JP2012243517A - Organic light-emitting element, method for manufacturing the same, display device, and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic light-emitting element which has high luminous efficiency even when using an electrode made of a metal, and has high luminance uniformity in a light-emitting surface and high durability.SOLUTION: In an organic light-emitting element 10, a first electrode layer 12 made of a metal, an organic compound layer 13 including a light-emitting layer, and a second electrode layer 14 made of a metal are sequentially laminated. A plurality of through parts 15 passing through the first electrode layer 12 are formed in the first electrode layer 12 and are filled with dielectrics 17. For example, an upper surface of each of the dielectrics 17 on the side of the organic compound layer 13 has a curved surface shape recessed in a central portion of the through part 15.

Description

  The present invention relates to an organic light emitting element used for a display device or a lighting device.

  In recent years, organic light-emitting devices using organic compounds as light emitters are expected to be used for lighting applications due to the characteristics of surface light sources, and technology for improving luminance uniformity and durability within the light-emitting surface has been actively developed. ing.

In Patent Document 1, a plurality of holes are provided in one of the anode and the cathode, thereby providing an inclined surface to the electrode facing the electrode, and the inclined surface is naturally formed in the hole portion in the lamination process. An organic electroluminescence element that is formed and improves the light extraction efficiency by utilizing reflection by the inclined surface of the counter electrode is disclosed.
Patent Document 2 discloses a method for manufacturing an organic light emitting device in which an organic electroluminescent layer is formed between a first electrode and a second electrode, wherein the first electrode is formed on the main surface of the substrate, An insulating layer is formed on the first electrode and the region between the first electrodes so as to cover the electrodes so that the surface thereof is substantially flat, and the surface of the insulating layer is formed on the surface of the first electrode. A manufacturing method is disclosed in which an organic electroluminescent layer and a second electrode are formed on a surface after the surface of the insulator layer and the surface of the first electrode are made to coincide with each other until the clean surface is exposed.

Japanese Patent Laid-Open No. 11-214163 JP 11-329751 A

  However, in the conventional organic light emitting device, light emitted from the organic light emitting layer is confined in the organic light emitting layer, and the light emission efficiency may be lowered. In particular, when an electrode made of a metal is used, since this electrode does not transmit light, it has been a problem to extract light efficiently.

  The inventors have solved the above problem by the following organic light emitting device in which a plurality of through portions formed in a metal electrode are filled with a dielectric, and an organic compound layer and a metal counter electrode are formed thereon. Settled.

  The organic light-emitting device of the present invention is formed by sequentially laminating a first electrode layer made of metal, an organic compound layer including a light-emitting layer, and a second electrode layer made of metal. A plurality of through portions penetrating the electrode layer are formed, and the inside of the through portion is filled with a dielectric.

Here, it is preferable that the upper surface on the organic compound layer side of the dielectric filled in the through portion has a curved shape that is recessed in the central portion of the through portion, and the through portion is in the plane of the first electrode layer. The planar shape has a circular shape or a substantially regular polygonal shape with a maximum width of 10 μm or less, and 10 ⁴ to 10 ⁸ are formed in 1 mm ² in any plane of the first electrode layer. Is preferred.
The distance a between the upper surface of the first electrode layer and the maximum width d of the penetrating portion in the central portion of the penetrating portion of the dielectric filled in the penetrating portion satisfies 0.02 ≦ (a / d) ≦ 0.15. It is preferable to satisfy the relational expression.
Furthermore, it is preferable that the maximum width d of the penetrating portion and the film thickness h of the first electrode layer satisfy the relational expression of 1 ≦ (d / h) ≦ 5, and the dielectric has a refractive index different from that of the organic compound layer. Is preferred.
A transparent conductive layer is preferably formed between and in contact with the first electrode layer between the first electrode layer and the organic compound layer, and the penetrating portion preferably further penetrates the conductive layer.

Further, the method for manufacturing an organic light emitting device of the present invention includes a first electrode layer forming step of forming a first electrode layer on a substrate, a through portion forming step of forming a through portion penetrating the first electrode layer, and a dielectric. A filling step of filling the penetrating portion with the composition by applying a composition containing, an organic compound layer forming step of forming an organic compound layer including a light emitting layer, and forming a second electrode layer on the organic compound layer A second electrode layer forming step.
Here, it is preferable to further include a conductive layer forming step of forming a conductive layer formed in contact with the first electrode layer. In the penetration part forming step, the penetration part can be formed so as to further penetrate the conductive layer.

  Moreover, the display apparatus of this invention is equipped with said organic light emitting element.

  Moreover, the illuminating device of this invention is equipped with said organic light emitting element.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses the electrode which consists of metals, it can provide an organic light emitting element with high luminous efficiency, high brightness uniformity in a light emitting surface, and high durability.

(A)-(b) is the fragmentary sectional view explaining the 1st example of the organic light emitting element to which this Embodiment is applied. It is a fragmentary sectional view explaining the 2nd example of the organic light emitting element to which this Embodiment is applied. It is the fragmentary sectional view explaining the 3rd example of the organic light emitting element to which this Embodiment is applied. (A)-(e) is the figure explaining the manufacturing method of the organic light emitting element to which this Embodiment is applied. It is a figure explaining an example of the display apparatus using the organic light emitting element in this Embodiment. It is a figure explaining an example of an illuminating device provided with the organic light emitting element in embodiment.

(First form of organic light emitting device)
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIGS. 1A to 1B are partial cross-sectional views illustrating a first example of an organic light emitting device to which the present embodiment is applied.
The organic light emitting element 10 shown in FIG. 1A is laminated on a substrate 11 when the substrate 11 side is the lower side, a first electrode layer 12 made of metal, and a first electrode layer 12. The organic compound layer 13 is formed on the organic compound layer 13 and includes a light emitting layer that emits light when a voltage is applied, and the second electrode layer 14 made of metal formed on the organic compound layer 13. The organic compound layer 13 and the second electrode layer 14 are continuously formed over the entire light emitting surface. In the first electrode layer 12, a plurality of through portions 15 penetrating the first electrode layer 12 are formed, and the inside of the through portion 15 is filled with a dielectric 17.

  The substrate 11 serves as a support for forming the first electrode layer 12, the organic compound layer 13, the second electrode layer 14, and the dielectric 17. A material that satisfies the mechanical strength required for the organic light emitting device 10 is used for the substrate 11.

  In the organic light emitting device 10 of the present embodiment, since light is extracted from the substrate 11 side, the material of the substrate 11 needs to be transparent to the light emitted from the light emitting layer. Specifically, glass such as sapphire glass, soda lime glass, and quartz glass; transparent resin such as acrylic resin, methacrylic resin, polycarbonate resin, polyester resin, and nylon resin; silicon resin; transparent metal oxide such as aluminum nitride and alumina Such as things. In addition, when using the resin film etc. which consist of the said transparent resin as the board | substrate 11, it is preferable that the gas permeability with respect to gas, such as water and oxygen, is low. When using a resin film or the like having high gas permeability, it is preferable to form a barrier thin film that suppresses gas permeation as long as light permeability is not impaired.

  The thickness of the substrate 11 is preferably 0.1 mm to 10 mm, more preferably 0.25 mm to 2 mm, although it depends on the required mechanical strength.

  The first electrode layer 12 is a layer for injecting carriers into the organic compound layer 13, and functions as an anode in the present embodiment. The metal material used for the first electrode layer 12 has electrical conductivity, and preferably has a surface resistance of 100Ω / □ or less in a temperature range of −5 ° C. to 80 ° C., and is 10Ω / □ or less. More preferably. Further, it is preferable that the light reflectivity is high and the thermal conductivity is excellent. As materials satisfying such conditions, for example, Al, Cr, In, Sn, Ta, Ti, V, W, Zn, Zr, Hf, Mo, Nb, Cd, Cu, Pb, Ag, Au, Pt, Pd , Ni and alloys thereof. Among them, Al, Cr, Ni, Ag, Pd, Pt and alloys of these metals and W are preferable because of high light reflectance and excellent smoothness.

  The thickness of the first electrode layer 12 is preferably thicker from the viewpoint of high electrical conductivity and thermal conductivity, but thinner from the viewpoint of easy processing for forming the through portion 15. . Therefore, in order to satisfy both conditions, the thickness of the first electrode layer 12 is preferably 10 nm to 10 μm. The first electrode layer 12 may also serve as the substrate 11. In this case, the first electrode layer 12 must have a mechanical strength similar to that of the substrate 11, and therefore the thickness of the first electrode layer 12 is 1 μm to 100 μm. Is preferred.

  A plurality of through portions 15 are formed in the first electrode layer 12. Here, it is preferable that the shape of the penetrating portion 15 is a substantially regular polygonal column shape such as a columnar shape or a quadrangular column from the viewpoint that the efficiency of taking out light from the substrate 11 side is high and the shape control is easy to perform. In these shapes, the in-plane shape of the first electrode layer 12 may change in the thickness direction of the first electrode layer 12, or the size of the shape may change. That is, for example, the shape may be a cone shape, a pyramid shape, a truncated cone shape, a truncated pyramid shape, or the like. By appropriately selecting the shape of the penetrating portion 15, the ratio of light emitted from the substrate 11 side to the light incident from the organic compound layer 13, light distribution characteristics, and the like can be controlled.

  In the partial cross-sectional view of FIG. 1A, the side surface of the penetrating portion 15 is formed perpendicular to the surface of the substrate 11, and the inclination angle of the side surface of the penetrating portion 15 in this case is 90 degrees. However, the inclination angle is not limited to this, and can be changed as appropriate by selecting a material used for the first electrode layer 12, an etching method, and the like, and the efficiency of extracting light emitted from the organic compound layer 13 to the outside is increased. can do. In the present embodiment, the inclination angle is preferably 60 degrees to 90 degrees, more preferably 75 degrees to 90 degrees, and further preferably 80 degrees to 90 degrees.

As the size of the through portion 15 in the plane of the first electrode layer 12 is increased, the light transmitting area in the first electrode layer 12 is increased, and the light is easily extracted to the outside. On the other hand, in this case, since the area where charge can be injected from the first electrode layer 12 to the organic compound layer 13 is reduced, the light emission area is reduced, and the electrical conductivity and thermal conductivity of the first electrode layer 12 are also reduced. Therefore, in the present embodiment, it is preferable that the maximum width of the shape on the surface of the first electrode layer 12 (the diameter of the minimum circle including the shape) is 0.1 μm to 10 μm, and from the viewpoint of easy manufacture, Furthermore, it is more preferable that it is 0.5 micrometer-10 micrometers. In addition, it is preferable that 10 ⁴ to 10 ⁸ such penetrating portions 15 are formed in 1 mm ² in an arbitrary plane of the first electrode layer 12. The arrangement of the through portions 15 on the first electrode layer 12 may be a regular arrangement such as a tetragonal lattice shape or a hexagonal lattice shape, or an irregular arrangement. About this arrangement | positioning, it selects suitably from viewpoints, such as the wavelength of the light which injects into the penetration part 15 from the organic compound layer 13, the light distribution of the light radiate | emitted from the organic light emitting element 10, and spectrum control.

  The dielectric 17 filled in the penetrating portion 15 is transparent to the incident light because it is necessary to extract light incident from the organic compound layer 13 side to the outside from the substrate 11 side. Specific materials include metal nitrides such as silicon nitride, boron nitride, and aluminum nitride; metal oxides such as silicon oxide (silicon dioxide) and aluminum oxide, sodium fluoride, lithium fluoride, magnesium fluoride, and fluoride. Examples include metal fluorides such as calcium and barium fluoride, but also high molecular compounds such as polyimide, polyvinylidene fluoride, and parylene, and spin-on glass (SOG) such as poly (phenylsilsesquioxane). Can also be used.

  The dielectric 17 preferably has a refractive index different from that of the organic compound layer 13. Specifically, the refractive index of the dielectric 17 is preferably larger than the refractive index of the organic compound layer 13, and the difference in refractive index is preferably 0.1 or more. In the present embodiment, the refractive index of the dielectric 17 is larger than the refractive index of the organic compound layer 13. Therefore, the light emitted from the organic compound layer 13 is refracted at an angle closer to the normal direction of the substrate 11 when entering the dielectric 17. As a result, the light reaching the first electrode layer 12 and the substrate 11 is less likely to cause total reflection at the interface between the dielectric 17 and the first electrode layer 12 and at the interface between the first electrode layer 12 and the substrate 11. Therefore, it becomes easier to enter the first electrode layer 12 and the substrate 11. That is, more light emitted from the organic compound layer 13 can be extracted from the substrate 11 side, and the light extraction efficiency is improved.

  The dielectric 17 may not be completely filled in the through portion 15. That is, the upper surface of the dielectric 17 and the upper surface of the first electrode layer 12 do not have to form the same plane. For example, as shown in FIG. It may have a curved surface shape in which the central portion is slightly depressed. As shown in FIG. 1B, when the distance from the upper surface of the first electrode layer 12 in the central portion of the through portion 15 of the recessed dielectric 17 is a, the shape of the through portion 15 on the first electrode layer 12 surface. The preferable range of the ratio (a / d) with respect to the maximum width d depends on the refractive index of the dielectric 17 and the organic compound layer 13. However, when the difference in refractive index is 0.1 to 0.2, it is preferable that (a / d) is 0.02 to 0.15 because light extracted to the outside of the substrate 11 increases. In addition, in order for the dielectric 17 to be formed into a lens shape that can extract a large amount of light, the ratio (d / h) is preferably 5 or less, but (d / h) is preferably 1 or more from the viewpoint of easy formation of the penetrating portion 15.

  Although the dielectric 17 may be formed on the upper surface of the first electrode layer 12, the thickness of the dielectric 17 on the first electrode layer 12 is used to inject charges from the first electrode layer 12 to the organic compound layer 13. The thickness should be 5 nm or less, or formed such that a part of the upper surface of the first electrode layer 12 is exposed.

  The dielectric 17 may include a material that absorbs at least part of the light incident from the organic compound layer 13 and emits light having a wavelength different from the absorbed light. Examples of such materials include known organic phosphors such as coumarin dyes and rhodamine dyes, and known inorganic phosphors such as barium-aluminum-magnesium phosphors and sulfide phosphors. . Thereby, the light observed from the outside of the organic light emitting element 10 is a mixture of the light from the organic compound layer 13 and the light emitted from the above material, and for example, white light emission can be easily obtained. .

  The light emitting layer included in the organic compound layer 13 includes a light emitting material that emits light when a voltage is applied between the first electrode layer 12 and the second electrode layer 14. As such a light emitting material, both an organic material and an inorganic material can be used. As long as it is an organic compound, both a low molecular compound and a high molecular compound can be used. As the luminescent organic material, a phosphorescent organic compound and a metal complex are preferable. Some metal complexes exhibit phosphorescence, and such metal complexes are also preferably used. In the present invention, it is particularly desirable to use a cyclometalated complex from the viewpoint of improving luminous efficiency. Examples of cyclometalated complexes include 2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives, 2- (2-thienyl) pyridine derivatives, 2- (1-naphthyl) pyridine derivatives, 2-phenylquinoline derivatives, and the like. Examples of the complex include Ir, Pd and Pt having a ligand, and an iridium (Ir) complex is particularly preferable. The cyclometalated complex may have other ligands in addition to the ligands necessary for forming the cyclometalated complex. The cyclometalated complex includes a compound that emits light from triplet excitons, which is preferable from the viewpoint of improving luminous efficiency.

Examples of the light-emitting polymer compound include poly-p-phenylene vinylene (PPV) derivatives such as MEH-PPV (Poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene]); polyfluorene Π-conjugated high molecular compounds such as derivatives and polythiophene derivatives; polymers obtained by introducing low molecular weight dyes and tetraphenyldiamine or triphenylamine into the main chain or side chain; and the like. A light emitting high molecular compound and a light emitting low molecular weight compound can also be used in combination.
The light emitting layer includes a host material together with the light emitting material, and the light emitting material may be dispersed in the host material. Such a host material preferably has a charge transporting property, and is preferably a hole transporting compound or an electron transporting compound.

  The organic compound layer 13 may include a hole transport layer for receiving holes from the first electrode layer 12 and transporting them to the light emitting layer. As a hole transport material for forming such a hole transport layer, a known material can be used. For example, TPD (N, N′-dimethyl-N, N ′-(3-methylphenyl) -1,1′-biphenyl-4,4′diamine); α-NPD (4,4′-bis [N— (1-naphthyl) -N-phenylamino] biphenyl); low molecular triphenylamine derivatives such as m-MTDATA (4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine); polyvinyl Carbazole; a polymer compound obtained by polymerizing a triphenylamine derivative by introducing a polymerizable substituent. The above hole transport materials may be used singly or in combination of two or more, or different hole transport materials may be laminated and used. Since the thickness of the hole transport layer depends on the conductivity of the hole transport layer and the like, it cannot be unconditionally limited, but is preferably 1 nm to 5 μm, more preferably 5 nm to 1 μm, and particularly preferably 10 nm to 500 nm. Is desirable.

  In addition, a hole injection layer may be provided between the hole transport layer and the first electrode layer 12 in order to relax the hole injection barrier. As the material for forming the hole injection layer, known materials such as copper phthalocyanine, a mixture of polyethylene dioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) (PEDOT: PSS), fluorocarbon, silicon dioxide and the like are used. A mixture of a hole transport material used for the hole transport layer and an electron acceptor such as 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) can also be used. .

  Furthermore, the organic compound layer 13 may include an electron transport layer for receiving electrons from the second electrode layer 14 serving as a cathode and transporting them to the light emitting layer. Examples of materials that can be used for such an electron transport layer include quinoline derivatives, oxadiazole derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorene derivatives, and the like. More specifically, tris (8-quinolinolato) aluminum (abbreviation: Alq), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) ) -1,3,4-oxadiazole.

  In addition, a hole blocking layer is provided between the electron transport layer and the light emitting layer for the purpose of suppressing holes from passing through the light emitting layer and efficiently recombining holes and electrons in the light emitting layer. It may be. In order to form the hole blocking layer, a known material such as a triazole derivative, an oxadiazole derivative, or a phenanthroline derivative is used. This hole blocking layer can also be regarded as one of the layers included in the organic compound layer 13.

The second electrode layer 14 is a layer for injecting electrons into the organic compound layer 13 and functions as a cathode.
The material used for the second electrode layer 14 is not particularly limited as long as it is a metal. Specific examples include materials such as Al, MgAg alloy, Al and alkali metal alloys such as AlLi, and Al and alkaline earth metal alloys such as AlCa. When the second electrode layer 14 is a cathode, the thickness is preferably 0.01 μm to 1 μm, more preferably 0.05 μm to 0.5 μm.

  When the second electrode layer 14 is a cathode, the electron injection layer is used as the second electrode layer 14 for the purpose of lowering the electron injection barrier from the second electrode layer 14 to the electron transport layer and increasing the electron injection efficiency. You may provide adjacent to. As a material for forming the electron injection layer, a metal material having a work function lower than that of the second electrode layer 14 or a compound thereof is preferably used. For example, alkali metals (Na, K, Rb, Cs), alkaline earth metals (Sr, Ba, Ca, Mg), rare earth metals (Pr, Sm, Eu, Yb), or fluorides or chlorides of these metals, A simple substance selected from oxides or a mixture of two or more can be used. The thickness of the electron injection layer is preferably from 0.05 nm to 50 nm, more preferably from 0.1 nm to 20 nm, and even more preferably from 0.5 nm to 10 nm.

(Second form of organic light emitting device)
FIG. 2 is a partial cross-sectional view illustrating a second example of an organic light emitting device to which the present embodiment is applied.
The organic light emitting device 20 shown in FIG. 2 is formed on the substrate 21, the first electrode layer 22 made of a metal, and the first electrode layer 22 stacked on the substrate 21 when the substrate 21 side is the lower side. The organic compound layer 23 includes a light emitting layer that emits light when a voltage is applied, and the second electrode layer 24 made of metal formed on the organic compound layer 23. The first electrode layer 22 has a plurality of through portions 25 penetrating the first electrode layer 22, and the inside of the through portion 25 is filled with a dielectric 27. In the above configuration, the organic light emitting element 20 is the same as the organic light emitting element 10 shown in FIG. On the other hand, in the organic light emitting element 20, a conductive layer 26 is further formed between the first electrode layer 22 and the organic compound layer 23 in contact with the first electrode layer 22. The conductive layer 26 is also formed between the dielectric 27 filled in the through portion 25 and the organic compound layer 23.

  The conductive layer 26 receives electric charge from the first electrode layer 22 and injects electric charge into the organic compound layer 23, but covers the upper part of the dielectric 27 filled in the first electrode layer 22 and the through portion 25. Thus, charge injection can be performed over the entire light emitting surface. In the present embodiment, since light is extracted from the organic compound layer 23 to the lower side of the substrate 21 through the penetrating portion 25, the conductive layer 26 needs to be transparent to the light emitted from the organic compound layer 23. Therefore, as a material for forming the conductive layer 26, for example, a metal oxide such as ITO (indium tin oxide), IZO (indium-zinc oxide), and tin oxide is used. By forming such a conductive layer 26, not only the contact area with the organic compound layer 23 for injecting charges is increased, but also the injection of charges into the organic compound layer 23 rather than the first electrode layer 22 made of metal. The barrier can be reduced.

(Third form of organic light emitting device)
FIG. 3 is a partial cross-sectional view illustrating a third example of the organic light emitting device to which the present embodiment is applied.
The organic light emitting device 30 shown in FIG. 3 is formed on the substrate 31, the first electrode layer 32 made of metal, and the first electrode layer 32 stacked on the substrate 31 when the substrate 31 side is the lower side. The organic compound layer 33 includes a light emitting layer that emits light when a voltage is applied, and the second electrode layer 34 made of metal formed on the organic compound layer 33. In the first electrode layer 32, a plurality of through portions 35 penetrating the first electrode layer 32 are formed. In the above configuration, the organic light emitting element 30 is the same as the organic light emitting element 10 shown in FIG. Further, in the organic light emitting device 30, the conductive layer 36 is formed between the first electrode layer 32 and the organic compound layer 33 in contact with the first electrode layer 32, and the organic light emitting device 20 shown in FIG. The same. On the other hand, in the organic light emitting element 30, the penetrating portion 35 is formed so as to penetrate the conductive layer 36, and the inside of the penetrating portion 35 is filled with a dielectric 37.

  The conductive layer 36 is formed of a metal oxide such as ITO (Indium Tin Oxide), IZO (Indium-Zinc Oxide), or tin oxide that allows easier injection of charges into the organic compound layer 33 than the first electrode layer 32. It is preferable. In the organic light emitting element 30, since the electrical conductivity and thermal conductivity of the first electrode layer 32 are rarely impaired, the luminance uniformity in the light emitting surface and the durability are high, and the luminous efficiency can be increased.

  In the organic light emitting devices 10, 20, and 30 described in detail above, the first electrode layers 12, 22, and 32 are anodes, and the second electrode layers 14, 24, and 34 are cathodes. The anode and the cathode may be reversed. That is, the first electrode layers 12, 22, and 32 may be cathodes, and the second electrode layers 14, 24, and 34 may be anodes.

  In this embodiment mode, the hole and electron injection efficiency can be improved by forming both the anode and the cathode from a metal. In addition, it is possible to manufacture an organic light emitting device having high luminance uniformity in the light emitting surface and high durability. And by providing the penetration parts 15, 25, and 35 and filling the dielectrics 17, 27, and 37 inside the penetration parts 15, 25, and 35, light can be extracted from this location. Therefore, even if both the anode and the cathode are made of metal, an organic light emitting device having excellent light extraction efficiency and high light emission efficiency can be manufactured.

(Method for manufacturing organic light emitting device)
Next, a method for manufacturing an organic light emitting device to which the present embodiment is applied will be described taking the case of the organic light emitting device 10 described in FIG. 1 as an example.
4A to 4E are diagrams illustrating a method for manufacturing the organic light emitting device 10 to which the exemplary embodiment is applied.
First, the first electrode layer 12 is formed on the substrate 11 (FIG. 4A: first electrode layer forming step).
In order to form the first electrode layer 12 on the substrate 11, a resistance heating vapor deposition method, an electron beam vapor deposition method, a sputtering method, an ion plating method, a CVD method, or the like can be used. In addition, when a coating film forming method, that is, a method in which the target material is dissolved in a solvent and applied to the substrate 11 and dried, a spin coating method, a dip coating method, an ink jet method, a printing method, a spray method is used. It is also possible to form a film using a method such as a method or a dispenser method.

Next, the penetration part 15 which penetrates the 1st electrode layer 12 formed at the process of Fig.4 (a) is formed (FIG.4 (b): penetration part formation process).
As a method of forming the through portion 15 in the first electrode layer 12, for example, a method using lithography can be used. In order to do this, first, a resist solution is applied on the first electrode layer 12, and the excess resist solution is removed by spin coating or the like to form a resist layer. Next, when a mask on which a predetermined pattern for forming the penetrating part 15 is drawn is put on and exposed by ultraviolet (UV), electron beam (EB) or the like, the penetrating part 15 is formed on the resist layer. A predetermined pattern corresponding to is exposed. Then, when the exposed portion of the resist layer is removed using a developer, the resist layer in the exposed pattern portion is removed. Thus, the surface of the first electrode layer 12 is exposed corresponding to the exposed pattern portion.
Next, the exposed portion of the first electrode layer 12 is removed by etching using the remaining resist layer as a mask. As the etching, either dry etching or wet etching can be used. In this case, the shape of the through portion 15 can be controlled by combining isotropic etching and anisotropic etching. As dry etching, reactive ion etching (RIE) or inductively coupled plasma etching can be used. As wet etching, a method of immersing in dilute hydrochloric acid or dilute sulfuric acid can be used. Finally, the remaining resist layer is removed with a resist removing solution or the like, and the first electrode layer 12 in which the through portions 15 are formed is obtained.

  Moreover, formation of the penetration part 15 can be performed by the method by a nanoimprint method. Specifically, after forming the resist layer, a mask on which a predetermined convex pattern for forming a pattern is drawn is pressed against the surface of the resist layer while applying pressure. In this state, the resist layer is cured by irradiating the resist layer with heat and / or light. Next, by removing the mask, a pattern of the through portion 15 corresponding to the convex pattern is formed on the surface of the resist layer. Subsequently, the penetrating portion 15 can be formed by performing the etching described above.

Next, the composition for forming the dielectric 17 is applied to fill the penetration portion 15 with this composition (FIG. 4C: filling step). As a result, the dielectric 17 is filled in the through portion 15.
As a method for filling the through-hole 15 with the dielectric 17, a resistance heating vapor deposition method, an electron beam vapor deposition method, a sputtering method, and an ion plating method are used similarly to the method for forming the first electrode layer 12 on the substrate 11. Further, a dry method such as a CVD method, a spin coating method, a dip coating method, an inkjet method, a printing method, a spray method, a dispenser method, or the like can be used. After filling the through hole 15 with the dielectric 17 by these methods, the dielectric formed on the first electrode layer 12 is removed by a method such as etching or polishing, and the thickness of the dielectric 17 is set to the above-mentioned thickness. Or at least a portion of the first electrode layer 12 is exposed. Thereby, the first electrode layer 12 having the through portion 15 filled with the dielectric 17 can be formed. In order to make the dielectric 17 have a shape in which the central portion of the penetrating portion 15 is depressed, part of the dielectric 17 is removed by dry etching, or the wettability of the surface of the first electrode layer 12 is increased, It is simple and preferable to dry after applying the composition for forming the dielectric 17. However, it is not limited to these methods. In the formation method of the through portion 15 described above, after the through portion 15 is formed, the dielectric layer 17 is filled without removing the remaining resist layer, and then the resist layer is removed, thereby removing the first layer. The step of removing the dielectric on the electrode layer 12 can be omitted.

Next, the organic compound layer 13 including the light emitting layer is formed (FIG. 4D: organic compound layer forming step).
In order to form the organic compound layer 13, the same technique as that for forming the first electrode layer 12 can be used. However, the resistance heating vapor deposition method or the coating method is more preferable for the film formation of each layer included in the organic compound layer 13, and the coating method is particularly preferable for the film formation of the layer containing the polymer organic compound. When film formation is performed by a coating method, a coating solution in which a material constituting a layer to be formed is dispersed in a predetermined solvent such as an organic solvent or water is applied. When applying, various methods such as spin coating, spray coating, dip coating, ink jet, slit coating, dispenser, and printing can be used. After the application, a layer to be formed is formed by drying the application solution by heating and / or evacuation.

Next, the second electrode layer 14 is formed on the organic compound layer 13 (FIG. 4E: second electrode layer forming step).
In order to form the second electrode layer 14, the same technique as that used to form the first electrode layer 12 and the organic compound layer 13 can be used.

  In addition, the method similar to film-forming of the 1st electrode layer 12 in the organic light emitting element 10 is used for film-forming of the conductive layers 26 and 36 in the organic light-emitting elements 20 and 30 (conductive layer formation process). In the case of the organic light emitting element 30, after the conductive layer 36 is formed, the through portion forming process is performed to form the through portion 35 that further penetrates the conductive layer 36 as well as the first electrode layer 32. be able to.

The organic light emitting device 10 can be manufactured through the above steps.
In addition, it is preferable to use the organic light emitting element 10 stably for a long period of time and to attach a protective layer or a protective cover (not shown) for protecting the organic light emitting element 10 from the outside. As the protective layer, polymer compounds, metal oxides, metal fluorides, metal borides, silicon compounds such as silicon nitride and silicon oxide, and the like can be used. And these laminated bodies can also be used. Further, as the protective cover, a glass plate, a plastic plate whose surface has been subjected to low water permeability treatment, a metal, or the like can be used. It is preferable that the protective cover is sealed with a thermosetting resin or a photo-curing resin and bonded to the element substrate. In this case, it is preferable to use a spacer because a predetermined space can be maintained and the organic light emitting element 10 can be prevented from being damaged. If an inert gas such as nitrogen, argon, or helium is sealed in this space, it becomes easy to prevent the upper electrode from being oxidized. In particular, when helium is used, heat conduction is high, and thus heat generated from the organic light emitting element 10 when voltage is applied can be effectively transmitted to the protective cover, which is preferable. Further, by installing a desiccant such as barium oxide in this space, it becomes easy to suppress the moisture adsorbed in the series of manufacturing steps from damaging the organic light emitting element 10.

  The organic light-emitting element of the present embodiment is suitably used for a display device as a pixel by a matrix method or a segment method, for example. Further, it can be suitably used as a surface emitting light source without forming pixels. Specifically, computers, televisions, mobile terminals, mobile phones, car navigation systems, signs, signboards, video camera viewfinders, display devices, backlights, electrophotography, illumination, resist exposure, readers, interior lighting, light It is suitably used for a surface emitting light source in a communication system or the like.

(Display device)
Next, a display apparatus provided with the organic light emitting element detailed above will be described.
FIG. 5 is a diagram illustrating an example of a display device using the organic light emitting element 10 in the present embodiment.
The display device 200 shown in FIG. 5 is a so-called passive matrix display device, and includes a display device substrate 202, an anode wiring 204, an anode auxiliary wiring 206, a cathode wiring 208, an insulating film 210, a cathode partition wall 212, and the organic light emitting device 10. , A sealing plate 216, and a sealing material 218.

  As the display device substrate 202, for example, a transparent substrate such as a rectangular glass substrate can be used. Although the thickness of the display apparatus substrate 202 is not specifically limited, For example, the thing of 0.1 mm-1 mm can be used.

  A plurality of anode wirings 204 are formed on the display device substrate 202. The anode wirings 204 are arranged in parallel at a constant interval. The anode wiring 204 is made of a transparent conductive film, and for example, ITO (Indium Tin Oxide) can be used. The thickness of the anode wiring 204 can be set to 100 nm to 150 nm, for example. An anode auxiliary wiring 206 is formed on the end of each anode wiring 204. The anode auxiliary wiring 206 is electrically connected to the anode wiring 204. With this configuration, the anode auxiliary wiring 206 functions as a terminal for connecting to the external wiring on the end portion side of the display device substrate 202, and the anode auxiliary wiring 206 is connected from an external driving circuit (not shown). A current can be supplied to the anode wiring 204 through the wiring. The anode auxiliary wiring 206 is made of, for example, a metal film having a thickness of 500 nm to 600 nm.

  In addition, a plurality of cathode wirings 208 are provided on the organic light emitting element 10. The plurality of cathode wirings 208 are arranged so as to be parallel to each other and orthogonal to the anode wiring 204. As the cathode wiring 208, Al or an Al alloy can be used. The thickness of the cathode wiring 208 is, for example, 100 nm to 150 nm. Further, similarly to the anode auxiliary wiring 206 for the anode wiring 204, a cathode auxiliary wiring (not shown) is provided at the end of the cathode wiring 208 and is electrically connected to the cathode wiring 208. Therefore, current can flow between the cathode wiring 208 and the cathode auxiliary wiring.

  An insulating film 210 is formed on the display device substrate 202 so as to cover the anode wiring 204. The insulating film 210 is provided with a rectangular opening 220 so as to expose a part of the anode wiring 204. The plurality of openings 220 are arranged in a matrix on the anode wiring 204. In the opening 220, the organic light emitting element 10 is provided between the anode wiring 204 and the cathode wiring 208 as described later. That is, each opening 220 is a pixel. Accordingly, a display area is formed corresponding to the opening 220. Here, the thickness of the insulating film 210 can be, for example, 200 nm to 300 nm, and the size of the opening 220 can be, for example, 300 μm × 300 μm.

  The organic light emitting element 10 is formed at a location corresponding to the position of the opening 220 on the anode wiring 204. The organic light emitting device 10 is sandwiched between the anode wiring 204 and the cathode wiring 208 in the opening 220. That is, the first electrode layer 12 of the organic light emitting element 10 is in contact with the anode wiring 204, and the second electrode layer 14 is in contact with the cathode wiring 208. The thickness of the organic light emitting element 10 can be set to, for example, 150 nm to 200 nm.

  On the insulating film 210, a plurality of cathode partition walls 212 are formed along a direction perpendicular to the anode wiring 204. The cathode partition 212 plays a role in spatially separating the plurality of cathode wirings 208 so that the wirings of the cathode wirings 208 are not electrically connected to each other. Accordingly, the cathode wiring 208 is disposed between the adjacent cathode partition walls 212. As the size of the cathode partition wall 212, for example, one having a height of 2 μm to 3 μm and a width of 10 μm can be used.

  The display device substrate 202 is bonded via a sealing plate 216 and a sealing material 218. Thereby, the space in which the organic light emitting element 10 is provided can be sealed, and the organic light emitting element 10 can be prevented from being deteriorated by moisture in the air. As the sealing plate 216, for example, a glass substrate having a thickness of 0.7 mm to 1.1 mm can be used.

  In the display device 200 having such a structure, a current is supplied to the organic light emitting element 10 through the anode auxiliary wiring 206 and the cathode auxiliary wiring (not shown) by a driving device (not shown), the light emitting layer is caused to emit light, and light is emitted. be able to. An image can be displayed on the display device 200 by controlling light emission and non-light emission of the organic light emitting element 10 corresponding to the above-described pixel by the control device.

(Lighting device)
Next, an illumination device using the organic light emitting element of this embodiment will be described.
FIG. 6 is a diagram illustrating an example of an illumination device including the organic light emitting element 10 according to the present embodiment.
6 is installed adjacent to the organic light emitting element 10 and the substrate 11 (see FIG. 1) of the organic light emitting element 10, and is connected to the first electrode layer 12 (see FIG. 1). A terminal 302, a terminal 303 installed adjacent to the substrate 11 (see FIG. 1) and connected to the second electrode layer 14 (see FIG. 1) of the organic light emitting device 10, and connected to the terminals 302 and 303 and organic And a lighting circuit 301 for driving the light emitting element 10.

  The lighting circuit 301 has a DC power source (not shown) and a control circuit (not shown) inside, and supplies a current between the first electrode layer 12 and the second electrode layer 14 of the organic light emitting element 10 through the terminal 302 and the terminal 303. To do. Then, the organic light emitting element 10 is driven, the light emitting layer emits light, and the light is emitted through the substrate 11 from the penetrating portion 15 to be used as illumination light. The light emitting layer may be composed of a light emitting material that emits white light, and each of the organic light emitting elements 10 using the light emitting material that emits green light (G), blue light (B), and red light (R). A plurality of them may be provided so that the combined light is white. In the lighting device 300 of the present embodiment, when light is emitted with the diameter and interval of the penetrating portion 15 (see FIG. 1) being reduced, it appears to the human eye to emit light.

[Preparation of luminescent material solution]
The following phosphorescent polymer compound (A) was synthesized according to the method described in WO2010-16512. The weight average molecular weight of the polymer compound (A) was 52,000, and the molar ratio of each repeating unit was k: m: n = 6: 42: 52.

  3 parts by weight of this phosphorescent polymer compound (A) was dissolved in 97 parts by weight of toluene to prepare a light emitting material solution (hereinafter also referred to as “solution A”).

[Production of organic light-emitting element]
Example 1
As the organic light emitting device, the organic light emitting device 10 shown in FIG. 1 was produced by the following method.
First, a Pt thin film of 200 nm was formed as the first electrode layer 12 on a glass substrate (25 mm square, 1 mm thick) as the substrate 11 using a sputtering apparatus (E-401s manufactured by Canon Anelva Co., Ltd.). .

Next, a photoresist (AZ 1500 made by AZ Electronic Materials Co., Ltd.) was formed to a thickness of about 1 μm by spin coating. Next, a mask A corresponding to a pattern in which circles (plate thickness: 3 mm) are used as base materials and circles are arranged in a square lattice shape is prepared, and using a stepper exposure apparatus (manufactured by Nikon Corporation, model NSR-1505i6), Exposure was performed at 1/5 scale. Next, the resist layer was patterned by developing with a 1.2% solution of TMAH (Tetramethyl ammonium hydroxide: (CH ₃ ) ₄ NOH). Thereafter, heat was applied at 130 ° C. for 10 minutes (post-baking treatment).

Next, using a reactive ion etching apparatus (RIE-200iP manufactured by Samco Co., Ltd.), dry etching treatment was performed using argon as a reactive gas. Then, a plurality of through portions 15 were formed in the first electrode layer 12 by removing the resist residue with a resist removing solution. The through portions 15 have a cylindrical shape with a diameter of 1 μm, and are arranged in a square lattice pattern on the entire surface of the first electrode layer 12 so that the distance between the centers of the circles of the through portions 15 is 2 μm.

  Next, aluminum oxide (refractive index: 1.75) was filled as the dielectric 17 in the plurality of through portions 15 formed. The filling is performed by depositing aluminum oxide with a thickness of 300 nm on the first electrode layer 12 on which the plurality of through portions 15 are formed using a sputtering apparatus, and then until the upper portion of the first electrode layer 12 is exposed. Polishing was performed so that the upper surfaces of the first electrode layer 12 and the dielectric 17 were flat.

  Next, the solution A is applied by spin coating (rotation speed: 3000 rpm) on the first electrode layer 12 having the plurality of through portions 15 filled with the dielectric material 17, and at 140 ° C. in a nitrogen atmosphere. By leaving it to stand for 1 hour and drying, an organic compound layer 13 composed of one light emitting layer was formed. The refractive index of the light emitting layer was 1.60.

  Next, on the organic compound layer 13, sodium fluoride (4 nm) is formed as a cathode buffer layer, and aluminum (130 nm) is sequentially formed as a second electrode layer 14 by a vapor deposition method to emit organic light. Element 10 was produced.

(Example 2)
An organic light emitting device 10 was fabricated in the same manner as in Example 1 except that the formation conditions of the dielectric 17 were changed. Here, the penetrating part 15 was filled with SOG (Spin On Glass) as the dielectric 17. For the filling, SOG was applied by spin coating on the first electrode layer 12 in which a plurality of through portions 15 were formed, and then sintered. The refractive index of this dielectric 17 (SOG) was 1.75. Next, using a reactive ion etching apparatus (RIE-200iP manufactured by Samco Co., Ltd.), CHF ₃ was used as a reactive gas, and the surface of SOG was dry-etched until the surface of the first electrode layer 12 was exposed. The treated penetrating part 15 was filled with SOG, and the upper surface of the SOG was a central part of the penetrating part 15 and had a shape recessed with respect to the surface of the first electrode layer 12.
Thereafter, an organic compound layer 13, a cathode buffer layer, and a second electrode layer 14 are formed on the first electrode layer 12 having the plurality of through portions 15 filled with the dielectric material 17 in the same manner as in Example 1. An organic light emitting device was produced.

(Example 3)
As the organic light emitting device, the organic light emitting device 20 shown in FIG. 2 was produced by the following method.
First, in the same manner as in Example 2, a first electrode layer 22 having a plurality of through portions 25 filled with SOG as a dielectric 27 was produced.
Subsequently, a 100 nm ITO film was formed as the conductive layer 26 using a sputtering apparatus so as to cover the upper surfaces of the first electrode layer 22 and the dielectric 27. Then, the organic compound layer 23, the cathode buffer layer, and the 2nd electrode layer 24 were formed on the ITO film | membrane like Example 1, and the organic light emitting element 20 was produced.

Example 4
As the organic light emitting device, the organic light emitting device 30 shown in FIG. 3 was produced by the following method.
First, in the same manner as in Example 1, a 200 nm Pt thin film was formed as a first electrode layer 32 on a glass substrate. Subsequently, an ITO film having a thickness of 100 nm was formed as the conductive layer 36 on the first electrode layer 32 by using a sputtering apparatus.
Next, a patterned resist layer is formed in the same manner as in Example 1, and after performing a dry etching process, a plurality of penetrations that penetrate the first electrode layer 32 and the conductive layer 36 are performed by removing the resist residue. Part 35 was formed. The through portions 35 have a cylindrical shape with a diameter of 1 μm, and are arranged in a square lattice pattern on the entire surface of the first electrode layer 32 so that the distance between the centers of the circles of the through portions 35 is 2 μm.
Thereafter, in the same manner as in Example 2, the penetrating portion 35 is filled with a dielectric 37 made of SOG, and the organic compound layer 33, the cathode buffer layer, and the second electrode layer 34 are formed on the dielectric 37 and the first electrode layer 32. The organic light emitting device 30 was fabricated.

(Examples 5 to 9)
An organic light emitting device 10 was fabricated in the same manner as in Example 2 except that the concentration of the SOG material in the dielectric coating solution filled in the through portion was changed as shown in Table 1 below.
By changing the solid content concentration of SOG, the value of a / d can be changed.

(Example 10)
First, Al was used instead of Pt, and an Al thin film having a thickness of 250 nm was formed on the glass substrate as the first electrode layer 12 in the same manner as in Example 1. Next, using the mask B corresponding to a pattern in which circles are arranged in a square lattice pattern, a plurality of through portions 15 were formed in the first electrode layer 12 in the same manner as in Example 1. The through portions 15 have a columnar shape with a diameter of 0.75 μm, and are arranged in a square lattice pattern on the entire surface of the first electrode layer 12 so that the distance between the centers of the circles of the through portions 15 is 1.5 μm. Thereafter, using the electrode substrate thus prepared, the dielectric material 17 is filled into the penetrating portion 15 and the organic compound layer 13, the cathode buffer layer, and the second electrode layer 14 are formed in the same manner as in Example 2. An organic light emitting device was produced.

(Example 11)
First, Ag was used instead of Pt, and a 300-nm-thick Ag thin film was formed on the glass substrate as the first electrode layer 12 in the same manner as in Example 1. Next, a plurality of through portions 15 were formed in the first electrode layer 12 in the same manner as in Example 1 using a mask C corresponding to a pattern in which circles were arranged in a square lattice pattern. The through portions 15 have a cylindrical shape with a diameter of 1.5 μm, and are arranged in a square lattice pattern on the entire surface of the first electrode layer 12 so that the distance between the centers of the circles of the through portions 15 is 3 μm. Thereafter, using the electrode substrate thus prepared, the dielectric material 17 is filled into the penetrating portion 15 and the organic compound layer 13, the cathode buffer layer, and the second electrode layer 14 are formed in the same manner as in Example 2. An organic light emitting device was produced.

(Comparative Example 1)
An organic light-emitting device was fabricated in the same manner as in Example 2 except that 200 nm of ITO, which is a transparent electrode, was formed as the first electrode layer 12 instead of forming a thin film of Pt with a thickness of 200 nm.

[Evaluation method]
A voltage was applied stepwise to the organic light-emitting devices produced in Examples 1 to 11 and Comparative Example 1 using a constant voltage power supply ammeter (SM2400 manufactured by Keith Instruments Inc.), and the light emission intensity of the organic light-emitting device was determined by luminance. It measured with the total (BM-9 by Topcon Co., Ltd.). And luminous efficiency was determined from the ratio of luminous intensity to current density. Moreover, the driving voltage at the time of lighting 100 cd / m ^{2 was} also measured.

[Evaluation results]
The results are shown in Table 1 below.

As can be seen from Table 1, in Examples 1 to 11, the luminous efficiency equal to or higher than that of Comparative Example 1 using a transparent electrode was obtained even though an opaque metal was used for both electrode layers. Yes. That is, in this embodiment, it can be seen that light can be extracted more efficiently from the organic light emitting element. Furthermore, in the configuration of FIGS. 2 and 3 (Examples 3 and 4), the drive voltage can be reduced.
Further, none of the organic light-emitting elements produced in Examples 1 to 11 showed luminance unevenness (visual confirmation) in the light emitting surface, while all of the organic light-emitting elements of Comparative Example 1 showed luminance unevenness. It was. This is presumably because the organic light emitting device of the present embodiment can use a metal electrode and thus has high thermal uniformity.

10, 20, 30 ... organic light emitting device, 11, 21, 31 ... substrate, 12, 22, 32 ... first electrode layer, 13, 23, 33 ... organic compound layer, 14, 24, 34 ... second electrode layer, DESCRIPTION OF SYMBOLS 15, 25, 35 ... Penetration part, 26, 36 ... Conductive layer, 17, 27, 37 ... Dielectric, 200 ... Display apparatus, 300 ... Illumination device

Claims (13)

A first electrode layer made of metal, an organic compound layer including a light emitting layer, and a second electrode layer made of metal are sequentially laminated,
In the first electrode layer, a plurality of through portions penetrating the first electrode layer are formed,
An organic light emitting device in which the inside of the through portion is filled with a dielectric.   2. The organic light emitting device according to claim 1, wherein an upper surface on the organic compound layer side of the dielectric filled in the through portion has a curved shape that is recessed at a central portion of the through portion. In the planar shape in the plane of the first electrode layer, the penetrating portion has a circular shape or a substantially regular polygonal shape having a maximum width of 10 μm or less,
The organic light-emitting device according to claim 1, wherein 10 ⁴ to 10 ⁸ are formed in 1 mm ² in an arbitrary plane of the first electrode layer.   The distance “a” between the upper surface of the first electrode layer and the maximum width “d” of the penetrating portion at the center of the penetrating portion of the dielectric filled in the penetrating portion is 0.02 ≦ (a / d) ≦. The organic light emitting element according to any one of claims 1 to 3, which satisfies a relational expression of 0.15.   5. The organic light emitting device according to claim 1, wherein a maximum width d of the penetrating portion and a film thickness h of the first electrode layer satisfy a relational expression of 1 ≦ (d / h) ≦ 5.   The organic light emitting element according to claim 1, wherein the dielectric has a refractive index different from that of the organic compound layer.   The organic light emitting element according to claim 1, wherein a transparent conductive layer is formed between the first electrode layer and the organic compound layer so as to be in contact with the first electrode layer.   The organic light-emitting device according to claim 7, wherein the penetrating portion further penetrates the conductive layer. A first electrode layer forming step of forming a first electrode layer on the substrate;
A penetrating portion forming step of forming a penetrating portion penetrating the first electrode layer;
A filling step of filling the penetrating portion with the composition by applying a composition containing a dielectric;
An organic compound layer forming step of forming an organic compound layer including a light emitting layer;
A second electrode layer forming step of forming a second electrode layer on the organic compound layer;
The manufacturing method of the organic light emitting element containing this.   The method for manufacturing an organic light-emitting element according to claim 9, further comprising a conductive layer forming step of forming a conductive layer formed in contact with the first electrode layer.   The method of manufacturing an organic light-emitting element according to claim 10, wherein in the penetration part forming step, the penetration part is formed so as to further penetrate the conductive layer.   A display apparatus provided with the organic light emitting element of any one of Claims 1 thru | or 8.   An illuminating device provided with the organic light emitting element of any one of Claims 1 thru | or 8.

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