JP2011233512A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting device in which voltage drop can be suppressed without needlessly increasing the film thickness of wires on a support substrate.SOLUTION: A light emitting device has a support substrate 11, plural organic EL elements 15 each of which is constructed by laminating a first electrode 16, an organic EL layer 17 and a second electrode 18 in this order on the support substrate, a counter substrate 31 disposed so as to face the support substrate, a projecting portion 34 projecting from the support substrate to the counter substrate, and a connection electrode 35 which is formed to extend from the second electrode onto the projecting portion 34. A member 33 having conductivity is provided on a surface portion of the counter substrate which faces the support substrate, and the connection electrode formed on the projecting portion comes into contact with the counter substrate.

Description

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

  There are various types of display devices having different configurations and principles. As one of them, a display device using an organic EL (Electro Luminescence) element as a light source of a pixel is being put into practical use.

The display device has a display area for displaying image information, and a plurality of organic EL elements are arranged in alignment in this display area. Electric power is supplied to each organic EL element from a power supply source, but the voltage applied to each organic EL element decreases due to a voltage drop that occurs in the middle wiring.
Since the voltage drop increases as the distance between the power supply source and the organic EL element increases, the magnitude varies depending on the arrangement of the organic EL elements. For example, the magnitude of the voltage drop that occurs when power is supplied differs between the organic EL element arranged at the center of the display area and the organic EL element arranged at the peripheral edge of the display area. Since the magnitude of the voltage drop varies depending on the arrangement of the organic EL elements as described above, the voltage applied to each organic EL element also varies depending on the arrangement, and as a result, the emission intensity in the display region is uneven (for example, Patent Document 1) reference).

  In order to reduce the voltage drop, the electrical resistance of the wiring on the way may be reduced, and for this purpose, the thickness of the wiring may be increased. However, in order to increase the thickness of the wiring, the time required for the manufacturing becomes longer accordingly. In particular, in a display device on which an organic EL element is mounted, in order to suppress damage to the organic EL element, the wiring is usually formed by a vacuum deposition method having a low film forming speed, and therefore the time required for forming the wiring becomes longer. . The unevenness of the light emission intensity caused by the voltage drop becomes more prominent as the display area becomes larger. Therefore, as the display device becomes larger, it is necessary to increase the thickness of the wiring, and the time required for forming the wiring also becomes longer. There is a problem.

JP-A-2005-70295

  Accordingly, an object of the present invention is to provide a light emitting device in which a voltage drop is suppressed without unnecessarily thickening a wiring on a supporting substrate.

The present invention includes a support substrate,
A plurality of organic EL elements configured by laminating a first electrode, an organic EL layer, and a second electrode in this order on the support substrate;
A counter substrate disposed to face the support substrate;
A protrusion that protrudes from the support substrate toward the counter substrate;
A connection electrode formed extending from the second electrode onto the protrusion,
The surface portion facing the support substrate of the counter substrate is provided with a conductive member.
The present invention relates to a light emitting device in which a connection electrode formed on the protrusion is in contact with the counter substrate.
The present invention further includes a partition wall provided on the support substrate and separating the plurality of organic EL elements,
The protrusion relates to a light emitting device provided on the partition.
The present invention also relates to a light emitting device in which the counter substrate is made of a conductive member.
The present invention also relates to a light emitting device, wherein the counter substrate includes an insulating substrate exhibiting electrical insulation and a conductive thin film provided on the insulating substrate.
The present invention also relates to a light emitting device, wherein the conductive thin film is formed on an insulating substrate by a sputtering method.
According to the present invention, the conductive thin film is one or more metal thin films selected from the group consisting of Ag, Al, Au, Cr, Cu, In, Mg, Mo, Pt, Sn, Ta, W, and Zn. It is related with the light-emitting device comprised by these.
Further, the present invention is a method for manufacturing a light emitting device for manufacturing the light emitting device,
A step of preparing a support substrate on which the protrusion, the organic EL element, and the connection electrode are provided;
A step of preparing a counter substrate provided with a conductive member on the surface portion;
A method for manufacturing a light emitting device, comprising a step of bonding the support substrate and the counter substrate.

  According to the present invention, it is possible to realize a light emitting device in which a voltage drop is suppressed without unnecessarily thickening the wiring on the support substrate.

It is a top view which expands and schematically shows a part of light-emitting device. FIG. 3 is an enlarged cross-sectional view schematically showing a region where one organic EL element 15 is provided in the light emitting device. It is a top view which shows a light-emitting device typically. It is a top view which shows a light-emitting device typically. It is a top view which shows a light-emitting device typically.

  The light emitting device of the present invention includes a support substrate, a plurality of organic EL elements configured by laminating a first electrode, an organic EL layer, and a second electrode in this order on the support substrate, and facing the support substrate. A counter substrate disposed from the support substrate, the projecting portion projecting from the support substrate toward the counter substrate, and a connection electrode formed extending from the second electrode onto the projecting portion, In the light emitting device, a conductive member is provided on a surface portion of the counter substrate facing the support substrate, and a connection electrode formed on the protrusion is in contact with the counter substrate.

  The light emitting device of the present invention is used as a display device, for example. There are mainly two types of display devices: an active matrix drive type device and a passive matrix drive type device. Although the present invention can be applied to both types of display devices, in the present embodiment, a light emitting device applied to an active matrix drive type display device will be described as an example.

<Configuration of light emitting device>
First, the structure of the light emitting device will be described. FIG. 1 is a plan view schematically showing an enlarged part of the light emitting device. FIG. 2 is a cross-sectional view schematically showing an enlarged region where one organic EL element 15 is provided in the light emitting device. In FIG. 1, hatching is applied to a region where a partition wall 12 to be described later is provided.

  The light emitting device of the present embodiment mainly includes a support substrate 11, a plurality of organic EL elements 15 provided in alignment on the support substrate 11, and a counter substrate 31 disposed to face the support substrate 11. Consists of.

  In the present embodiment, the partition wall 12 is provided on the support substrate 11. The partition wall 12 is provided to demarcate a preset section on the support substrate 11. The plurality of organic EL elements 15 are respectively provided in the sections defined by the partition walls 12. The partition 12 in the present embodiment is configured by laminating a first partition member 13 and a second partition member 14 in this order from the support substrate 11 side. Hereinafter, when the first partition member 13 and the second partition member 14 are described without particular distinction, the first partition member 13 and the second partition member 14 are collectively referred to as the partition 12.

  The partition walls 12 in the present embodiment are provided in a lattice shape when viewed from one side in the thickness direction Z of the support substrate 11 (hereinafter sometimes referred to as “in plan view”). That is, the partition wall 12 includes a plurality of members extending in the row direction X and a plurality of members extending in the column direction Y. A plurality of members extending in the row direction X are arranged at a predetermined interval in the column direction Y, and a plurality of members extending in the column direction Y are arranged at a predetermined interval in the row direction X. Is done. The plurality of members extending in the row direction X and the members extending in the column direction Y are orthogonal to each other and are integrally formed. In other words, the partition wall 12 has a shape in which a plurality of openings 19 are formed in a flat insulating member. That is, the partition wall is formed with a plurality of openings 19 that are spaced apart in the row direction X and spaced apart in the column direction Y. In the present specification, the row direction X and the column direction Y mean directions perpendicular to each other and perpendicular to the thickness direction Z of the support substrate 11. The width of the plurality of members constituting the partition 12 is determined by the specifications of the light emitting device, the simplicity of the manufacturing process, and the like, but is usually about 10 μm to 100 μm.

  The first partition member 13 and the second partition member 14 are provided in a lattice shape as described above in plan view, but their outer edges are different from each other in plan view. The outer edge of the second partition member 14 is formed by retracting from the outer edge of the first partition member 13 to the inside on the first partition member 13. In other words, the first partition member 13 is formed so that its outer edge protrudes from the outer edge of the second partition member 14 in plan view.

  Although the thickness of the 1st partition member 13 is decided by the specification of a light-emitting device, the simplicity of a manufacturing process, etc., it is about 30 nm-500 nm normally. The thickness of the second partition member 14 is usually about 0.5 μm to 5 μm, although it depends on the specifications of the light emitting device and the simplicity of the manufacturing process.

  A plurality of organic EL elements 15 are provided on the support substrate 11. Each organic EL element 15 is provided in a region surrounded by the partition wall 12. That is, each organic EL element 15 is provided in each of a plurality of openings 19 formed in the partition wall 12. In this embodiment, since the grid | lattice-like partition 12 is provided, the some organic EL element 15 is arrange | positioned at a matrix form, respectively. That is, the plurality of organic EL elements 15 are arranged at predetermined intervals in the row direction X and at predetermined intervals in the column direction Y, respectively. The size of the organic EL element 15 or the opening 19 is determined by the specifications of the light emitting device, the simplicity of the manufacturing process, etc. For example, in the display device, the width in the row direction X and the column direction Y of the organic EL element 15 or the opening 19 is Each is about 30 μm to 300 μm.

  The light emitting device further includes a protrusion 34 that protrudes from the support substrate 11 toward the counter substrate 31. In the present embodiment, the protruding portion 34 is provided separately from the partition wall 12. In addition, as will be described later, a protruding portion may be provided separately from the partition wall, and a partition wall that also functions as a protruding portion may be provided.

In the present embodiment, the protrusion 34 is provided on the partition wall 12. The protrusions 34 may be formed on the partition wall 12 so as to be continuous in a predetermined direction, or may be formed discretely with a predetermined interval. FIG. 3 is a plan view schematically showing a light-emitting device having continuous protrusions 34, and FIG. 4 is a plan view schematically showing a light-emitting device having protrusions 34 arranged at a predetermined interval. . In FIG. 3 and FIG. 4, the area where the protrusion is provided is hatched.
The protrusion 34 is formed in a tapered shape as the protrusion 34 is separated from the support substrate 11. Thus, by forming the protrusion 34 in a tapered shape, the connection electrode 35 and the second electrode 18 that are continuous with each other can be easily formed.

  When providing continuous protrusions, for example, a lattice-like protrusion may be formed in the same manner as the partition wall 12 (see FIG. 3A), and a plurality of stripes extending in the row direction X or the column direction Y. A protruding portion may be formed (see FIG. 3B). Such a continuous protrusion has a trapezoidal cross-sectional shape, for example. When the protrusions are discretely arranged, for example, the protrusions may be formed at the intersecting portions of the grid-like partition walls (see FIG. 4 (1)), and the organic adjacent in the row direction X or the column direction Y. Projections may be formed between the EL elements 15 (see FIG. 4B). Such discretely arranged protrusions are formed in a truncated cone shape such as a truncated cone shape and a truncated pyramid shape, for example.

  Note that when the support substrate 11 and the counter substrate 31 are bonded together, even if unintended particles exist on the support substrate 11, the particles are normally accommodated in the recesses, so that the counter substrate and the protrusions are It is possible to prevent the particles from being connected so as to sandwich the particles. From such a viewpoint, it is preferable to dispose the protrusions discretely.

  The size of the protrusion 34 is determined by the specifications of the light emitting device, the simplicity of the manufacturing process, and the like. For example, in the display device, the height of the protrusion 34 is about 1 μm to 10 μm.

  The organic EL element 15 includes a pair of electrodes composed of an anode and a cathode, and an organic EL layer 17 provided between the electrodes. The organic EL layer 17 may be composed of only one layer, but may be composed of a plurality of layers stacked. The organic EL element 15 includes at least one light emitting layer as an organic EL layer.

  In the following, of the pair of electrodes composed of the anode and the cathode, one electrode disposed near the support substrate is referred to as the first electrode 16, and is disposed farther from the support substrate 11 than the first electrode 16. The other electrode is called the second electrode 18.

In this embodiment, an active matrix driving type substrate is used. Therefore, the same number of first electrodes 16 as the organic EL elements 15 are provided on the support substrate 11. The plurality of first electrodes 16 are arranged in a matrix like the plurality of organic EL elements 15. That is, the plurality of first electrodes 16 are arranged at predetermined intervals in the row direction X and at predetermined intervals in the column direction Y, respectively. The first electrode 16 is formed in a thin film shape, and is formed in, for example, a substantially rectangular shape or a substantially elliptical shape in plan view. The first electrode 16 is mainly formed in a region excluding the region where the first partition member 13 is provided in a plan view, but in the present embodiment, the peripheral portion is covered with the first partition member 13.
In other words, the first partition member 13 in the present embodiment is formed so as to cover the peripheral edge of the first electrode 16.

  The organic EL layer 17 means all layers sandwiched between the first electrode 16 and the second electrode 18 in the organic EL element 15. As described above, at least a light emitting layer is provided as the organic EL layer 17, but in addition to this, a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, an electron injection layer, and the like. Is provided as necessary. The organic EL layer 17 is provided on the first electrode 16 and in a region surrounded by the partition walls 12. That is, the organic EL layer 17 is provided on the opening 19 on the first electrode 16.

  In the present embodiment, the second electrode 18 is provided as a common electrode for the plurality of organic EL elements 15. That is, the second electrode 18 is provided not only on the organic EL layer 17 but also on the partition wall 12 and the protrusion 34 and continuously formed across the plurality of organic EL elements 15.

  As described above, in this embodiment, the conductive member is formed to extend from the second electrode to the protrusion 34. In this specification, the conductive member formed on the protrusion is referred to as a connection electrode 35.

  The counter substrate 31 is disposed to face the support substrate 11. The counter substrate is provided with a conductive member on the surface portion facing the support substrate. Since the counter substrate 31 only needs to be provided with a member exhibiting conductivity on at least the surface portion thereof, all of the counter substrate 31 may be configured by a member exhibiting conductivity. In this embodiment, the counter substrate 31 is electrically The insulating substrate 32 is made up of an insulating substrate 32 and a conductive thin film 33 provided on the insulating substrate 32.

  The counter substrate 31 is bonded to the support substrate 11 with the conductive thin film 33 disposed on the support substrate 11 side. By disposing the counter substrate 31 in this way, the connection electrode 35 formed on the protrusion 34 abuts the counter substrate 31. In the present embodiment, the connection electrode 35 is in contact with the conductive thin film 33.

<Method for manufacturing light emitting device>
Next, a method for manufacturing the light emitting device will be described.

(Process for preparing support substrate)
In this step, a support substrate on which the protrusion, the organic EL element, and the connection electrode are provided is prepared.

  In this embodiment, in order to realize an active matrix display device, a substrate on which circuits for individually driving a plurality of organic EL elements are formed in advance can be used as the support substrate 11. For example, a substrate on which a TFT (Thin Film Transistor), a capacitor, and the like are formed in advance can be used as the support substrate 11.

  Next, a plurality of first electrodes 16 are formed in a matrix on the support substrate 11. The first electrode 16 is formed, for example, by forming a transparent conductive thin film on one surface of the support substrate 11, patterning it in a matrix by photolithography, and removing unnecessary portions by etching. In addition, for example, a mask having an opening formed at a predetermined portion is disposed on the support substrate 11, and a transparent conductive material is selectively deposited on the predetermined portion on the support substrate 11 through the mask to thereby form the first electrode. 16 may be patterned. The material of the first electrode 16 will be described later.

Next, the partition wall 12 is formed on the support substrate 11. In this embodiment, first, the first partition member 13 is formed. The first partition member 13 is made of an organic material or an inorganic material. Examples of the organic material constituting the first partition member 13 include resins such as acrylic resin, phenol resin, and polyimide resin. Examples of the inorganic material constituting the first partition member 13 include SiO _x and SiN _x .

  When the first partition member 13 made of an organic material is formed, first, for example, a positive or negative photosensitive resin is applied on one surface, and a predetermined portion is exposed and developed. Further, by curing this, a lattice-shaped first partition wall member 13 is formed. When forming the first partition member 13 made of an inorganic material, a thin film made of an inorganic material is formed on one surface by a plasma CVD method, a sputtering method, or the like, and then a predetermined portion is removed to thereby form a lattice-shaped first partition member 13. Is formed. The predetermined portion is removed by, for example, photolithography and etching.

  Next, a grid-like second partition member 14 is formed. The second partition member 14 can be formed in a lattice shape in the same manner as the method for forming the first partition member 13 using, for example, the material exemplified as the material of the first partition member 13.

Next, the protrusion 34 is formed. The protrusions 34 can be patterned on the barrier ribs 12 in the same manner as the method of forming the first barrier rib members 13 using, for example, the material exemplified as the material of the first barrier rib members 13.
The partition wall 12 is made liquid repellent as necessary before forming the organic EL layer. For example, when the 2nd partition member 14 is comprised from organic substance, liquid repellency can be provided to the surface of the 2nd partition member 14 by performing a plasma process in the atmosphere containing a fluoride. In this treatment, CF ₄ , CHF ₃ , CH ₂ F ₂ , C ₃ F ₈ , C ₄ F ₆ , C ₄ F ₈ or the like can be used as the fluoride. Thus, by providing liquid repellency to the surface of the second partition member 14, the ink supplied to the region (opening 19) surrounded by the partition 12 can be held in the opening 19.

  Next, an organic EL element is formed. In this embodiment, since the first electrode 16 is formed in advance, the organic EL element 15 is fabricated by further forming the organic EL layer 17 and the second electrode 18.

The organic EL layer 17 is formed by, for example, a coating method. First, ink containing an organic EL material to be the organic EL layer 17 is selectively supplied to a region (opening 19) surrounded by the partition wall 12.
Examples of methods for selectively supplying ink include ink-jet printing methods, letterpress printing methods, intaglio printing methods, and nozzle coating methods. Next, an organic EL layer is formed by solidifying the supplied ink.

  When a layer common to all organic EL elements is formed, it may not be necessary to selectively supply an ink containing an organic EL material to a region surrounded by the partition wall 12. A layer common to all organic EL elements may be formed by selectively supplying ink in the same manner as described above. For example, the entire surface may be formed by spin coating, capillary coating, dip coating, or the like. You may form by apply | coating an ink and solidifying this.

Next, the second electrode 18 is formed. In the present embodiment, the second electrode 18 is formed on the entire surface. That is, a conductive thin film is formed on the entire surface of the organic EL layer 17, the partition wall 12, and the protrusion 34.
As a result, the second electrode 18 continuously provided on all the organic EL elements 15 is formed, and as a result, the connection electrode 35 is formed on the protrusion 34. The material of the second electrode 18 will be described later.

  Next, the counter substrate 31 is prepared. In the present embodiment, a counter substrate 31 composed of an insulating substrate 32 and a conductive thin film 33 provided on the insulating substrate 32 is prepared.

  The insulating substrate 32 is constituted by, for example, a glass substrate or a quartz glass substrate.

  The conductive thin film 33 is formed on the insulating substrate 32 by, for example, a sputtering method or an ion plating method. Since the second electrode 18 may damage the organic EL element when forming the film, it is preferable to form the second electrode 18 by a method that causes little damage to the organic EL element, and the film forming method may be limited. On the other hand, since the method for forming the conductive thin film 33 is not particularly limited, the conductive thin film 33 is preferably formed by a method having a film formation rate faster than that of the second electrode 18, for example, by sputtering. .

  The conductive thin film 33 is preferably made of, for example, a material having low electric resistance, and is selected from the group consisting of Ag, Al, Au, Cr, Cu, In, Mg, Mo, Pt, Sn, Ta, W, and Zn. It is preferable that the thin film is formed of one or more kinds of metals.

  The counter substrate 31 is bonded to the support substrate 11 by a predetermined adhesive member, for example. For example, an adhesive member is first disposed on the peripheral edge of the counter substrate 31, and then the counter substrate 31 is bonded to the support substrate 11. Thereafter, the counter substrate 31 and the support substrate 11 can be bonded by curing the adhesive member. The step of bonding the counter substrate 31 to the support substrate 11 is preferably performed in, for example, an inert gas atmosphere or a vacuum atmosphere. For the adhesive member, for example, a thermosetting resin, a photocurable resin, or frit glass is used.

  As described above, in the light emitting device of this embodiment, the conductive thin film 33 that is electrically connected to the second electrode 18 through the connection electrode 35 is provided on the counter substrate 31. Since the current supplied from the power supply source flows not only through the second electrode 18 but also through the conductive thin film 33, by providing the conductive thin film 33, power is supplied from the power supply source to each organic EL element. It is possible to reduce the voltage drop that occurs during the process. As a result, it is possible to realize a light emitting device in which the voltage drop is suppressed without unnecessarily thickening the second electrode 18 on the support substrate.

  Further, as described above, since there is no limitation on the method for forming the conductive thin film 33, the conductive thin film 33 can be formed by a method having a high film forming speed, and the time required for manufacturing the light emitting device can be shortened. it can.

  Further, by providing the conductive thin film 33, the second electrode 18 can be prevented from being thickened, so that damage to the organic EL element when the second electrode 18 is formed can be suppressed.

  Although it is not considered that the protrusion 34 is formed on the counter substrate side, in this case, when the counter substrate and the support substrate are bonded together, it is necessary to align the both with high accuracy. By forming the protrusions 34 on the support substrate side as in the embodiment, bonding can be performed without highly accurate alignment, and the process can be simplified.

  Further, since the protrusion 34 also functions as a spacer, the stress applied to the counter substrate 31 can be dispersed and the counter substrate 31 can be prevented from bending. Thus, by using the projection 34 as a spacer, it is not necessary to separately form a spacer, and the process can be simplified.

  In the light emitting device of the above-described embodiment, the counter substrate 31 is composed of the insulating substrate 32 exhibiting electrical insulation and the conductive thin film 33 provided on the insulating substrate 32. 31 may be comprised from the electroconductive member. For example, the counter substrate may be composed of one or more thin metal plates selected from the group consisting of Ag, Al, Au, Cr, Cu, In, Mg, Mo, Pt, Sn, Ta, W, and Zn. .

In the light emitting device according to the above-described embodiment, the protrusion 34 is provided separately from the partition wall 12. However, for example, a protrusion that exhibits both functions of the protrusion and the partition wall may be provided. FIG. 5 is a plan view schematically showing a light emitting device including a protrusion that exhibits both functions of the protrusion and the partition.
Thus, when providing the projection part which exhibits the function of both a projection part and a partition, since it becomes unnecessary to form a projection part separately from a partition, a process can be simplified.

  In the present embodiment, the partition walls are configured such that the first partition member 13 and the second partition member 14 are laminated in this order from the support substrate 11 side. However, the partition wall may have a single-layer structure. Good.

  In the present embodiment, both the first partition member 13 and the second partition member 14 have a lattice shape, but the shape of the partition is not limited to the lattice shape. For example, a stripe-shaped second partition member may be provided on the lattice-shaped first partition member 13, and both the first partition member 13 and the second partition member 14 may be formed in a stripe shape.

<Configuration of organic EL element>
As described above, the organic EL element can have various layer configurations. Hereinafter, the layer structure of the organic EL element, the configuration of each layer, and the method of forming each layer will be described in more detail.

As described above, the organic EL element includes a pair of electrodes including an anode and a cathode, and one or more organic EL layers provided between the electrodes, and includes at least one layer as one or more organic EL layers. Having a light emitting layer. The organic EL element may include a layer containing an inorganic substance and an organic substance, an inorganic layer, and the like. The organic substance constituting the organic layer may be a low molecular compound or a high molecular compound, or a mixture of a low molecular compound and a high molecular compound. The organic layer preferably contains a polymer compound, and preferably contains a polymer compound having a polystyrene-equivalent number average molecular weight of 10 ³ to 10 ⁸ .

  Examples of the organic EL layer provided between the cathode and the light emitting layer 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 and the light emitting layer, the layer close to the cathode is called an electron injection layer, and the layer close to the light emitting layer is called an electron transport layer. Examples of the organic EL layer provided between the anode and the light emitting layer 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, a layer close to the anode is referred to as a hole injection layer, and a layer close to the light emitting layer is referred to as a hole transport layer.

An example of a layer structure that can be taken by the organic EL element of the present embodiment is shown below.
a) anode / light emitting layer / cathode b) anode / hole injection layer / light emitting layer / cathode c) anode / hole injection layer / light emitting layer / electron injection layer / cathode d) anode / hole injection layer / light emitting layer / Electron transport layer / cathode e) anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode f) anode / hole transport layer / light emitting layer / cathode g) anode / hole transport layer / light emitting layer / Electron injection layer / cathode h) anode / hole transport layer / light emitting layer / electron transport layer / cathode i) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode j) anode / hole Injection layer / hole transport layer / light emitting layer / cathode k) anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode l) anode / hole injection layer / hole transport layer / light emitting layer / Electron transport layer / cathode m) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode n) anode / light emitting layer / electron injection layer / cathode o) anode / Photo layer / electron transport layer / cathode p) anode / light emitting layer / electron transport layer / electron injection layer / cathode (here, the symbol “/” indicates that the layers sandwiching the symbol “/” are stacked adjacent to each other) Indicates.
same as below. )
The organic EL element of the present embodiment may have two or more light emitting layers. In any one of the layer configurations of a) to p) above, when the laminate sandwiched between the anode and the cathode is referred to as “structural unit A”, the configuration of the organic EL element having two light emitting layers is obtained. And the layer structure shown in the following q). Note that the two (structural unit A) layer structures may be the same or different.
q) Anode / (structural unit A) / charge generating layer / (structural unit A) / cathode If “(structural unit A) / charge generating layer” is “structural unit B”, it has three or more light emitting layers. Examples of the structure of the organic EL element include the layer structure shown in the following r).
r) anode / (structural unit B) x / (structural unit A) / cathode The symbol “x” represents an integer of 2 or more, and (structural unit B) x is a stack in which the structural unit B is stacked in x stages. Represents the body. A plurality of (structural units B) may have the same or different layer structure.

  Here, 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, indium tin oxide (abbreviated as ITO), molybdenum oxide, or the like.

  In the organic EL element, the anode of the pair of electrodes composed of the anode and the cathode may be disposed closer to the support substrate than the cathode, and the cathode may be disposed closer to the support substrate than the anode. And you may provide in a support substrate. For example, in the above a) to r), each layer may be laminated on the support substrate in order from the right side to constitute an organic EL element, or each layer may be laminated on the support substrate in order from the left side to constitute an organic EL element. May be.

  The order of the layers to be laminated, the number of layers, and the thickness of each layer can be appropriately set in consideration of the light emission efficiency and the element lifetime.

  Next, the material and forming method of each layer constituting the organic EL element will be described more specifically.

<Anode>
In the case of an organic EL element having a configuration in which light emitted from the light emitting layer is emitted outside the element through the anode, an electrode exhibiting optical transparency is used for the anode. As the electrode exhibiting light transmittance, a thin film of metal oxide, metal sulfide, metal or the like can be used, and an electrode having high electrical conductivity and light transmittance is preferably used. Specifically, a thin film made of indium oxide, zinc oxide, tin oxide, ITO, indium zinc oxide (abbreviated as IZO), gold, platinum, silver, copper, or the like is used. Among these, ITO, IZO Or a thin film made of tin oxide is preferably used.

  Examples of a method for producing the anode include a vacuum deposition method, a sputtering method, an ion plating method, and a plating method. Further, as the anode, 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 is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

<Cathode>
A material for the cathode is preferably a material having a low work function, easy electron injection into the light emitting layer, and high electrical conductivity. Further, in the organic EL element configured to extract light from the anode side, a material having a high reflectivity with respect to visible light is preferable as the cathode material in order to reflect light emitted from the light emitting layer to the anode side by the cathode. As the cathode, for example, an alkali metal, an alkaline earth metal, a transition metal, a group 13 metal of the periodic table, or the like can be used. Examples of cathode materials include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like. A metal, two or more alloys of the metals, one or more of the metals, and one or more of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin An alloy, graphite, or a graphite intercalation compound is used. Examples of alloys include magnesium-silver alloys, magnesium-indium alloys, magnesium-aluminum alloys, indium-silver alloys, lithium-aluminum alloys, lithium-magnesium alloys, lithium-indium alloys, calcium-aluminum alloys, and the like. it can. As the cathode, a transparent conductive electrode made of a conductive metal oxide or a conductive organic material can be used. Specifically, examples of the conductive metal oxide include indium oxide, zinc oxide, tin oxide, ITO, and IZO, and examples of the conductive organic substance include polyaniline or a derivative thereof, polythiophene or a derivative thereof, and the like. The cathode may be composed of a laminate in which two or more layers are laminated. The electron injection layer may be used as a cathode.

  The film thickness of the cathode is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

  Examples of the method for producing the cathode include a vacuum deposition method and an ion plating method.

<Hole injection layer>
The hole injection material constituting the hole injection layer includes oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide, and aluminum oxide, phenylamine compounds, starburst amine compounds, phthalocyanine compounds, amorphous carbon , Polyaniline, and polythiophene derivatives.

  The film thickness of the hole injection layer is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm. is there.

<Hole transport layer>
As the hole transport material constituting the hole transport layer, polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in a side chain or a main chain, a pyrazoline derivative, an arylamine derivative, a 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 derivative thereof, or poly (2,5-thienylene vinylene) or Examples thereof include derivatives thereof.

  The film thickness of the hole transport layer is set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm. .

<Light emitting layer>
The light emitting layer is usually formed of an organic substance that mainly emits fluorescence and / or phosphorescence, or an organic substance and a dopant that assists the organic substance. The dopant is added, for example, in order to improve the luminous efficiency and change the emission wavelength. In addition, the organic substance which comprises a light emitting layer may be a low molecular compound or a high molecular compound, and when forming a light emitting layer by the apply | coating method, it is preferable that a light emitting layer contains a high molecular compound. The number average molecular weight in terms of polystyrene of the polymer compound constituting the light emitting layer is, for example, about 10 ³ to 10 ⁸ . Examples of the light emitting material constituting the light emitting layer include the following dye materials, metal complex materials, polymer materials, and dopant materials.

(Dye material)
Examples of dye-based materials include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds. Pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, oxadiazole dimers, pyrazoline dimers, quinacridone derivatives, coumarin derivatives, and the like.

(Metal complex materials)
Examples of the metal complex material include rare earth metals such as Tb, Eu, and Dy, or Al, Zn, Be, Ir, Pt, etc. as a central metal, and oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline. Examples include metal complexes having structures as ligands, such as iridium complexes, platinum complexes and other metal complexes that emit light from triplet excited states, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc A complex, a benzothiazole zinc complex, an azomethylzinc complex, a porphyrin zinc complex, a phenanthroline europium complex, and the like can be given.

(Polymer material)
As polymer materials, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinyl carbazole derivatives, the above dye materials and metal complex light emitting materials are polymerized. The thing etc. can be mentioned.

  The thickness of the light emitting layer is usually about 2 nm to 200 nm.

<Electron transport layer>
As the electron transport material constituting 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, tetracyanoanthra. Quinodimethane or derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene or derivatives thereof, diphenoquinone derivatives, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof, etc. Can be mentioned.

  The film thickness of the electron transport layer is appropriately set in consideration of the required characteristics and the simplicity of the film forming process, and is, for example, 1 nm to 1 μm, preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm. .

<Electron injection layer>
As a material constituting the electron injection layer, an optimal material is appropriately selected according to the type of the light emitting layer, and an alloy containing one or more of alkali metals, alkaline earth metals, alkali metals and alkaline earth metals, Alkali metal or alkaline earth metal oxides, halides, carbonates, mixtures of these substances, and the like can be given. Examples of alkali metals, alkali metal oxides, halides, and carbonates 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 alkaline earth metals, alkaline earth metal oxides, halides and carbonates include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, Examples thereof include barium fluoride, strontium oxide, strontium fluoride, and magnesium carbonate. An electron injection layer may be comprised by the laminated body which laminated | stacked two or more layers, for example, LiF / Ca etc. can be mentioned.

  The thickness of the electron injection layer is preferably about 1 nm to 1 μm.

  Each organic EL layer described above can be formed by the above-described coating method, vacuum deposition method, laminating method, or the like.

  In the coating method, an organic EL layer is formed by coating and forming an ink containing an organic EL material to be each organic EL layer. Examples of the ink solvent used at that time include chloroform, methylene chloride, Chlorine solvents such as dichloroethane, ether solvents such as tetrahydrofuran, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, butyl acetate and ethyl cellosolve acetate , And water are used.

DESCRIPTION OF SYMBOLS 11 Support substrate 12 Partition 13 First partition member 14 Second partition member 15 Organic EL element 16 First electrode 17 Organic EL layer 18 Second electrode 19 Opening 31 Counter substrate 32 Insulating substrate 33 Conductive thin film 34 Protrusion 35 Connection electrode

Claims (7)

A support substrate;
A plurality of organic EL elements configured by laminating a first electrode, an organic EL layer, and a second electrode in this order on the support substrate;
A counter substrate disposed to face the support substrate;
A protrusion that protrudes from the support substrate toward the counter substrate;
A connection electrode formed extending from the second electrode onto the protrusion,
The surface portion facing the support substrate of the counter substrate is provided with a conductive member.
A light emitting device, wherein a connection electrode formed on the protrusion is in contact with the counter substrate.   The light-emitting device according to claim 1, further comprising a partition wall provided on the support substrate and separating the plurality of organic EL elements, wherein the protrusion is provided on the partition wall.   The light emitting device according to claim 1, wherein the counter substrate is made of a conductive member.   The light emitting device according to claim 1, wherein the counter substrate includes an insulating substrate that exhibits electrical insulation and a conductive thin film provided on the insulating substrate.   The light emitting device according to claim 4, wherein the conductive thin film is formed on an insulating substrate by a sputtering method.   The conductive thin film is composed of a thin film of one or more metals selected from the group consisting of Ag, Al, Au, Cr, Cu, In, Mg, Mo, Pt, Sn, Ta, W, and Zn. The light emitting device according to claim 4. A method for manufacturing a light emitting device for manufacturing the light emitting device according to claim 1,
A step of preparing a support substrate on which the protrusion, the organic EL element, and the connection electrode are provided;
A step of preparing a counter substrate provided with a conductive member on the surface portion;
A method for manufacturing a light emitting device, comprising a step of bonding the support substrate and the counter substrate.

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