JP2009037802A - Light-emitting element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting element incorporating a function of controlling direction independency of light-extraction intensity, without giving rise to increase of an occupancy space of the element. <P>SOLUTION: By forming a three-dimensional structure capable of controlling directional dependency of light-extraction intensity at the same time as formation of the organic layer on one face of at least one organic layer of a light-emitting element with a light-extraction side of a light-emitting element sealed by a multilayer film having at least one organic layer, a light-emitting element excellent in light-extraction property is obtained. The organic layer is preferred to be formed with the use of energy hardened resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light emitting device excellent in light extraction performance and a method for manufacturing the same.

  In light emitting elements such as organic EL elements and light emitting diode display elements, a light emitting layer sandwiched between an anode and a cathode is laminated on a substrate, and a multilayer sealing film is laminated so as to cover the light emitting layer. In a conventional light emitting device, a glass substrate is used as a substrate. However, in order to meet the demands of lightening the device, improving impact resistance, increasing the area of the device, and increasing the efficiency of manufacturing, a plastic substrate is used. It has begun to be used (for example, Patent Document 1).

  The plastic substrate is flexible and can be easily obtained in a large area, and the cutting work for dividing the light emitting layer into units after the lamination is facilitated. However, the plastic substrate has higher gas and liquid permeability than the glass substrate. Display materials such as the organic EL light-emitting layer encapsulated by the substrate and the upper multilayer sealing film are easily oxidized and are easily decomposed by contact with water. Therefore, when using a plastic substrate, a lower sealing film having a high barrier property against gas and liquid is laminated on the substrate, and then a light emitting layer is laminated on the lower multilayer sealing film, and the laminated light emitting layer An upper multilayer sealing film is laminated so as to cover the surface.

  The lower sealing film is usually formed with the same configuration and the same material as the upper multilayer sealing film. These lower multilayer sealing film and upper multilayer sealing film usually have at least one inorganic layer and at least one organic layer. The number of stacked layers is determined as necessary. Basically, inorganic layers and organic layers are alternately stacked.

  Light extraction from the light emitting element may be performed from the substrate side, from the upper multilayer sealing film side, or from both the substrate side and the upper multilayer sealing film side. The type of light emitting element that extracts light from the substrate side is called a bottom emission type light emitting element, and the type of light emitting element that extracts light from the upper multilayer sealing film side is called a top emission type light emitting element. This light emitting element is called a dual emission type light emitting element. In these types of light emitting elements, the common thing to say is that the multilayer sealing film on the light extraction side needs to be transparent or translucent, and the light extraction efficiency is affected by its physical characteristics. It is. Therefore, in the conventional light emitting device, the multilayer sealing film on the light extraction side is made of a flat layer that is as transparent as possible.

Special table 2003-53745 gazette

  In the conventional light emitting element, it may be necessary to control the direction dependency of the light extraction intensity depending on the application of the various lighting devices, various display devices, and various electronic devices. In such a case, various optical elements such as a scattering sheet are provided on the entire light extraction surface of the light emitting element. However, the installation of these additional optical elements necessitates an occupied space for the various devices on which the light emitting elements are mounted, and this tends to become a bottleneck in downsizing the devices, so improvement is required. Yes.

  The present invention has been made in view of the above-described conventional circumstances, and the problem is that a light-emitting element incorporating a function for controlling the direction dependency of the light extraction intensity is accompanied by an increase in the occupied space of the element. There is no provision. Here, the control of the direction dependency of the light extraction intensity in the light emitting element means the control of the viewing angle on the light emitting surface of the light emitting element or the improvement of the light extraction efficiency in front of the light emitting element.

  In order to solve the above problems, a light emitting device according to the present invention is a light emitting device in which a light extraction side of a light emitting unit is sealed with a multilayer sealing film having at least one organic layer. One side has a three-dimensional structure capable of controlling the direction dependency of the extracted light intensity.

  The light-emitting element having the above-described structure is characterized in that the three-dimensional structure on one side of the organic layer is formed simultaneously with the formation of the organic layer.

  The light emitting device manufacturing method according to the present invention includes a light emitting element having a light emitting side sealed with a multilayer sealing film having at least one organic layer, and the light intensity extracted from the at least one organic layer of the light emitting device. A method of manufacturing a light-emitting device by obtaining a light-emitting device with excellent light extraction by forming a three-dimensional structure capable of controlling the direction dependency of the organic layer, wherein the three-dimensional structure on one side of the organic layer is formed simultaneously with the formation of the organic layer It is characterized by doing.

  The said structure WHEREIN: It is preferable to form the said organic layer using energy curable resin.

  Moreover, in the said structure, the three-dimensional structure of the said organic layer can be formed simultaneously with formation of this organic layer by once semi-hardening the coating film of the said energy curable resin, and then hardening completely.

  Moreover, in the said structure, the three-dimensional structure of the said organic layer is formed simultaneously with formation of this organic layer by hardening in the state which formed the coating film of the said energy curable resin on the lyophobic surface. be able to.

  The present invention is particularly useful when the target light-emitting element is an organic EL light-emitting element.

  The light emitting device according to the present invention is transparent from the front, but becomes opaque when viewed from an oblique direction, and the front luminance of the light emitting device is improved. Such an effect can be achieved by simultaneously forming a three-dimensional structure on one surface of at least one organic layer in the multilayer sealing film on the light extraction side. When a three-dimensional structure is formed on the inorganic layer in the multilayer sealing film, advanced etching and patterning are required. However, in the present invention, the organic layer is formed by manipulating the conditions during polymerization of the monomer that is a material for forming the organic layer. Simultaneously with the formation of the layer, a three-dimensional structure can be easily formed on one side thereof. In addition, in the case of using an optical film which is a conventional means, an advanced pasting process and an optical film member are required. However, in the manufacturing method of the present invention, the three-dimensional structure of one side of the organic layer is a normal sealing. Since the process can be performed during the film formation step, a light-emitting element that has a simple process and excellent light extraction efficiency can be easily manufactured.

  Therefore, according to the light emitting element and the manufacturing method thereof according to the present invention, it is possible to provide a light emitting element with improved light extraction efficiency without increasing the space occupied by the light emitting element.

Below, the light emitting element concerning this invention and its manufacturing method are demonstrated in more detail.
As described above, the light emitting device according to the present invention is a light emitting device in which the light extraction side of the light emitting unit is sealed with a multilayer sealing film having at least one organic layer, and the at least one organic layer is on one side. It has a three-dimensional structure capable of controlling the direction dependency of the extracted light intensity. The light emitting device having this configuration is characterized in that the three-dimensional structure of one side of the organic layer is formed simultaneously with the formation of the organic layer.

  The light emitting device manufacturing method according to the present invention includes a light emitting element having a light emitting side sealed with a multilayer sealing film having at least one organic layer, and the light intensity extracted from the at least one organic layer of the light emitting device. A method of manufacturing a light-emitting device by obtaining a light-emitting device with excellent light extraction by forming a three-dimensional structure capable of controlling the direction dependency of the organic layer, wherein the three-dimensional structure on one side of the organic layer is formed simultaneously with the formation of the organic layer It is characterized by doing.

  In the above structure, the organic layer is formed using an energy curable resin. The energy curable resin means a resin that is cured by irradiation with actinic rays (light energy) such as ultraviolet rays and electron beams, or a resin that is cured by application of thermal energy.

  The three-dimensional structure of the organic layer can be formed simultaneously with the formation of the organic layer by semi-curing the coating film of the energy curable resin and then completely curing it. Alternatively, the three-dimensional structure of the organic layer can be formed simultaneously with the formation of the organic layer by curing in a state where the coating film of the energy curable resin is formed on a lyophobic surface.

  In the present invention, the semi-curing means a state brought about by applying a quantity energy lower than the energy quantity of light or heat energy when the monomer is completely cured to the monomer coating. More specifically, deformation occurs when the coating film is touched, but the coating film does not flow out or deform even when the coating film surface is inclined. In this semi-cured state, the coating film has a mixture of a portion where curing has progressed at a micro level and a portion where curing has hardly progressed. When high energy is applied to such a semi-cured coating film, curing of the entire coating film is completed with unevenness according to the local unevenness of the curing. This is because the curing speed is high in the portion where the curing is progressing. That is, the coating liquid in the part where the curing has not progressed is attracted to the part where the curing has progressed, and the curing reaction proceeds with the curing part as a nucleus. It is speculated that it is to grow up. In other words, it is presumed that complete curing proceeds epitaxially centering on a portion where curing has progressed at the time of semi-curing, and micro-sized irregularities are formed on the surface simultaneously with the formation of the organic layer.

  On the other hand, when a coating film is formed on the lyophobic surface, the coating solution on the lyophobic surface is repelled from the surface, and the cohesive force of the liquid becomes apparent. As a result, the coating liquid on the lyophobic surface is unevenly distributed at the micro level, and sea-island unevenness is generated on the liquid surface. When light or heat energy is applied to the coating film in this state, the coating film is cured while maintaining the sea-like irregularities on the surface.

  The lyophobic surface specifically means the surface of the inorganic layer constituting the multilayer sealing film that is not lyophilic, or the surface of the substrate that has not been lyophilicized. Moreover, it can also be made lyophobic by performing plasma treatment using a gas having fluorine atoms on the surface.

  When the organic layer is an intermediate layer of a multilayer sealing film, one surface on which a three-dimensional structure (unevenness) is formed serves as an interface with the upper inorganic layer, and the uneven organic layer is an upper sealing layer. When it is located in the uppermost layer, the one surface on which the irregularities are formed is the surface of the organic layer. Further, the organic layer having the unevenness is at least one organic layer of the upper multilayer sealing film when the light emitting element is a top emission type light emitting element, and when the light emitting element is a bottom emission type light emitting element. Is at least one organic layer of the lower multilayer sealing film, and when the light emitting element is a dual emission type light emitting element, if necessary, at least one organic layer of either or both multilayer sealing films Is a layer.

  Among the organic layers used in the present invention, at least one of the organic layers has a three-dimensional structure capable of controlling the direction dependency of the extracted light intensity on one side. The structure is uneven and transparent when viewed from the front, but is preferably opaque when viewed from an oblique direction. Specifically, it is preferably opaque when viewed from an oblique angle of 60 degrees from the vertical direction of the light emitting element, more preferably opaque when viewed from an oblique angle of 45 degrees, and oblique by 30 degrees. More preferably, it is opaque when viewed from an angle.

  The dimension of the irregularities formed on one side of the organic layer is the material of the organic layer, the concentration of the coating solution, if semi-cured, the amount of energy applied during semi-curing, if the liquid-phobic surface, the lyophobic surface Can be controlled by various conditions such as the degree of lyophobicity, that is, the degree of water repellency. In order to improve the target light extraction efficiency, it is preferable that the unevenness has a height difference in the range of 0.1 to 2.0 μm. The total film thickness of the organic film is usually set in the range of 50 to 10 μm. This is a range set as suitable mainly considering the maintenance of the mechanical strength of the film and the film sealing property.

In the present invention, the lower multilayer sealing film formed on the substrate may be directly laminated on the substrate or may be laminated via some intermediate layer. As such an intermediate layer, for example, a lyophilic layer for making the substrate surface lyophilic can be considered. Such a direct or indirect stacking relationship is the same in the stacking relationship of the lower multilayer sealing film-the light emitting layer-the upper multilayer sealing film in the light emitting device of the present invention. That is, the light emitting part may be directly laminated on the lower multilayer sealing film, or indirectly laminated. Similarly, the upper multilayer sealing film formed on the light emitting layer may be directly laminated on the light emitting layer or indirectly laminated. For example, when an example of a laminated structure in an organic EL element is given, flexible substrate / (organic / inorganic) lower multilayer sealing film / anode (for example, ITO) / hole injection layer (for example, MoO ₃ film / poly (3, 4) Ethylenedioxythiophene / polystyrene sulfonic acid film) / polymer organic light emitting material layer / electron injection layer (for example, Ba film) / cathode layer (for example, Al film) / (organic / inorganic) upper multilayer sealing film) ).

  The thickness of the organic layer and the inorganic layer constituting the lower and upper multilayer sealing films is preferably in the range of 50 to 10 μm. When the thickness is less than 50 mm, it is difficult to maintain the mechanical properties of the film well. When the thickness exceeds 10 μm, the entire film thickness is increased. In an organic EL element or the like, the light extraction efficiency from the light emitting layer is affected. In some cases.

(Constituent material of lower and upper multilayer sealing films)
As the inorganic layer constituting the lower and upper multilayer sealing films, materials such as silicon oxide (SiO ₂ ), silicon nitride (SiN), silicon oxynitride (SiON), and aluminum oxide (Al ₂ O ₃ ) are preferably used. Used. As a method for forming the inorganic film, a known thin film forming method such as a sputtering method or a plasma CVD method can be used.

  On the other hand, as the organic layer constituting the lower and upper multilayer sealing films, mainly an organic monomer having a (meth) acryl group having good adhesion to the inorganic layer material, that is, a (meth) acrylic compound is polymerized. The acrylic polymer formed is preferably used.

  The (meth) acrylic compound is formed into a coating film by a known coating film forming method such as a solution coating method or a spray coating method, and light energy (chemical rays such as electron beam, plasma beam, ultraviolet ray) is applied to the coating film. It polymerizes by irradiating or applying thermal energy to obtain an acrylic polymer. At this time, in the present invention, a solid structure is formed on one side of the organic layer simultaneously with the complete curing of the organic layer by the semi-curing means or the coating film forming means on the lyophobic surface for at least one organic layer.

  The (meth) acrylic compound is not particularly limited as long as it is a compound containing one or more (meth) acrylic groups in the molecule. When there is one (meth) acryl group, higher adhesion to the inorganic layer can be obtained. When the number is two or three, the crosslink density is high, and the film strength of the organic layer is higher. Since the size of the unevenness is influenced by the selectivity of the crosslinking density, it is preferable to select the material in consideration of this point.

  Examples of the (meth) acrylic compound include compounds having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) ) Acrylates, compounds having amino groups such as diethylaminoethyl (meth) acrylate, (meth) acrylic acid, 2- (meth) acryloisooxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, etc. It has a cyclic skeleton such as a compound having a carboxyl group, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate ( Acrylate), isoamyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol ( Acrylic monofunctional compounds such as (meth) acrylate, diethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol (meth) acrylate, 1,9-nonanediol di (meth) ) Acrylate, triethylene di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 400 di (meth) acrylate, PEG # 600 di (meth) acrylate, neo Bifunctional (meth) acrylic compounds such as bifunctional urethane (meth) acrylates, such as bifunctional epoxy (meth) acrylates, bifunctional acrylic (meth) acrylates, etc., such as ntil di (meth) acrylate and dimethylol tricyclodecane di (meth) acrylate Can be mentioned. Examples of the compound having three or more (meth) acrylic acids include dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane triacrylate, and trimethylol. An acrylic polyfunctional monomer such as propanetetraacrylate, (meth) acryl polyfunctional epoxy acrylate, (meth) acryl polyfunctional urethane acrylate, and the like can be used.

  The light emitting device and the method for manufacturing the light emitting device according to the present invention having the above-described configuration are particularly useful when the light emitting device is an organic EL device. Also in such an organic EL element, the configuration of the multilayer sealing film described in detail above is the same. Therefore, other main components such as a substrate and a light emitting layer in the organic EL element to which the present invention can be suitably applied will be described in detail below.

(substrate)
The substrate used for the organic EL element may be any substrate that does not change when the electrode is formed and the organic layer is formed. For example, glass, plastic, polymer film, silicon substrate, or a laminate of these is used. It is done.

(Electrode and light emitting layer)
As a basic structure of the organic EL element, at least one light emitting layer is provided between an electrode composed of a pair of an anode (first electrode) and a cathode (second electrode) in which at least the cathode is transparent or translucent with light transmission. Have For the light emitting layer, a low molecular weight and / or high molecular weight organic light emitting material is used.

  In the organic EL element, examples of components around the light emitting layer include those provided between the cathode and the light emitting layer and those provided between the anode and the light emitting layer as layers other than the cathode, the anode, and the light emitting layer. Examples of the material provided between the cathode and the light emitting layer include an electron injection layer, an electron transport layer, and a hole blocking layer.

  The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode, and the electron transport layer is a layer having a function of improving electron injection from the electron injection layer or the electron transport layer closer to the cathode. is there. When the electron injection layer or the electron transport layer has a function of blocking hole transport, these layers may be referred to as a hole blocking layer. Having the function of blocking hole transport makes it possible, for example, to produce an element that allows only hole current to flow, and confirm the blocking effect by reducing the current value.

  Examples of what is provided between the anode and the light emitting layer include a hole injection layer, a hole transport layer, and an electron block layer.

  The hole injection layer is a layer having a function of improving the hole injection efficiency from the cathode, and the hole transport layer improves the hole injection from the hole injection layer or the hole transport layer closer to the anode. This is a functional layer. When the hole injection layer or the hole transport layer has a function of blocking electron transport, these layers may be referred to as an electron block layer. Having the function of blocking electron transport makes it possible, for example, to manufacture an element that allows only electron current to flow, and confirm the blocking effect by reducing the current value.

Various combinations around the light emitting layer as described above include a structure in which a hole transport layer is provided between the anode and the light emitting layer, a structure in which an electron transport layer is provided between the cathode and the light emitting layer, and a cathode and light emission. Examples include a configuration in which an electron transport layer is provided between the layers and a hole transport layer is provided between the anode and the light emitting layer. For example, the following structures a) to d) are specifically exemplified.
a) Anode / light emitting layer / cathode b) Anode / hole transport layer / light emitting layer / cathode c) Anode / light emitting layer / electron transport layer / cathode d) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (Here, / indicates that each layer is laminated adjacently. The same shall apply hereinafter.)

  Here, as described above, the light emitting layer is a layer having a function of emitting light, the hole transporting layer is a layer having a function of transporting holes, and the electron transporting layer has a function of transporting electrons. It is a layer having. The electron transport layer and the hole transport layer are collectively referred to as a charge transport layer. Two or more light emitting layers, hole transport layers, and electron transport layers may be used independently. Further, among the charge transport layers provided adjacent to the electrodes, those having a function of improving the charge injection efficiency from the electrodes and having the effect of lowering the driving voltage of the element are particularly charge injection layers (hole injection layers). , An electron injection layer).

  Furthermore, in order to improve the adhesion with the electrode or the improvement of charge injection from the electrode, the charge injection layer or the insulating layer having a thickness of 2 nm or less may be provided adjacent to the electrode, and the adhesion at the interface may be increased. In order to improve or prevent mixing, a thin buffer layer may be inserted at the interface between the charge transport layer and the light emitting layer. The order and number of layers to be laminated, and the thickness of each layer can be appropriately used in consideration of light emission efficiency and element lifetime.

Moreover, as an organic EL element provided with a charge injection layer (electron injection layer, hole injection layer), an organic EL element provided with a charge injection layer adjacent to the cathode, and a charge injection layer provided adjacent to the anode. An organic EL element is mentioned. For example, the following structures e) to p) are specifically mentioned.
e) Anode / charge injection layer / light emitting layer / cathode f) Anode / light emitting layer / charge injection layer / cathode g) Anode / charge injection layer / light emitting layer / charge injection layer / cathode h) Anode / charge injection layer / hole Transport layer / light emitting layer / cathode i) anode / hole transport layer / light emitting layer / charge injection layer / cathode j) anode / charge injection layer / hole transport layer / light emitting layer / charge injection layer / cathode k) anode / charge Injection layer / light emitting layer / charge transport layer / cathode l) anode / light emitting layer / electron transport layer / charge injection layer / cathode m) anode / charge injection layer / light emitting layer / electron transport layer / charge injection layer / cathode n) anode / Charge injection layer / hole transport layer / light emitting layer / charge transport layer / cathode o) anode / hole transport layer / light emitting layer / electron transport layer / charge injection layer / cathode p) anode / charge injection layer / hole transport Layer / light emitting layer / electron transport layer / charge injection layer / cathode

(anode)
For the anode, for example, as a transparent electrode or a semitransparent electrode, a metal oxide, metal sulfide or metal thin film with high electrical conductivity can be used, and a high transmittance can be suitably used. Are appropriately selected and used. Specifically, indium oxide, zinc oxide, tin oxide, and a composite film made of conductive glass made of indium / tin / oxide (ITO), indium / zinc / oxide, etc. (NESA) Etc.), gold, platinum, silver, copper and the like are used, and ITO, indium / zinc / oxide, and tin oxide are preferable. Examples of the production method include a vacuum deposition method, a sputtering method, an ion plating method, a plating method, and the like. Further, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the anode.

  The film thickness of the anode can be appropriately selected in consideration of light transmittance and electrical conductivity, and is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, more preferably 50 nm to 500 nm. is there.

(Hole injection layer)
As described above, the hole injection layer can be provided between the anode and the hole transport layer or between the anode and the light emitting layer. Materials for forming the hole injection layer include phenylamine, starburst amine, phthalocyanine, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide and other oxides, amorphous carbon, polyaniline, polythiophene derivatives, etc. It is done.

(Hole transport layer)
Materials constituting the hole transport layer include polyvinyl carbazole or derivatives thereof, polysilane or derivatives thereof, polysiloxane derivatives having aromatic amines in the side chain or main chain, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine. Derivatives, polyaniline or derivatives thereof, polythiophene or derivatives thereof, polyarylamine or derivatives thereof, polypyrrole or derivatives thereof, poly (p-phenylene vinylene) or derivatives thereof, or poly (2,5-thienylene vinylene) or derivatives thereof, etc. Is exemplified.

  Among these, as a hole transport material used for the hole transport layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a derivative thereof, Polymeric hole transport materials such as polythiophene or derivatives thereof, polyarylamine or derivatives thereof, poly (p-phenylene vinylene) or derivatives thereof, or poly (2,5-thienylene vinylene) or derivatives thereof are preferred, and more preferred Is polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in a side chain or a main chain. In the case of a low-molecular hole transport material, it is preferably used by being dispersed in a polymer binder.

(Light emitting layer)
In the present invention, the light emitting layer is an organic light emitting layer, and usually has organic substances (low molecular compounds and high molecular compounds) that mainly emit fluorescence or phosphorescence. Further, a dopant material may be further included. Examples of the material for forming the light emitting layer that can be used in the present invention include the following.

(Light-emitting layer forming material 1: dye-based material)
Examples of dye-based materials include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds. Pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

(Light emitting layer forming material 2: metal complex material)
Examples of the metal complex material include metal complexes that emit light from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc complexes, benzothiazole zinc complexes, azomethyls. Zinc complex, porphyrin zinc complex, europium complex, etc., which has Al, Zn, Be or the like as the central metal or rare earth metal such as Tb, Eu, or Dy, and the ligand is oxadiazole, thiadiazole, phenylpyridine, phenylbenzo Examples thereof include metal complexes having an imidazole or quinoline structure.

(Light-emitting layer forming material 3: polymer material)
Polymeric materials include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polymerized chromophores and metal complex light emitting materials. Etc.

  Examples of the material that emits blue light among the light emitting layer forming materials include distyrylarylene derivatives, oxadiazole derivatives, and polymers thereof, polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives. Of these, polymer materials such as polyvinyl carbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives are preferred.

  Examples of the light emitting layer forming material that emits green light include quinacridone derivatives, coumarin derivatives, polymers thereof, polyparaphenylene vinylene derivatives, and polyfluorene derivatives. Of these, polymer materials such as polyparaphenylene vinylene derivatives and polyfluorene derivatives are preferred.

  Examples of the material that emits red light among the light emitting layer forming materials include coumarin derivatives, thiophene ring compounds, and polymers thereof, polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives. Among these, polymer materials such as polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives are preferable.

(Light-emitting layer forming material 4: dopant material)
A dopant can be added to the light emitting layer for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such dopants include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazolone derivatives, decacyclene, phenoxazone, and the like.

(Electron transport layer)
As the material for forming the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinones or derivatives thereof, tetracyanoanthraquinodi. Examples include methane or derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene or derivatives thereof, diphenoquinone derivatives, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof, and the like. The

  Of these, oxadiazole derivatives, benzoquinone or derivatives thereof, anthraquinones or derivatives thereof, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof are preferred, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferable.

(Electron injection layer)
As described above, the electron injection layer is provided between the electron transport layer and the cathode, or between the light emitting layer and the cathode. Depending on the type of the light emitting layer, the electron injection layer is an electron injection layer having a single layer structure of Ca layer, or a metal of group IA and IIA of the periodic table excluding Ca and having a work function of 1. It is possible to provide an electron injection layer having a laminated structure of a Ca layer and a layer formed of one or more of 5-3.0 eV metal and oxides, halides and carbonates of the metal. . Examples of metals of Group IA of the periodic table having a work function of 1.5 to 3.0 eV or oxides, halides, and carbonates thereof include lithium, lithium fluoride, sodium oxide, lithium oxide, lithium carbonate, and the like. Can be mentioned. Examples of metals of Group IIA of the periodic table excluding Ca having a work function of 1.5 to 3.0 eV or oxides, halides and carbonates thereof include strontium, magnesium oxide, magnesium fluoride, fluorine Strontium fluoride, barium fluoride, strontium oxide, magnesium carbonate and the like.

(cathode)
For the cathode, as transparent or semi-transparent electrode, metal, graphite or graphite intercalation compound, inorganic semiconductor such as ZnO (zinc oxide), ITO (indium tin oxide), IZO (indium zinc zinc oxide), etc. And conductive oxides such as strontium oxide and barium oxide. Examples of the metal include alkali metals such as lithium, sodium, potassium, rubidium and cesium; alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium, gold, silver, platinum, copper, manganese, titanium, cobalt, Transition metals such as nickel and tungsten; tin, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium; and alloys of two or more thereof. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, calcium-aluminum alloy, and the like. The cathode may have a laminated structure of two or more layers. Examples of this include a laminated structure of the above metals, metal oxides, fluorides, alloys thereof, and metals such as aluminum, silver, and chromium.

  Examples of the present invention will be described below. The following examples are only suitable examples for explaining the present invention in more detail, and do not limit the present invention. In the following examples, an organic EL element is assumed as a light emitting element. The present invention is particularly effective in the case of an organic EL element, but is similarly effective in other light emitting elements.

  In the organic EL element of Example 3 below, as described above, the electrode element is most simply composed of only an anode and a cathode, and these are laminated on both sides of the light emitting layer to form a light emitting portion. In addition to the anode and cathode, other electrode elements such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer can be combined in various ways, and these can be formed on the light emitting layer. In some cases, a light emitting portion is formed by stacking. In Example 3 below, the electrode elements formed on both sides of the light-emitting layer are simply described, but it is apparent that the present invention can be similarly applied to any configuration of electrode elements stacked on the light-emitting layer. It is. That is, after various combinations of electrode elements are laminated on the light emitting layer, a multilayer sealing film is laminated thereon. In the present invention, the fact that the light emitting layer or the light emitting portion is sealed by the multilayer sealing film means the above-described configuration.

Example 1
(Formation of an organic film having a sea-island structure 1)
This example uses a glass substrate as a surface for forming an organic layer having irregularities on one side in the present invention, and the organic layer coating film formed on this substrate is completely cured through semi-curing, whereby the organic layer It is an experimental example which formed the unevenness | corrugation in one side.

First, a glass substrate was subjected to a lyophilic treatment with a UV-O ₃ (ozone) treatment device (trade name “Model 312 UV-O ₃ Cleaning System” manufactured by Technovision Co., Ltd.), and then a membrane sealing device (US VITEX Corporation). Manufactured and trade name “Guardian200”). An organic monomer material (product name “Vitex Barix Resin System material (Vitex 701)” manufactured by VITEX) is introduced into a vaporizer and vaporized to eject monomer vapor from the slit nozzle, and the substrate is moved on the nozzle at a constant speed. By passing, the monomer was deposited on the substrate to a uniform thickness, and a coating film composed of the monomer on the substrate was formed.

  Next, the substrate on which the monomer coating film was formed was irradiated with UV light (lamp power 30%) in an amount insufficient to crosslink and cure the monomer of the coating film, thereby semi-curing the coating film.

  Subsequently, the semi-cured coating film was irradiated with UV light sufficient to completely cure the coating film (lamp power 60%). When the obtained cured film (organic layer) was observed with an optical microscope, it had a sea-island structure, and irregularities with a height difference of about 1.2 μm corresponding to the sea-island structure were formed on the surface.

  When the obtained substrate was observed from the front, that is, from the coating film side, it was colorless and transparent and exhibited a high transmittance. However, when observed from an oblique direction, the transmittance decreased due to light scattering, resulting in a pale white color.

(Comparative Example 1)
In Example 1, an organic film was formed in the same manner as in Example 1 except that UV light sufficient for monomer curing (lamp power 60%) was irradiated. The surface of the obtained organic film was flat and showed a high transmittance that was colorless and transparent regardless of the observation direction.

  Compared with the element manufactured in Comparative Example 1, the element manufactured in Example 1 has higher luminance observed from the front and higher efficiency.

(Example 2)
(Formation of organic film with sea-island structure 2)
In this example, a glass substrate is used as a surface on which an organic layer having irregularities on one side in the present invention, and the surface of the substrate remains lyophobic, and an organic layer coating formed on the lyophobic surface is used. This is an experimental example in which unevenness is formed on one side of the organic layer by completely curing the film.

The glass substrate was set in an organic film forming chamber of a film sealing device (trade name “Guardian 200” manufactured by VITEX, USA) without performing lyophilic treatment using a UV-O ₃ (ozone) treatment device. An organic monomer material (product name “Vitex Barix Resin System monomer material (Vitex 701)” manufactured by VITEX Co., Ltd.) is introduced into the vaporizer and vaporized to eject monomer vapor from the slit nozzle, and the substrate is moved at a constant speed on the nozzle. By passing, the monomer was adhered to the substrate with a uniform thickness, and a coating film of the monomer was formed on the lyophobic surface of the substrate.

  Next, the substrate on which the monomer coating film was formed was irradiated with a sufficient amount of UV light to crosslink and cure the monomer of the coating film (lamp power 60%). When the obtained cured film (organic layer) was observed with an optical microscope, it had a sea-island structure, and irregularities with a height difference of about 1.2 μm corresponding to the sea-island structure were formed on the surface.

  When the obtained substrate was observed from the front, that is, from the coating film side, it was colorless and transparent and exhibited a high transmittance. However, when observed from an oblique direction, the transmittance decreased due to light scattering, resulting in a pale white color.

(Example 3)
(Manufacture of an organic EL device using a multilayer sealing film including an organic layer having a sea-island structure)
A glass substrate on which ITO (transparent electrode) having a thickness of about 150 nm formed by sputtering is patterned is washed with an organic solvent, an alkaline detergent, and ultrapure water, and then dried on a UV-O3 apparatus. Then, UV-O ₃ treatment was performed.

  On the ITO surface side of the substrate, a suspension of poly (3,4) ethylenedioxythiophene / polystyrene sulfonic acid (manufactured by HC Starck B-Tech, trade name “Bytron P TP AI 4083”) having a 0.5 μm diameter filter The suspension was formed into a film having a thickness of 70 nm by spin coating, and dried at 200 ° C. for 10 minutes on a hot plate in the air.

  Next, a 1.5% by weight solution of a polymer organic light-emitting material (trade name “Lumation GP1300” manufactured by Cymation Co., Ltd.) was prepared using a solvent in which xylene and anisole were mixed 1: 1. This solution was deposited to a thickness of 80 nm on the substrate on which “Bytron P” had been deposited, using spin coating.

The light emitting layer of the extraction electrode part and the sealing area part is removed, introduced into a vacuum chamber, and transferred to a heating chamber (hereinafter, the process in vacuum or nitrogen is performed, and the element in the process is exposed to the atmosphere. Absent.). Next, it was heated for 60 minutes at a temperature of about 100 ° C. in a vacuum (degree of vacuum is 1 × 10 ⁻⁴ Pa or less).

  Thereafter, the substrate was transferred to a vapor deposition chamber, aligned with a cathode mask, and vapor deposited so that a cathode was formed on the light emitting portion and the extraction electrode portion. For the cathode, Ba metal is heated by resistance heating, the deposition rate is about 2 mm / sec, and the film thickness is 50 mm. And deposited.

(Formation of upper multilayer sealing film)
After the device was created, the substrate was transferred to a film sealing device (trade name “Guardian 200” manufactured by VITEX, USA) without being exposed to the atmosphere from the vapor deposition chamber. The mask was aligned and set on the substrate. Next, the substrate was transferred to the inorganic film formation chamber, and aluminum oxide, which was the first inorganic layer, was formed by sputtering. Argon gas and oxygen gas were introduced using an Al metal target having a purity of 5N, and an aluminum oxide film was formed on the substrate. A transparent and flat aluminum oxide film having a thickness of about 60 nm was obtained.

  After the first inorganic layer was formed, the inorganic layer mask was removed, replaced with an organic layer mask, and transferred to the organic film formation chamber. An organic monomer material (product name “Vitex Barix Resin System monomer material (Vitex 701)” manufactured by VITEX) is introduced into a vaporizer, vaporized, and monomer vapor is ejected from the slit nozzle, and the substrate is moved at a constant speed. The monomer was attached to the substrate so that the thickness would be uniform by passing through the substrate. Next, UV light was irradiated to the substrate on which the monomer was adhered to crosslink and cure the monomer to form a first organic layer. The obtained film was a transparent and flat film, and the film thickness was about 1.3 μm.

  After forming the first organic layer, the substrate was moved to the inorganic film formation chamber, and argon and oxygen were introduced, and the film formation of aluminum oxide as the second inorganic layer was performed by a sputtering method. A transparent and flat aluminum oxide film having a thickness of about 40 nm was formed. After the second inorganic layer is formed, the second organic layer is formed in the same manner as the first organic layer, and after the second organic layer is formed, the third inorganic layer is formed in the same manner as the second inorganic layer. A layer was formed. Similarly, a third organic layer and a fourth inorganic layer were formed.

(Formation of an organic layer with sea-island irregularities (three-dimensional structure) on one side)
As described above, after the formation of the fourth inorganic layer, the monomer was adhered in the same manner as in the first organic layer. The conditions for curing the monomer by UV light were the same as in Example 1. That is, the UV light irradiation is divided into two stages. In the first stage, UV light that is insufficient to be cured is irradiated to semi-harden the coating film, and the surface (one side) of the sea island structure is uneven. In the second stage, the semi-cured coating film was irradiated with UV light sufficient for curing to fix the irregularities of the sea-island structure generated in the first bullet, and an organic layer (cured film) was formed.

  When the organic EL element obtained as described above was caused to emit light and the angle dependency of the extracted light was confirmed, it had a desired angle dependency.

  As described above, the light emitting device according to the present invention is a light emitting device in which the light extraction side of the light emitting unit is sealed with a multilayer sealing film having at least one organic layer, and the at least one organic layer is disposed on one side thereof. It has a three-dimensional structure capable of controlling the direction dependency of the extracted light intensity. The method for manufacturing a light emitting device according to the present invention includes: a light emitting element having a light emitting side sealed with a multilayer sealing film having at least one organic layer; A method of manufacturing a light-emitting device by obtaining a light-emitting device with excellent light extraction by forming a three-dimensional structure capable of controlling the direction dependency of the organic layer, wherein the three-dimensional structure on one side of the organic layer is formed simultaneously with the formation of the organic layer It is characterized by doing.

  The light emitting device according to the present invention is transparent from the front, but becomes opaque when viewed from an oblique direction, and the front luminance of the light emitting device is improved. Since the three-dimensional structure of one surface of the organic layer in this light emitting device can be performed during the normal sealing film forming step by the production method of the present invention, the light emitting device is simple in process and excellent in light extraction efficiency. Can be easily manufactured.

  As described above, according to the light emitting device and the method for manufacturing the same according to the present invention, it is possible to provide a light emitting device with improved light extraction efficiency at a low cost without increasing the space occupied by the light emitting device. The present invention having such characteristics is particularly suitable for improving light extraction efficiency in an organic EL element.

Claims (11)

In the light emitting device in which the light extraction side of the light emitting part is sealed by the multilayer sealing film having at least one organic layer,
The light emitting device according to claim 1, wherein the at least one organic layer has a three-dimensional structure capable of taking out on one side thereof and controlling a direction dependency of light intensity.   2. The light emitting device according to claim 1, wherein the three-dimensional structure of one surface of the organic layer is formed simultaneously with the formation of the organic layer.   The light emitting device according to claim 1, wherein the organic layer is made of an energy curable resin.   The three-dimensional structure of the organic layer is formed simultaneously with the formation of the organic layer by semi-curing the coating film of the energy curable resin and then completely curing the coating film. Item 4. A light emitting device according to Item 3.   The three-dimensional structure of the organic layer is formed simultaneously with the formation of the organic layer by being cured in a state where the coating film of the energy curable resin is formed on a lyophobic surface. The light emitting device according to claim 3, wherein   It is an organic EL light emitting element, The light emitting element of any one of Claims 1-5 characterized by the above-mentioned. Forming a three-dimensional structure capable of controlling the direction dependency of the extracted light intensity on one side of the at least one organic layer of the light emitting element in which the light extraction side of the light emitting part is sealed by the multilayer sealing film having at least one organic layer A method of manufacturing a light-emitting device that obtains a light-emitting device with excellent light extraction performance,
A method for manufacturing a light-emitting element, wherein the three-dimensional structure on one side of the organic layer is formed simultaneously with the formation of the organic layer.   The method for manufacturing a light-emitting element according to claim 7, wherein the organic layer is formed using an energy curable resin.   The three-dimensional structure of the organic layer is formed simultaneously with the formation of the organic layer by semi-curing the coating film of the energy curable resin and then completely curing the organic layer. Manufacturing method of light emitting element.   9. The three-dimensional structure of the organic layer is formed simultaneously with the formation of the organic layer by curing in a state where the coating film of the energy curable resin is formed on a lyophobic surface. The manufacturing method of the light emitting element as described in any one of.   The method for manufacturing a light-emitting element according to claim 7, wherein the light-emitting element is an organic EL light-emitting element.