 at%), Al'Li (Li: 0.01 to: L4at%),
• the thickness of the electron injecting electrode thin film should be a certain thickness or more for sufficiently injecting electrons.
• the thickness should be at least 0.1 nm, preferably at least 0.5 nm, particularly at least lnm. Although there is no particular upper limit, the film thickness is usually about l to 500 nm.
• An auxiliary electrode (protection electrode) may be further provided on the electron injection electrode.
• the thickness of the auxiliary electrode may be a certain thickness or more, preferably 50 nm or more, more preferably 10 Onm or more, in order to secure electron injection efficiency and to prevent entry of moisture, oxygen, or an organic solvent. A range of 100 to 50 Onm is preferred. If the auxiliary electrode layer is too thin, the effect cannot be obtained, and the step coverage of the auxiliary electrode layer is reduced, and the connection with the terminal electrode is not sufficient. On the other hand, if the auxiliary electrode layer is too thick, the stress of the auxiliary electrode layer will be large, causing adverse effects such as a high dark spot growth rate.
• an optimum material may be selected and used depending on the material of the electron injection electrode to be combined. For example, if it is important to secure electron injection efficiency, a low-resistance metal such as A1 may be used.If sealing property is important, a metal compound such as TiN may be used. .
• the total thickness of the electron injection electrode and the auxiliary electrode is not particularly limited, it is usually about 50 to 50 Onm.
• the hole injection electrode material is preferably a material capable of efficiently injecting holes into the hole injection layer, and is preferably a material having a work function of 4.5 eV to 5.5 eV.
• tin-doped indium oxide (I TO), zinc de one flop indium oxide (I ZO), oxide Injiumu (I n 2 0 3), tin oxide (S n0 2) and acid zinc (Z nO ) Is preferred as a main composition. These oxides may deviate somewhat from their stoichiometric composition.
• the mixing ratio of Zn 2 to In 2 3 in IZO is usually about 12 to 32 wt%. Degrees.
• Hole injecting electrode in order to adjust the work function may contain silicon oxide (S i 0 2).
• the content of silicon oxide (Si 2 ) is preferably about 0.5 to 10% in terms of the molar ratio of Si 2 to ITO. Inclusion of Si 2 increases the work function of the ITO.
• the electrode on the light extraction side preferably has an emission wavelength band, usually 400 to 70 Onm, and particularly has a light transmittance of 80% or more, particularly 90% or more for each emitted light.
• the transmittance is low, the light emission from the light emitting layer itself is attenuated, and it becomes difficult to obtain the luminance required for the light emitting element.
• the thickness of the electrode is preferably in the range of 50 to 500 nm, particularly preferably 50 to 300 nm.
• the upper limit is not particularly limited. However, if the thickness is too large, there is a concern that the transmittance may decrease or peeling may occur. If the thickness is too small, sufficient effects cannot be obtained, and there is a problem in film strength during production.
• the light emitting layer has a conjugated polymer.
• the conjugated polymer of the light-emitting layer is preferably a poly (p-phenylenevinylene) [PPV] of the following formula (I), in which the phenylene rings are each independently an alkyl group if necessary. (Preferably methyl), alkoxy (preferably methoxy or ethoxy), halogen (preferably chlorine or bromine) or nitro, even if it has one or more substituents. Good.
• conjugated polymers derived from poly (p-phenylenevinylene) Further, it is suitable to be used as a conjugated polymer of the organic EL device according to the present invention.
• polycyclic systems may also have one or more substituents as described for the phenylene ring above.
• the furan ring may also have one or more substituents described for the phenylene ring with respect to the phenylene ring.
• y represents 2, 3, 4, 5, 6, or 7. Also Usually, n is about 3 to 1,000,000.
• these ring systems may have various substituents as described for the phenylene ring above.
• Conjugated polymer membranes can be made by chemical and / or heat treatment of solution-processable or melt-processable “precursor” polymers.
• the latter precursor polymer can be subsequently purified or pretreated to the desired shape before being converted to a conjugated polymer by an elimination reaction.
• the above-mentioned various PPV derivative films can be similarly formed on an organic EL structure by using an appropriate sulfonium precursor.
• a polymer precursor which preferably has a higher solubility in organic solvents than the sulfonium salt precursor (II).
• the solubility in organic solvents can be increased by substituting the sulfonium moiety in the precursor with a less hydrophilic group such as an alkoxy group (usually methoxy) or a pyridinium group.
• a poly (phenylene vinylene) film is formed on a substrate on which electrodes, and if necessary, a hole injection layer, an electron injection layer, and the like are formed by a method based on the following reaction formula. be able to.
• the sulfonium salt monomer (II) is synthesized into the precursor polymer (III) in an aqueous solution, a mixed solution of water and ethanol, or methanol.
• a solution of prepolymer- (III) can be formed on a substrate by common spin-coating techniques used in the semiconductor industry for photoresist processing.
• the film can also be formed by a casting method, a dive method, a vacuum coating method, a roll coating method, or the like.
• the membrane is typically converted to poly (phenylenevinylene) (I) by heating to a temperature of 200 to 350.
• the thickness of the poly (phenylenevinylene) film is preferably 0. Inn! ⁇ 10 / m, more preferably 0.5 ⁇ ! ⁇ 1 / zm, especially 10 to 50 Onm. These PPV films have only a few pinholes.
• the PVV film has a semiconductor energy gap of about 2.5 eV (50 Onm). PPV membranes are strong, hardly react with oxygen at room temperature, and are stable besides air at temperatures above 300 ° C.
• the ordering of the material can be improved by modifying the leaving group of the precursor polymer to ensure that the elimination reaction proceeds in a single reaction without creating another intermediate structure .
• the n-dialkyl sulfonium component can be replaced by a tetrahydrothiophene component.
• the latter component leaves as a single leaving group without decomposing into alkylmercaptan as found in dialkyl sulfides.
• the precursor polymer used was a dialkyl sulfonium Includes both sulfides and those selected as tetratryebrothiophene. Together, these precursors produce a PPV film suitable for use in organic EL devices.
• a preferred material for forming the conjugated polymer film is poly (phenylene).
• This material can be produced starting from biochemically synthesized derivatives of 5,6-dihydroxycyclohexa-1,3-gen. These derivatives can be polymerized by using a radical initiator to form a precursor polymer that is soluble in a single solvent. The preparation of this poly (phenylene) is described in more detail by Ballard et al, J. Chem. Comm. 954 (1983).
• the polymer precursor solution is spin-coated as a thin film on a substrate and then heat treated, typically in the range of 140 ° C to 240 ° C, to convert to a conjugated poly (phenylene) polymer.
• Copolymerization using vinyl or diene monomers can also be performed to obtain phenylene copolymers.
• conjugated polymer membranes are by the presence of large side groups attached to the main conjugated chain, or by combining the conjugated polymer with one or more of its components.
• conjugated polymers which are either themselves solution processable or melt processable by incorporation into a non-conjugated copolymer structure.
• the former examples include:
• PDPV Poly (4,4 'diphenylenediphenylvinylene)
• PDPV Poly (4,4 'diphenylenediphenylvinylene)
• a Poly (4,4 'diphenylenediphenylvinylene) [PDPV] is an arylenevinylene polymer in which both vinylene carbons are replaced by phenyl rings. It is soluble in common organic solvents and can form thin films.
• Poly (1,4-phenylene-1—phenylvinylene) and poly (1,4-phenylenediphenylene) polymers are analogous to PPV, and One or both vinylene carbons are replaced with a phenyl group. They are each dissolved in organic solvents and cast or spin-coated to form thin films.
• melt-processable poly (3-alkylthiophene) polymers (alkyl is propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, pentadecyl) Le, dodecyl, etc.).
• Poly (3-alkylpyrrol) polymers are expected to be similar to poly (3-alkylthiophene) polymers.
• a polymer blend of a conjugated polymer and another polymer is used to obtain the required processability of the polymer and facilitate the formation of a uniform thin film on the substrate (electrode and the required functional thin film). It may be suitable to form.
• the active site of the electroluminescent device incorporating the conjugated polymer film is the same as the percolation threshold of the copolymer or polymer blend. Or more large conjugated polymer sites.
• the emissive layer has different band gaps and poly- or multi-charged species. Since it is formed as a composite layer having a limmer layer, for example, concentration of injected charges from the hole injection layer to the light emitting layer or a specific region in the light emitting layer is achieved.
• the composite layer can be formed by continuous deposition of a polymer layer. When the various films are deposited in a precursor form on a conjugated polymer by spinning or drawing, subsequent conversion layers to a conjugated polymer render the films insoluble and subsequent The same can be applied without dissolving the membrane.
• conjugated polymer used in the light emitting layer the following can be used as those not requiring the thermal polymerization step.
• a solvent-soluble conjugated polymer number average Koryou of this conjugated polymer is 1 0 3 to 1 0 7
• the conjugated polymer is Ri structures der a conjugated bond continuous
• This conjugated polymer has two or more different types of repeating units different from each other, and each of the repeating units has at least one conjugated bond.
• the peak wavelength of the absorption spectrum and the fluorescence of the thin film of this conjugated polymer The difference between the peak wavelengths of the spectrum is 12 O nm or more.
• the conjugated polymer contains at least 0.01 mol% and not more than 40 mol% of the repeating unit having the minimum optical absorption edge energy in the homopolymer composed of each repeating unit.
• the number average molecular weight is a number average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC) using chloroform as a solvent.
• the conjugated polymer fluorescent substance is preferably a conjugated polymer phosphor having a repeating structure represented by the following (1) to (3). Further, a conjugated polymer having a repeating structure in which a vinylene group and an aryl group or a heterocyclic compound group represented by the following (4) or (5) are alternately bonded is preferable.
• R and R 57 are each independently hydrogen, an alkyl group, an alkoxy group or an alkylthio group having 1 to 20 carbon atoms; an aryl group and an arylyloxy group having 6 to 18 carbon atoms; It is a group selected from the group consisting of 14 heterocyclic compound groups.
• a r 4, A r 5 , A r 6 are different from each other, respectively Ariren group or a divalent heterocyclic compound group forming a conjugated bond continuing to a vinylene group, and A r 4, A r 5, a at least one of r 6, the number 4 to 22 alkyl group carbon, ⁇ alkoxy group and alkylthio group, 6 or more carbon atoms 60 following Ariru group and Ariruokishi group and having 4 to 60 carbon atoms
• phenylene group, substituted phenylene group, biphenylene group, substituted biphenylene group, naphthalenediyl group, substituted naphthalenediyl group, anthracene-9,10-diyl group, substituted anthracene-9 , 10-Diyl group, pyridin-1,2,5-diyl group, substituted pyridine-2,5-diyl group, chenylene group and substituted chenylene group are preferred. More preferred are a phenylene group, a biphenylene group, a naphthylenediyl group, a pyridine-1,2,5-diyl group, and a celenylene group.
• the alkyl group having 1 to 20 carbon atoms includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, Examples thereof include a lauryl group, and a methyl group, an ethyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group are preferable.
• alkoxy group having 1 to 20 carbon atoms examples include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptoxy group, an octyloxy group, a decyloxy group, and a lauryloxy group.
• alkylthio group examples include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, a decylthio group, a laurylthio group, and the like, and a methylthio group, an ethylthio group, and a pentylthio group.
• Groups, hexylthio, heptylthio, and octylthio groups are preferred.
• Examples of the aryloxy group include a phenoxy group.
• Heterocyclic compound groups include 2 Examples thereof include a nyl group, a 2-pyrrolyl group, a 2-furyl group, a 2-, 3- or 4-pyridyl group.
• a conjugated polymer selected from these repeating units wherein the repeating unit having the minimum optical absorption edge energy is contained in the range of 0.01 mol% or more and 40 mol% or less. Coalescence is more preferred. It is preferable to select, from these repeating units, those having a difference in optical absorption edge energy of 0.05 eV or more in the case of a homopolymer since a light emitting material with a particularly high quantum yield of fluorescence can be obtained. For this, it is necessary to select from at least two or more different chemical structures.
• Ar Ar 2 and Ar 3 shown above are selected from those not having the same chemical structure. Further, the optical absorption edge energy is zero.
• the 0 5 eV or more different repeating units, A r,, when A r 2, A r 3 has a substituent, at least one alkoxy group of the substituent , An alkylthio group, an aryloxy group, or a heterocyclic compound group having 4 or more carbon atoms, or one or two of Ar 2> Ar 3 are selected from heterocyclic compound groups. Things are shown.
• a conjugated polymer can be obtained.
• the conjugated polymer is a random, block or graft copolymer. Or a polymer having an intermediate structure between them, for example, a random copolymer having a block property. From the viewpoint of obtaining a copolymer having a high quantum yield of fluorescence, a random copolymer having block properties or a block or graft copolymer is preferable to a completely random copolymer.
• Preferred solvents for the polymeric fluorescent substance of the present invention include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene and the like. Although it depends on the structure and molecular weight of the polymeric fluorescent substance, it can usually be dissolved in these solvents in an amount of 0.1 wt% or more.
• a combination of Ar, Ar 2 , and Ar 3 , or a combination of Ar 4 , Ar 5 , and Ar At least one of which is an alkyl group, an alkoxy group or an alkylthio group having 4 to 22 carbon atoms; an aryl group or an aryloxy group having 6 to 60 carbon atoms; or a heterocyclic compound group having 4 to 60 carbon atoms Is preferably an aryl group or a heterocyclic compound group in which one or more nuclei are substituted.
• alkyl group having 4 to 22 carbon atoms examples include a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a lauryl group, and the like.A pentyl group, a hexyl group, a heptyl group And an octyl group is preferred.
• alkoxy group having 4 to 22 carbon atoms examples include a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, a lauryloxy group, and the like.
• a pentyloxy group, a hexyloxy group Groups, heptyloxy groups and octyloxy groups are preferred.
• alkylthio group examples include a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, a decylthio group, a raditylthio group, and the like.
• a pentylthio group, a hexylthio group, a heptylrethio group, and an octylthio group are preferable.
• Examples of the aryloxy group include a phenoxy group
• heterocyclic compound groups include a 2-phenyl group and a 2-pyrrolyl group. Group, 2-furyl group, 2-, 3- or 4-pyridyl group and the like.
• the content of the repeating unit having these substituents in the polymer is 5 to 100 mol%, preferably 15 to 100 mol%. 0 mol%.
• a typical example of the copolymer of the present invention is an arylenevinylene-based copolymer, and the synthesis method thereof is not particularly limited.
• the copolymer can be obtained by a method similar to the method described in Japanese Patent Application Laid-Open No. 1792217.
• two or more corresponding bis (methyl halide) compounds more specifically, for example, 2,5-diethyl-P-xylylenedibromide, 2,5-diheptyloxy-P-
• a dehydrohalogenation method in which xylylene dibromide and p-xylylene dibromide are copolymerized in a xylene / tertiary butyl alcohol mixed solvent using tertiary butoxy potassium. This mixture usually becomes a random copolymer, but a block copolymer can also be obtained by using oligopolymer.
• the corresponding bis (methyl halide) compound more specifically, for example, 2,5-diethyl-p-xylylene dibromide and 2,5-diheptyloxy-P-xylylene dibromide can be N, N —Synthesize phosphonium salt by reacting with trifenylphosphine in dimethylformamide solvent and use the corresponding dialdehyde compound, more specifically, for example, using terephthalaldehyde, for example, using lithium ethoxide in ethyl alcohol.
• the reaction may be a Witting reaction in which the polymerization is carried out.
• two or more diphosphonium salts and / or two or more dialdehyde compounds may be reacted.
• Other examples include a sulfonium salt decomposition method in which the corresponding sulfonium salt is polymerized in the presence of an alkali, followed by desulfonium salt treatment.
• these polymers are used as a light-emitting material for an organic EL device, their purity affects the light-emitting characteristics. Therefore, after synthesis, purification treatment such as reprecipitation purification, fractionation by chromatography, etc., may be required. desirable.
• At least one of the light emitting layers provided between a pair of transparent or translucent electrodes has the light emitting material comprising the polymer described above in a light emitting layer.
• the light emitting material comprising the polymer described above in a light emitting layer.
• a pair of light-emitting layers composed of the above-described polymeric fluorescent substance or a mixture of the above-described polymeric fluorescent substance and a charge transporting material (which means a general term for an electron transporting material and a hole transporting material) are provided on both surfaces.
• an electron transporting layer containing an electron transporting material between the light emitting layer and the electron injecting electrode, and a hole containing a hole transporting material between the light emitting layer and the hole injecting electrode. The thing which laminated the transport layer is illustrated.
• the present invention includes a single light emitting layer and a charge transport layer and a combination of a plurality of layers.
• a light emitting material other than the polymer fluorescent substance described below may be mixed and used in the light emitting layer.
• a layer in which the polymeric fluorescent substance and / or the charge transporting material is dispersed in a polymeric compound may be used.
• charge transporting material used with the polymer of the present invention that is, an electron transporting material or a hole transporting material
• known materials can be used, and there is no particular limitation.
• the hole transporting material include pyrazoline derivatives, arylamine derivatives, and still pens.
• Derivatives triphenylenediamine derivatives, etc. have been reported as oxadiazole derivatives, anthraquinodimethane and its derivatives, benzoquinone and its derivatives, naphthoquinone and its derivatives, anthraquinone and its derivatives, tetracyano anthraquinodimethane and Derivatives, fluorenone derivatives, diphenyldisocyanoethylene and derivatives thereof, diphenquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof are exemplified.
• JP-A-63-70257, JP-A-63-175580, JP-A-2-135359, JP-A-135361, JP-A Examples are those described in JP-A Nos. 20-9988, 3-37992 and 3-152184.
• the hole transporting material is preferably a triphenyldiamine derivative, and the electron transporting material is preferably a metal complex of oxaziazole derivative, benzoquinone and its derivative, anthraquinone and its derivative, 8-hydroquinquinoline and its derivative, and in particular, as the hole transporting material.
• Is 4,4-bis (N (3-methylphenyl) -1-N-phenylamino) biphenyl, and electron-transporting material is 2- (4-biphenylyl) -1-5- (4-t-butylphenyl) —1,3,4 Oxaziazol, Penzoquinone, Anthraquinone, Tris (8 Quinolinol) Alminium is preferred. Of these, one or both of the electron-transporting compound and the hole-transporting compound may be used simultaneously. These may be used alone or as a mixture of two or more.
• an organic charge injection layer can be formed using these charge transport materials.
• the charge transporting material is used in a mixture with the light emitting layer, the amount of the charge transporting material varies depending on the kind of the compound to be used. It may be determined appropriately in consideration of them. Usually, it is 1 to 40% by weight, more preferably 2 to 30% by weight based on the luminescent material.
• Known light-emitting materials that can be used together with the polymeric fluorescent substance of the present invention are not particularly limited, and include, for example, naphthylene derivative, anthracene and its derivative, perylene and its derivative, polymethine, xanthene, coumarin, and cyanine And the like, metal complexes of 8-hydroxyquinoline and its derivatives, aromatic amines, tetraphenylcyclopentene and its derivatives, tetraphenylbutadiene and its derivatives, and the like.
• known materials such as those described in JP-A-57-51781 and JP-A-59-193'4393 can be used. is there.
• the above polymer as a light emitting material or a light emitting layer containing this polymer and a charge transport material is formed on an electrode.
• the forming method include a coating method such as a spin coating method, a casting method, a diving method, a bar coating method, and a roll coating method using a solution, a mixed solution, or a molten solution of these materials.
• a coating method such as a spin coating method, a casting method, a dive method, a bar coating method, and a roll coating method.
• the thickness of the light emitting layer is 0.5 thigh to 1 0 nm, preferably lnm to l in. In order to increase luminous efficiency by increasing current density, the range is preferably from 10 to 500 nm.
• the film is formed into a thin film by a coating method, it is dried by heating at a temperature of 30 to 200 ° C., preferably 60 to 100 ° C. under reduced pressure or an inert atmosphere to remove the solvent. It is desirable to do so. When such a heating and drying step is required, it is preferable to form an inorganic charge injection layer shown below between the electrode and the electrode.
• the organic EL device of the present invention has at least an inorganic insulating electron injecting and transporting layer as an inorganic charge injecting layer, and preferably both an inorganic hole injecting and transporting layer, between the light emitting layer and a pair of electrodes.
• an inorganic insulating electron injecting and transporting layer as an inorganic charge injecting layer, and preferably both an inorganic hole injecting and transporting layer, between the light emitting layer and a pair of electrodes.
• the first component, the second component, and the third component make up the inorganic insulating electron injecting and transporting layer, making it unnecessary to form an electrode with a special electron injecting function, making it relatively stable
• a metal electrode having high conductivity and good conductivity can be used. Then, the electron injection / transport efficiency of the inorganic insulating electron injection / transport layer is improved, and the life of the device is extended.
• the inorganic insulating electron injecting and transporting layer is composed of lithium oxide (L i 2 ⁇ ), rubidium oxide (Rb 2 ⁇ ), potassium oxide (K 20 ), sodium oxide ( ⁇ a 20 ), and cesium oxide as the first components. Contains one or more of (C s 20 ). These may be used alone or in combination of two or more, and the mixing ratio when two or more are used is arbitrary. Further, the most preferred oxidizing lithium (L i 2 ⁇ ) is Among these, then rubidium oxide (R b 2 ⁇ ), followed by potassium oxide (K 2 0), and sodium oxide (N a 2 0) is preferable. When these are used as a mixture, it is preferable that the total content of lithium oxide and rubidium oxide is at least 40 mol%, particularly at least 50 mol%. Good.
• the inorganic insulating electron injecting and transporting layer contains one or more of strontium oxide (SrO), magnesium oxide (Mg ⁇ ), and calcium oxide (CaO) as a second component. These may be used alone or as a mixture of two or more kinds. When two or more kinds are used, the mixing ratio is arbitrary. Of these, strontium oxide is most preferred, followed by magnesium oxide and calcium oxide in that order. When these are used as a mixture, it is preferable that strontium oxide is contained in the mixture in an amount of 40 mol% or more.
• the third component oxide silicon as (stabilizer) (S i 0 2)
• Each of the above oxides is normally present in a stoichiometric composition, but may deviate slightly from this.
• the inorganic insulative electron injecting and transporting layer of the present invention is to provide preferably above constituents all components, S and rO, Mg_ ⁇ , C a 0 L i 2 ⁇ , Rb 2 ⁇ , K 2 0, N a 2 ⁇ , C s 2 ⁇ , S i ⁇ 2 , Ge ⁇ 2
• First component 5 to 95 mol%, more preferably 50 to 90 mol%,
• Second component 5 to 95 mol%, more preferably 50 to 90 mol%,
• Third component 0.5 to 20 mol%, more preferably 5 to 10 mol%,
• the thickness of the inorganic insulating electron injecting and transporting layer is preferably from 0.1 to 2 nm, more preferably from 0.3 to 0.8 ⁇ .
• the method of manufacturing the above-mentioned inorganic insulating electron injecting and transporting layer includes a sputtering method, EB Various physical or chemical thin film forming methods such as a vapor deposition method can be considered, but a sputtering method is preferable.
• the pressure of the sputtering gas at the time of sputtering is preferably in the range of 0.1 to 1 Pa.
• the sputter gas an inert gas used in a general sputter device, for example, Ar, Ne, Xe, Kr or the like can be used. Further, N 2 may be used if necessary.
• Sputtering is an atmosphere at evening, it may be mixed 1 about 99% 0 2 is added to the sputtering evening gas.
• the above oxide may be used as a getter and may be a one- or multi-element sputter.
• the target is usually a mixed target containing the main component, sub-components and additives. In this case, the composition of the formed film is almost the same as that of the target, or a composition containing a little less oxygen.
• a high-frequency sputtering method using an RF power source, a DC sputtering method, or the like can be used, but an RF sputtering method is particularly preferable.
• the electric power of the sputtering apparatus is preferably in the range of 0.1 to 10 WZcm 2 for RF sputtering, and the film formation rate is preferably in the range of 0.1 to 5 OmnZmin, especially 1 to 1 OnmZmin.
• the inorganic electron injecting layer When stacking the inorganic electron injecting and transporting layer, if the organic layer and the like are ashed and may be damaged, the inorganic electron injecting layer may be stacked in two layers. That is, the layers are stacked thinly without adding oxygen first, and then thickened by adding oxygen. In this case, the film thickness when no oxygen is added is about 1 to 5 to 4 to 5 as a whole.
• the oxygen-deficient layer formed without adding oxygen is preferably about 60 to 90% of the normal oxygen content.
• the oxide layer formed by adding oxygen has a stoichiometric composition as a normal oxide, but may be slightly deviated from this. Therefore, the difference in oxygen content between the oxygen-deficient layer and the oxidized layer is preferably at least 10%, particularly preferably at least 20%. In addition, The amount of oxygen may change continuously in the surroundings.
• the substrate temperature during film formation is from room temperature (25 ° C.) to about 150 ° C.
• the inorganic insulating hole injecting / transporting layer preferably used in the present invention contains silicon and / or germanium oxide as a main component.
• the oxide which is the main component of the inorganic insulating hole injecting and transporting layer can be efficiently injected from the hole injecting electrode to the organic layer on the light emitting layer side.
• the movement of electrons from the organic layer to the hole injection electrode can be suppressed, and the recombination of holes and electrons in the light emitting layer can be performed efficiently.
• it since it is intended for hole injection transport, it does not emit light when a reverse bias is applied. In particular, it can be effectively applied to a display requiring high luminous brightness such as a time-division driving method, and an organic EL element having both the advantages of an inorganic material and the advantages of an organic material can be obtained. it can.
• the organic EL device of the present invention has the same brightness as the device having the conventional organic hole injection layer, and has a longer heat life and higher leakage resistance and dark spots than the conventional device because of its high heat resistance and weather resistance. Also less. Further, since an inorganic material that is inexpensive and easily available is used instead of an organic material that is relatively expensive, the production becomes easy and the production cost can be reduced.
• Y representing the oxygen content may be in the above composition range, and is not less than 1.7 and not more than 1.99. If y is greater than this, y is less than this At the same time, the hole injection ability decreases and the brightness decreases. It is also preferably 1.85 or more and 1.98 or less.
• the inorganic insulating hole injecting and transporting layer may be silicon oxide or germanium oxide, or a mixed thin film thereof.
• X representing these composition ratios is 0x ⁇ l.
• X is at most 0.4, more preferably at most 0.3, particularly preferably at most 0.2.
• X may be preferably at least 0.6, more preferably at least 0.7, especially at least 0.8.
• the oxygen content is the average composition in the film obtained by Rutherford backscattering.
• Ne, Ar, Kr, Xe, etc. used for the sputter gas as impurities are preferably 10 al% or less in total, more preferably 0.01 to 2 wt%, particularly 0 to 2 wt%. .05 to 1.5 wt% may be contained.
• One or more of these elements may be contained, and the mixing ratio when using two or more of these elements is arbitrary.
• These elements are used as a sputtering gas and are mixed in when forming the inorganic insulating hole injecting and transporting layer. When the content of these elements is increased, the trapping effect is extremely reduced, and desired performance cannot be obtained.
• the content of the sputter gas is determined by the pressure at the time of film formation, the flow ratio of the sputter gas and oxygen, the film formation rate, and the like, particularly the pressure at the time of film formation.
• the film is formed on the high vacuum side, specifically, 1 Pa or less, particularly 0.1 to 1 Pa.
• the average value of the entire hole injection layer is not necessarily uniform as long as the composition is such, and a structure having a concentration gradient in the film thickness direction may be employed.
• the organic layer (light emitting layer) interface side is preferably oxygen poor.
• the inorganic insulating hole injecting and transporting layer is usually in an amorphous state.
• the thickness of the inorganic insulating hole injecting and transporting layer is not particularly limited, but is preferably 0.05 to: L Onm, more preferably 0.1 to 5 nm, particularly l to 5 nm, or 0 It is about 5 to 3. Even if the hole injection layer is thinner or thicker, hole injection cannot be performed sufficiently.
• a force sputtering method which can use various physical or chemical thin film forming methods such as a sputtering method and an EB vapor deposition method, is preferable.
• the pressure of the sputtering gas at the time of the sputtering is preferably in the range of 0.1 to 1 Pa.
• the sputtering gas an inert gas used in a normal sputtering apparatus, for example, Ar, Ne, Xe, Kr, or the like can be used. Further, N 2 may be used if necessary.
• Sputter The evening when the atmosphere, the reaction may be carried out with sputtering evening in addition to the above sputter evening gas 0 2 were mixed for about 1 to 99%.
• the target may be one of the above oxides and a one- or multi-element sputter.
• the sputtering method a high-frequency sputtering method using an RF power source, a DC-responsive sputtering method, or the like can be used, but an RF sputtering method is particularly preferable.
• the electric power of the sputtering apparatus is preferably in the range of 0.1 to 10 WZcm 2 in RF sputtering, and the film formation rate is preferably in the range of 0.5 to 1 OnmZmin, particularly 1 to 5 nmZmin.
• the substrate temperature during film formation is from room temperature (25 ° C) to about 150 ° C.
• reactive sputtering may be performed.
• the reactive gas when nitrogen is mixed, N 2 , NH 3 , N ⁇ , N ⁇ 2 , N 2 O, etc. are listed, and when carbon is mixed, CH 4 , C 2 H 2 , CO and the like can be mentioned. These reactive gases may be used alone or as a mixture of two or more.
• the organic EL device of the present invention by providing an inorganic hole injection layer and an inorganic electron injection layer, heat resistance and weather resistance are improved, and the life of the device can be extended.
• an inorganic material that is inexpensive and easily available is used instead of a relatively expensive organic substance, the production becomes easy and the production cost can be reduced.
• the connectivity with the electrode which is a conventional inorganic material, is improved. For this reason, generation of a leak current and generation of a dark spot can be suppressed.
• a hole injection / transport layer made of an organic material may be provided instead of the inorganic hole injection / transport layer.
• a heating polymerization step is required to form the light emitting layer, heating to about 300 ° C. is performed on the high temperature side, so that the element located below the light emitting layer is used as the inorganic electron injecting and transporting layer. It is good to have composition.
• hole injection / transport material for the hole injection / transport layer made of an organic material.
• the hole injecting and transporting compound it is preferable to use an amine derivative having strong fluorescence, for example, the above-mentioned hole transporting compound such as a triphenyldiamine derivative, a styrylamine derivative, and an amine derivative having an aromatic fused ring. Good.
• the above-mentioned hole transporting compound such as a triphenyldiamine derivative, a styrylamine derivative, and an amine derivative having an aromatic fused ring. Good.
• the hole injecting / transporting compound is described in, for example, JP-A-63-295695, JP-A-2-191694, JP-A-3-7992, JP-A-5-92. — 2 3 4 6 81, Japanese Patent Application Laid-Open No. 5-2394 55, Japanese Patent Application Laid-Open No. 5-2991 74, Japanese Patent Application Laid-Open Various organic compounds described in, for example, Kaihei 7-125626, JP-A-8-010172, EP 0 650 555 A1, and the like can be used.
• tetraarylbenzene compounds triaryldiamine or triphenyldiamine: TPD
• aromatic tertiary amines hydrazone derivatives
• phorazole derivatives triazoles Derivatives
• imidazole derivatives oxadiazole derivatives having an amino group, polythiophene and the like.
• a certain degree of heat resistance is required when a heat polymerization step is required for forming the light emitting layer.
• a hole injecting / transporting compound having a glass transition temperature of preferably 200 ° C. or more, more preferably 300 ° C. or more, and particularly 350 T: or more is preferable.
• the thickness of the organic hole injection layer and the thickness of the electron injection layer are not particularly limited and vary depending on the forming method, but are usually about 5 to 500 nm, particularly about 10 to 30 O nm. It is preferable that When a hole or electron injection layer and a transport layer are provided, the injection layer is preferably at least 1 mn, and the transport layer is preferably at least 1 nm. At this time, the upper limit of the thickness of the injection layer and the transport layer is usually about 500 nm for the injection layer and about 50 O nm for the transport layer.
• the organic hole injection transport layer and the electron injection layer it is preferable to use a vacuum deposition method since a uniform thin film can be formed.
• a vacuum deposition method is used, a homogeneous thin film having an amorphous state or a crystal grain size of 0. 0 or less is obtained. If the crystal grain size exceeds 0.2 im, non-uniform light emission will occur, and the driving voltage of the device must be increased, and the electron and hole injection efficiency will be significantly reduced.
• the conditions for vacuum deposition are not particularly limited, but it is preferable that the degree of vacuum be 10 to 4 Pa or less and the deposition rate be about 0.01 to I nmZs ec. Further, it is preferable to form each layer continuously in a vacuum. If they are continuously formed in a vacuum, high characteristics can be obtained because impurities can be prevented from adsorbing at the interface between the layers. It also lowers the driving voltage of the device and suppresses the occurrence of dark spots. be able to.
• each boat containing the compounds When a plurality of compounds are contained in one layer when a vacuum evaporation method is used to form each of these layers, it is preferable to co-deposit each boat containing the compounds by individually controlling the temperature.
• the sealing plate is bonded and sealed using an adhesive resin layer to prevent moisture from entering.
• the sealing gas is preferably an inert gas such as Ar, He, and N 2 .
• the moisture content of the sealing gas is preferably 100 ppm or less, more preferably 1 ppm or less, and particularly preferably 1 ppm or less. Although there is no particular lower limit for this water content, it is usually about 0.1 ppm.
• the material of the sealing plate is preferably a flat plate, and includes a transparent or translucent material such as glass, quartz, and resin, and glass is particularly preferable.
• an alkali glass is preferable in terms of cost, but in addition, a glass composition such as a soda-lime glass, a lead alkali glass, a borosilicate glass, an aluminosilicate glass, and a silica glass is also preferable.
• soda glass, a glass material having no surface treatment can be used at a low cost and is preferable.
• the sealing plate a metal plate, a plastic plate, or the like can be used in addition to the glass plate.
• the sealing plate may be adjusted in height using a spacer and maintained at a desired height. Resin beads, silica beads, glass beads, glass fibers, etc. And glass beads.
• the spacer is usually a granular material having a uniform particle size, but the shape is not particularly limited, and various shapes may be used as long as the function as the spacer is not hindered. There may be.
• the diameter in terms of a circle is preferably 1 to 20 m, more preferably 1 to 1 O tm, and particularly preferably 2 to 8 m. It is preferable that the particles having such a diameter have a grain length of about 100 ⁇ ⁇ ⁇ or less, and the lower limit is particularly restricted. It is usually not less than the diameter.
• the spacer When a recess is formed in the sealing plate, the spacer may or may not be used.
• the preferred size when used is in the above range, but is particularly preferably in the range of 2 to 8 mm.
• the spacer may be previously mixed into the sealing adhesive or may be mixed during bonding.
• the content of the spacer in the sealing adhesive is preferably from 0.01 to 30% by weight, more preferably from 0.1 to 5% by weight.
• the adhesive is not particularly limited as long as it can maintain stable adhesive strength and has good airtightness. However, it is preferable to use a cationically curable ultraviolet-curable epoxy resin adhesive.
• the substrate for forming the organic EL structure is an amorphous substrate such as glass or quartz, and a crystalline substrate such as Si, GaAs, ZnSe, ZnS, GaP, InP, and the like, and a substrate in which a crystalline, amorphous, or metal buffer layer is formed on these crystalline substrates can also be used.
• a metal substrate Mo, A, Pt, Ir, Au, Pd, or the like can be used, and a glass substrate is preferably used.
• the substrate is on the light extraction side, it is preferable that the substrate has the same light transmittance as the above-mentioned electrodes.
• a large number of the elements of the present invention may be arranged on a plane. By changing the emission color of each element arranged on a plane, a color display can be created.
• the emission color may be controlled by using a color filter film, a color conversion film containing a fluorescent substance, or a dielectric reflection film on the substrate.
• a color filter used in a liquid crystal display or the like may be used for the color filter film.However, the characteristics of the color filter are adjusted according to the light emitted from the organic EL element to improve the extraction efficiency and color purity. It should be optimized. In addition, if a color filter that can cut off external light having a short wavelength such that the EL element material or the fluorescence conversion layer absorbs light is used, the light resistance of the element and the display contrast are improved.
• an optical thin film such as a dielectric multilayer film may be used instead of the color filter.
• the fluorescence conversion filter film absorbs the EL light and emits light from the phosphor in the fluorescence conversion film to convert the color of the emitted light.
• the composition is a binder and a fluorescent material.
• the light absorbing material is formed from three.
• a fluorescent material having a high fluorescence quantum yield may be used, and it is desirable that the fluorescent material has strong absorption in the EL emission wavelength region.
• laser monodye is suitable, for example, rhodamine compounds, perylene compounds, cyanine compounds, phthalocyanine compounds (including subphthalocyanines) naphthaloimide compounds, condensed ring hydrocarbon compounds, condensed complex Ring compounds, styryl compounds, coumarin compounds and the like may be used.
• the binder basically, a material that does not quench the fluorescence may be selected, and a binder that can be finely patterned by photolithography, printing, or the like is preferable. Further, when the hole injection electrode is formed on the substrate in contact with the hole injection electrode, a material that does not damage the film at the time of forming the hole injection electrode ( ⁇ , ⁇ ) is preferable.
• the light absorbing material is used when the light absorption of the fluorescent material is insufficient, but may be omitted when unnecessary.
• a material that does not quench the fluorescence of the fluorescent material may be selected as the light absorbing material.
• the organic EL device of the present invention is usually used as a DC drive type or pulse drive type EL device, but it can be AC drive.
• the applied voltage is usually about 2 to 30 V.
• a substrate 1 / hole injection electrode 2 Z light emitting layer 4 / inorganic insulating electron injection layer 5 / negative electrode (electron injection electrode) 6 are sequentially laminated. It may be configured.
• the substrate 1 / hole injection electrode 2 inorganic insulating hole injection transport layer 3 Z light emitting layer 4 Z inorganic insulating electron injection layer 5 Z negative electrode (electron injection electrode) 6 A configuration in which layers are sequentially stacked may be used.
• the inorganic insulating hole injection layer may be a hole injection layer made of an organic material.
• a so-called reverse lamination structure in which the above lamination order is reversed may be adopted. These are appropriately selected and configured according to, for example, the specifications of the display and the manufacturing process.
• a drive power supply E is connected between the hole injection electrode 2 and the negative electrode (electron injection electrode) 6.
• the device of the present invention may further include an electrode layer Z inorganic layer (inorganic insulating hole injection layer, inorganic insulating electron injection layer), a light emitting layer Z electrode layer, an inorganic layer, and a light emitting layer /
• the electrode layer ' ⁇ ' may be stacked in multiple stages. With such an element structure, it is also possible to adjust the color tone of emitted light and to increase the number of colors.
• the organic EL element of the present invention can be applied to various optical applications such as an optical pickup used for memory read / write, a relay device in a transmission line of optical communication, a photo power blur, etc., in addition to a display application. Can be used for devices.
• Example 1 An optical pickup used for memory read / write, a relay device in a transmission line of optical communication, a photo power blur, etc., in addition to a display application. Can be used for devices.
• a substrate of Corning Corp. (product name: 759) was scrub-cleaned with a neutral detergent.
• An ITO hole injection electrode having a substrate temperature of 250 nm and a film thickness of 20 nm was formed on this substrate by RF magnetron sputtering using an ITO oxide getter. A layer was formed.
• a precursor methanol solution of PPV having a polymer concentration of 1 g to 10 to 25 g of methanol was spin-coated on the substrate on which the inorganic insulating hole injection layer was formed. That is, a polymer solution was applied to the entire surface of the substrate, and then coated while rotating the surface up to 500 Or.pm while keeping the upper surface horizontal.
• the obtained substrate and the polymer precursor layer were heated in a vacuum oven at a temperature of 300 ° C. for 12 hours. This heat treatment converted the precursor polymer to PPV.
• the resulting PPV film was 100-30 Onm thick.
• An inorganic electron injection / transport layer was formed to a thickness of 0.8 nm using a target mixed such that
• the film forming conditions at this time were a substrate temperature of 25 ° C., a sputter gas Ar, a film forming rate of 1 nm, an operating pressure of 0.5 Pa, and an input power of 5 WZcm 2 .
• the initially sputter evening gas A r 1 as 100% 1 0 to 0SCCM subjected sheet by forming a inorganic electron injecting and transporting layer to a thickness of 0. 4 nm while, A Rz0 2 continued: 1/1 While supplying 100 SCCM, an inorganic electron injecting and transporting layer was formed to a thickness of 0.4M.
• A1 is deposited to a thickness of 20 Onm to form a negative electrode.
• glass sealing was performed to obtain an organic EL device.
• a sample in which a negative electrode was formed on a light emitting layer without forming an inorganic electron injection layer was prepared.
• the comparative sample obtained only an emission luminance of 10 OcdZm 2 , while the sample of the present invention exhibited a luminance of 50 OcdZm 2 . was gotten. In addition, the luminance half-life was improved more than 5 times compared with the comparative sample.
• Example 1 the main component, the subcomponent, and the stabilizer of the inorganic insulating electron injecting and transporting layer were respectively changed from 31 " ⁇ to 1 ⁇ 80, CaO, or a mixed oxide thereof, from Li 2 ⁇ to K 2 ⁇ , Rb 2 ⁇ , the K 2 ⁇ , N a 2 0, C s 2 0 or these mixed-oxide, mixing of S I_ ⁇ 2 from Ge_ ⁇ 2 or S I_ ⁇ 2 and Ge_ ⁇ 2, Substantially the same results were obtained when the oxide was replaced with a negative electrode, and the materials constituting the negative electrode were changed from A1, Ag, In, Ti, Cu, Au, Mo, W, Pt, Pd, N The same was true for i and their alloys.
• Example 1 after UVZOa cleaning the surface of the substrate I TO electrode layer or the like is formed, was fixed to a substrate holder of a vacuum deposition apparatus, which was evacuated to a vacuum of less than 1 X 10- 4 Pa.
• Example 2 Thereafter, a PPV film was formed in the same manner as in Example 1, and an inorganic electron injection layer, an A 1 Li (Li: 7 at%) film, and an A 1 film were formed to obtain an organic EL device.
• Example 1-3 the inorganic insulative hole injecting 0 2 flow transport layer spa Tsu evening gas when depositing, and film its composition by changing the target by the composition S i ⁇ 7, S i Omicron,. 95, G e ⁇ , .96 ⁇ S i 0. 5 Ge 0. 5 ⁇ teeth except that the 92 in the same manner as in example 1 to produce an organic EL element, almost emission luminance, and to evaluate the life characteristics rollers Similar results were obtained.
• Phosphonium salt (A) was synthesized by reacting 2,5-getyl-P-xylylene dibromide with triphenylphosphine in N, N-dimethylformamide solvent.
• 2,5-diheptyloxy-p-xylylene dibromide was reacted with triphenyl phosphine in N, N-dimethylformamide solvent to synthesize a phosphonicum salt (B).
• the obtained two kinds of phosphonium salts (A) (4.1 parts by weight), (B) 1.0 parts by weight, and terephthal aldehyde 0.8 parts by weight were dissolved in ethyl alcohol.
• polymeric fluorescent substance 1 An ethyl alcohol solution containing 0.8 parts by weight of lithium methoxide was added dropwise to a solution of phosphonium salt and dialdehyde in ethyl alcohol, and polymerized at room temperature for 3 hours. After leaving overnight at room temperature, the precipitate was filtered off, washed with ethyl alcohol, and dissolved in chloroform. Then, ethanol was added thereto to reprecipitate. This was dried under reduced pressure to obtain 0.35 parts by weight of a polymer. This is called polymeric fluorescent substance 1. The repeating units of polymeric fluorescent substance 1 and their molar ratios, which are calculated from the charging ratio of the monomers, are shown below.
• the polystyrene-equivalent number average molecular weight of this polymeric fluorescent substance 1 was 5.0 ⁇ 10 3 .
• Examples 1 to 4 an organic EL device was obtained in the same manner as in Examples 1 to 5, except that a 1.0 wt% chloroform solution of the polymeric fluorescent substance 1 was used to form the PPV film. .
• the above solution was formed into a film having a thickness of 5 Onm by a diving method, and dried at 80 ° C. for 1 hour under reduced pressure.
• the obtained organic EL device was evaluated in the same manner as in Example 1.
• an organic EL device having high efficiency, long life, and low cost, having the advantages of organic materials and inorganic materials.

Landscapes

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

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=18412703

Family Applications (1)

Country Status (7)

Families Citing this family (31)

Citations (7)

Family Cites Families (13)

• 1998
  • 1998-11-25 JP JP10350762A patent/JP2000164361A/ja active Pending
• 1999
  • 1999-06-25 KR KR1020007008085A patent/KR100345032B1/ko not_active Expired - Fee Related
  • 1999-06-25 US US09/339,877 patent/US6404126B1/en not_active Expired - Fee Related
  • 1999-06-25 WO PCT/JP1999/003391 patent/WO2000032014A1/ja not_active Ceased
  • 1999-06-25 TW TW088110794A patent/TW439393B/zh not_active IP Right Cessation
  • 1999-06-25 EP EP99926809A patent/EP1061778A4/en not_active Withdrawn
  • 1999-06-25 CN CNB99802371XA patent/CN1292497C/zh not_active Expired - Fee Related

Patent Citations (7)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events