KR102267176B1 - Organic Light Emitting Device and Method of manufacturing the same and Organic Light Emitting Display Device using the same - Google Patents

Abstract

The present invention provides an organic light emitting device capable of improving productivity by minimizing a vacuum deposition process, a method for manufacturing the same, and an organic light emitting display device using the same. A hole injection layer, a hole transport layer provided on the hole injection layer, a light emitting layer provided on the hole transport layer and made of a polymer material including a host material and a dopant material, provided on the light emitting layer, alkali soluble in an organic solvent It may include an electron transport layer including an inorganic material, an electron injection layer provided on the electron transport layer, and a cathode provided on the electron injection layer.

Description

Organic Light Emitting Device and Method of manufacturing the same and Organic Light Emitting Display Device using the same

The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device that can be manufactured using a solution process.

The organic light emitting device has a structure in which a light emitting layer is formed between a cathode for injecting electrons and an anode for injecting holes, and electrons generated from the cathode and holes generated from the anode are transferred into the light emitting layer. It is a device that emits light as the injected electrons and holes combine to generate excitons, and the generated excitons fall from an excited state to a ground state.

Hereinafter, a conventional organic light emitting device will be described with reference to the drawings.

1 is a schematic cross-sectional view of a conventional organic light emitting device.

As can be seen in Figure 1, the conventional organic light emitting device has an anode, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (Emitting Layer; EML), an electron transport layer ( It consists of an Electron Transporting Layer (ETL), an Electron Injecting Layer (EIL), and a cathode.

Organic layers such as a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) provided between the anode and the cathode are vacuum It is formed through a vacuum deposition process in a chamber. However, when the vacuum deposition process is used, expensive vacuum deposition equipment is required, which may increase the manufacturing cost. In particular, when the size of the organic light emitting device is increased, the size of the vacuum deposition equipment is further increased, and thus productivity is lowered in mass production.

Therefore, research on a method of forming the organic layers by a solution process is continuously being conducted. As a result, a method for forming the hole injection layer (HIL), the hole transport layer (HTL), and the light emitting layer (EML) in a solution process has been proposed. However, a method for forming the electron transport layer (ETL) positioned on the emission layer (EML) by a solution process has not yet been developed. This is because, when the electron transport layer ETL is formed by a solution process, the surface of the light emitting layer EML may be damaged by the solvent present in the solution for forming the electron transport layer ETL. . Therefore, until now, only the hole injection layer (HIL), the hole transport layer (HTL), and the light emitting layer (EML) are formed by a solution process, and the electron transport layer (ETL) and the electron injection layer (EIL) are formed through a vacuum deposition process. are doing In this case, productivity may be improved compared to a case in which the entire organic layers are formed by a vacuum deposition process, but productivity is still lowered in the case of manufacturing an organic light emitting device having a large size. In particular, organic material deposition when the electron transport layer (ETL) is formed Since an expensive vacuum deposition chamber is also separately required for this, an increase in manufacturing cost and inconvenience in a manufacturing process follow.

The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide an organic light emitting device capable of improving productivity by minimizing a vacuum deposition process, a method for manufacturing the same, and an organic light emitting display device using the same.

In order to achieve the above technical problem, the present invention is provided on an anode, a hole injection layer provided on the anode, a hole transport layer provided on the hole injection layer, the hole transport layer, including a host material and a dopant material a light emitting layer made of a polymer material comprising: an electron transport layer provided on the light emitting layer and comprising an alkali-based inorganic material soluble in an organic solvent, an electron injection layer provided on the electron transport layer, and a cathode provided on the electron injection layer It provides an organic light emitting device comprising.

The present invention also provides a process for forming a hole injection layer on an anode by a solution process, a process for forming a hole transport layer on the hole injection layer by a solution process, preparing a mixture of a light emitting layer material and an electron transport layer material, and then using the mixture as described above. A process of applying a solution process on the hole transport layer, a process of phase-separating the mixture to form a light emitting layer made of the light emitting layer material on the hole transport layer and forming an electron transport layer made of the electron transport layer material on the light emitting layer, the electron transport layer Provided is a method of manufacturing an organic light emitting device comprising: forming an electron injection layer on the electron injection layer by a vacuum deposition process; and forming a cathode on the electron injection layer.

The present invention also includes a substrate, a thin film transistor provided on the substrate, and an organic light emitting device in which light emission is controlled by the thin film transistor, wherein the organic light emitting device includes an anode, a hole injection layer provided on the anode, and the A hole transport layer provided on the hole injection layer, a light emitting layer provided on the hole transport layer and made of a polymer material including a host material and a dopant material, and an alkali-based inorganic material dissolved in an organic solvent and provided on the light emitting layer Provided is an organic light emitting display device including an electron transport layer, an electron injection layer provided on the electron transport layer, and a cathode provided on the electron injection layer.

According to the present invention as described above, there are the following effects.

According to the present invention, the vacuum deposition process can be minimized by changing the deposition method of the electron transport layer (ETL), thereby reducing manufacturing cost and improving productivity.

In addition to the effects of the present invention mentioned above, other features and advantages of the present invention will be described below or will be clearly understood by those of ordinary skill in the art from such description and description.

1 is a schematic cross-sectional view of a conventional organic light emitting device.
2 is a schematic cross-sectional view of an organic light emitting diode according to an embodiment of the present invention.
3A to 3E are schematic cross-sectional views of a manufacturing process of an organic light emitting diode according to an embodiment of the present invention.
4A is a graph showing a change in driving voltage-current characteristics of an organic light emitting diode according to the present invention.
4B is a graph showing the brightness-efficiency characteristics of the organic light emitting diode according to the present invention.
5 is a schematic cross-sectional view of an organic light emitting display device according to an embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described with 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be implemented independently of each other or may be implemented together in a related relationship. may be

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

2 is a schematic cross-sectional view of an organic light emitting diode according to an embodiment of the present invention.

As can be seen from FIG. 2 , the organic light emitting diode according to an embodiment of the present invention has an anode, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and electron injection. It comprises a layer (EIL), and a cathode (Cathode).

The anode may be made of a transparent conductive material having high conductivity and work function, for example, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), SnO2 or ZnO, etc., but is not necessarily limited thereto no.

The hole injection layer (HIL) is formed on the anode and is MTDATA(4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), CuPc(copper phthalocyanine), or PEDOT/PSS(poly(3, 4-ethylenedioxythiphene, polystyrene sulfonate), etc., but is not necessarily limited thereto.

Such a hole injection layer (HIL) is formed through a solution process. That is, the hole injection layer (HIL) prepares a solution for the hole injection layer (HIL) by dissolving an organic material having a hole injection characteristic in a solvent, and then applies the prepared solution to the anode through an inkjet process or a slit coating process. ) can be formed through the process of coating on the top.

The hole transport layer (HTL) is formed on the hole injection layer (HIL), and TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-bi-phenyl-4 ,4'-diamine), NPD (N, N-dinaphthyl-N, N'-diphenyl benzidine), or NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine) and the like, but is not necessarily limited thereto.

Such a hole transport layer (HTL) is also formed through a solution process. That is, the hole transport layer (HTL) is prepared by dissolving an organic material having hole transport properties in a solvent to prepare a solution for the hole transport layer (HTL), and then applying the prepared solution to the hole injection layer (HIL) through an inkjet process or a slit coating process. ) can be formed through the process of coating on the top.

Meanwhile, it is preferable that the hole injection layer HIL is not damaged by the solvent present in the solution for the hole transport layer HTL when the hole transport layer HTL is formed. Therefore, it is preferable that the organic material having hole injection characteristics included in the hole injection layer (HIL) is not dissolved in a solvent present in the solution for the hole transport layer (HTL). For example, an organic material having a hole injection characteristic included in the hole injection layer (HIL) is soluble in water but not soluble in a specific organic solvent, and an organic material having a hole transport characteristic included in the hole transport layer (HTL) is used. When the organic material dissolved in the specific organic solvent is used, the hole injection layer HIL may not be damaged when the hole transport layer HTL is formed by a solution process.

In addition, it is preferable that the hole transport layer HTL is not damaged by the solvent present in the solution for the light emitting layer EML when the light emitting layer EML is formed. To this end, it is preferable that a cross-linking agent is added to the hole transport layer (HTL) to improve the bonding strength of the hole transport layer (HTL). That is, when the crosslinking agent is included in the hole transport layer (HTL), the bonding strength of the organic material is improved by the crosslinking agent, so that the hole transport layer (HTL) is prevented from being dissolved by the solvent present in the solution for the light emitting layer (EML). have.

On the other hand, by including a crosslinking agent in the light emitting layer (EML), the bonding strength of the light emitting layer (EML) may be enhanced, and accordingly, even if the electron transport layer (ETL) is formed on the upper surface of the light emitting layer (EML) by a solution process, the light emitting layer (EML) ) to prevent damage to the upper surface. However, when a crosslinking agent is included in the light emitting layer EML, the light emitting efficiency of the light emitting layer EML rapidly decreases, so it is impossible to include a crosslinking agent in the light emitting layer EML. This makes it difficult to form the electron transport layer (ETL). Accordingly, in an embodiment of the present invention, the light emitting layer EML and the electron transport layer ETL are formed together in a single process using a phase separation phenomenon without separately forming the light emitting layer EML and the electron transport layer ETL. , which will be described later.

The emission layer EML is formed on the hole transport layer HTL. The emission layer EML may be formed of a red (R) emission layer, a green (G) emission layer, a blue (B) emission layer, or in some cases, a white (W) emission layer.

The red (R) emission layer may include an organic material capable of emitting red (R) light, for example, red (R) light having a peak wavelength range of 600 nm to 640 nm, specifically, A phosphorescent host material made of a sol-based compound or a metal complex may be doped with a red (R) dopant, but is not limited thereto. The red dopant may be formed of a metal complex of iridium (Ir) or platinum (Pt), but is not limited thereto.

The green (R) emission layer may include an organic material capable of emitting green (G) light, for example, green (G) light having a peak wavelength range of 500 nm to 570 nm, specifically, A phosphorescent green (G) dopant may be doped into a phosphorescent host material made of a sol-based compound or a metal complex, but is not limited thereto. The carbazole-based compound may include CBP (4,4-N,N'-dicarbazole-biphenyl), a CBP derivative, mCP (N,N'-dicarbazolyl-3,5-benzene) or an mCP derivative, and the like. The metal complex may include a phenyloxazole (ZnPBO) metal complex or a phenylthiazole (ZnPBT) metal complex.

The blue (B) light emitting layer may include an organic material capable of emitting blue (B) light, for example, blue (B) light having a peak wavelength range of 430 nm to 490 nm, specifically, anthracene At least one fluorescent host material selected from the group consisting of an (anthracene) derivative, a pyrene derivative, and a perylene derivative may be doped with a fluorescent blue (B) dopant, but is not limited thereto.

The white (W) light emitting layer may be formed by doping a host material with the aforementioned red (R) dopant, green (G) dopant, and blue (B) dopant, or a blue fluorescent host material for emitting blue (B) of red. The (R) dopant and the green (G) dopant may be doped, but the present invention is not limited thereto.

The emission layer EML is made of a polymer material including the aforementioned host material and dopant material. Here, the polymer material refers to a material having a molecular weight of 10,000 or more. The polymer material has high solubility and is easily soluble, and through mixing with a material having a density lower than the density of the polymer material, the light emitting layer (EML) is effectively positioned as a lower layer during the phase separation process.

The electron transport layer ETL is formed on the emission layer EML. The electron transport layer (ETL) is made of an alkali-based inorganic material including a material having an electron transport property. The alkali-based inorganic material is used to be soluble in an organic solvent. Accordingly, the electron transport layer (ETL) material has good conductivity so as to transmit electrons well, and has different properties from the light emitting layer (ETL) material, so that it can be effectively phase-separated.

As such, the light emitting layer (EML) and the electron transport layer (ETL) may be formed by preparing a mixture of materials having different properties to enable phase separation, and then applying the mixture on the hole transport layer (HTL) in a solution process. have.

That is, the layer formed by applying the mixture by a solution process is initially formed by mixing the light emitting layer (EML) material and the electron transport layer (ETL) material to form a layer, but then phase separation through a process of drying the mixture An emission layer EML made of the emission layer material is formed on the hole transport layer HTL, and an electron transport layer ETL made of the electron transport layer material is formed on the emission layer EML.

Since the density of the polymer material constituting the light emitting layer (EML) is greater than the density of the alkali inorganic material constituting the electron transport layer (ETL), the lower layer of the light emitting layer material having a relatively high density during phase separation of the mixture (EML) is formed, and an electron transport layer (ETL) made of an electron transport layer material having a relatively low density is formed on the emission layer (EML).

Meanwhile, since the light emitting layer EML and the electron transport layer ETL have a structure in which two layers are separated through a phase separation process, the interface between the light emitting layer EML and the electron transport layer ETL is not clearly separated in a plane. It may be made of a wave pattern or an uneven structure. Similarly, between the light emitting layer (EML) and the electron transport layer (ETL), the light emitting layer material and the electron transport layer material are not clearly separated, and an interfacial layer in which both the light emitting layer material and the electron transport layer material are mixed is formed. can be The interfacial layer region close to the light emitting layer (EML) contains more of the light emitting layer material, and the interfacial layer region close to the electron transport layer (ETL) contains more of the electron transport layer material can be included. More specifically, the light emitting layer material included in the interfacial layer gradually decreases from the light emitting layer (EML) to the electron transport layer (ETL), and the electron transport layer material included in the interfacial layer (Interfacial Layer) is gradually increased from the emission layer EML to the electron transport layer ETL. The interfacial layer may also have a wave pattern or a concave-convex structure.

The electron injection layer EIL is formed on the electron transport layer ETL. The electron injection layer (EIL) 700 may be formed of LIF or lithium quinolate (LiQ), but is not limited thereto.

The cathode is formed on the electron injection layer EIL. The cathode may be made of a metal having a low work function, for example, aluminum (Al), silver (Ag), magnesium (Mg), lithium (Li) or calcium (Ca), but is not necessarily limited thereto. it is not

3A to 3E are schematic cross-sectional views illustrating a manufacturing process of an organic light emitting device according to an embodiment of the present invention, which relates to the above-described method of manufacturing the organic light emitting device according to FIG. 2 . Hereinafter, repeated description of the same configuration as described above, such as the material of the component, may be omitted.

First, as shown in FIG. 3A , the hole injection layer HIL is formed on the anode, and the hole transport layer HTL is formed on the hole injection layer HIL.

In the process of forming the hole injection layer (HIL), a first solution for the hole injection layer (HIL) is prepared by dissolving an organic material having hole injection properties in a first solvent, and then the prepared first solution is applied to the inkjet process or slit coating. It may be formed by a process of coating on the anode through a process or the like.

In the process of forming the hole transport layer (HTL), a second solution for the hole transport layer (HTL) is prepared by dissolving an organic material having hole transport properties in a second solvent, and then the prepared second solution is used in an inkjet process or a slit coating process, etc. It may be formed by a process of applying on the hole injection layer (HIL) through the.

In this case, it is preferable that the organic material having the hole injection characteristic is not dissolved in the second solvent to prevent damage to the surface of the hole injection layer (HIL) when the hole transport layer (HTL) is formed.

In addition, it is preferable that the second solution for the hole transport layer (HTL) further includes a cross-linking agent in order to improve the bonding strength of the organic material having the hole transport property.

Next, as shown in FIG. 3B , a mixture of an emission layer (EML) material and an electron transport layer (ETL) material is formed on the hole transport layer (HTL). Specifically, after preparing a mixture of an emission layer (EML) material and an electron transport layer (ETL) material, the mixture may be applied on the hole transport layer in a solution process to form the mixture.

In the process of preparing the mixture, a light emitting layer (EML) material made of a polymer material including a host material and a dopant material and an electron transport layer (ETL) material made of an alkali inorganic material including a material having electron transport properties are dissolved in an organic solvent. This can be done by the process

As another example of a process for preparing the mixture, a process for preparing a first organic solution by dissolving an emission layer (EML) material made of a polymer material including a host material and a dopant material in a first organic solvent, electron transport characteristics A process of preparing a second organic solution by dissolving an electron transport layer (ETL) material made of an alkali-based inorganic material including a material with a second organic solvent, and a third step by mixing the first organic solution and the second organic solution It may include a process for preparing an organic solution. Here, since the first organic solution and the second organic solution have different properties, it can be induced to be more effectively separated into two layers in the process of phase-separating the mixture, which will be described later.

Next, as shown in FIG. 3c, the mixture is phase-separated to form an emission layer (EML) made of the light emitting layer material on the hole transport layer, and an electron transport layer (ETL) made of the electron transport layer material on the emission layer (EML) to form

The process of phase-separating the mixture includes a process of drying a solvent included in the mixture formed by a solution process on the hole transport layer (HTL). That is, the solvent contained in the mixture can be dried through a hot plate or an oven, and in this process, the light emitting layer (EML) material and the electron transport layer (ETL) material mixed in the mixture are It is formed by being separated into two layers by a phase separation phenomenon.

At this time, since the density of the polymer material constituting the light emitting layer (EML) is greater than the density of the alkali-based inorganic material constituting the electron transport layer (ETL), the lower layer during phase separation of the mixture has a relatively high density light emitting layer (EML) An emission layer EML made of a material may be formed, and an electron transport layer ETL made of an electron transport layer ETL material having a relatively low density may be formed on the emission layer EML.

Next, as shown in FIG. 3D , an electron injection layer EIL is formed on the emission layer EML.

The electron injection layer EIL is formed through a vacuum deposition process known in the art, such as evaporation or sputtering.

Next, as shown in FIG. 3E , a cathode is formed on the electron injection layer EIL. The cathode is formed through a method known in the art.

As described above, the organic light emitting device according to an embodiment of the present invention enables the formation of the electron transport layer (ETL) on the light emitting layer (EML) by a solution process using a phase separation phenomenon, thereby simplifying the manufacturing process in a single process. In addition, since the deposition chamber process for organic material deposition can be substituted when the electron transport layer (ETL) is formed, a reduction in manufacturing cost and improvement in productivity can be expected.

4A is a graph showing a change in driving voltage-current characteristics of the organic light-emitting device according to the present invention, and FIG. 4B is a graph showing the brightness-efficiency characteristics of the organic light-emitting device according to the present invention. The graph of Comparative Example 1 shows the characteristics of a conventional organic light emitting device having a structure of an electron transport layer (ETL) formed on the light emitting layer (EML) through a vacuum deposition process, and the graph of Comparative Example 2 shows the light emitting layer (EML) material and the electron transport layer When the (ETL) material has a mixed structure without phase separation, the characteristics of the organic light emitting diode are shown.

As can be seen from FIGS. 4A and 4B , in Comparative Example 2, the light emitting layer (EML) has electron-rich characteristics in a state in which the electron transport layer (ETL) material is mixed, so that the driving voltage is lowered, but the electron - The hole recombination state is not good, and the efficiency drops to 49.1cd/A. In addition, the hole transport layer HTL diffuses into the light emitting layer EML, thereby reducing the lifetime of the device.

In the case of the organic light emitting device according to the present invention, since the light emitting layer (EML) and the electron transport layer (ETL) are formed by phase separation, the driving voltage is lower than that of the organic light emitting device according to Comparative Example 1 and the luminous efficiency is also increased to improve device performance. It works.

The organic light emitting device according to the present invention described above may be applied as an organic light emitting display device for displaying an image described below, but is not limited thereto, and may be applied to various light emitting devices known in the art, such as a lighting device.

5 is a schematic cross-sectional view of an organic light emitting display device according to an embodiment of the present invention, which uses the organic light emitting diode of FIG. 2 described above.

As can be seen from FIG. 5 , the organic light emitting display device according to an embodiment of the present invention includes a substrate 100 , a thin film transistor layer 200 , a planarization layer 300 , a bank layer 400 , an anode, and an organic layer. (1), and a cathode (Cathode).

The substrate 100 may be glass or a transparent plastic that can be bent or bent, for example, polyimide, but is not limited thereto.

The thin film transistor layer 200 is formed on the substrate 100 . The thin film transistor layer 200 includes a gate electrode 210 , a gate insulating layer 220 , a semiconductor layer 230 , a source electrode 240a , a drain electrode 240b , and a protective layer 250 .

The gate electrode 210 is patterned on the substrate 100 , the gate insulating layer 220 is formed on the gate electrode 210 , and the semiconductor layer 230 is the gate insulating layer 220 . ), the source electrode 240a and the drain electrode 240b are patterned to face each other on the semiconductor layer 230 , and the passivation layer 250 is formed with the source electrode 240a and It is formed on the drain electrode 240b.

The thin film transistor shown in the thin film transistor layer 200 relates to a driving thin film transistor, and the drawing shows a driving thin film transistor having a bottom gate structure in which a gate electrode 210 is formed under the semiconductor layer 230 . However, a driving thin film transistor having a top gate structure in which the gate electrode 210 is formed on the semiconductor layer 230 may be formed. Light emission of the organic light emitting device is controlled by such a driving thin film transistor.

The planarization layer 300 is formed on the thin film transistor layer 200 to planarize the substrate surface. The planarization layer 300 may be formed of an organic insulating layer such as photoacrylic, but is not limited thereto.

The anode is formed on the planarization layer 300 and is connected to the drain electrode 240b of the thin film transistor.

The bank layer 400 is formed on the anode and is patterned in a matrix structure to define a pixel area.

The organic layer 1 is formed on the anode, and in particular, is formed in a pixel area defined by the bank layer 400 . Although not specifically illustrated, the organic layer 1 includes a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL), and each layer Since is the same as in FIG. 2 described above, a repeated description will be omitted.

The cathode is formed on the organic layer 1 . A common voltage may be applied to the cathode, and thus the cathode may be formed on the bank layer 400 as well as the organic layer 1 in each pixel.

Meanwhile, although not shown, an encapsulation layer is formed on the cathode to prevent penetration of oxygen or moisture into the organic layer 1 . Such an encapsulation layer may have a structure in which different inorganic materials are alternately stacked, an inorganic material and an organic material may be alternately stacked, or a metal layer adhered by an adhesive.

The organic light emitting display device according to an embodiment of the present invention may be formed in a so-called top emission method in which the light emitted from the organic layer 1 is emitted in an upward direction, and in the organic layer 1 A so-called bottom emission method in which the emitted light is emitted in the direction of the lower substrate 100 may be used.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Anode: anode Cathode: cathode
HIL: hole injection layer HTL: hole transport layer
EML: light emitting layer ETL: electron transport layer
EIL: electron injection layer

Claims (12)

anode;
a hole injection layer provided on the anode;
a hole transport layer provided on the hole injection layer;
a light emitting layer provided on the hole transport layer and made of a polymer material including a host material and a dopant material dissolved in an organic solvent;
an electron transport layer provided on the light emitting layer and including an alkali-based inorganic material dissolved in the organic solvent;
an interface layer between the light emitting layer and the electron transport layer, the interfacial layer including both a material constituting the light emitting layer and a material constituting the electron transport layer;
an electron injection layer provided on the electron transport layer; and
a cathode provided on the electron injection layer;
An organic light emitting device having a density of the polymer material constituting the light emitting layer greater than a density of the alkali-based inorganic material constituting the electron transport layer. delete delete The method of claim 1,
The interfacial layer region close to the light emitting layer contains more of the light emitting layer material, and the interfacial layer region close to the electron transport layer contains more of the electron transport layer material. 5. The method of claim 4,
The light emitting layer material included in the interface layer gradually decreases from the light emitting layer to the electron transport layer,
The material of the electron transport layer included in the interface layer gradually increases from the emission layer to the electron transport layer. According to claim 1,
The interface layer is an organic light emitting device having an uneven structure. delete forming a hole injection layer on the anode by a solution process;
forming a hole transport layer on the hole injection layer by a solution process;
preparing a mixture by dissolving a light emitting layer material made of a polymer material including a host material and a dopant material and an electron transport layer material made of an alkali inorganic material in an organic solvent;
applying the mixture on the hole transport layer in a solution process;
forming a light emitting layer made of the light emitting layer material on the hole transport layer by phase-separating the mixture, and forming an electron transport layer made of the electron transport layer material on the light emitting layer;
forming an electron injection layer on the electron transport layer by a vacuum deposition process; and
and forming a cathode on the electron injection layer. delete 9. The method of claim 8,
The process of preparing the mixture is
preparing a first organic solution by dissolving the polymer material including the host material and the dopant material in a first organic solvent;
dissolving the alkali-based inorganic material in a second organic solvent to prepare a second organic solution; and
and mixing the first organic solution and the second organic solution to prepare a third organic solution. 9. The method of claim 8,
The step of phase-separating the mixture includes a step of drying the organic solvent included in the mixture. Board;
a thin film transistor provided on the substrate; and
An organic light emitting device in which light emission is controlled by the thin film transistor,
The organic light emitting device is an organic light emitting display device comprising the organic light emitting device according to any one of claims 1 and 4 to 6 described above.

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