JP2010205528A - Manufacturing method of organic electroluminescent device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device capable of producing an organic EL element in a simple process. <P>SOLUTION: In the manufacturing method of the organic EL device provided with a support substrate 11, a plurality of organic EL elements 18 fitted on the support substrate 11, and a plurality of barrier ribs 15 for zoning the organic EL elements 18, the organic EL element 18 is equipped with first electrodes 12, a second electrode 17, and a light-emitting layer 16 containing an organic compound arranged between the first and the second electrodes. The manufacturing method of the organic EL device 10 includes a preparation process of preparing a support substrate 11 with the first electrodes 12 formed, a barrier-rib forming process for forming a plurality of barrier ribs 15 by supplying ink containing a material to be the barrier ribs discharged in a liquid column shape along a site where the barrier ribs are to be made, and furthermore, solidifying it, a light-emitting layer forming process of forming light-emitting layers 16 between the barrier ribs 15, and a second electrode forming process of forming the second electrode 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic electroluminescence device (hereinafter, “electroluminescence” may be referred to as “EL”).

  Research and development of a display device including a plurality of organic electroluminescence elements (hereinafter, “electroluminescence” may be referred to as “EL”) as a light source is in progress.

  An organic EL element is a light emitting element that emits light when a voltage is applied, and includes a pair of electrodes and a light emitting layer provided between the electrodes. When a voltage is applied to the organic EL element, holes are injected from one electrode and electrons are injected from the other electrode, and light is emitted by combining these holes and electrons in the light emitting layer.

  An organic EL element is usually produced on a support substrate by laminating layers constituting the organic EL element in a predetermined order. Each layer is appropriately formed by an optimum method in consideration of required characteristics and process simplicity. For example, from the viewpoint of simplicity of the process, it has been studied to form a light emitting layer by a coating method.

  When forming a light emitting layer by the apply | coating method, the partition for accommodating the ink used in order to form a light emitting layer for every organic EL element is usually provided on the support substrate. As such a partition, for example, a lattice-shaped or stripe-shaped partition is provided on the support substrate. A light emitting layer can be formed by selectively supplying the ink to a region surrounded by the partition walls by a predetermined coating method and further solidifying the ink.

  Since the partition is provided to partition each organic EL element, it is necessary to form the partition in a predetermined pattern (for example, a lattice shape or a stripe shape) according to the arrangement of the organic EL elements. Therefore, photolithography has been generally used for forming the partition walls. However, since photolithography has a large number of steps and is complicated, a method for patterning barrier ribs by a simpler method has been demanded.

  In view of this, a method of easily forming partition walls (banks) using an inkjet printing method has been disclosed (for example, see Patent Document 1). The ink jet printing method is one of coating methods that can selectively supply ink to a desired site by moving a nozzle that drops ink intermittently as droplets along a predetermined course. By using this ink jet printing method, the ink containing the material for forming the partition wall is supplied in a predetermined pattern, and further solidified, whereby the partition wall can be easily formed in the predetermined pattern.

JP 2006-171365 A

  In the ink jet printing method described above, it is difficult to form a partition having a gentle surface. As described above, when the light emitting layer is formed by the coating method, the ink for forming the light emitting layer is supplied to the region surrounded by the partition wall, and the layer is formed by solidifying the ink. A light emitting layer will be formed in the state which contacted the partition side surface. The properties of the light emitting layer to be formed are greatly affected by the properties of the side wall of the partition wall, so it is difficult to form a light emitting layer with a flat and uniform film thickness in the region surrounded by the side surface of the uneven partition wall. It is difficult to form a light emitting layer.

  Therefore, the objective of this invention is providing the manufacturing method of the organic EL apparatus which can produce an organic EL element with a simple process.

In order to solve the above problems, the present invention employs the following configuration.
[1] a support substrate;
A plurality of organic electroluminescence elements provided on the support substrate;
A plurality of partition walls for partitioning the organic electroluminescence element;
With
The organic electroluminescence element has a first electrode, a second electrode, and a light emitting layer containing an organic compound disposed between the first and second electrodes.
A method for manufacturing an organic electroluminescence device, comprising:
Preparing a supporting substrate on which the first electrode is formed;
A partition forming step of forming a plurality of partition walls by supplying ink containing a material to be the partition walls while discharging in a liquid column shape along a site where the partition walls are provided, and further solidifying;
A light emitting layer forming step of forming the light emitting layer between the partition walls;
A second electrode forming step of forming the second electrode;
A method for producing an organic electroluminescence device, comprising:
[2] The organic electroluminescence element includes a common layer common to the plurality of organic electroluminescence elements between the first electrode and the light emitting layer,
The organic electroluminescence according to [1], further including a common layer forming step of integrally forming a common layer across the plurality of organic electroluminescence elements after the preparation step and before the partition formation step. Device manufacturing method.
[3] The method for manufacturing an organic electroluminescence device according to [2], wherein in the common layer formation step, the common layer is formed by a spin coating method.
[4] The method for manufacturing an organic electroluminescence device according to [2], wherein in the common layer forming step, the common layer is formed by a vacuum vapor deposition method or a chemical vapor deposition method.
[5] The first electrode is an anode,
The second electrode is a cathode;
The light emitting layer is disposed in contact with the common layer;
In the common layer forming step, a common layer including a hole injection layer disposed at a position in contact with the anode and an electron blocking layer disposed at a position in contact with the light emitting layer is formed. ] The manufacturing method of the organic electroluminescent apparatus as described in any one of.
[6] The method for manufacturing an organic electroluminescent device according to [5], wherein in the common layer forming step, the hole injection layer having a film thickness of 0.5 nm or more and 20 nm or less is formed.
[7] The method for manufacturing an organic electroluminescence device according to [5] or [6], wherein in the common layer forming step, the hole injection layer is formed of a silane coupling material.
[8] The method for manufacturing an organic electroluminescent device according to any one of [5] to [7], wherein in the common layer forming step, an electron blocking layer having a film thickness of 40 nm or more and 200 nm or less is formed.
[9] In the light emitting layer forming step, the light emitting layer is formed by a coating method using an ink containing a material to be the light emitting layer,
In the partition formation step, the organic electroluminescence according to any one of [1] to [8], wherein the partition surface has a contact angle of 40 degrees or more with respect to the ink including the material used as the light emitting layer. Device manufacturing method.
[10] The method for manufacturing an organic electroluminescent device according to any one of [1] to [9], wherein in the partition formation step, a partition having a height of 0.5 nm or more and 20 nm or less is formed.
[11] In the light emitting layer forming step, ink containing a material to be the light emitting layer is supplied while being discharged in a liquid column shape along a portion where the light emitting layer is provided, and further solidified to form the light emitting layer. The method for producing an organic electroluminescent device according to any one of [1] to [10] above.

  According to the present invention, an organic EL device having high characteristics can be produced by a simple process.

FIG. 1 is a cross-sectional view showing a first embodiment of an organic EL device manufactured by the manufacturing method of the present invention. FIG. 2 is a perspective view of a support substrate on which an anode and a pixel region defining layer are formed. FIG. 3 is a perspective view of the support substrate when the hole injection layer is stacked on the support substrate. FIG. 4 is a perspective view of the support substrate when the electronic block layers are stacked. FIG. 5 is a diagram showing the movement of the nozzle and the panel in the partition forming process. FIG. 6 is a diagram illustrating a nozzle trajectory in the partition formation process. FIG. 7 is a perspective view schematically showing a state in which ink containing a material to be a partition wall is applied. FIG. 8 is a diagram showing the trajectory of the nozzle in the light emitting layer forming step. FIG. 9 is a perspective view schematically showing a state in which an ink containing a material that becomes a light emitting layer is applied. FIG. 10 is a perspective view schematically showing another state of applying an ink containing a material to be a light emitting layer.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the scale of each member in the drawing may differ from the actual scale. The present invention is not limited to 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, but these are not directly necessary in the description of the present invention, and the description thereof is omitted. For convenience of explanation, in the example shown below, the explanation will be made with the figure in which the support substrate is arranged below. However, the organic EL element of the present invention and the organic EL device equipped with the organic EL element are not necessarily arranged in this arrangement. Is not done. In the following description, one of the support substrate in the thickness direction may be referred to as “upper” or “upper”, and the other of the support substrate in the thickness direction may be referred to as “lower” or “lower”.

1. Method for Manufacturing Organic EL Device of the Present Invention [First Embodiment]
The manufacturing method of the organic EL device of the present invention (hereinafter sometimes referred to as the manufacturing method of the present invention) is a method of manufacturing an organic EL device including a plurality of organic EL elements. An organic EL element constitutes a pixel in an organic EL device as a display device.

  The manufacturing method of the present invention is not limited by the specific embodiment of the organic EL element to be manufactured. However, in order to facilitate understanding of the manufacturing method of the present invention, in the following description of the embodiment, organic EL As an element, the example shown in FIG.

  FIG. 1 is a cross-sectional view showing the organic EL device of the first embodiment. The organic EL device according to this embodiment includes a flat support substrate 11 having light transmittance, a plurality of organic EL elements 18 provided on the support substrate 11, and a plurality of partition walls 15 that partition the organic EL elements 18. With. The organic EL element 18 includes a first electrode 12, a second electrode 17, and a light emitting layer 16 including an organic compound disposed between the first and second electrodes 12 and 17.

  In the present embodiment, a plurality of anodes 12 having optical transparency are arranged on the support substrate 11 as the first electrodes 12. The plurality of anodes 12 are arranged in parallel at a predetermined interval. On the support substrate 11 on which the plurality of anodes 12 are formed, a pixel region defining layer 13 for insulating the organic EL elements 18 from each other and driving them independently as pixels is disposed. The pixel region defining layer 13 is formed so as to cover the support substrate 11 on which the anode 12 is formed, and corresponds to a pixel when viewed from one side in the thickness direction of the support substrate 11 (hereinafter sometimes referred to as “plan view”). An opening is formed in the area to be operated. Hereinafter, the opening formed in the pixel region defining layer 13 may be referred to as a pixel opening 21. The pixel openings 21 are discretely formed along the anode 12 in plan view. The pixel region defining layer 13 is composed of a member that exhibits insulating properties. By providing such a pixel region defining layer 13, the plurality of anodes 12 are electrically insulated from each other, and adjacent pixel openings 21 are electrically insulated in the extending direction of the anodes 12. The organic EL element 18 is electrically insulated.

  The organic EL element 18 of this embodiment further includes a common layer 14 common to the plurality of organic EL elements between the anode 12 and the light emitting layer 16. In other embodiments, the common layer 14 may not be provided. The common layer 14 is provided on the pixel region defining layer 13. Since the pixel opening 21 is formed in the pixel region defining layer 13, the common layer 14 is filled in the pixel opening 21 and disposed in contact with the anode 12. In this embodiment, the common layer 14 includes a hole injection layer 14a disposed at a position in contact with the anode and an electron block layer 14b disposed at a position in contact with the light emitting layer.

  The plurality of partition walls 15 are provided on the common layer 14 so as to extend in the same direction as the direction in which the anode 12 extends, and are provided between the anodes 12 in a plan view. In other words, each partition wall 15 is provided between the pixel openings 21 formed on the adjacent anodes 12 in plan view.

  The light emitting layer 16 is provided on the common layer 14 between the partition walls 15.

  Further, a cathode 17 is formed as the second electrode 17 so as to cover the partition wall 15 and the light emitting layer 16.

  As described above, the organic EL element 18 is formed by the laminated body including the anode 12, the common layer 14, the light emitting layer 16, and the cathode 17 formed on the support substrate 11. The anode 12, the common layer 14, and the cathode 17 are formed across a plurality of organic EL elements 18, but by providing the pixel region defining layer 13, each organic EL element 18 is electrically insulated, thereby Each organic EL element 18 can be driven electrically independently.

  In this specification, “light-transmitting support substrate” and “light-transmitting electrode” mean a support substrate and an electrode through which at least part of incident light is transmitted.

  In the present embodiment, the first electrode 12 is an anode and the second electrode 17 is a cathode, but the present invention is also suitable for an organic EL element in which the first electrode is a cathode and the second electrode is an anode. Can be applied to.

  Next, with reference to FIG. 1 to FIG. 9, a process for manufacturing an organic EL element by the manufacturing method of the present invention will be described. In the method of manufacturing the organic EL device 10 according to the present embodiment, a preparation step of preparing the support substrate 11 on which the anode 12 (first electrode) is formed, and an ink containing a material that becomes the partition wall 15 are applied to the portion where the partition wall is provided. A partition wall forming step of forming a plurality of partition walls 15 by supplying the liquid while discharging in a liquid column form and solidifying, a light emitting layer forming step of forming a light emitting layer 16 between the partition walls 15, and a cathode 17 (second Forming a second electrode).

<1. Preparation process>
The preparation step is a step of preparing the support substrate 11 on which the anode 12 is formed. In the preparation step, for example, a circuit for driving the organic EL element 18 such as a TFT (Thin Film Transistor) substrate and a substrate on which the anode 12 electrically connected to the circuit is formed in advance may be obtained. The support substrate 11 on which the anode 12 is formed may be prepared by forming the anode 12 on the support substrate 11.

  Examples of the method for forming the anode 12 include vacuum deposition, sputtering, ion plating, and plating.

  In the present embodiment, the pixel region defining layer 13 is further formed. FIG. 2 is a perspective view of the support substrate 11 on which the anode 12 and the pixel region defining layer 13 are formed. As described above, the pixel opening 21 is formed in the pixel region defining layer 13. The pixel opening 21 is formed in, for example, a substantially rectangular shape, a substantially oval shape, or an oval shape in plan view.

  Examples of the method for forming the pixel region defining layer 13 include a plasma CVD (Chemical Vapor Deposition) method, a sputtering method, and an electron beam evaporation method. Examples of the method of forming the pixel opening 21 in the pixel region defining layer 13 include a method of forming an opening at a predetermined portion by photolithography after forming a thin film by the above method.

<2. Common layer formation process>
In the present embodiment, the common layer 14 common to the plurality of organic EL elements is provided between the first electrode and the light emitting layer. The common layer 14 is formed before the barrier rib is formed, and the common layer forming step is performed after the preparation step and before the barrier rib forming step.

  In the common layer forming step, the common layer is integrally formed across the plurality of organic EL elements 18. The common layer is a layer provided in common regardless of the type of the organic EL element 18. For example, when three types of organic EL elements that emit red light, green light, and blue light are provided, a light emitting layer is usually formed according to the type of the element. However, as in the present embodiment, the organic EL element 18 is used. Therefore, the number of steps can be reduced by integrally forming the common layers.

  In the present embodiment, the common layer 14 is constituted by a two-layered laminate. The common layer 14 includes a hole injection layer 14 a provided at a position adjacent to the anode 12 and an electron block layer 14 b provided at a position adjacent to the light emitting layer 16.

  FIG. 3 is a perspective view of the support substrate 11 when the hole injection layer 14a is stacked on the support substrate 11, and FIG. 4 is a support when the electron block layer 14b is stacked on the hole injection layer 14a. 2 is a perspective view of a substrate 11. FIG. 3 and 4, reference numeral 21 denotes a portion corresponding to the pixel opening.

  As shown in FIGS. 3 and 4, after the hole injection layer 14a is stacked as the common layer 14, the electron blocking layer 14b is stacked. The exposed surface 12a of the anode 12 is defined by making the opening 21 in the pixel region defining layer 13, but when the pixel region defining layer 13 is not provided, the entire upper surface of the anode 12 becomes an exposed surface.

  In the present embodiment, two layers of the hole injection layer 14a and the electron blocking layer 14b are provided as the common layer 14. However, the present invention is not limited to this, and one common layer 14 is configured. Alternatively, three or more common layers 14 may be formed. For example, the common layer 14 may be composed of only one layer of the hole injection layer 14a.

  The hole injection layer 14a and the electron block layer 14b, which are the common layer 14, are formed in a lump. As a method for forming the common layer 14, any method can be used as long as the flat common layer 14 can be easily formed in a short time. Examples of the method include a vacuum evaporation method, a chemical vapor deposition method, and a coating method with a simple process. Among these, the coating method is preferable.

  As the coating method, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, slit coating method, capillary coating method, wire bar coating method, dip coating method, spray coating method, A screen printing method, a flexographic printing method, an offset printing method, an ink jet printing method, and the like can be given, and a spin coating method is preferable. By using the spin coating method, the flat common layer 14 can be easily formed in a short time.

  Even in a layer (common layer in the present embodiment) that is commonly used for each organic EL element, it is usually provided for each organic EL element, unlike the present embodiment. As described above, when the light emitting layer is formed between the barrier ribs, the property of the barrier rib surface affects the shape of the light emitting layer. Similarly, when the common layer is formed between the barrier ribs, the properties of the barrier rib surface affect the common layer. Therefore, when the common layer is formed between the barrier ribs, the barrier wall surface affects the common layer and the light emitting layer. As a result, the barrier wall surface influence on the entire element is increased. Since the common layer is formed before the barrier rib is formed, the flat common layer can be formed without the influence of the barrier wall surface on the common layer, and light emission formed on the common layer The layer can be formed flat. Thereby, an organic EL element having high characteristics can be realized.

<3. Partition formation process>
In the partition forming step, the ink 23 containing the material to be the partition 15 is supplied to the surface 22 of the common layer 14 formed in the common layer forming step while being discharged in a liquid column shape along the portion where the partition 15 is provided. Then, by further solidifying, a plurality of partition walls are formed. Here, the liquid column means a state in which ink is continuously supplied in a columnar shape. In addition, droplet ink such as the inkjet printing method supplies ink droplets intermittently. However, ink droplets are supplied intermittently and ink is continuously supplied in a columnar shape. In this specification, the state which is different means a different state. By forming the partition wall 15, the region where the light emitting layer 16 is provided can be partitioned.

  As a coating method for forming the partition wall 15, a nozzle printing method can be used. By using the nozzle printing method, it is possible to easily apply the ink 23 containing a material to be a partition wall to a predetermined portion on the common layer 14 in a short time.

  Moreover, as an apparatus which discharges the ink 23 containing the material used as a partition in a liquid column shape, a nozzle printing apparatus etc. are mentioned, for example. The nozzle printing apparatus is an apparatus that continuously ejects ink from nozzles having minute openings. The nozzle printing apparatus can stably apply the ink in a fine line shape with a stable line width. As a result, the partition wall 15 can be formed in a shorter time than when the ink-jet printing method is used.

  5 to 7 show the state of the partition wall forming process. FIG. 5 is a diagram showing how the nozzles and the panel move in the partition forming step of the present embodiment, and FIG. 6 is a diagram showing the trajectory of the nozzles in the partition forming step. FIG. 7 is a perspective view schematically showing a state in which ink containing a material to be a partition wall is applied. 6 to 7, reference numeral 21 denotes a portion corresponding to the pixel opening.

  As shown in FIGS. 5 to 7, a panel 25 having four matrix portions (display area portions) 24 provided on the support substrate 11 is conveyed in the Dd direction. Ink 23 containing a material to be a partition is ejected from a nozzle 26 of a nozzle printing apparatus (not shown). The nozzle 26 reciprocates in a direction Nm perpendicular to the transport direction Dd of the panel 25 and the thickness direction of the support substrate.

  Application of the ink 23 includes a step in which the nozzle 26 moves from one side in the Nm direction to the other, a step in which the panel 25 moves in the transport direction Dd by the pitch at which the partition 15 is arranged, and a nozzle in the other direction from the other in the Nm direction. It is performed by repeating the four steps of the step of moving 26 and the step of moving the panel 25 in the transport direction Dd by the amount of the pitch of the partition wall 15, and the nozzle 26 draws the track Ip so as to draw the track Ip. It will move up (see FIG. 6). When the panel 25 passes under the nozzle 26, the ink 23 containing the material to be a partition wall is ejected from the nozzle 26, and the pixel region defining layer 13 on the common layer 14 is drawn while drawing a locus as shown in FIG. Ink 23 containing a material to be a partition is applied to the upper portion.

  The ink 23 containing the material to be the partition is discharged from the nozzle 26 and applied to the upper layer of the common layer 14, and then the solvent is evaporated from the ink 23 containing the material to be the partition, so that the ink is dried and cured. When the ink 23 containing the partition wall material is dried, the solvent is distilled off from the ink 23 containing the partition wall material to fix the components forming the partition wall 15. Further, the ink 23 containing a material for the partition wall applied from the nozzle 26 is in a liquid state, has a surface tension, and shrinks during the drying process. The ink 23 containing the material to be the partition walls applied on the common layer 14 is dried to form the partition walls 15. Thereby, the partition walls 15 arranged in a plurality of stripes can be formed on the common layer 14. From the viewpoint of working speed efficiency, it is preferable that the drying of the ink 23 including the material to be the partition wall is completed in a short time. In addition, you may provide the process of baking the ink 23 containing the material used as a partition after drying.

  By supplying the ink 23 containing the material for the partition wall in the form of a liquid column to the upper portion of the pixel region defining layer 13 on the common layer 14 using the nozzle printing method, and further solidifying the ink 23, A plurality of partition walls arranged in parallel on the layer 14 can be easily formed in a short time.

  Further, after the partition wall forming step, a second partition wall forming step is further provided, and a plurality of partition walls are provided in a direction substantially orthogonal to the plurality of partition walls previously provided by the second partition wall forming step, A lattice-like partition wall 15 may be formed.

In addition, since the ink for forming the light emitting layer is supplied between the partition walls 15 as will be described later, the partition wall 15 is also used to securely hold and store the ink supplied between the partition walls 15. It is preferable that the surface of the upper part 15a of 15 shows liquid repellency with respect to the ink 31 containing the material used as a light emitting layer, and it is more preferable that the whole surface of the partition 15 shows liquid repellency. For example, a component showing liquid repellency may be mixed with a component constituting the partition, or a film showing liquid repellency may be formed on the surface of the partition 15. Specifically, liquid repellency can be imparted to the surface of the partition 15 by treating the surface of the partition 15 in a plasma atmosphere containing CF ₄ gas. By using the partition walls 15 exhibiting liquid repellency in this way, since the ink for forming the light emitting layer supplied between the partition walls 15 is repelled by the partition walls, the ink flows into the adjacent pixels beyond the partition walls. Can be prevented.

  As the ink 23 containing the material that becomes the partition wall, a solution containing the material that becomes the partition wall and a solvent that dissolves the material, or a suspension that contains the material that becomes the partition wall and a dispersion medium that dissolves the material is used. It is done. In addition, the liquid illustrated as a solvent below can be used suitably suitably also as a dispersion medium.

  Examples of the material for the partition include a photoresist material such as a photosensitive novolak resin or a photosensitive polyimide to which a photosensitive material such as naphthoquinone diazide is added.

  Examples of the solvent for the ink 23 including the material that forms the partition walls include one selected from the group consisting of water, alcohol solvents, glycol solvents, ether solvents, ester solvents, chlorine-containing solvents, and aromatic hydrocarbon solvents, or two of these. A mixture of seeds or more can be mentioned. Examples of the alcohol include methanol, ethanol, propanol, isopropanol, butanol and the like. Examples of the glycol solvent include ethylene glycol and propylene glycol. Examples of the ether solvent include tetrahydrofuran, methoxybenzene and the like. Examples of the ester solvent include ethyl acetate and butyl acetate. Examples of the chlorine-containing solvent include chloroform, chlorobenzene, and methylene chloride. Examples of the aromatic hydrocarbon solvent include toluene, xylene, trimethylbenzene, tetramethylbenzene and the like.

  In the present embodiment, the nozzle printing method has been described as an example from the viewpoint that a continuous liquid column can be applied with high accuracy as a method for applying the ink 23 including the material to form the partition wall 15. Any method can be used as long as it can supply columnar ink. For example, in addition to the nozzle printing method, a coating method such as a dispenser can be used.

  In the conventional technique, the partition wall is formed by intermittently dropping droplet-like ink by the ink jet printing method, so that the time required for the partition formation process is long, but liquid columnar ink is supplied. As a result, the time required for the partition formation step can be shortened, and the organic EL element can be more easily produced. In addition, in the ink jet printing method, it has been difficult to form the partition walls smoothly. On the other hand, as described above, the ink 23 is supplied while being ejected in a liquid column shape and further solidified, whereby the gentle partition walls 15 are formed. Can be formed.

<4. Light emitting layer forming step>
In the light emitting layer forming step, the light emitting layer 16 is formed in a region partitioned by the partition 15. Specifically, the light emitting layer 16 is formed between the partition walls 15 on the common layer 14.

  The light emitting layer 16 can be formed by a coating method as in the case of forming the partition wall 15. The light emitting layer is formed by supplying ink 31 containing a material to be the light emitting layer between the partition walls 15 and further solidifying. As a coating method for forming the light emitting layer 16, any method can be used as long as it can apply a droplet or liquid column ink between the partition walls 15, and examples thereof include a nozzle printing method, an ink jet printing method, a flexographic printing method, and the like. The nozzle printing method is preferred. By using the nozzle printing method, the ink 31 containing the material to be the light emitting layer can be continuously discharged between the partition walls 15, so that the light emitting layer 16 can be easily applied between the partition walls 15 in a short time. .

  8 and 9 show the state of the light emitting layer forming step. FIG. 8 is a diagram showing the trajectory of the nozzle in the light emitting layer forming step. FIG. 9 is a perspective view schematically showing a state in which an ink containing a material that becomes a light emitting layer is applied. 8 and 9, reference numeral 21 indicates a portion corresponding to the pixel opening.

  Application of the ink 31 includes a step in which the nozzle 26 moves from one side to the other in the Nm direction, a step in which the panel 25 moves in the transport direction Dd by the pitch at which the partition 15 is disposed, and a nozzle in the other direction from the other in the Nm direction. It is performed by repeating the four steps of the step of moving 26 and the step of moving the panel 25 in the transport direction Dd by the amount of the pitch of the partition wall 15, and the nozzle 26 draws the trajectory Iq. It will move up (see FIG. 8).

  Examples of a device that ejects the ink 31 containing the material that becomes the light emitting layer include a nozzle printing device. By using a nozzle printing apparatus, the line width can be stabilized and ink can be continuously applied to fine lines.

  After the ink 31 containing the material to be the light emitting layer is ejected from the nozzle 32, the solvent (or dispersion medium) is gradually dried and solidified to form the light emitting layer 16. As described above, when the partition wall 15 exhibits liquid repellency with respect to the ink 31, the supplied ink 31 can be prevented from flowing out to the adjacent pixel beyond the partition wall 15.

  Since the common layer 14 on which the light emitting layer 16 is formed is integrally formed across each organic EL element as described above, it is formed flat with a uniform film thickness over each organic EL element. The By forming the light emitting layer 16 on the common layer 14 having such high flatness, the light emitting layer 16 having high film flatness and a uniform film thickness can be formed. In particular, by forming the common layer 14 by a spin coating method, a common layer with higher flatness can be formed, and a light-emitting layer having a flatter and uniform film thickness can be formed.

  By forming the light emitting layer on the common layer 14 having a flat and uniform thickness in this way, the flat light emitting layer 16 can be formed with a designed thickness, so that uniform light emission is realized in each element. can do.

  In the ink jet printing method, the ink 31 is dropped in a discrete manner in the pixel opening 21, but the ink that has landed in the pixel opening 21 spreads in the pixel opening 21 to some extent, but due to the influence of the surface tension of the ink 31, In some cases, the ink 31 does not spread sufficiently evenly throughout the pixel opening 21. In this case, the light emitting layer 16 may be defective, for example, a layer may not be formed in the portion after drying, or the layer may be insufficient with respect to the designed thickness.

  However, in the present embodiment, since the ink 31 is ejected in the form of a liquid column and supplied between the partition walls 15, the ink 31 containing the material that becomes the light emitting layer can be supplied to the end portion in the pixel opening 21, The formation failure of the light emitting layer can be suppressed.

  Further, if the amount of ink ejected is simply increased, the ink supplied between the partition walls 15 flows out to the adjacent pixels beyond the partition walls 15 and causes color mixing. On the other hand, as in the present embodiment, since the ink 31 containing the material that becomes the light emitting layer is continuously applied along the longitudinal direction of the partition wall 15, even if the amount of ink to be ejected is suppressed, in the process of drying. The ink 31 containing the material that becomes the light emitting layer can be supplemented to the portion where the layer thickness tends to be insufficient.

  Thus, the organic EL element with high film flatness is producible with a simple process by apply | coating the ink 31 containing the material used as a light emitting layer continuously in liquid column shape. As a result, an organic EL element with high characteristics can be manufactured at low cost.

  For the ink, a solution containing a material that becomes the light emitting layer and a solvent that dissolves the material, or a suspension that contains a material that becomes the light emitting layer and a dispersion medium that dissolves the material is used. In addition, the liquid illustrated as a solvent below can be used suitably suitably also as a dispersion medium. Examples of the solvent or dispersion medium include liquids exemplified as the solvent or dispersion medium of the ink containing the material that forms the partition walls.

As the material for the light emitting layer 16, an organic material that emits fluorescence and / or phosphorescence is used. As the organic substance, a low molecular compound and / or a high molecular compound is used, and a high molecular compound is preferably used from the viewpoint of solubility. The light emitting layer preferably contains a polymer compound having a polystyrene-equivalent number average molecular weight of 10 ³ or more and 10 ⁸ or less. In addition to the organic material, the light emitting layer may include an optional component such as a dopant. For example, the dopant is added for the purpose of improving the light emission efficiency or changing the light emission wavelength. Examples of the light emitting material mainly constituting the light emitting layer 16 include the following.

(Dye-based luminescent materials)
Examples of dye-based light emitting materials include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophenes. Examples include a ring compound, a pyridine ring compound, a perinone derivative, a perylene derivative, an oligothiophene derivative, a trifumanylamine derivative, an oxadiazole dimer, a quinacridone derivative, a coumarin derivative, and a pyrazoline dimer.

(Metal complex-based luminescent materials)
The metal complex-based light emitting material includes Al, Zn, Be or the like as a central metal, or a rare earth metal such as Tb, Eu, or Dy, and oxadiazole, thiadiazole, phenylpyridine, or phenylbenzo as ligands. Examples of the polymer complexes of metal complexes having an imidazole or quinoline structure, such as iridium complexes, platinum complexes, etc., metal complexes that emit light from triplet excited states, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, etc. Benzoxazolyl zinc complex, benzothiazole zinc complex, azomethylzinc complex, porphyrin zinc complex, europium complex and the like.

(Polymer-based luminescent materials)
Examples of the polymer light-emitting material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, and polyvinylcarbazole derivatives.

(Dopant material)
The light emitting material mainly constituting the light emitting layer 16 may further include a dopant material in addition to the above light emitting material, for example, for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such dopant materials include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazolone derivatives, decacyclene, phenoxazone, and the like. The thickness of such a light emitting layer is usually about 2 nm or more and 200 nm or less.

  In the present embodiment, the light emitting layer 16 is applied by the nozzle printing method from the viewpoint that the light emitting layer 16 can be easily formed in a short time as in the case of forming the partition wall 15. In addition, as a coating method for forming a light emitting layer, any pattern coating method may be used, and coating such as a micro gravure coating method, a gravure coating method, a screen printing method, a flexographic printing method, an offset printing method, and an ink jet printing method. The law can be mentioned.

<5. Cathode formation process>
In the cathode formation step, the cathode 17 is provided so as to cover the light emitting layer 16 and the partition 15. Examples of the method for forming the cathode 17 include a vacuum deposition method, a sputtering method, and a laminating method in which a metal thin film is thermocompression bonded.

  According to the manufacturing method of the organic EL element of the present embodiment described above, an organic EL element having a simple process and low cost, high film flatness, and excellent light emission performance capable of uniform light emission is manufactured. Can do.

2. Structure of organic EL element and other members

<A> Support Substrate The support substrate 11 is preferably one that does not change in the step of forming the organic EL element, 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 A laminated plate obtained by laminating these is preferably used. In a so-called bottom emission type organic EL element that takes out light emitted from the light emitting layer 16 from the support substrate 11 side, the support substrate 11 having a high light transmittance in the visible light region is preferably used. In the top emission type organic EL element that extracts light emitted from the light emitting layer 16 from the side opposite to the substrate, the support substrate may be opaque.

<B> Anode The anode in the present embodiment is a transparent electrode that is provided as the first electrode and has a light transmission property that transmits light from the light emitting layer 16. For the anode 12, 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 12 can be appropriately selected according to the constituent material of the light emitting layer 16. Can be used.

  Examples of the material of the anode 12 include indium oxide, zinc oxide, tin oxide, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), gold, platinum, silver, copper, A thin film such as aluminum or an alloy containing two or more of these metals is used. Among these, ITO, IZO, and tin oxide are preferable.

  Further, as a constituent material of the anode 12, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used.

  The film thickness of the anode 12 can be appropriately selected in consideration of required characteristics and process simplicity, 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. As mentioned above, it is 500 nm or less.

<C> Pixel region defining layer The pixel region defining layer is provided to electrically insulate each organic EL element. Since a circuit, wiring, etc. (not shown) are provided between the anodes 12 on the support substrate 11, the pixel region defining layer 13 is composed of, for example, an insulating layer so as to protect the circuit, wiring, etc. (not shown). Yes. In the present embodiment, the pixel region defining layer 13 is provided on the support substrate 11, but the present invention is not limited to this and may not be provided on the support substrate 11.

  The material constituting the pixel region defining layer may be any material having an insulating property, for example, a photosensitive novolac resin to which a photosensitive material such as naphthoquinone diazide is added, a photoresist material such as photosensitive polyimide, or an inorganic material such as silicon dioxide. An inorganic nitride film such as an oxide film or silicon nitride can be used.

<D> Common Layer The organic EL element 18 shown in FIG. 1 shows a form in which a common layer 14 is provided between the anode 12 and the light emitting layer 16, and includes a hole injection layer 14a, an electron blocking layer 14b, The hole injection layer 14a and the electron blocking layer 14b are laminated in this order from the support substrate 11 side.

  The thickness of the hole injection layer 14a is preferably 0.5 nm or more and 20 nm or less. This is because if the thickness of the hole injection layer 14a is smaller than 0.5 nm, pinholes may be generated in the hole injection layer 14a. Further, when the thickness of the hole injection layer 14a is increased, the resistance of the hole injection layer 14a in the lateral direction perpendicular to the thickness direction of the support substrate 11 is decreased. Since the hole injection layer 14a is provided in common between the pixels, if the resistance in the lateral direction is low, an unintended current may flow to the adjacent pixel. Therefore, the thickness of the hole injection layer 14a is 20 nm or less. As described above, the current can be prevented from moving in the lateral direction of the hole injection layer 14a by reducing the film thickness. Moreover, you may make it use the thing with high resistance of the positive hole injection layer 14a.

  The thickness of the electron blocking layer 14b is preferably 40 nm or more and 200 nm or less. This is because if the thickness of the electron blocking layer 14b is smaller than 40 nm, the unevenness on the surface of the electrode 12 cannot be absorbed by the electron blocking layer 14b and dielectric breakdown may occur due to local electric field concentration. On the other hand, if the thickness of the electron blocking layer 14b is larger than 200 nm, the resistance between the electrode 12 and the electrode 17 becomes high, current may not flow, and sufficient EL light emission may not be obtained. The electron blocking layer 14b may be made of a material with low resistance, and the electron blocking layer 14b is preferably formed thick with a low resistance.

  Further, the configuration of the layer provided between the anode 12 and the light emitting layer 16 is not limited to the configuration example shown in FIG. When the anode 12 is provided as the first electrode, the hole injection layer 14a, the electron blocking layer 14b, and the like may be provided as the common layer 14. When a cathode is provided as the first electrode, a common layer 14 electron injection layer, electron transport layer, hole blocking layer, or the like may be provided.

  Note that although a common layer is provided in this embodiment, a common layer may not be provided in other embodiments, and a layer described as a common layer in this embodiment may be provided between partition walls.

<E> Partition Wall The partition wall is provided in contact with a part of the common layer in FIG.

  The height of the partition wall 15 is preferably 0.5 nm or more and 20 nm or less. If the height of the partition wall 15 is smaller than 0.5 nm, it is difficult to form a partition wall having a uniform height, which may cause a defective partition wall formation or a region where the partition wall is not formed. is there. On the other hand, if the height of the partition wall 15 is larger than 20 nm, the amount of the ink 31 attached to the side surface of the partition wall increases, and the variation in the film thickness of the light emitting layer increases, so that uniform EL emission may not be obtained. It is.

  Moreover, it is preferable that the surface of the partition 15 shows a contact angle of 40 degrees or more with respect to the ink 31 containing the material used as a light emitting layer. This is because if the contact angle is less than 40 degrees, the ink 31 supplied between the partition walls 15 is not held in the partition walls and overflows, which may cause uneven light emission and color mixing.

  In the form in which the common layer is not provided, the partition wall is not provided in the common layer, but is provided, for example, on the pixel region defining layer.

<F> Light-Emitting Layer In the organic EL element 18 shown in FIG. 1, the light-emitting layer 16 is provided between the common layer 14 and the cathode 17 and is partitioned by the partition walls 15. Two or more light emitting layers 16 are provided between the common layer 14 and the cathode 17 as necessary.

  The material constituting the light emitting layer and the film forming method are as described above in the section “Method for producing organic EL element”.

<G> Cathode The cathode in the present embodiment is provided as a second electrode disposed to face the first electrode. The material of the cathode 17 is preferably a material having a low work function and easy electron injection into the light emitting layer. The cathode material is preferably a material having high electrical conductivity and high visible light reflectance. 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 alloys containing at least one of the above metals. Specifically, magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium -A magnesium alloy, a lithium-indium alloy, a calcium-aluminum alloy, etc. can be mentioned.

  The cathode 17 is an electrode having optical transparency as required, for example, when light is taken out from the cathode side. Examples of such a light-transmitting cathode material include conductive oxides such as indium oxide, zinc oxide, tin oxide, ITO, and IZO (Indium Zinc Oxide), polyaniline or a derivative thereof, polythiophene or Examples thereof include conductive organic substances such as derivatives thereof.

  The cathode 17 may have a laminated structure of two or more layers. In some cases, the electron injection layer is used as a cathode.

  The film thickness of the cathode 17 can be appropriately selected in consideration of electric conductivity and durability. For example, the film thickness is 10 nm or more and 10 μm or less, preferably 20 nm or more and 1 μm or less, and more preferably 50 nm or more. , 500 nm or less.

<H> Sealing member After forming an organic EL element, you may provide the sealing member for protecting this organic EL element.
<I> Arbitrary Component Layer In the organic EL element 18 shown in FIG. 1, the common layer 14 and the light emitting layer 16 are provided between the anode 12 and the cathode 17, and the hole injection layer 14 a and the electronic block are provided as the common layer 14. The form in which the layer 14b is provided is shown. The configuration of the layer provided between the anode 12 and the cathode 17 is not limited to the configuration example shown in FIG. 1, and a hole injection layer 14a and an electron blocking layer are provided between the anode 12 and the cathode 17. In addition to 14b, for example, a hole transport layer, an electron injection layer, an electron transport layer, a hole block layer, and the like may be provided.

  Examples of the layer that can be provided between the anode 12 and the light emitting layer 16 include a hole injection layer, a hole transport layer, and an electron block layer. When both the hole injection layer and the hole transport layer are provided between the anode 12 and the light emitting layer 16, the layer located on the side close to the anode 12 is referred to as the hole injection layer and is close to the light emitting layer 16. The layer located on the side is called a hole transport layer.

  Examples of the layer that can be provided between the cathode 17 and the light emitting layer 16 include an electron injection layer, an electron transport layer, and a hole blocking layer. When both the electron injection layer and the electron transport layer are provided between the cathode 17 and the light emitting layer 16, the layer located on the side close to the cathode 17 is referred to as the electron injection layer, and is located on the side close to the light emitting layer 16. This layer is called an electron transport layer.

  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.

Hereinafter, the layer provided between the anode 12 and the cathode 17 will be described.
<I-1> Hole Injection Layer The hole injection layer is a layer having a function of improving the hole injection efficiency from the anode 12. The hole injection layer can be provided between the anode 12 and the hole transport layer or between the anode 12 and the light emitting layer 16. As a material constituting the hole injection layer, a known material can be appropriately used, and there is no particular limitation. 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, silane coupling materials, and the like, and silane coupling materials are preferred.

  Examples of the method for forming the hole injection layer include the above-described coating method and vapor deposition method.

<I-2> Hole transport layer The hole transport layer is a layer having a function of improving hole injection from the anode 12, the hole injection layer, or the hole transport layer closer to the anode 12, and the hole transport layer. Is a layer having a function of transporting holes.

  The material constituting the hole transport layer is not particularly limited. For example, N, N′-diphenyl-N, N′-di (3-methylphenyl) 4,4′-diaminobiphenyl (TPD), 4 , 4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB) and other aromatic amine derivatives, polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, aromatic amines in the side chain or main chain Polysiloxane derivative having pyrazole, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole or derivative thereof, poly (p-phenylene vinylene) Or its derivatives, or Poly (2,5-thienylene vinylene) or derivatives thereof such as are exemplified.

  Among these, as the hole transport material used for the hole transport layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof as a silane coupling material, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain , Polyaniline or derivatives thereof, polythiophene or derivatives thereof, polyarylamine or derivatives thereof, poly (p-phenylene vinylene) or derivatives thereof, or poly (2,5-thienylene vinylene) or derivatives thereof The material is preferable, and polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in a side chain or a main chain are more preferable. 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.

<I-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.

<I-4> Electron Injection Layer The electron injection layer is a layer having a function of improving the efficiency of electron injection from the cathode 17. The electron injection layer is provided between the electron transport layer and the cathode 17 or between the light emitting layer 16 and the cathode 17. Depending on the type of the light emitting layer, the electron injection layer may be an alkali metal or alkaline earth metal, an alloy containing one or more of the above metals, an oxide, halide and carbonate of the metal, or a mixture of the substances. Etc.

  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, calcium fluoride, barium oxide, fluorine. Barium fluoride, strontium oxide, strontium fluoride, magnesium carbonate and the like.

  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.

<I-5> Electron Transport Layer The electron transport layer is a layer having a function of improving electron injection from the cathode 17, the electron injection layer or the electron transport layer closer to the cathode 17, and the electron transport layer transports electrons. This is a functional layer.

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

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

  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 etc. are 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.

<I-6> 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.

<J> Combination of Layer Configurations of Organic EL Element As described above, the organic EL element can employ various layer configurations as its embodiment. A specific example of the layer structure that the organic EL element can take when a charge injection layer, a charge transport layer, and a charge block layer are added as options is shown below.
Aa) Anode / hole injection layer / light emitting layer / cathode Ab) Anode / hole injection layer / electron blocking layer / light emitting layer / cathode Ba) Anode / light emitting layer / electron injection layer / cathode Bb) Anode / light emitting layer / positive Hole blocking layer / electron injection layer / cathode Ca) anode / hole injection layer / light emitting layer / electron injection layer / cathode Cb) anode / hole injection layer / electron blocking layer / light emitting layer / electron injection layer / cathode Cc) anode / Hole injection layer / light emitting layer / hole blocking layer / electron injection layer / cathode Cd) anode / hole injection layer / electron blocking layer / light emitting layer / hole blocking layer / electron injection layer / cathode Da) anode / positive Hole injection layer / hole transport layer / light emitting layer / cathode Db) anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / cathode Ea) anode / light emitting layer / electron transport layer / electron injection layer / Cathode Eb) Anode / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode Fa) anode Hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode Fb) anode / hole injection layer / electron blocking layer / light emitting layer / electron transport layer / electron injection layer / cathode Fc) anode / hole injection layer / Light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode Fd) anode / hole injection layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode Ga) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode Gb) anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / electron injection layer / cathode Gc) anode / Hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron injection layer / cathode Gd) anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron Injection layer / cathode Ha) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / Pole Hb) Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / electron transport layer / electron injection layer / cathode Hc) Anode / hole injection layer / hole transport layer / light emitting layer / hole Block layer / electron transport layer / electron injection layer / cathode Hd) anode / hole injection layer / hole transport layer / electron block layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode (here The symbol “/” indicates that the layers sandwiching the symbol “/” are stacked adjacent to each other.

In the embodiment shown in FIG. 1, the single light emitting layer 16 is provided, but as a modification thereof, a form in which two or more light emitting layers are provided in an overlapping manner may be employed. Here, in any one of the layer configurations (Aa) to (Hd) described above, when the layered body sandwiched between the anode and the cathode is “structural unit A”, for example, the following (I) The layer structure shown can also be employed. Note that the two (structural unit A) layer structures may be the same or different.
I) Anode / (structural unit A) / charge generation layer / (structural unit A) / cathode

Further, as an organic EL device having three or more light emitting layers, when “(structural unit A) / charge injection layer” is “structural unit B”, for example, the layer configuration shown in (J) below can be exemplified. .
J) Anode / (Structural unit B) _n / (Structural unit A) / Cathode

The symbol “n” represents an integer of 2 or more, and (structural unit B) _n represents a stacked body in which n layers of the structural unit B are stacked. A plurality of (structural units B) may have the same or different layer structure.

  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.

  In the embodiment shown in FIG. 1, an embodiment in which the anode 12 is provided on the support substrate 11 is shown. In these cases, in each of the above forms Aa) to J), the layers are arranged on the support substrate 11 in order from the layer shown on the left side (anode side).

  On the other hand, as the organic EL element of the present invention, a form in which a cathode is disposed on a support substrate can be employed. In this case, in each of the above forms Aa) to J), the layers are arranged on the support substrate in order from the layer shown on the right side (cathode side). In this case, a layer provided between the cathode and the light emitting layer may be formed across the plurality of organic EL elements as a common layer.

[Second Embodiment]
Next, a second embodiment of the organic EL element manufactured by the manufacturing method of the present invention will be described with reference to FIG. FIG. 10 is a perspective view schematically showing a state in which an ink containing a material that becomes a light emitting layer is applied. In FIG. 10, members that are the same as those in the first embodiment are denoted by the same reference numerals as in FIGS. 1 to 9, and redundant descriptions are omitted. Hereinafter, differences from the first embodiment will be mainly described.

  In the present embodiment, light emitting layers having different emission colors are formed for each column in regions partitioned by the partition formed by the partition forming step. That is, a first light emitting layer is formed in a first region partitioned by the partition 15 formed by the partition forming step, and the first light emitting layer is formed in a second region adjacent to the first region in parallel. Forms a second light-emitting layer having a different emission color, and a third light-emitting layer having a light emission color different from any of the first and second light-emitting layers is formed in a third region adjacent to the second region in parallel. To form.

As shown in FIG. 10, a device (illustrated) provided with a triple nozzle 33 having three nozzles is used to supply the ink 31 containing the material to be the light emitting layer. 3-nozzle 33 has a red nozzles N _R for ejecting ink containing a red light-emitting material, a green nozzle N _G for ejecting ink containing a green light-emitting material, the blue nozzles N _B for ejecting ink containing a blue luminescent material ing. Three nozzles N _R 3-nozzle 33, N _G, while discharging the respective inks 31a~31c from N _B along the longitudinal direction of the partition wall 15, moves to the other direction of movement Nm. Thus, the red light emitting layer 16a, the green light emitting layer 16b, and the blue light emitting layer 16c are formed simultaneously by apply | coating the ink 31a-31c containing the material used as a light emitting layer to each area | region divided by the partition 15.

  Next, inks 31 a to 31 c containing a material that becomes a light emitting layer are applied to regions partitioned by other adjacent partition walls 15. Such operations are repeated, and inks 31 a to 31 c containing a material that becomes a light emitting layer are sequentially applied to a plurality of regions partitioned by the partition on the support substrate 11.

  Thus, the first region that emits red (R), green (G), or blue (B) to the first region among the plurality of regions partitioned by the partition 15 formed by the partition formation step. An organic EL element is formed, a second organic EL element that emits one color different from the emission color of the first organic EL element is formed in a column adjacent to one of the first columns, and the first column An organic EL element that emits one color different from the emission color of the first and second organic EL elements is formed in a column adjacent to the other of the first and second organic EL elements.

  By the method described above, an organic EL element having a light emitting layer of a different emission color can be formed, and an organic EL element having high characteristics can be manufactured by a simple process as in the first embodiment.

[Third Embodiment]
The organic EL element provided in the organic EL device manufactured according to the first embodiment has a bottom emission type element structure that emits light emitted from the light emitting layer to the outside through the anode and the support substrate. The organic EL device included in the organic EL device manufactured according to the third embodiment is an organic EL device having a top emission type structure that emits light from the opposite side of the support substrate using a light-transmitting cathode. This is an EL element. The present invention can also be applied to an organic EL element provided in the organic EL device manufactured according to the third embodiment.

  For such a transparent cathode, for example, a metal thin film can be used as the transparent cathode. Since the metal thin film used for the transparent cathode is formed into a thin film that can transmit light, the sheet resistance is increased. Therefore, the transparent cathode is preferably constituted by a laminate in which a transparent electrode such as an ITO thin film is laminated on a metal thin film. In addition, it is preferable to provide a reflective film having a high reflectance such as silver between the anode and the support substrate, and by providing such a reflective film, light directed toward the support substrate is reflected to the transparent cathode side. And the light extraction efficiency can be improved.

  In each of the above-described embodiments, the first electrode is formed in a stripe shape. However, the first electrode may be provided for each organic EL element, or the first electrode may be provided in an island shape discretely. Good. In addition, the organic EL device of each of the above-described embodiments can function as a display device by configuring, for example, an active matrix driving system or passive matrix driving circuit.

<Organic EL device>
The organic EL device that can be manufactured by the manufacturing method of the present invention is a device in which a plurality of pixels configured with organic EL elements are mounted as described above. Regarding the installation of electrical wiring, driving means, etc., various modes in the manufacture of a normal organic EL device can be adopted.

  The organic EL device that can be produced by the production method of the present invention can be suitably used as a curved or flat illumination device, for example, a planar light source, a segment display device, or a dot matrix display device.

10 Organic EL device 11 Support substrate 12 Anode (first electrode)
12a Exposed surface 13 Pixel region defining layer 14 Common layer 14a Hole injection layer 14b Electron blocking layer 15 Partition 16 Light emitting layer 17 Cathode (second electrode)
18 Organic EL element 21 Pixel opening 22 Surface of common layer 23 Ink containing material for partition wall 24 Matrix part (display area part)
Ink 32 containing the material to be 25 panel 31,31a~31c emitting _{layer, N R, N G, N} B conveying direction Ip of the nozzle 33 3-nozzle Dd panel, the trajectory of Iq nozzle

Claims (11)

A support substrate;
A plurality of organic electroluminescence elements provided on the support substrate;
A plurality of partition walls for partitioning the organic electroluminescence element;
With
The organic electroluminescence element has a first electrode, a second electrode, and a light emitting layer containing an organic compound disposed between the first and second electrodes.
A method for manufacturing an organic electroluminescence device, comprising:
Preparing a supporting substrate on which the first electrode is formed;
A partition forming step of forming a plurality of partition walls by supplying ink containing a material to be the partition walls while discharging in a liquid column shape along a site where the partition walls are provided, and further solidifying;
A light emitting layer forming step of forming the light emitting layer between the partition walls;
A second electrode forming step of forming the second electrode;
A method for producing an organic electroluminescence device, comprising: The organic electroluminescence element includes a common layer common to the plurality of organic electroluminescence elements between the first electrode and the light emitting layer,
The organic electroluminescent device according to claim 1, further comprising a common layer forming step of integrally forming a common layer across the plurality of organic electroluminescent elements after the preparation step and before the partition formation step. Production method.   The method for manufacturing an organic electroluminescence device according to claim 2, wherein in the common layer forming step, the common layer is formed by a spin coating method.   The method of manufacturing an organic electroluminescence device according to claim 2, wherein in the common layer forming step, the common layer is formed by a vacuum vapor deposition method or a chemical vapor deposition method. The first electrode is an anode;
The second electrode is a cathode;
The light emitting layer is disposed in contact with the common layer;
5. The method according to claim 2, wherein, in the common layer forming step, a common layer including a hole injection layer disposed at a position in contact with the anode and an electron blocking layer disposed at a position in contact with the light emitting layer is formed. A method for producing an organic electroluminescence device according to claim 1.   The method for manufacturing an organic electroluminescence device according to claim 5, wherein in the common layer forming step, the hole injection layer having a film thickness of 0.5 nm or more and 20 nm or less is formed.   The method for manufacturing an organic electroluminescent device according to claim 5 or 6, wherein, in the common layer forming step, the hole injection layer is formed of a silane coupling material.   8. The method of manufacturing an organic electroluminescence device according to claim 5, wherein in the common layer forming step, an electron block layer having a thickness of 40 nm or more and 200 nm or less is formed. In the light emitting layer forming step, the light emitting layer is formed by a coating method using an ink containing a material to be the light emitting layer,
The organic electroluminescence device according to any one of claims 1 to 8, wherein in the partition formation step, a partition having a contact angle of 40 degrees or more with respect to the partition surface with respect to ink including a material to be a light emitting layer is formed. Method.   10. The method of manufacturing an organic electroluminescence device according to claim 1, wherein in the partition formation step, a partition having a height of 0.5 nm or more and 20 nm or less is formed.   In the light emitting layer forming step, ink containing a material to be a light emitting layer is supplied while being discharged in a liquid column along a portion where the light emitting layer is provided, and further solidified to form the light emitting layer. The manufacturing method of the organic electroluminescent apparatus as described in any one of 1 to 10.

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