JP2010160945A - Method for manufacturing organic electroluminescence device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an organic electroluminescence device, capable of forming an organic luminescent layer with a uniform thickness in a predetermined area by a simple method. <P>SOLUTION: The method for manufacturing an organic EL (Electroluminescence) device 10A including a plurality of organic EL elements including an anode 12, a cathode 24, and an organic luminescent layer 23, and a substrate 11 for mounting the plurality of organic EL elements includes: a partition wall forming step of forming a partition wall 15 for partitioning each of the plurality of organic EL elements on the substrate 11; a liquid repellent treatment step of performing liquid repellent treatment to the surface of the substrate 11 with the partition wall 15 formed thereon from the side for mounting the organic EL elements; a hydrophilic bed layer forming step of forming a lipophilic bed layer 19 higher in lyophilicity to organic luminescent ink than the partition wall 15 subjected to liquid repellent treatment on the anode 12; a surface treatment step of performing surface treatment to the lipophilic bed layer 19 with an organic solvent; and an organic luminescent layer forming step of forming the organic luminescent layer 23 by supplying organic luminescent ink to an area partitioned by the partition wall 15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic electroluminescence device (hereinafter also referred to as an organic EL device) having a plurality of organic electroluminescence elements (hereinafter also referred to as organic EL devices) on a substrate.

  The organic EL element includes a pair of electrodes and an organic light emitting layer. When a voltage is applied to the organic EL element, holes and electrons are injected from each electrode, and light is emitted by combining the injected holes and electrons in the organic light emitting layer. Compared to inorganic EL elements, organic EL elements can be driven at a low voltage and have high luminance. Therefore, practical application of organic EL devices such as display devices and lighting devices having a plurality of organic EL elements has been studied. ing.

  In a display device using a plurality of organic EL elements, for example, a grid-like partition is provided on a substrate, and each organic EL element is provided in a region partitioned by the partition (hereinafter sometimes referred to as a pixel region). Therefore, it is necessary to form an organic light emitting layer constituting each organic EL element for each pixel region.

  As a method for forming an organic light emitting layer in each pixel region, a coating method has been studied from the simplicity of the process. For example, an ink containing an organic light-emitting material (hereinafter sometimes referred to as an organic light-emitting ink) is selectively supplied to each pixel area using a coating method such as a relief printing method or an ink-jet printing method, and further dried to emit organic light. A method of forming a layer has been proposed (see, for example, Patent Document 1).

  When an organic light emitting layer is formed by a coating method, in order to prevent the ink supplied to a predetermined pixel area from flowing out to other adjacent pixel areas, usually, ink repellency is given to the partition wall surface in advance. Yes. With reference to FIGS. 6A and 6B, an outline of a method for forming an organic light emitting layer according to the conventional technique will be described. As shown in FIG. 6A, a plurality of first electrodes 102 made of an ITO film or the like, an inorganic insulating layer 103 that insulates between adjacent first electrodes 102, and an organic partition layer disposed on the inorganic insulating layer 103 104 is first formed on the substrate 101. At the stage where the inorganic insulating layer 103 and the organic partition layer 104 are formed, these are members that are lyophilic with respect to the organic light emitting ink.

Next, CF ₄ plasma treatment (liquid repellent treatment) is performed on the surface of the substrate 101 on which the above-described members are formed. Since members made of organic material (organic partition wall layer 104) is likely to be fluorinated by the CF ₄ plasma treatment, the organic partition wall layer 104 by the CF ₄ plasma treatment surface readily fluorinated, liquid repellency is imparted. Member (inorganic insulating layer 103, first electrode 102) made of other inorganic Because hardly fluorinated by CF ₄ plasma treatment, this CF ₄ inorganic insulating layer 103 by plasma treatment, the first electrode 102 is maintained lyophilic To do. Therefore, only the organic partition layer 104 is selectively given liquid repellency to the organic light emitting ink by the CF ₄ plasma treatment, and the surface state is selectively changed.

  In the prior art shown in FIG. 6B, the organic light emitting ink 106 is ejected from the inkjet head 105 to the pixel region (between the organic partition walls 104). The organic light-emitting ink 106 that has landed on a predetermined pixel region is repelled by the organic partition layer 104 having liquid repellency, so that it does not flow out to the adjacent pixel region beyond the organic partition layer 104, and does not flow into the landed pixel region. It is kept as it is. By drying the organic light-emitting ink 106, the organic light-emitting layer can be patterned on the first electrode 102.

JP 2006-286243 A

  Although the surface of the layer on which the organic light emitting layer is formed (the first electrode 102 in FIG. 6) is lyophilic as described above, the organic light emitting ink is still selectively supplied into each pixel region. Sometimes, the organic light emitting ink is repelled in the periphery of the pixel region and in the pixel region, and there is a possibility that uniform application of the organic light emitting ink to the entire pixel region may not be realized. The organic light emitting layer thus formed has a non-uniform film thickness, and in some cases, a hole is generated in a portion where the organic light emitting ink is repelled. For this reason, the area of the pixel region that actually emits light may be less than the design value, or unevenness in light emission may occur, and as a result, the light emission characteristics will be significantly degraded.

  The present invention has been made in view of the problems of the above-described conventional technology, and the problem is to manufacture an organic EL device capable of forming an organic light emitting layer having a uniform film thickness in a predetermined region by a simple method. It is to provide a method.

In order to solve the above problems, the present invention employs the following configuration.
[1] A plurality of organic electro circuits each including a first electrode, a second electrode paired with the first electrode, and an organic light emitting layer disposed between the first electrode and the second electrode. A method for producing an organic electroluminescence device comprising a luminescence element and a substrate on which the plurality of organic electroluminescence elements are mounted,
Preparing a substrate on which the first electrode is formed;
A partition wall forming step for forming partition walls for partitioning the plurality of organic electroluminescence elements on the substrate,
A liquid repellent treatment step of performing a liquid repellent treatment on the surface of the substrate on which the partition walls are formed from the side on which the organic electroluminescence element is mounted in the thickness direction of the substrate;
More lyophilic to form on the first electrode a lyophilic underlayer having higher lyophilicity to the ink containing the organic light emitting material for forming the organic light emitting layer than the liquid repellent treated partition. An underlayer forming step;
A surface treatment step of surface-treating the lyophilic underlayer with an organic solvent;
After the surface treatment step, an organic light emitting layer forming step of forming an organic light emitting layer by supplying ink containing an organic light emitting material in a region partitioned by the partition;
An electrode forming step of forming the second electrode;
A method for producing an organic electroluminescence device, comprising:
[2] The method for manufacturing an organic electroluminescence device according to the above [1], wherein the liquid repellent treatment is a plasma treatment using a fluorine-based gas.
[3] The method for producing an organic electroluminescent device according to the above [1] or [2], wherein in the lyophilic underlayer forming step, the lyophilic underlayer is formed by a dry method.
[4] The method for producing an organic electroluminescent device according to any one of [1] to [3], wherein the lyophilic underlayer is a layer made of a metal oxide or a metal complex oxide. .
[5] The method for producing an organic electroluminescent device according to the above [4], wherein the metal oxide forming the lyophilic underlayer is molybdenum oxide or tungsten oxide.
[6] The manufacturing of the organic electroluminescence device according to any one of [1] to [5], wherein the surface treatment step is a step of bringing the organic solvent into contact with the surface of the lyophilic underlayer. Method.
[7] The method for manufacturing an organic electroluminescent device according to [6], wherein in the surface treatment step, the organic solvent is brought into contact with the surface of the lyophilic underlayer by a spin coating method.
[8] The organic electroluminescence device according to [6] or [7], wherein, in the surface treatment step, the organic solvent is dried after contacting the surface of the lyophilic underlayer. Production method.
[9] The method for producing an organic electroluminescent device according to any one of [1] to [8], wherein in the organic light emitting layer forming step, ink containing the organic light emitting material is supplied by a flexographic printing method. .

According to the present invention, an organic EL device having an organic EL element that can form an organic light emitting layer with a uniform film thickness in a predetermined region by a simple method, has reduced light emission unevenness, and has excellent light emission characteristics. can do.
Therefore, the organic EL device of the present invention can be suitably used as a planar light source, a lighting device, and a display device.

  Embodiments of the present invention will be described below with reference to the drawings. For ease of understanding, the scale of each member in the drawing may differ from the actual scale. Further, the present invention is not limited by the following description, and can be appropriately changed without departing from the gist of the present invention. In the organic EL device, there are members such as electrode lead wires. However, in the explanation of the present invention, the description is omitted because it is not directly required. For the convenience of explanation of the layer structure and the like, in the example shown below, the explanation is made with the figure in which the substrate is arranged below. However, the organic EL element of the present invention and the organic EL device equipped with the same are necessarily manufactured in this arrangement. Or use etc. are not made. In the following description, one of the thickness directions of the substrate may be referred to as “upper” or “upper”, and the other of the substrate thickness directions may be referred to as “lower” or “lower”.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
An embodiment of a method for manufacturing an organic EL device according to the present invention will be described, and then an embodiment of the structure of the organic EL device targeted by the manufacturing method according to the present invention will be described.
The organic EL device 10A (see FIG. 1-8) manufactured according to the first embodiment is provided with a plurality of pixels. A region where pixels are formed, that is, a pixel region, is partitioned by a partition wall surrounding the region, and a planar shape thereof is appropriately set according to specifications, and may be, for example, a substantially rectangular shape, a substantially elliptical shape, or an oval shape. Each pixel is composed of an organic EL element. An organic EL element includes a pair of electrodes and a light emitting layer containing an organic compound sandwiched between the electrodes (hereinafter referred to as “organic light emitting layer”), and various layers are sequentially stacked on a substrate. Made.

  The method for manufacturing an organic EL device of the present invention includes a first electrode, a second electrode paired with the first electrode, and an organic light emitting layer disposed between the first electrode and the second electrode. A method for manufacturing an organic electroluminescence device, comprising: a plurality of organic electroluminescence elements each comprising a plurality of organic electroluminescence elements; and a substrate on which the plurality of organic electroluminescence elements are mounted. From the side on which the organic electroluminescence element is mounted in the thickness direction of the substrate in the preparation step, the partition forming step for forming the partition for partitioning the plurality of organic electroluminescence elements on the substrate, and the partition In order to form an organic light emitting layer rather than a liquid repellent treatment step for liquid repellent treatment of the surface of the substrate on which the liquid crystal is formed and the liquid repellent treated partition A lyophilic underlayer forming step for forming a lyophilic underlayer having high lyophilicity with respect to ink containing an organic light emitting material on the first electrode, and surface treatment of the lyophilic underlayer with an organic solvent An organic light emitting layer forming step of forming an organic light emitting layer by supplying an ink containing an organic light emitting material into a region partitioned by the partition after the surface treatment step, and the second electrode. An electrode forming step to be formed.

<A> Substrate Preparation Step The substrate preparation step is a preparation step of preparing a substrate on which the first electrode is formed. A substrate on which the first electrode is formed is prepared by forming the first electrode on the substrate. Alternatively, a substrate on which the first electrode is formed may be prepared by obtaining a substrate on which the first electrode is formed from the market. In this embodiment, the first electrode is used as an anode and the second electrode is used as a cathode. However, as another embodiment, the first electrode may be used as a cathode and the second electrode may be used as an anode.
In this embodiment, a substrate on which a first electrode is formed is prepared by forming a first electrode on the substrate. FIG. 1-1 is a cross-sectional configuration diagram illustrating a substrate preparation process of the method for manufacturing an organic EL device according to the first embodiment of the present invention, and is a cross-sectional line (II)-(I It is sectional drawing seen from -I). FIG. 2A is a plan view of the substrate of FIG. 1-1.
In the substrate preparation step, first, a substrate made of any of the substrate materials described below is prepared. When using a substrate having a low gas barrier property such as a plastic substrate, a lower sealing film is formed on the substrate 11 as necessary.

  An anode 12 corresponding to the first electrode is pattern-formed on the substrate 11 using any of the anode materials described later. When the anode 12 is a transparent electrode, as described later, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), tin oxide, zinc oxide, indium oxide, A transparent electrode material such as zinc aluminum composite oxide is used. For example, in the case of using ITO, the electrode pattern is formed as a uniform deposited film on the substrate 11 by a sputtering method, and then patterned into an island shape or a line shape by photolithography. In addition to the sputtering method, the anode may be formed by a vacuum deposition method, an ion plating method, a plating method, or the like.

After forming the anode 12, it is preferable to form, for example, a lattice-like insulating layer 13. The insulating layer 13 is formed by forming an insulating film made of an inorganic insulating material such as SiO ₂ or SiN by a known method such as a plasma CVD method or a sputtering method, and then performing photolithography and etching, followed by patterning. The A region where the insulating film is removed corresponds to the pixel region 14. The insulating layer 13 exhibits electrical insulation. The insulating layer 13 ensures electrical insulation between the pixel regions.

As shown in FIG. 2A, the rectangular region covered with the lattice-like insulating layer 13 becomes the pixel region 14, and the patterned anode 12 is exposed in the pixel region 14. The opening shape of the pixel defined by the insulating layer 13 may be any of a circle, an ellipse, and a square. However, since the ink composition has a surface tension, in the case of a quadrangle, the corner is rounded. Is preferred.
In the case where the insulating layer 13 is not provided, the anode 12 is exposed in a strip shape, but this strip-shaped region becomes a pixel region. Further, the insulating layer 13 is formed in a lattice shape by patterning the insulating film, but a plurality of the insulating layers 13 may be placed in parallel in a straight line between the pixel regions.

<B> Partition Formation Step The partition formation step is a step of forming a partition that partitions each of the plurality of organic electroluminescence elements.
After forming the insulating layer 13, a photosensitive material is applied on the substrate 11 on which the insulating layer 13 is formed, and a photoresist film is stacked. Next, this photoresist film is patterned into a lattice shape by photolithography. 1-2 is a cross-sectional view taken along section line (I-II)-(I-II) in FIG. 2-2, and FIG. 2-2 is a plan view of the substrate in FIG. 1-2. . As shown in FIGS. 1-2 and 2-2, the insulating partition 15 is formed by patterning the photoresist film of the substrate 11 in a lattice pattern. A region partitioned by the partition 15 forms a concave groove 16, and a light emitting layer forming region 17 in which an organic light emitting layer is formed so as to surround the pixel region 14 when viewed from one side in the thickness direction of the substrate. It is divided into.
The light emitting layer forming region 17 is a region sandwiched between the facing surfaces 15 a of the adjacent partition walls 15. 1-2 to 1-8, the cross-sectional shape of the partition wall 15 cut along a plane perpendicular to the extending direction of the partition wall 15 is a trapezoidal shape having a wide substrate 11 side. As the distance from the insulating layer 13 increases, the width increases.

  The insulating photosensitive material (photoresist composition) forming the partition wall 15 may be either a positive resist or a negative resist. As the photosensitive material (photoresist composition) constituting the partition wall 15, specifically, polyimide, acrylic resin and novolak resin photosensitive compounds can be used. This photosensitive material may contain a light-shielding material for the purpose of improving the display quality of the organic EL element.

  The partition walls 15 are formed in a lattice shape having a predetermined desired size by, for example, photolithography.

  As shown in FIGS. 1-2 to 1-8, the sectional shape of the partition wall 15 cut along a plane perpendicular to the extending direction of the partition wall 15 is a trapezoidal shape having a wide substrate 11 side. The shape is not limited to this, and may be a rectangular shape or a bowl shape.

  The partition walls 15 are provided in a lattice shape on the insulating layer 13, but a plurality of linear partition walls placed substantially in parallel with each other may be formed between the pixel regions 14.

  In addition, the anodes 12 are insulated from each other by the insulating layer 13 on the substrate 11 and the light emitting layer forming region 17 is partitioned by the partition 15. However, the partition is formed integrally with the insulating layer, and the anodes 12 are connected to the partition. You may make it have the function to insulate and the function to partition the ink apply | coated between partition walls simultaneously. In this case, the partition wall to be formed is formed using the same material as the partition wall 15 described above.

<C> Liquid-repellent treatment step The liquid-repellent treatment step is a step of performing a liquid-repellent treatment on the surface of the substrate on which the partition walls are formed from the side on which the organic electroluminescence element is mounted in the thickness direction of the substrate.

  In the present specification, “liquid repellency” means that the ink supply target surface has a low affinity for an ink (organic light-emitting ink) (or a solvent thereof) containing an organic light-emitting material for forming an organic light-emitting layer. . The presence or absence of liquid repellency can be determined by the contact angle between the organic light emitting ink and the substrate. The contact angle is defined as the angle formed by the contact portion of the liquid droplet dropped on the solid surface and the solid surface.

  In this specification, it is defined that the solid surface has liquid repellency when the contact angle between the droplet and the solid surface is 30 ° or more. In addition, when the contact angle is less than 30 °, the solid surface is defined as being lyophilic with respect to the liquid and easily wet. In this case, when a liquid is applied, a good quality film is formed which spreads uniformly on the solid surface.

The liquid repellent treatment is a treatment for increasing the contact angle between the droplet and the solid surface, and includes a method of performing plasma treatment using a fluorine-based gas and a method of applying a material having liquid repellency, These can be appropriately selected depending on the material of the surface to which liquid repellency is desired.
When the surface to which liquid repellency is to be imparted is formed of an organic material, both a method of applying a liquid repellent material as a liquid repellent treatment and a method of performing a plasma treatment using a fluorine-based gas You can choose. In the plasma treatment using a fluorine-based gas, a vacuum plasma treatment using a fluorine-based gas such as CF ₄ or SF ₆ or an atmospheric pressure plasma treatment can be applied.

  On the other hand, if the surface to which liquid repellency is to be imparted is formed of an inorganic material, it is difficult to impart good liquid repellency even if plasma treatment using a fluorine-based gas is performed. Therefore, it is preferable to perform the liquid repellent treatment by a method of applying a liquid repellent material. As the liquid repellent material, a fluorine-based resin having a fluorine in the molecule, a surfactant, a silane coupling material, or the like can be used.

As shown in FIG. 1C, in this embodiment, the surface of the partition wall 15 is subjected to a liquid repellent treatment, and the liquid repellent layer 18 is formed on the surface of the partition wall 15. Thereby, high liquid repellency can be imparted to the surface of the partition wall 15.
1-3 to 1-8, the liquid repellent layer 18 represents the state of the surface of the partition wall 15 that has been subjected to the liquid repellent treatment. In the case of using the plasma treatment, in practice, until the layer is formed. However, for the sake of convenience of illustration, it is represented as a layer. In addition, when using a method of applying a material having liquid repellency without using plasma treatment, a layer is formed.

As a method of forming a liquid repellent film on the surface of the partition wall 15 after the partition wall 15 is formed, a method of modifying the surface by replacing the functional group of the organic material on the surface of the partition wall 15 with fluorine, The method of vaporizing and depositing on the partition 15 surface can be mentioned. Specifically, plasma treatment using CF ₄ gas as an introduction gas can be given. Compared to the electrode such as the anode 12 and the insulating layer 13, the organic partition 15 is easily fluorinated by CF ₄ gas, and the surface of the partition 15 can be selectively made liquid-repellent by performing plasma treatment.

In the present embodiment, the partition wall 15 is formed of an organic material, the anode 12, and the insulating layer 13 are formed of an inorganic material. Since the partition 15 which is a surface to which liquid repellency is desired is formed of an organic material, the surface of the substrate 11 is subjected to plasma treatment using a fluorine-based gas. Thereby, the lyophilic surface of the partition wall 15 is lyophobic, the liquid repellent layer 18 is formed, and high liquid repellency can be imparted only to the surface of the partition wall 15.
Note that since the anode 12 and the insulating layer 13 are formed of an inorganic material, the anode 12 and the insulating layer 13 remain in a lyophilic surface even when the plasma treatment is performed.

  When the anode 12, the insulating layer 13, and the partition wall 15 are all formed of an inorganic material, the partition wall 15 that is a surface to which liquid repellency is desired is formed of an inorganic material. The process which apply | coats the material which has property is performed. As a result, the surfaces of the anode 12, the insulating layer 13, and the partition wall 15 are made liquid repellent.

  In addition, in order to impart liquid repellency to the surface of the partition wall 15, the partition wall 15 is formed and then coated with a liquid repellent material to impart liquid repellency to the surface of the partition wall 15. A liquid repellent material may be added to the photosensitive material for formation. The liquid repellency is preferably liquid repellant even for an ink for a hole injection layer described later and an organic light emitting ink containing an organic light emitting material for forming an organic light emitting layer.

  As the liquid repellent compound used when a liquid repellent substance is added to the photosensitive material, a silicone compound or a fluorine-containing compound is used. Since these liquid repellent compounds exhibit liquid repellency in both the organic light emitting ink (coating liquid) used for forming the organic light emitting layer described later and the organic material ink (coating liquid) such as a hole injection layer, the liquid repellent compound is suitably used. Can be used.

<D> Lipophilic underlayer forming step The lyophilic underlayer forming step is performed on an ink (organic light emitting ink) containing an organic light emitting material for forming an organic light emitting layer rather than a liquid-repellent-treated partition wall. This is a step of forming a lyophilic underlayer having high lyophilicity on the first electrode.

As shown in FIG. 1-4, a lyophilic ground layer 19 is formed on the anode 12 and the insulating layer 13 in the light emitting layer forming region 17. The region where the lyophilic underlayer 19 is formed is in the light emitting layer forming region 17.
In this step, the mask 20 having the opening 20a is disposed on the substrate 11, and the lyophilic underlayer 19 is formed in the light emitting layer forming region 17 by vacuum vapor deposition. The lyophilic underlayer 19 is for making the organic luminescent ink uniformly wet and spread on it in a later step, and provides a lyophilic surface.

  Further, as a method of forming the lyophilic underlayer 19 having a predetermined pattern, a lyophilic underlayer is formed on the entire surface of the anode 12 and the insulating layer 13 in the light emitting layer forming region 17 of the substrate 11 in addition to the above-described vacuum deposition method. A method of patterning the lyophilic underlayer 19 by a photolithography process after forming 19 may be employed.

  In the present embodiment, the lyophilic underlayer 19 provided between the anode and the organic light emitting layer functions as at least one of layers such as a hole injection layer, a hole transport layer, and an electron blocking layer as described later. .

<E> Surface treatment process A surface treatment process is a process of surface-treating a lyophilic foundation layer with an organic solvent from the side in which the partition was installed with respect to the board | substrate in which the lyophilic foundation layer was formed.
In the conventional method of manufacturing an organic EL device, as described later, an organic light emitting layer is formed after forming a hole injection layer or the like as necessary in each pixel. The surface of the substrate 11 is treated with an organic solvent from the side where the partition wall 15 is installed (hereinafter may be referred to as the substrate surface on the side where the partition wall is formed).
As shown in FIGS. 1-5, the surface treatment layer 21 is formed by surface-treating the surface of the lyophilic underlayer 19 with an organic solvent. In FIGS. 1-5 to 1-8, Actually, the layers are not formed yet and are surface-treated, but are shown as layers for convenience of illustration.

  This surface treatment step is realized by bringing an organic solvent into contact with the surface of the lyophilic underlayer 19 from the side where the partition wall 15 is installed with respect to the substrate 11. The contact of the organic solvent needs to be performed at least on the surface of the lyophilic underlayer 19 and may not be the entire surface of the substrate 11, but the lyophilic solution of the substrate 11 on the side where the partition wall 15 is formed. It is preferable to carry out over the entire surface of the conductive underlayer 19.

  As a method for bringing the organic solvent into contact with the surface of the lyophilic underlayer 19 on the substrate 11, a spin coating method in which the organic solvent is dropped onto the rotating substrate and the whole surface of the substrate is brought into contact with the organic solvent is applied. A method of applying or spraying a solvent, a method of pulling up the substrate after immersing the substrate in an organic solvent, and the like are used. After bringing the organic solvent into contact with the entire surface of the substrate or the partition walls and the surface of the pixel region by any method, it is preferable to dry the organic solvent in contact with the surface so that no droplets of the organic solvent remain. Drying methods include heat drying, natural drying, and air blowing.

  As an organic solvent to be used, it is preferable that it is 1 type, or 2 or more types of the solvent for inks, and it is further more preferable that it is 1 type or 2 or more types of the solvent for organic luminescent materials mentioned later among the solvents for inks. Examples of the solvent for the organic light emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and a mixed solvent thereof. Aromatic organic solvents such as toluene, xylene, and anisole are preferable, Anisole is more preferred.

  Although the liquid repellency of the surface of the partition wall 15 may be somewhat relaxed by the surface treatment with the organic solvent, the liquid repellency is not impaired. That is, even when the organic light-emitting ink is applied onto the partition wall 15 after the partition wall 15 is surface-treated with an organic solvent, the surface of the partition wall 15 is not deteriorated in performance of repelling the organic light-emitting ink, and is required. Maintains liquid repellency.

<F> Organic Light-Emitting Layer Formation Step The organic light-emitting layer formation step is a step of forming the organic light-emitting layer by supplying organic light-emitting ink into the region partitioned by the partition after the surface treatment step.
As shown in FIG. 1-6, after the surface treatment layer 21 is formed on the lyophilic underlayer 19 which is a lyophilic region by the above-described surface treatment process, the region partitioned by the partition 15 (light emitting layer formation) The organic light-emitting ink 22 is applied in the region) by a coating method.
The surface of the lyophilic base layer 19 (surface treatment layer 21) is lyophilic, and the surface of the surrounding partition wall 15 (liquid repellent layer 18) is lyophobic. The organic light-emitting ink 22 applied to the surface treatment layer 21 is repelled by the liquid repellent layer 18, so that it does not flow into the adjacent light-emitting layer forming region 17 across the partition 15 and is partitioned by the partition 15. It fits in the light emitting layer forming region 17. Accordingly, the organic light emitting ink 22 is disposed on the surface treatment layer 21 in the light emitting layer forming region 17.

  In addition, when the organic light emitting ink 22 that is a coating liquid is applied to the entire surface of the substrate 11 by a coating method, the organic light emitting ink 22 may be applied onto the partition wall 15. By being repelled by the surface of the liquid repellent layer 18 exhibiting liquid repellency, it flows into the optical layer forming region 17 separated by the partition wall 15 and is disposed on the surface treatment layer 21 in each light emitting layer forming region 17.

  In addition, after the partition wall 15 is formed as described above, the partition surface 15 is subjected to a liquid repellent treatment so that the opposing surface 15a where the partition walls 15 face each other is also subjected to the liquid repellent treatment, thereby forming the liquid repellent layer 18. Therefore, the organic light emitting ink 22 disposed on the exposed surface 13a of the insulating layer 13 in the light emitting layer forming region 17 after the partition wall 15 is formed is applied to the liquid repellent layer 18 on the surface of the facing surface 15a where the partition walls 15 face each other. In the vicinity where the exposed surface 13a and the opposing surface 15a come into contact with each other, the organic light emitting ink 22 is not disposed and coating unevenness may occur in a part of the light emitting layer forming region 17. However, since there is a gap between the facing surface 15a of the partition wall 15 and the pixel region 14 by the exposed surface 13a of the insulating layer 13, the pixel region 14 is not affected by the liquid repellent layer 18 on the facing surface 15a. The organic light emitting ink 22 can be disposed on the entire surface of the lyophilic underlayer 19 and the surface treatment layer 21 in the pixel region 14.

As the organic light emitting material used for the organic light emitting layer, a polymer organic light emitting material and / or a low molecular organic light emitting material is used as described later.
In the case of using a polymer organic light emitting material, an ink (organic light emitting ink) containing an organic light emitting material for forming an organic light emitting layer is prepared by dissolving or stably dispersing the polymer material in a solvent. Examples of the solvent for dissolving or dispersing the organic light-emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, or a mixed solvent thereof. Among these, aromatic organic solvents such as toluene, xylene, and anisole are preferable because they have good solubility of the organic light emitting material. Moreover, you may add surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. to organic luminescent ink as needed.

  As a method of supplying the organic light emitting ink into the partition, when the organic EL element is monochromatic light used in, for example, a lighting device, selective coating does not have to be taken into consideration, so a spin coating method, a micro gravure coating method, A coating method such as a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a slit coating method, a capillary coating method, a spray coating method, or a nozzle coating method may be used. Further, a casting method, a blade coating method, a dispenser method, or the like may be used. When the organic EL element emits multicolor light for use in a color display device, it is necessary to selectively apply a predetermined organic light emitting ink to each pixel region to avoid color mixing. For such selective coating, printing methods such as gravure printing, screen printing, flexographic printing, offset printing, reverse printing, and inkjet printing can be used. Among these, the inkjet printing method and the flexographic printing method are preferable, and the flexographic printing method is particularly preferable in order to apply the organic light-emitting ink in the partition more accurately.

Next, as shown in FIGS. 1-7, the organic light emitting ink 22 is dried to form the organic light emitting layer 23 on the surface treatment layer 21.
By drying the organic light emitting ink 22, an organic light emitting layer 23 made of an organic light emitting material is formed on the surface treatment layer 21.
The organic light-emitting ink 22 can be dried by a drying mechanism such as a hot plate, an oven, or a dryer while the temperature is adjusted by a temperature adjusting mechanism attached to a stage (not shown) that holds the substrate 11.

In addition, you may repeat the application | coating process and drying process of the organic luminescent ink 22 in multiple times. By repeating a plurality of times as described above, the organic light emitting layer 23 having a desired thickness can be obtained, and the organic light emitting layer 23 having a more uniform thickness can be formed by dispersing coating unevenness.
Moreover, you may repeat an application | coating process and a drying process in multiple times using different organic luminescent ink 22. FIG. Thus, the organic light emitting layer 23 having a more complicated layer structure can be formed by using a plurality of types of organic light emitting inks 22.

  When applying the organic light emitting ink 22 in the partition wall 15, in the conventional method, the organic light emitting ink 22 is repelled on the surface of the layer on which the organic light emitting layer 23 is provided, and the coating film has defects (uneven coating). Sometimes. On the other hand, in this embodiment, before forming the organic light emitting layer 23, the organic light emitting ink 22 is formed by previously forming the lyophilic underlayer 19 on the anode 12 and the insulating layer 13 in the light emitting layer forming region 17. On the other hand, the wettability of the lyophilic underlayer 19 can be improved by forming the surface treatment layer 21 using an organic solvent. . Therefore, the organic light emitting ink 22 supplied into the light emitting layer forming region 17 partitioned by the partition wall 15 is applied so as to spread over the entire surface of the pixel region 14 defined by the insulating layer 13 without causing uneven coating. An organic light emitting coating film can be formed on the entire surface of each pixel region 14, and the organic light emitting layer 23 can be formed on the entire surface of the pixel region 14.

  In addition, the surface after the surface treatment layer 21 is formed has a liquid-repellent portion of the facing surface 15a of the partition wall 15 while improving the wettability by making the light emitting layer forming region 17 lyophilic. Even when the organic light emitting ink 22 is supplied so as to protrude from the light emitting layer forming region 17 partitioned by the partition wall 15, the organic light emitting ink 22 is repelled in areas other than the light emitting layer forming region 17, and only the light emitting layer forming region 17 has the organic light emitting ink. 22 is supplied. Therefore, the organic light emitting layer 23 can be formed in the light emitting layer forming region 17 with almost no defects.

  Further, the organic light emitting ink 22 is repelled by the liquid repellent layer 18 on the facing surface 15 a of the partition wall 15, and the organic light emitting ink 22 is not disposed on a part of the exposed surface 13 a, and coating unevenness is partially applied in the light emitting layer forming region 17. May occur. However, since there is a gap between the opposing surface 15a of the partition wall 15 and the pixel region 14 by the exposed surface 13a of the insulating layer 13, the pixel region 14 is affected by the liquid repellent layer 18 on the opposing surface 15a. The organic light emitting ink 22 can be disposed on the entire surface of the pixel region 14 without any problem. Therefore, the organic light emitting layer 23 can be formed in the pixel region 14 without causing defects.

  According to the present embodiment, the coating property when the organic light emitting ink 22 is applied to the pixel region 14 is improved, and the application failure of the organic light emitting ink 22 can be greatly improved. Therefore, film defects in a predetermined region on the substrate 11 can be suppressed, and the uniform organic light emitting layer 23 can be formed by a simple method with low cost, and the light emission unevenness on the light emitting surface is reduced and the light emission characteristics are excellent. An organic EL device can be realized.

<G> Cathode Formation Step As shown in FIG. 1-8, the cathode 24 is formed on the surface of the organic light emitting layer 23. The cathode 24 is formed using any of the materials described later by a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a laser ablation method, a laminating method for press-bonding a metal thin film, or the like.

  After the cathode 24 is formed, an upper sealing film (not shown) is formed in order to protect the light emitting function part 25 having the anode 12 -the organic light emitting layer 23 -the cathode 24 as a basic structure. The upper sealing film is composed of at least one inorganic layer and at least one organic layer as necessary. The number of these layers is determined as necessary. Basically, the inorganic layers and the organic layers are alternately stacked.

  As described above, the feature of the method for manufacturing the organic EL device according to the present embodiment is that the partition wall forming step of forming a partition wall for partitioning a plurality of organic electroluminescence elements, and the thickness direction of the substrate, A liquid repellent treatment step for performing a liquid repellent treatment on the surface of the substrate on which the partition is formed from the side on which the organic electroluminescence element is mounted, and an organic layer for forming an organic light emitting layer rather than the partition subjected to the liquid repellent treatment A lyophilic underlayer forming step for forming a lyophilic underlayer having high lyophilicity with respect to the ink containing the light emitting material on the first electrode, and surface treatment of the lyophilic underlayer with an organic solvent. A surface treatment step. The details of each of these steps are as described above.

Therefore, according to the manufacturing method of the organic EL device according to the present embodiment described above, the coating property when the organic light emitting ink is applied to the pixel region is improved, and the application failure of the organic light emitting ink is greatly improved. Can do. Therefore, an organic light emitting layer having a uniform film thickness can be formed in a predetermined pixel region by a simple method, and an organic EL device with excellent light emission characteristics can be realized with reduced light emission unevenness.
Therefore, the organic EL device of the present invention can be suitably used as a planar light source, a lighting device, a display device, or the like as a light source such as a backlight and a scanner.

  Next, each configuration of the organic EL device manufactured by the above-described method for manufacturing an organic EL device will be described.

<a> Substrate Any substrate may be used as long as it does not change in the process of forming the organic EL device, and may be a rigid substrate or a flexible substrate. For example, a glass plate, a plastic plate, a polymer film, a silicon plate, and these For example, a laminated board in which is laminated is preferably used. Further, a plastic, a polymer film or the like that has been subjected to a low water permeability treatment can also be used. A commercially available substrate can be used as the substrate. Moreover, the said board | substrate can also be manufactured by a well-known method.

In the bottom emission type organic EL device that extracts light from the organic light emitting layer from the substrate side, a substrate having a high light transmittance in the visible light region is preferably used.
In the top emission type organic EL device that takes out light from the organic light emitting layer from the cathode side, the substrate may be transparent or opaque.

<B> First electrode The first electrode is one of an anode and a cathode, and is provided closer to the substrate than the second electrode which is the other electrode. The first electrode in the present embodiment is an anode, and the anode is a transparent electrode that transmits light from the organic light emitting layer. However, as another form, an organic EL device in which the cathode is formed of a transparent electrode is also possible. is there. As the anode, a metal oxide, metal sulfide or metal thin film having high electrical conductivity can be used, and a material having a high transmittance can be suitably used. The anode is appropriately selected according to the constituent material of the light emitting layer. be able to. Examples of transparent anode materials include indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide (IZO), gold, platinum, silver, and copper. A thin film such as is used. Among these, ITO, IZO, and tin oxide are preferable.

  Further, as the constituent material of the anode, a transparent organic conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used.

  In addition, from the viewpoint of facilitating charge injection into the organic light emitting layer, a conductive polymer such as a phthalocyanine derivative and a polythiophene derivative, Mo oxide, amorphous carbon, fluoride is formed on the surface of the anode on the organic light emitting layer side. A layer of 1 nm or more and 200 nm or less, such as carbon or a polyamine compound, or a layer having an average film thickness of 10 nm or less made of a metal oxide, a metal fluoride, an organic insulating material, or the like may be provided.

  The film thickness of the anode can be appropriately selected in consideration of light transmittance and electrical conductivity, and is, for example, 5 nm or more and 10 μm or less, preferably 10 nm or more and 1 μm or less, more preferably 20 nm or more. , 500 nm or less.

<C> Insulating layer The insulating layer ensures electrical insulation between the organic EL elements and defines a pixel region in which the organic light emitting layer is formed. After forming the anode, usually, an insulating layer is formed on the anode and further patterned, so that the pixel region where the organic light emitting layer is formed is divided as viewed from one side in the thickness direction of the substrate. The pixel area corresponds to a light emitting area.

The insulating layer 13 is formed using an inorganic insulating material such as SiO ₂ or SiN. Further, the insulating layer 13 may be formed using the same material as the partition wall 15 described later.

  When a plurality of organic EL elements are formed on a substrate, the insulating layer is patterned to ensure electrical insulation between the organic EL elements and to define a light emitting region. The thickness of the insulating layer is usually set to 0.1 μm or more and 0.2 μm or less.

<D> Partition The partition defines an application region of a constituent material such as an organic light emitting layer. After the insulating layer 13 is formed and the pixel region 14 is formed, a photosensitive material is applied to the substrate on which the anode is formed, and a photoresist film is laminated. Next, this photoresist film is patterned into a lattice shape by photolithography to form an insulating partition.

  As described above, the insulating photosensitive material (photoresist composition) for forming the partition wall 15 may be either a positive resist or a negative resist. As for the photosensitive material (photoresist composition) constituting the partition wall 15, as described above, polyimide, acrylic resin, and novolak resin photosensitive compounds are used. This photosensitive material may contain a light-shielding material for the purpose of improving the display quality of the organic EL element.

  As described above, the photosensitive material (photoresist composition) for forming the partition walls 15 can be applied by a coating method using a spin coater, bar coater, roll coater, die coater, gravure coater, slit coater, or the like. it can. After curing, the coating film is patterned into a lattice shape having a desired dimension using conventional photolithography.

<E> Liquid-repellent layer The liquid-repellent layer is a layer formed on the surface of the partition wall by subjecting the substrate on which the light emitting layer forming region is divided by forming the partition wall to liquid-repellent treatment. The liquid repellent layer is formed by a plasma process using a fluorine-based gas or a process of applying a liquid repellent material on the substrate. According to such a configuration, when the surface subjected to the liquid repellent treatment is made of an organic material, it is possible to select from both the plasma treatment using the fluorine-based gas and the treatment for applying the liquid repellent material. In addition, when the surface to be subjected to the liquid repellent treatment is made of an inorganic material such as metal or metal oxide, the surface is hardly fluorinated by the plasma treatment using a fluorine-based gas, so that the liquid repellent property is difficult to impart. The liquid repellent treatment can be carried out by applying the material.

  In this embodiment, the partition wall 15 to be subjected to the liquid repellent treatment is made of an organic material, and the anode 12 and the insulating layer 13 are made of an inorganic material such as a metal or a metal oxide. In order to form the liquid repellent layer 18 and prevent the liquid repellent layer 18 from being formed on the anode 12 and the insulating layer 13, the liquid repellent layer 18 is formed using plasma treatment using a fluorine-based gas as the liquid repellent treatment. In FIGS. 1-3 to 1-8, the liquid repellent layer 18 represents the state of the surface of the partition wall 15 that has been subjected to the liquid repellent treatment as described above. However, for convenience of illustration, it is shown as a layer. In addition, when using a method of applying a material having liquid repellency without using plasma treatment, a layer is formed.

<F> Lipophilic underlayer The lyophilic underlayer is a layer that is provided in contact with the surface of the organic light emitting layer on the anode side, and serves to form the organic light emitting layer uniformly by a coating method. Has lyophilicity to ink.

  In the light emitting layer forming region 17, layers such as a hole injection layer, a hole transport layer, and an electron blocking layer are provided between the anode 12 and the organic light emitting layer 23 as necessary. In this embodiment, the lyophilic underlayer 19 provided between the anode 12 and the organic light emitting layer 23 functions as at least one of the above-described layers such as the hole injection layer, the hole transport layer, and the electron blocking layer.

<F-1> Material of the lyophilic underlayer Further, in the present embodiment, the lyophilic underlayer can use an inorganic material or an organic material, and is not particularly limited.
As the inorganic material, a metal oxide or a metal composite is preferable. Specific examples include tungsten oxide, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, nickel oxide, barium titanate, and strontium titanate. be able to.
Examples of the organic material include organic materials that are insoluble in organic light-emitting inks, such as organic materials used for a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer.

<F-2> Method for Forming Lipophilic Underlayer In the present embodiment, the lyophilic underlayer is formed directly on the surface of the anode 12 and the insulating layer 13 on the light emitting layer forming region 17.

  In the step of forming the lyophilic foundation layer 19, the lyophilic foundation layer 19 is formed by a dry method. By forming the lyophilic underlayer 19 by a dry method rather than a coating method, the lyophilic underlayer 19 can be formed without being affected by the wettability of the surface on which the lyophilic underlayer 19 is formed. it can. As the dry method, general methods such as vapor deposition, sputtering, and CVD can be used. In addition, as a method for patterning the lyophilic underlayer by a dry method, for example, a method using a mask having a film formation region as an opening can be employed.

<G> Surface treatment layer The surface treatment layer is provided between the lyophilic underlayer and the organic light emitting layer, and is formed by bringing an organic solvent into contact with the surface of the lyophilic underlayer on the substrate and drying it. Layer. As shown in FIG. 1-5, the surface treatment layer 21 is formed by surface-treating the surface of the lyophilic underlayer 19 with an organic solvent, and as described above, as shown in FIGS. In FIG. 8, the surface treatment is actually performed until the layer is not formed, but is represented as a layer for convenience of illustration.
The surface treatment layer also functions as at least one of a layer such as a hole injection layer, a hole transport layer, and an electron block layer, like the lyophilic underlayer.

  As described above, the organic solvent to be used is preferably one or two or more types of ink solvents, and among the ink solvents, it may be one or more types of solvents for organic light-emitting materials described below. Further preferred. Specific examples of the solvent for the organic light emitting material include toluene, xylene, acetone, anisole, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and a mixed solvent thereof, and anisole is preferable.

<H> Organic Light Emitting Layer The light emitting layer is a layer containing a light emitting material, and the organic light emitting layer is a layer containing an organic compound as the light emitting material. Usually, the organic light emitting layer contains an organic substance (low molecular compound and / or high molecular compound) that mainly emits fluorescence and / or phosphorescence. Among the materials forming the light emitting layer, low molecular compounds (sometimes referred to as light emitting low molecular organic compounds) and high molecular compounds (light emitting high molecular organic compounds) used as organic compounds that emit fluorescence and / or phosphorescence. May be used as the light-emitting material. In the present specification, the polymer is a compound having a polystyrene-equivalent number average molecular weight of 10 ³ or more. In the present invention, there is no particular reason for defining the upper limit, but the number average molecular weight in terms of polystyrene is usually 10 ⁸ or less. The organic light emitting layer may further contain a dopant material. Examples of the material for forming the organic light emitting layer that can be used in the present invention include the following dye-based materials, metal complex-based materials, polymer-based materials, and dopant materials. Although only one organic light emitting layer is included between the anode and the cathode, a plurality of organic light emitting layers may be provided.

<H-1> Dye-type material Examples of the dye-type material include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, and distyrylarylene. Derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

<H-2> Metal Complex Materials As metal complex materials, for example, metal complexes having light emission from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyls A zinc complex, a benzothiazole zinc complex, an azomethylzinc complex, a porphyrin zinc complex, a europium complex, etc. can be mentioned. Further, as another example of the metal complex material, the center metal has Al, Zn, Be, Ir or the like, or the rare earth metal such as Tb, Eu, Dy or the like, and the ligand is oxadiazole, thiadiazole, phenylpyridine. , Phenylbenzimidazole, metal complexes having a quinoline structure, and the like.

<H-3> Polymeric material Examples of the polymeric material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, quinacridone derivatives, and coumarins. Derivatives, thiophene ring compounds, those obtained by polymerizing the above dye bodies and metal complex light emitting materials, and the like.
Among the above light-emitting materials, examples of materials that emit blue light include distyrylarylene derivatives, oxadiazole derivatives, and polymers thereof, polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives. it can. Of these, polymer materials such as polyvinyl carbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives are preferred.
Examples of materials that emit green light include quinacridone derivatives, coumarin derivatives, and polymers thereof, polyparaphenylene vinylene derivatives, polyfluorene derivatives, and the like. Of these, polymer materials such as polyparaphenylene vinylene derivatives and polyfluorene derivatives are preferred.
Examples of materials that emit red light 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.

<H-4> Dopant material A dopant may be added to the light emitting layer for the purpose of improving the light emission efficiency or 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. In addition, the thickness of such a light emitting layer is usually about 2 nm or more and 2000 nm or less.

<H-5> Method for Forming Organic Light-Emitting Layer As a method for forming an organic light-emitting layer, as described above, a method of applying a solution containing a light-emitting material on an underlayer on which the organic light-emitting layer is laminated is used. it can. The solvent used for film formation from a solution is not particularly limited as long as it can dissolve the light-emitting material mainly constituting the light-emitting layer. For example, water, chlorine-based solvents such as chloroform, methylene chloride, and dichloroethane, and ethers such as tetrahydrofuran. And solvent solvents, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate.

Further, a layer other than the organic light emitting layer may be provided between the anode and the cathode as necessary. Examples of the layer provided on the anode side with respect to the organic light emitting layer include a hole injection layer, a hole transport layer, and an electron block layer.
Examples of the layer provided on the cathode side with respect to the organic light emitting layer include an electron injection layer, an electron transport layer, and a hole blocking layer.
These hole injection layer, hole transport layer, electron block layer, electron injection layer, electron transport layer, and hole block layer will be described later.

<I> Second electrode The second electrode is the other of the anode and the cathode. The second electrode in the present embodiment is the cathode 24, and the cathode material is preferably a material having a small work function and easy electron injection into the organic light emitting layer. The cathode material is preferably a material having high electrical conductivity and high visible light reflectance. Specific examples of such cathode materials include metals, metal oxides, alloys, graphite or graphite intercalation compounds, and inorganic semiconductors such as zinc oxide (ZnO).

  As the metal, an alkali metal, an alkaline earth metal, a transition metal, a group 13 metal of the periodic table, or the like can be used. Specific examples of these metals include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, and aluminum. , Scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like.

  Examples of the alloy include an alloy containing at least one of the above metals. Specifically, a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, Examples thereof include a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy.

  The cathode is an electrode having optical transparency as required, for example, when light is taken out from the cathode side. Examples of such light-transmitting cathode materials include conductive metal oxides such as indium oxide, zinc oxide, tin oxide, ITO and IZO, and conductive organic materials such as polyaniline or derivatives thereof, polythiophene or derivatives thereof. be able to.

  Note that the cathode may have a laminated structure of two or more layers. Moreover, an electron injection layer may be used as a cathode.

  The thickness of the cathode can be appropriately selected in consideration of electric conductivity and durability, but is, for example, 10 nm or more and 10 μm or less, preferably 20 nm or more and 1 μm or less, more preferably 50 nm or more, 500 nm or less.

  Examples of the method for forming the cathode include a vacuum deposition method, a sputtering method, and a laminating method in which a metal thin film is thermocompression bonded as described above. Note that the cathode may have a laminated structure of two or more layers.

<J> Protective Film After the cathode 24 is formed as described above, the basic structure includes (anode)-(layer between the anode and the organic light emitting layer)-(organic light emitting layer)-(cathode). In order to protect the light emitting function part 25, a protective film (upper sealing film) for sealing the light emitting function part 25 is formed. This protective film usually has 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.

  Note that a plastic substrate is higher in gas and liquid permeability than a glass substrate, and a light emitting substance such as an organic light emitting layer is easily oxidized and deteriorated by contact with water. When used, even if the light emitting function part is encapsulated by the substrate and the protective film, it is easy to change over time. Therefore, a lower sealing film having a high barrier property against gas and liquid is laminated on the plastic substrate, and then this The light emitting function part is laminated on the lower sealing film. This lower sealing film is usually formed with the same configuration and the same material as the protective film (upper sealing film).

<K> Layer provided between anode and organic light emitting layer In this embodiment, a hole injection layer, a hole transport layer, an electron blocking layer, etc. are provided between the anode and the organic light emitting layer as necessary. Provided.

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

<K-1> Hole Injection Layer The hole injection layer can be provided between the anode and the hole transport layer or between the anode and the organic light emitting layer as described above. As a material constituting the hole injection layer, a material having an ionization potential between one surface of the hole injection layer and two layers provided adjacent to the other surface is preferable. Specifically, the material has an ionization potential that is between the ionization potential of the anode 12 and the ionization potential of the surface portion of the organic light emitting layer 23 on the anode 12 side. For example, phenylamine, starburst amine, phthalocyanine, hydrazone derivative, carbazole derivative, triazole derivative, imidazole derivative, oxadiazole derivative having amino group, vanadium oxide, tantalum oxide, tungsten oxide, molybdenum oxide, ruthenium oxide And oxides such as aluminum oxide, amorphous carbon, polyaniline, polythiophene derivatives, and the like.

  As a method for forming the hole injection layer, it can be formed by a method similar to the method for forming the organic light emitting layer described above. Specifically, a coating solution in which a material to be a hole injection layer (a hole injection material) is dissolved in a solvent similar to a solvent for dissolving a light emitting material mainly constituting the organic light emitting layer is used. It can form into a film by apply | coating with the application | coating method used when forming.

  The thickness of the hole injection layer is preferably about 5 nm to 300 nm. If the thickness is less than 5 nm, the production tends to be difficult. On the other hand, if the thickness exceeds 300 nm, the driving voltage and the voltage applied to the hole injection layer tend to increase.

<K-2> Hole transport layer The material constituting the hole transport layer is not particularly limited. For example, N, N'-diphenyl-N, N'-di (3-methylphenyl) 4,4 Aromatic amine derivatives such as' -diaminobiphenyl (TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB), polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, Polysiloxane derivative having aromatic amine compound group in side chain or main chain, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole Or its derivatives, poly (p-phenylene vinylene) Properly derivative thereof or a poly (2,5-thienylene vinylene) or derivatives thereof is illustrated.

  Among these, as the 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 the side chain or main chain. In the case of a low-molecular hole transport material, it is preferably used by being dispersed in a polymer binder.

  The method for forming the hole transport layer is not particularly limited, but in the case of a low molecular hole transport material, film formation from a mixed solution containing a polymer binder and a hole transport material can be exemplified. Examples of molecular hole transport materials include film formation from a solution containing a hole transport material.

The solvent used for film formation from a solution is not particularly limited as long as it can dissolve a hole transport material. Chlorine solvents such as chloroform, methylene chloride, dichloroethane, ether solvents such as tetrahydrofuran, toluene, xylene And aromatic hydrocarbon solvents such as acetone, ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate.
Examples of the film forming method from a solution include the same coating method as the above-described film forming method of the hole injection layer.

  As the polymer binder to be mixed, those that do not extremely inhibit charge transport are preferable, and those that weakly absorb visible light are preferably used. For example, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, poly Examples thereof include vinyl chloride and polysiloxane.

  The thickness of the hole transport layer is not particularly limited, but can be appropriately changed according to the intended design, and is preferably about 1 nm or more and 1000 nm or less. When this thickness is less than the lower limit, production becomes difficult. Or, there is a tendency that the effect of hole transport is not sufficiently obtained. On the other hand, when the upper limit is exceeded, the driving voltage and the voltage applied to the hole transport layer tend to increase. Therefore, as described above, the thickness of the hole transport layer is preferably 1 nm or more and 1000 nm or less, more preferably 2 nm or more and 500 nm or less, and further preferably 5 nm or more and 200 nm or less. .

<K-3> Electron block layer The electron block layer is a layer having a function of blocking electron transport. When the hole injection layer and / or the hole transport layer has a function of blocking electron transport, these layers may also serve as an electron blocking layer.
The fact that the electron blocking layer has a function of blocking electron transport makes it possible, for example, to produce an element that allows only electron current to flow and confirm the blocking effect by reducing the current value.
As an electron block layer, the various materials illustrated as a material of the said positive hole injection layer or a positive hole transport layer, for example can be used.

  The organic EL device according to this embodiment is a bottom emission type element that transmits light from the organic light emitting layer through the transparent anode and emits the light from the transparent substrate to the outside. However, the light from the organic light emitting layer is transparent. The present invention can be similarly applied to other forms of the top emission type in which the cathode is transmitted and emitted from the transparent protective layer to the outside.

  In said other embodiment, the metal thin film illustrated as an anode can be used as a transparent cathode for the transparent cathode which permeate | transmits the light from an organic light emitting layer, for example. In addition, since the metal thin film used for the transparent cathode is formed into a thin film to such an extent that light can be transmitted, the sheet resistance is increased. Therefore, the transparent cathode is preferably composed of a laminate in which transparent electrodes such as ITO thin films are laminated in a metal thin film shape. Moreover, it is preferable to provide a reflective film having a high reflectance such as silver between the anode and the substrate, and by providing such a reflective film, light directed toward the substrate side can be reflected to the transparent cathode side. And the light extraction efficiency can be improved.

<Manufactured organic EL device>
The organic EL device 10A (see FIGS. 1-8) that can be manufactured by the method of manufacturing the organic EL device according to the present invention as described above has a plurality of pixels composed of organic EL elements mounted as described above. Device. Regarding the installation of electrical wiring, driving means, etc., various modes in the manufacture of a normal organic EL device can be adopted.

  Furthermore, the organic EL device that can be manufactured by the manufacturing method of the present invention can be used as a planar light source as a backlight and a light source of a scanner, a lighting device, a pixel of a display device, and a backlight. Examples of the display device include a segment display device, a dot matrix display device, and a liquid crystal display device.

[Second Embodiment]
A method for manufacturing an organic EL device according to the second embodiment of the present invention will be described.
FIG. 3 is a cross-sectional view showing a configuration of an organic EL device manufactured by the method for manufacturing an organic EL device according to the second embodiment of the present invention.
The manufacturing method of the organic EL device according to the present embodiment is substantially the same as the configuration of the organic EL device 10A manufactured by the manufacturing method of the organic EL device according to the first embodiment shown in FIGS. The same components as those of the organic EL device 10A according to the first embodiment shown in FIGS. 1-8 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 3, the organic EL device 10B manufactured by the method for manufacturing the organic EL device according to this embodiment is an organic EL device according to the first embodiment shown in FIGS. 1-1 to 1-8. The device is manufactured by reversing the order of the lyophobic treatment step and the lyophilic underlayer step of the device manufacturing method. After the lyophilic underlayer 19 is formed, the lyophobic treatment is performed to form the lyophobic layer 18. There is something to be formed. In the organic EL device 10B, as in the organic EL device 10A according to the first embodiment described above, the anode 12, the lyophilic ground layer 19, and the surface treatment are performed on the substrate 11 from the anode 12 side toward the cathode 24. The layer 21, the organic light emitting layer 23, and the cathode 24 are laminated in this order.

  Even if the order of the liquid repellent treatment step and the lyophilic underlayer forming step is reversed as in the method of manufacturing the organic EL device according to the present embodiment, it is possible to significantly improve the defective application of the organic light emitting ink. . Therefore, in the present embodiment, similarly to the first embodiment, an organic light emitting layer having a uniform film thickness can be formed in a predetermined pixel region by a simple method, light emission unevenness is reduced, and light emission characteristics are improved. An excellent organic EL device can be realized.

[Third Embodiment]
A method for manufacturing an organic EL device according to the third embodiment of the present invention will be described.
FIG. 4 is a cross-sectional view showing a configuration of an organic EL device manufactured by the method for manufacturing an organic EL device according to the third embodiment of the present invention.
The manufacturing method of the organic EL device according to the present embodiment is substantially the same as the configuration of the organic EL device 10A manufactured by the manufacturing method of the organic EL device according to the first embodiment shown in FIGS. The same components as those of the organic EL device 10A according to the first embodiment shown in FIGS. 1-8 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 4, the organic EL device 10C manufactured by the method of manufacturing the organic EL device according to this embodiment is an organic EL device according to the first embodiment shown in FIGS. A step of forming a hole transport layer is added between the lyophilic underlayer forming step and the surface treatment step of the device manufacturing method, and hole transport is performed between the lyophilic underlayer 19 and the surface treatment layer 21. It is manufactured by adding the layer 31. In the organic EL device 10 </ b> C, the anode 12, the lyophilic underlayer 19, the hole transport layer 31, the surface treatment layer 21, the organic light emitting layer 23, and the cathode 24 are formed on the substrate 11 from the anode 12 side toward the cathode 24. They are stacked in order.

  Even if a step of forming a hole transport layer is added between the lyophilic underlayer forming step and the surface treatment step, as in the method of manufacturing the organic EL device according to the present embodiment, the organic light emitting ink is poorly applied. Can be greatly improved. Therefore, in the present embodiment, similarly to the first embodiment, an organic light emitting layer having a uniform film thickness can be formed in a predetermined pixel region by a simple method, light emission unevenness is reduced, and light emission characteristics are improved. An excellent organic EL device can be realized.

[Fourth Embodiment]
A method for manufacturing an organic EL device according to the fourth embodiment of the present invention will be described.
FIG. 5 is a cross-sectional view showing a configuration of an organic EL device manufactured by the method for manufacturing an organic EL device according to the fourth embodiment of the present invention.
The manufacturing method of the organic EL device according to the present embodiment is substantially the same as the configuration of the organic EL device 10A manufactured by the manufacturing method of the organic EL device according to the first embodiment shown in FIGS. The same components as those of the organic EL device 10A according to the first embodiment shown in FIGS. 1-8 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 5, the organic EL device 10D manufactured by the method for manufacturing the organic EL device according to the present embodiment includes the organic EL device according to the first embodiment shown in FIGS. This is manufactured by adding a step of forming an electron injection layer after the organic light emitting layer forming step of the device manufacturing method, and adding an electron injection layer 32 after the organic light emitting layer 23. In the organic EL device 10D, the anode 12, the lyophilic underlayer 19, the surface treatment layer 21, the organic light emitting layer 23, the electron injection layer 32, and the cathode 24 are arranged in this order on the substrate 11 from the anode 12 side toward the cathode 24. Are stacked.

<Layer provided between cathode and organic light emitting layer>
An electron injection layer, an electron transport layer, a hole blocking layer, and the like are provided between the organic light emitting layer and the cathode as necessary.

When only one layer is provided between the organic light emitting layer and the cathode, the layer is referred to as an electron injection layer. When both the electron injection layer and the electron transport layer are provided between the organic light emitting layer and the cathode, the layer in contact with the cathode is referred to as the electron injection layer, and the layers other than the electron injection layer are referred to as the electron transport layer. .
The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode.
The electron transport layer is a layer having a function of improving electron injection from the cathode, the electron injection layer, or the electron transport layer closer to the cathode.
The hole blocking layer is a layer having a function of blocking hole transport.
In the case where the electron injection layer and / or the electron transport layer have a function of blocking hole transport, these layers may also serve as the hole blocking layer.
The fact that the hole blocking layer has a function of blocking hole transport makes it possible, for example, to produce an element that allows only a hole current to flow, and confirm the blocking effect by reducing the current value.

<1-1> Electron Injection Layer As described above, the electron injection layer is provided between the electron transport layer and the cathode, or between the organic light emitting layer and the cathode. The material of the electron injection layer is preferably a material having an electron affinity that is between the electron affinity of one surface of the electron injection layer and two layers provided adjacent to the other surface. Specifically, it is a material having an electron affinity that is between the electron affinity of the cathode 24 and the electron affinity of the surface portion of the organic light emitting layer 23 on the cathode 24 side. As the electron injection layer, depending on the type of the organic light emitting layer, for example, an alkali metal, an alkaline earth metal, an alloy containing one or more of the above metals, an oxide, halide and carbonate of the metal, or the above Examples include a mixture of substances.

  Examples of alkali metals or oxides, halides and carbonates thereof include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, potassium fluoride, rubidium oxide. , Rubidium fluoride, cesium oxide, cesium fluoride, lithium carbonate and the like.

  Examples of the alkaline earth metals or oxides, halides and carbonates thereof include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, barium fluoride, and oxide. Examples include strontium, strontium fluoride, and magnesium carbonate.

  Furthermore, a metal, a metal oxide, an organometallic compound doped with a metal salt, an organometallic complex compound, or a mixture thereof can also be used as a material for the electron injection layer.

This electron injection layer may have a stacked structure in which two or more layers are stacked. Specifically, Li / Ca etc. are mentioned. This electron injection layer is formed by vapor deposition, sputtering, printing, or the like.
The thickness of the electron injection layer is preferably about 1 nm or more and 1 μm or less.

<1-2> Electron Transport Layer As materials for forming the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinones or derivatives thereof, naphthoquinones or derivatives thereof, anthraquinones or Derivatives thereof, tetracyanoanthraquinodimethane 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, poly Examples include fluorene or a derivative thereof.

  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.

Although there is no restriction | limiting in particular as the film-forming method of an electron carrying layer, In the low molecular electron transport material, the vacuum evaporation method from powder or the method by the film-forming from a solution or a molten state is illustrated. Examples of the polymer electron transport material include a method of film formation from a solution or a molten state.
Further, when forming a film from a solution or a molten state, a polymer binder may be used in combination.
Examples of the method for forming the electron transport layer from the solution include the same film formation method as the method for forming the hole injection layer from the above-described solution.

  The film thickness of the electron transport layer varies depending on the material used, and is selected so that the driving voltage and the light emission efficiency are appropriate values. At least a thickness that does not cause pinholes is required. Too much is not preferable because the driving voltage of the element increases. Therefore, the thickness of the electron transport layer is, for example, 1 nm or more and 1 μm or less, preferably 2 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

<L-3> Hole blocking layer The hole blocking layer is a layer having a function of blocking hole transport. In the case where the electron injection layer and / or the electron transport layer have a function of blocking hole transport, these layers may also serve as the hole blocking layer.
The fact that the hole blocking layer has a function of blocking hole transport makes it possible, for example, to produce an element that allows only a hole current to flow, and confirm the blocking effect by reducing the current value.

<M> Combination of Layer Configurations of Light-Emitting Functional Units Containing Anode, Cathode, and Organic Light-Emitting Layer In the organic EL device of the present invention, examples of combinations of layer configurations from the anode 12 to the cathode 24 are shown below.
a) Anode / hole injection layer / organic light emitting layer / cathode b) Anode / hole injection layer / organic light emitting layer / electron injection layer / cathode c) Anode / hole injection layer / hole transport layer / organic light emitting layer / Cathode d) anode / hole injection layer / organic light emitting layer / electron transport layer / electron injection layer / cathode e) anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode f) anode / Hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode (where the symbol “/” indicates that the layers sandwiching the symbol “/” are stacked adjacent to each other) The same shall apply hereinafter.)
In a) to f), one of the layers provided between the anode and the organic light emitting layer is a lyophilic underlayer.

In the embodiment shown in FIGS. 1-8 and the like, a set of organic light emitting layers is provided. However, as a modification thereof, a mode in which two or more sets of organic light emitting layers are provided in an overlapping manner can be employed. Here, in any one of the layer configurations of (a) to (f) above, when the layered body sandwiched between the anode and the cathode is “repeating unit A”, for example, the following (g) The layer structure shown can also be employed.
g) Anode / (repeat unit A) / charge generation layer / (repeat unit A) / cathode

As an organic EL device having three or more organic light emitting layers, when “(repeating unit A) / charge generation layer” is “repeating unit B”, for example, the layer structure shown in (h) below can be cited. it can.
h) Anode / (Repeating unit B) _n / (Repeating unit A) / Cathode

The symbol “n” represents an integer of 2 or more. (Repeating unit B) _n represents a laminate in which n layers of repeating units B are laminated.
In the layer configurations g) and h), the layers other than the anode, the charge generation layer, the cathode, and the organic light emitting layer may be omitted as necessary.

  The charge generation layer is a layer that generates holes and electrons by applying an electric field. Examples of the charge generation layer include a thin film made of vanadium oxide, ITO, molybdenum oxide, or the like.

  In an organic EL element, an anode is usually disposed on the substrate side, but a cathode may be disposed on the substrate side.

The hole injection layer and the electron injection layer are sometimes collectively referred to as a charge injection layer. The hole transport layer and the electron transport layer may be collectively referred to as a charge transport layer. In addition, the electron block layer and the hole block layer may be collectively referred to as a charge block layer.
Two or more charge transport layers may be used independently.

  In the organic EL device of this embodiment, an insulating layer having a thickness of 2 nm or less may be provided adjacent to the electrode in order to further improve the adhesion with the electrode or improve the charge injection property from the electrode. In addition, a thin buffer layer may be inserted between each of the aforementioned layers in order to improve adhesion at the interface or prevent mixing.

  Even if the step of forming the electron injection layer is added after the step of forming the organic light emitting layer as in the method of manufacturing the organic EL device according to the present embodiment, the defective application of the organic light emitting ink can be greatly improved. Therefore, in the present embodiment, similarly to the first embodiment, an organic light emitting layer having a uniform film thickness can be formed in a predetermined pixel region by a simple method, light emission unevenness is reduced, and light emission characteristics are improved. An excellent organic EL device can be realized.

  Further, in the method for manufacturing the organic EL device according to the present embodiment, a step of forming only the electron injection layer is added between the organic light emitting layer and the cathode, but electron transport is performed before the step of forming the electron injection layer. A step of forming a layer may be added. At this time, the organic EL device 10D according to the present embodiment includes the anode 12, the lyophilic underlayer (hole injection layer) 19, the surface treatment layer 21, the substrate 12 from the anode 12 side toward the cathode 24. The organic light emitting layer 23, the electron transport layer, the electron injection layer 32, and the cathode 24 are laminated in this order.

  In addition to the step of forming the electron injection layer, the lyophilic underlayer forming step is similar to the organic EL device 10C manufactured by the method of manufacturing the organic EL device according to the third embodiment shown in FIG. You may make it add the process of forming a positive hole transport layer between surface treatment processes. At this time, the organic EL device 10D according to the present embodiment has the anode 12, the lyophilic underlayer (hole injection layer) 19, and the hole transport layer 31 on the substrate 11 from the anode 12 side toward the cathode 24. The surface treatment layer 21, the organic light emitting layer 23, the electron injection layer 32, and the cathode 24 are laminated in this order.

  Further, in addition to the step of forming the electron injection layer, the step of forming the electron transport layer and the organic EL device 10C manufactured by the method of manufacturing the organic EL device according to the third embodiment shown in FIG. The organic EL device may be manufactured by adding a step of forming a hole transport layer between the lyophilic underlayer forming step and the surface treatment step. At this time, the organic EL device 10D according to the present embodiment has the anode 12, the lyophilic underlayer (hole injection layer) 19, and the hole transport layer 31 on the substrate 11 from the anode 12 side toward the cathode 24. The surface treatment layer 21, the organic light emitting layer 23, the electron transport layer, the electron injection layer 32, and the cathode 24 are laminated in this order.

  In addition, in the manufacturing method of the organic EL device 10A according to the first embodiment to the manufacturing method of the organic EL device 10D according to the fourth embodiment, the anode 12 is disposed as the first electrode on the substrate 11 side and stacked. However, a configuration in which the cathode 24 is disposed as the first electrode on the substrate 11 side and stacked is also possible. At this time, the organic EL device has a cathode (first electrode) 24, a lyophilic underlayer (electron injection layer) 19, a surface treatment layer 21, an organic light emitting device on the substrate 11 from the cathode 24 side toward the anode 12. The layer 23 and the anode (second electrode) 12 are stacked in this order.

  Hereinafter, the present invention will be described more specifically based on production examples and comparative examples, but the present invention is not limited to the following production examples.

  In the following Production Examples 1-1 to 1-4 and Comparative Example 1, in order to confirm the effect of providing the lyophilic underlayer for forming the organic light emitting layer, the substrate was supplied before supplying the organic light emitting ink. On the other hand, an organic EL element having a laminated structure in which a lyophilic underlayer was provided between the anode and the organic light emitting layer was manufactured without performing the surface treatment step of treating with an organic solvent from the side where the partition walls were installed.

(Production Example 1-1)
A substrate obtained by patterning indium tin oxide (ITO) as a first electrode on a transparent glass substrate was prepared.
Next, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd .: OFPR-800) was applied to the entire surface by a spin coating method and dried to form a photoresist layer having a thickness of 1 μm.
Next, after irradiating ultraviolet rays with an alignment exposure machine using a photomask designed to cover the ITO edge, the photoresist in the exposed area is removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd .: NMD-3). did. Next, a heat treatment was performed at 230 ° C. for 1 hour on a hot plate to completely heat and cure the resist to obtain an organic insulating layer.

Next, a liquid repellent treatment was performed on the surface of the insulating layer by a vacuum plasma apparatus using CF ₄ gas.
Next, through a metal mask designed so that at least the ITO exposed portion (opening portion) becomes the opening portion, molybdenum oxide was patterned as a lyophilic underlayer by a resistance heating method using a vacuum vapor deposition machine.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) on an insulating layer and a lyophilic underlayer with an automatic contact angle measuring device (manufactured by EKO Co., Ltd .: OCA20), 48.7 was measured on the organic insulating layer. °, 10 ° or less on the lyophilic underlayer. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.

  Next, a liquid material using MEH-PPV (poly (2-methoxy-5- (2′-ethyl-hexyloxy) -para-phenylenevinylene) having a weight average molecular weight of about 200,000 as a thin film forming material manufactured by Aldrich Using a mixed solvent of toluene and anisole as a solvent, the concentration of PPV in the prepared liquid material was 1% by weight, and ink was applied onto the molybdenum oxide layer, which is a lyophilic underlayer, by a nozzle coating method. The prepared liquid material was applied and dried to prepare an organic light emitting layer having a thickness of 1000 mm.

(Evaluation 2)
As a result of observing the vicinity of the ITO opening with an optical microscope and observing the pattern formation state of the organic light emitting layer, it was confirmed that the organic light emitting layer was satisfactorily formed on the lyophilic underlayer.

  Next, calcium was vapor-deposited with a thickness of 100 mm as a second electrode, and silver was vapor-deposited with a thickness of 2000 mm as a protective layer. Thus, an organic EL element having a bottom emission structure was produced.

(Evaluation 3)
As a result of connecting the ITO electrode (first electrode) side to the positive electrode and the metal electrode (second electrode) side to the negative electrode, applying a direct current with a source meter and observing the state of the organic light emitting layer, a good light emitting state was obtained. It was confirmed that

(Production Example 1-2)
In Production Example 1-1, elements were produced by the same process except that CF ₄ gas was used as a reactive gas and liquid repellent treatment was performed using an atmospheric pressure plasma apparatus.

(Evaluation 1)
After plasma treatment, contact angle measurement was performed with an anisole (surface tension 35 dyn / cm) using an automatic contact angle measurement device (Eihiro Seiki Co., Ltd .: OCA20). As a result, 52.4 ° on the organic insulating layer, lyophilic underlayer The angle was 10 ° or less. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.
(Evaluation 2)
After forming the organic light emitting layer, the periphery of the ITO opening was observed with an optical microscope, and the pattern formation state of the organic light emitting layer was observed. As a result, it was confirmed that the organic light emitting layer was well formed on the lyophilic underlayer did.
(Evaluation 3)
The ITO electrode side was connected to the positive electrode, the metal electrode side was connected to the negative electrode, a direct current was applied by a source meter, and the state of the organic light emitting layer was observed. As a result, it was confirmed that a good light emitting state was obtained.

(Production Example 1-3)
Indium tin oxide (ITO) was patterned as a first electrode on the transparent glass substrate.
Next, a silicon oxide layer having a thickness of 2000 mm was formed by a sputtering method.
Next, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd .: OFPR-800) was applied to the entire surface by a spin coating method and dried to form a photoresist layer having a thickness of 1 μm.
Next, after irradiating ultraviolet rays with an alignment exposure machine using a photomask designed to cover the ITO edge, the photoresist in the exposed area is removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd .: NMD-3). did.

Next, the silicon oxide was etched using a gas in which CF ₄ and oxygen were mixed by a vacuum dry etching apparatus. Thereafter, the photoresist layer was peeled off to form an inorganic insulating layer.
Next, as a liquid repellent treatment, fluoroalkylsilane (manufactured by Tochem Products Co., Ltd .: MF-160E) was applied by a spin coat method and dried to form a liquid repellent layer.
Next, through a metal mask designed so that at least the ITO exposed portion (opening portion) becomes the opening portion, molybdenum oxide was patterned as a lyophilic underlayer by a resistance heating method using a vacuum vapor deposition machine.

(Evaluation 1)
As a result of contact angle measurement with anisole (surface tension 35 dyn / cm) on an insulating layer and a lyophilic underlayer with an automatic contact angle measuring device (Eihiro Seiki Co., Ltd .: OCA20), 60.5 was measured on the inorganic insulating layer. °, 10 ° or less on the lyophilic underlayer. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.

  A liquid material was prepared using MEH-PPV (poly (2-methoxy-5- (2′-ethyl-hexyloxy) -para-phenylenevinylene) having a weight average molecular weight of about 200,000 as a thin film forming material manufactured by Aldrich. Using a mixed solvent of toluene and anisole as a solvent, the concentration of PPV in the produced liquid material was 1% by weight, and ink was applied on the molybdenum oxide layer, which is a lyophilic underlayer, by a nozzle coating method, An organic light emitting layer having a thickness of 1000 mm was prepared by drying.

(Evaluation 2)
As a result of observing the vicinity of the ITO opening with an optical microscope and observing the pattern formation state of the organic light emitting layer, it was confirmed that the organic light emitting layer was satisfactorily formed on the lyophilic underlayer.

  Next, calcium was vapor-deposited with a thickness of 100 mm as a second electrode, and silver was vapor-deposited with a thickness of 2000 mm as a protective layer.

(Evaluation 3)
The ITO electrode side was connected to the positive electrode, the metal electrode side was connected to the negative electrode, a direct current was applied by a source meter, and the state of the organic light emitting layer was observed. As a result, it was confirmed that a good light emitting state was obtained.

(Production Example 1-4)
In Production Example 1-4, an organic EL element having a top emission structure was produced.
First, the board | substrate which patterned the laminated body formed in order of Cr and indium tin oxide (ITO) as a 1st electrode on the transparent glass substrate was prepared.
Next, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd .: OFPR-800) was applied to the entire surface by a spin coating method and dried to form a photoresist layer having a thickness of 1 μm.
Next, after irradiating ultraviolet rays with an alignment exposure machine using a photomask designed to cover the ITO edge, the photoresist in the exposed area is removed with a resist developer (manufactured by Tokyo Ohka Kogyo Co., Ltd .: NMD-3). did. Next, a heat treatment was performed at 230 ° C. for 1 hour on a hot plate to completely heat and cure the resist to obtain an organic insulating layer.

Next, a liquid repellent treatment was performed on the surface of the insulating layer by a vacuum plasma apparatus using CF ₄ gas.
Next, through a metal mask designed so that at least the ITO exposed portion (opening portion) becomes the opening portion, molybdenum oxide was patterned as a lyophilic underlayer by a resistance heating method using a vacuum vapor deposition machine.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) on an insulating layer and a lyophilic underlayer with an automatic contact angle measuring device (manufactured by EKO Co., Ltd .: OCA20), 48.7 was measured on the organic insulating layer. °, 10 ° or less on the lyophilic underlayer. As a result, it was confirmed that the insulating layer was a liquid repellent layer and the lyophilic underlayer was a lyophilic surface.

  Next, a liquid material using MEH-PPV (poly (2-methoxy-5- (2′-ethyl-hexyloxy) -para-phenylenevinylene) having a weight average molecular weight of about 200,000, manufactured by Aldrich as a thin film forming material. Using a mixed solvent of toluene and anisole as a solvent, the concentration of PPV in the prepared liquid material was 1% by weight, and ink was applied on the molybdenum oxide layer, which is a lyophilic underlayer, by a nozzle coating method. (Solution) was applied and dried to prepare an organic electroluminescence layer (organic light emitting layer) having a thickness of 1000 mm.

(Evaluation 2)
The periphery of the ITO opening was observed with an optical microscope to observe the state of pattern formation of the organic light emitting layer, and it was confirmed that the organic light emitting layer was satisfactorily formed on the lyophilic underlayer.

  Next, as a second electrode, calcium is deposited to a thickness of 100 mm, and subsequently aluminum is deposited to a thickness of 50 mm. Further, a transparent electrode layer is formed to a thickness of 2000 mm by a counter target type film forming apparatus using indium tin oxide (ITO) as a target. Vapor deposited. Thereby, an organic EL element having a top emission structure was produced.

(Evaluation 3)
The electrode on the laminate side of Cr and ITO is connected to the positive electrode, the electrode side of only ITO is connected to the negative electrode, a direct current is applied by a source meter, and the state of the organic light emitting layer is observed. It was confirmed that a good light emitting state was obtained.

(Comparative Example 1)
In Production Example 1-1, elements were produced by the same process except that the liquid repellent treatment was not performed.

(Evaluation 1)
As a result of contact angle measurement with an anisole (surface tension 35 dyn / cm) using an automatic contact angle measurement device (Eihiro Seiki Co., Ltd .: OCA20) on the insulating layer and the lyophilic underlayer, 12 ° on the organic insulating layer, It was 10 ° or less on the lyophilic underlayer. Thereby, it was confirmed that both the insulating layer and the lyophilic underlayer are lyophilic surfaces.
(Evaluation 2)
After forming the light emitting layer, the periphery of the ITO opening was observed with an optical microscope and the pattern formation state of the organic light emitting layer was observed. As a result, it was confirmed that the organic light emitting layer was significantly wider than the width of the lyophilic underlayer. confirmed.
(Evaluation 3)
When the ITO electrode side was connected to the positive electrode and the metal electrode side was connected to the negative electrode and a direct current was applied by a source meter, the electrodes were short-circuited, and light emission could not be confirmed.

(Production Example 2)
In Production Example 2 shown below, an organic EL element having a stacked structure in which a hole injection layer and a surface treatment layer were provided as a layer between the anode and the light emitting layer was used.
The feature of the present invention is that it has a surface treatment step with an organic solvent on the surface of the substrate on which the partition wall is formed. Therefore, all types of organic EL other than the laminated structure shown in the following fabrication examples are included. The present invention can be similarly applied to elements, and the same effects can be obtained.

(Preparation of substrate and formation of anode)
First, an ITO thin film was formed on a transparent glass plate of 200 mm (vertical) × 200 mm (horizontal) × 0.7 mm (thickness), and further patterned to form a striped anode. The repetition interval (pitch) of the anode was 80 μm, and the interval (space) between the anodes was 10 μm with respect to the width of the anode (line) of 70 μm (line / space = 70 μm / 10 μm). A pixel region in which pixels are formed when viewed from one side in the thickness direction of the substrate is set in an island shape on the ITO thin film extending in one direction at a predetermined interval in the one direction.

(Formation of partition walls)
Next, a positive photoresist (trade name “OFPR-800”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to the entire surface of the substrate by a spin coating method, and this coating film is dried to obtain a film thickness of 1 μm. A photoresist layer was formed.
Next, a photomask designed to shield the region excluding the pixel region where the pixel is formed from one side in the thickness direction of the substrate from ultraviolet rays is disposed on the photoresist layer, and an alignment exposure machine ( The photoresist layer was irradiated with ultraviolet rays through the photomask from Dainippon Screen Mfg. Co., Ltd. (trade name “MA1300”) (exposure process).
Following the exposure step, the exposed portion of the photoresist layer was removed using a resist developer (trade name “NMD-3”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) (development step).
Subsequently, the transparent glass plate was subjected to heat treatment at 230 ° C. for 1 hour on a hot plate, and the developed photoresist layer was completely heat-cured (thermosetting step).
Through the series of photolithography processes, a partition wall (organic insulating layer) surrounding the pixel region is formed, and the anode is exposed inside the partition wall. The width dimension of the obtained partition line was 20 μm, and the height dimension was 2 μm. Each pixel region was a rectangle of 60 μm × 180 μm.

Next, the partition walls were subjected to a liquid repellency treatment using a vacuum plasma apparatus using CF ₄ gas (trade name “RIE-200L” manufactured by Samco International Laboratories).

(Formation of hole injection layer)
Next, a suspension of poly (3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (manufactured by Bayer, trade name “BaytronP AI4083”) was filtered through a 0.2 μm membrane filter. This filtrate was applied to the pixel region by a nozzle coating method. Subsequently, this coating layer was heat-treated at 200 ° C. for 20 minutes to form a 60 nm-thick hole injection layer.

(Treatment of the partition wall substrate surface with a solvent)
Next, a total amount of 30 mL of anisole was continuously dropped on the substrate, and the anisole was contacted (coated) on the entire surface of the substrate by a spin coating method. Then, the board | substrate was dried by performing an air blow process for about 30 minutes.

(Formation of light emitting layer)
Organic light-emitting ink (concentration of polymer light-emitting material) in which a polymer light-emitting material (trade name “RP158”, manufactured by Sumation Corporation) is dissolved as an organic light-emitting material in a mixed solvent in which anisole and cyclohexylbenzene are mixed at a weight ratio of 1: 1. : 1% by weight). This organic light-emitting ink (viscosity: 28 cp) was applied to the insulating partition walls after the surface treatment with the anisole using a flexographic printing method. This coating film was dried to form a light emitting layer having a thickness of 60 nm in the pixel region. The time from the completion of the surface treatment with the anisole to the start of printing of the organic light emitting ink was about 30 minutes.

  Here, when the state of the organic light emitting layer formed in each pixel region was observed with an optical microscope (manufactured by Nikon Corporation, trade name “Optiphoto 88”, objective lens magnification: 50 ×), partition walls and holes were observed. There was no trace of the organic light emitting ink repelled from the injection layer, and it was confirmed that the organic light emitting layer was formed over the entire pixel area.

(Formation of cathode)
Next, on the organic light emitting layer, calcium was vapor-deposited with a thickness of 100 mm as a cathode, and aluminum was vapor-deposited with a thickness of 2000 mm as an oxidation protective layer. Thus, an organic EL element having a bottom emission structure was produced.

  When the organic EL device obtained as described above was caused to emit light, the emission intensity was uniform over the entire light emitting surface.

(Comparative Example 2)
An organic EL device was produced in the same manner as in Production Example 2 except that the treatment before the formation of the light emitting layer in the above Production Example 2 was not carried out (treatment with a solvent on the substrate surface on the partition wall side).

  Immediately after forming the light emitting layer, the state of the organic light emitting layer formed in each pixel region was observed with an optical microscope (manufactured by Nikon Corporation, trade name “Optiphoto 88”, objective lens magnification: 50 ×). When the organic light-emitting ink is repelled on the surface of the partition wall or the hole injection layer, a pixel region having a defective portion in which the organic light-emitting layer is not formed in the partition wall as viewed from one side in the thickness direction of the substrate. I confirmed that it was present.

  When the organic EL device obtained in this manner was allowed to emit light, uneven light emission occurred on the light emitting surface.

It is a section lineblock diagram showing a substrate preparation process of a manufacturing method of an organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing the partition formation process of the manufacturing method of the organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing a liquid repellent layer formation process of a manufacturing method of an organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing the lyophilic foundation layer formation process of the manufacturing method of the organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing a surface treatment process of a manufacturing method of an organic EL device concerning a 1st embodiment of the present invention. It is a section lineblock diagram showing the process of applying organic luminescent ink of the manufacturing method of the organic EL device concerning a 1st embodiment of the present invention. It is a cross-sectional block diagram which shows the light emitting layer formation process of the manufacturing method of the organic electroluminescent apparatus concerning the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the organic electroluminescent apparatus manufactured with the manufacturing method of the organic electroluminescent apparatus concerning the 1st Embodiment of this invention. It is a top view of the board | substrate of FIGS. 1-1. It is a top view of the board | substrate with which the partition concerning FIG. 1-2 was formed. It is sectional drawing which shows the structure of the organic electroluminescent apparatus manufactured by the manufacturing method of the organic electroluminescent apparatus concerning the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the organic electroluminescent apparatus manufactured by the manufacturing method of the organic electroluminescent apparatus concerning the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the organic electroluminescent apparatus manufactured by the manufacturing method of the organic electroluminescent apparatus concerning the 4th Embodiment of this invention. It is sectional drawing which shows the board | substrate before formation of the organic light emitting layer which concerns on a prior art. It is sectional drawing which shows the process of forming the organic light emitting layer which concerns on a prior art.

10A to 10D Organic EL device 11 Substrate 12 Anode 13 Insulating layer 13a Exposed surface 14 Pixel region 15 Partition 15a Opposing surface 16 Concave groove 17 Light emitting layer forming region 18 Liquid repellent layer 19 Lipophilic underlayer 20a Opening 20 Mask 21 Surface Treatment layer 22 Organic light-emitting ink 23 Organic light-emitting layer 24 Cathode 25 Light-emitting functional part 31 Hole transport layer 32 Electron injection layer

Claims (9)

A plurality of organic electroluminescence elements each including a first electrode, a second electrode paired with the first electrode, and an organic light emitting layer disposed between the first electrode and the second electrode; A method for producing an organic electroluminescence device comprising a substrate on which the plurality of organic electroluminescence elements are mounted,
Preparing a substrate on which the first electrode is formed;
A partition wall forming step for forming partition walls for partitioning the plurality of organic electroluminescence elements on the substrate,
A liquid repellent treatment step of performing a liquid repellent treatment on the surface of the substrate on which the partition walls are formed from the side on which the organic electroluminescence element is mounted in the thickness direction of the substrate;
More lyophilic to form on the first electrode a lyophilic underlayer having higher lyophilicity to the ink containing the organic light emitting material for forming the organic light emitting layer than the liquid repellent treated partition. An underlayer forming step;
A surface treatment step of surface-treating the lyophilic underlayer with an organic solvent;
After the surface treatment step, an organic light emitting layer forming step of forming an organic light emitting layer by supplying ink containing an organic light emitting material in a region partitioned by the partition;
An electrode forming step of forming the second electrode;
A method for producing an organic electroluminescence device, comprising:   The method for manufacturing an organic electroluminescence device according to claim 1, wherein the liquid repellent treatment is a plasma treatment using a fluorine-based gas.   The method for producing an organic electroluminescent device according to claim 1, wherein in the lyophilic underlayer forming step, the lyophilic underlayer is formed by a dry method.   The manufacturing method of the organic electroluminescent apparatus as described in any one of Claim 1 to 3 whose said lyophilic base layer is a layer which consists of a metal oxide or a metal complex oxide.   The manufacturing method of the organic electroluminescent apparatus of Claim 4 whose oxide of the metal which forms the said lyophilic base layer is molybdenum oxide or tungsten oxide.   The method for manufacturing an organic electroluminescence device according to claim 1, wherein the surface treatment step is a step of bringing the organic solvent into contact with the surface of the lyophilic underlayer.   The method of manufacturing an organic electroluminescence device according to claim 6, wherein in the surface treatment step, the organic solvent is brought into contact with the surface of the lyophilic underlayer by a spin coating method.   The method for producing an organic electroluminescent element according to claim 6 or 7, wherein, in the surface treatment step, the organic solvent is dried after contacting the organic solvent with a surface of the lyophilic underlayer.   In the said organic light emitting layer formation process, the manufacturing method of the organic electroluminescent apparatus as described in any one of Claim 1 to 8 which supplies the ink containing the said organic light emitting material by a flexographic printing method.

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