KR102372275B1 - Organic Light Emitting Device and Method of manufacturing the same and Organic Light Emitting Display Device using the same - Google Patents

Abstract

(상기 화학식1 중 M1, M2, 및 M3는 각각 독립적으로 상기 양극에 포함된 금속 성분에서 선택되며, R은 하기 화학식2로 표현되는 화합물로 이루어지고)
<화학식2>

(상기 화학식2 중 m은 1 내지 9의 정수 중 하나이고, n은 1 내지 3의 정수 중 하나이다)으로 표현되는 화합물로 이루어질 수 있다.The present invention is to provide an organic light emitting device capable of forming an organic layer through a solution process while reducing the difference in energy level between the work function of an anode and a hole injection layer, a method for manufacturing the same, and an organic light emitting display device using the same. The organic light emitting device according to the following includes an organic layer provided between an anode and a cathode and an interface layer provided between the anode and the organic layer, and the interface layer is represented by the following Chemical Formula 1:
<Formula 1>

(In Formula 1, M1, M2, and M3 are each independently selected from a metal component included in the positive electrode, and R is composed of a compound represented by Formula 2 below)
<Formula 2>

(In Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3).

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 having an improved driving voltage and a method of manufacturing the same.

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 inside the light emitting layer It is a device that emits light as the injected electrons and holes combine to generate an exciton, and the generated exciton falls from an excited state to a ground state.

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

1 is a schematic cross-sectional view of an organic light emitting display device according to an exemplary embodiment.

As can be seen from FIG. 1 , the organic light emitting display device according to an exemplary embodiment of the related art includes a substrate 10 , a thin film transistor layer 20 , a planarization layer 30 , an anode 40 , and a bank layer 50 . ), an organic layer 60 , and a cathode 70 .

The thin film transistor layer 20 is formed in each of a red (R) pixel, a green (G) pixel, and a blue (B) pixel on the substrate 10 . The thin film transistor layer 20 includes a gate electrode 21 , a gate insulating layer 22 , a semiconductor layer 23 , a source electrode 24a , a drain electrode 24b , and a protective layer 25 .

The planarization layer 30 is formed on the thin film transistor layer 20 to planarize the substrate surface.

The anode 40 is patterned on each of the red (R) pixel, the green (G) pixel, and the blue (B) pixel on the planarization layer 30 . The anode 40 is connected to the drain electrode 24b of the thin film transistor layer 20 .

The anode 40 may be made of a transparent conductive material having a high work function, for example, a transparent conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), SnO2 or ZnO.

The bank layer 50 is formed on a portion of the top surface of the planarization layer 30 or the anode 40 , and is patterned in a matrix structure to define a pixel area.

The organic layer 60 is formed on the anode 40 , and in particular, within each region of the red (R) pixel, the green (G) pixel, and the blue (B) pixel defined by the bank layer 50 . is formed Although not specifically shown, the organic layer 60 is a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL). , and an electron injection layer (EIL).

The cathode 70 is formed on the organic layer 60 . A common voltage may be applied to the cathode 70 , and thus the cathode 70 may be formed on the entire surface of the substrate without being patterned for each pixel. That is, the cathode 70 may be formed on the bank layer 50 as well as the organic layer 60 in the pixel.

However, such an organic light emitting display device has the following problems.

The organic layer 60 may be formed by an evaporation process or a soluble process.

When the organic layer 60 is formed through the deposition process, a problem does not occur in that the deposited organic layer material overflows out of the bank layer 50 because the pattern can be formed by depositing it for each pixel using a shadow mask or the like.

However, when the organic layer 60 is formed by a solution process, a problem arises that the composition in a solution state overflows the bank layer 50 to the outside. Therefore, the upper surface of the bank layer 50 is made hydrophobic, and such a problem can be prevented by using a solution-state organic layer composition having hydrophilicity.

On the other hand, before forming the hole injection layer (HIL) on the anode 40, the hole injection value of the work function of the anode 40 through gas plasma treatment such as N2, O2 (Gas Plasma Treatment). The driving voltage and performance of the device may be improved by leveling the layer HIL to be close to the HOMO (Highest Occupied Molecular Orbital) value.

Since the gas plasma treatment is performed on the entire surface of the substrate 10, it affects not only the anode 40 but also the bank layer 50, and the bank layer 50 having the upper surface hydrophobic. In this case, the hydrophobic surface is damaged and becomes hydrophilic. As a result, when the organic layer 60 is formed by a solution process, the problem that the composition in a solution state overflows the bank layer 50 cannot be prevented.

Accordingly, the present invention provides an organic light emitting device capable of forming the organic layer 60 by a solution process while reducing the energy level difference between the anode 40 and the hole injection layer (HIL), a manufacturing method thereof, and an organic light emitting display device using the same It is a technical task to provide

The present invention has been devised to solve the above problems, and an organic light emitting device capable of forming an organic layer by a solution process while reducing the difference in energy level between the work function of an anode and a hole injection layer, a manufacturing method thereof, and organic light emitting using the same It is a technical task to provide a display device.

In order to achieve the above technical object, the present invention provides an organic light emitting device comprising an organic layer provided between an anode and a cathode and an interface layer provided between the anode and the organic layer, wherein the interface layer contains fluorine .

The interface layer is in contact with the upper surface of the anode and the lower surface of the organic layer,

<Formula 1>

(In Formula 1, M1, M2, and M3 are each independently selected from a metal component included in the positive electrode, and R is composed of a compound represented by Formula 2 below)

<Formula 2>

(In Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3). M1, M2, and M3 may be each independently selected from the group consisting of indium (In), tin (Sn), zinc (Zn), and alloys of two or more thereof. The interfacial layer may also have an energy level in a range between a work function value of the anode and a Highest Occupied Molecular Orbital (HOMO) value of the organic layer in contact with the upper surface of the interfacial layer.

The anode is selected from indium tin oxide (ITO), indium zinc oxide (IZO), indium oxide (Indium Oxide), tin oxide (Tin Oxide) and zinc oxide (ZnO: Zinc Oxide) It may be made of one or more metal oxides, and the organic layer may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer.

The present invention also relates to the following formula 1:

<Formula 1>

(In Formula 1, M1, M2, and M3 are each independently selected from a metal component included in the positive electrode, and R is composed of a compound represented by Formula 2 below)

<Formula 2>

(in Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3) A process of forming an interface layer including a compound represented by the formula and forming a hole injection layer on the interface layer It provides a method of manufacturing an organic light emitting device comprising the step of:

The process of forming the interfacial layer is a solution state of the following Chemical Formula 3:

<Formula 3>

(m in Formula 3 is one of integers from 1 to 9, and n is one of integers from 1 to 3) It may include a step of heating the compound represented by the formula (3).

The present invention also includes a thin film transistor provided on a 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 organic layer provided between an anode and a cathode and between the anode and the organic layer an interfacial layer, wherein the interfacial layer has the following formula 1:

<Formula 1>

(In Formula 1, M1, M2, and M3 are each independently selected from a metal component included in the positive electrode, and R is composed of a compound represented by Formula 2 below)

<Formula 2>

(In Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3).

The organic light emitting display device may further include a bank layer for dividing the organic light emitting device for each pixel area, wherein the bank layer may include a base layer made of a hydrophilic material and a hydrophobic layer made of a hydrophobic material on the base layer.

According to the present invention, the driving voltage and performance of the organic light emitting diode can be improved by reducing the energy level difference between the anode and the hole injection layer without damaging the upper surface of the bank layer, and the organic layer can be formed by a solution process .

1 is a schematic cross-sectional view of an organic light emitting display device according to an exemplary embodiment.
2 is a schematic cross-sectional view of an organic light emitting diode according to an embodiment of the present invention.
3 is a schematic cross-sectional view of an organic light emitting diode according to another embodiment of the present invention.
4A to 4D are schematic cross-sectional views of a manufacturing process of an organic light emitting diode according to an embodiment of the present invention.
5A is a graph showing a change in driving voltage-current density characteristics of an organic light emitting diode according to the present invention.
5B is a graph showing a change in driving voltage-luminance characteristics of the organic light emitting diode according to the present invention.
5C is a graph showing a change in current density-luminance characteristics of an organic light emitting diode according to the present invention.
6 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 illustrative and 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 gist 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, cases including the plural are 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', 'next to', etc., 'right' Alternatively, one or more other parts may be positioned between 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 elements, these elements 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 can be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or implemented together in a related relationship. may be

Hereinafter, preferred embodiments 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 includes a substrate 1 , and a red (R) pixel, a green (G) pixel, and a blue (B) pixel formed on the substrate 1 . ) including pixels.

Specifically, the red (R) pixel, the green (G) pixel, and the blue (B) pixel are sequentially formed an anode, an interfacial layer, a hole injection layer (HIL), a hole transport layer (HTL), It includes an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode. Although not shown in the drawing, a bank layer is patterned in a matrix structure to separate each pixel area on the substrate 100, so that the hole injection layer (HIL), the hole transport layer (HTL), the light emitting layer (EML), and the electron transport layer ( ETL) and an organic layer including an electron injection layer (EIL) may be formed in a pixel area separated by the bank layer.

The anode is patterned on the substrate 1 in the red (R) pixel, the green (G) pixel, and the blue (B) pixel, respectively. The anode is a transparent conductive material having high conductivity and work function, for example, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Indium Oxide , tin oxide (Tin Oxide) and zinc oxide (ZnO: Zinc Oxide) may include one or more metal oxides selected from the group consisting of, but is not necessarily limited thereto.

The anode 100 may be patterned for each pixel by a combination of a Metal Organic Chemical Vapor Deposition (MOCVD) process and a photolithography process.

The interfacial layer is patterned on the anode in the red (R) pixel, the green (G) pixel, and the blue (B) pixel, respectively.

The interface layer (Interfacial Layer) is the following formula 1:

<Formula 1>

(M1, M2, and M3 in Formula 1 are each independently selected from the metal component included in the positive electrode,

R consists of a compound represented by the following formula (2))

<Formula 2>

(In Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3)

It consists of a compound represented by

M1, M2, and M3 may each independently be selected from the group consisting of indium (In), tin (Sn), zinc (Zn), and alloys of two or more thereof, but is not necessarily limited thereto.

Such an interfacial layer has a range between the work function value of the anode and the Highest Occupied Molecular Orbital (HOMO) value of the hole injection layer (HIL) by adjusting the values of m and n. It can have energy levels. For example, the energy level of the interfacial layer may be greater than the work function value of the anode by 0.1 eV to 1 eV.

That is, when the difference between the work function value of the anode 40 and the Highest Occupied Molecular Orbital (HOMO) value of the hole injection layer HIL increases, hole injection becomes difficult, but this According to an embodiment of the invention, the interfacial layer is in contact with the upper surface of the anode and the lower surface of the hole injection layer HIL, and the work function value of the anode and the hole injection Since the layer HIL is formed to have an energy level in a range between the HOMO (Highest Occupied Molecular Orbital) value, hole injection is facilitated, so that performance such as lowering the driving voltage of the device and increasing luminous efficiency can be improved.

The process of forming the interfacial layer will be described later in the manufacturing process of the organic light emitting device according to the present invention.

The hole injection layer HIL is patterned on the interface layer in the red (R) pixel, the green (G) pixel, and the blue (B) pixel, respectively. The hole injection layer (HIL) is MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine)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 patterned for each pixel through a patterning process in a solution state, for example, a spin-coating or inkjet printing process after preparing a hole injection layer composition in a solution state. can be formed.

The hole transport layer HTL is patterned on the hole injection layer HIL in the red (R) pixel, the green (G) pixel, and the blue (B) pixel, respectively. The hole transport layer (HTL) is TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-bi-phenyl-4,4'-diamine), NPB (N,N '-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), PVK(poly(N-vinyl carbazole), TFB(poly(9,9-dioctylfluorene-co-N-(4-butylphenyl-) diphenylamine))), or Poly-TPD (Poly(4-butylphenyl-diphenyl-amine)), but is not necessarily limited thereto.

Such a hole transport layer (HTL) may be patterned for each pixel through a patterning process in a solution state, for example, a spin-coating or inkjet printing process after preparing a hole transport layer composition in a solution state. can

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. Accordingly, 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 hole injection properties included in the hole injection layer (HIL) is soluble in water but not soluble in a specific organic solvent, and an organic material having hole transport properties 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). there is.

The emission layer EML is patterned on the hole transport layer HTL in the red (R) pixel, the green (G) pixel, and the blue (B) pixel, respectively.

The light emitting layer (EML) patterned on the red (R) pixel may include an organic material capable of emitting red (R) light, for example, red (R) light having a peak wavelength range of 550 nm to 730 nm. In particular, it may be formed by doping a phosphorescent host material made of a carbazole-based compound or a metal complex with a red (R) dopant, but is not necessarily limited thereto. The red (R) dopant may be formed of a metal complex of iridium (Ir) or platinum (Pt), but is not limited thereto.

The light emitting layer (EML) patterned on the green (G) pixel may include an organic material capable of emitting green (G) light, for example, green (G) light having a peak wavelength range of 490 nm to 600 nm. Specifically, the phosphorescent host material made of a carbazole-based compound or a metal complex may be doped with a phosphorescent green (G) dopant, but is not necessarily 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 mCP derivative, and the like, and the The metal complex may include, but is not limited to, a phenyloxazole (ZnPBO) metal complex or a phenylthiazole (ZnPBT) metal complex.

The light emitting layer (EML) 400 patterned on the blue (B) pixel is 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. may include, and specifically, a fluorescent blue (B) dopant is formed by doping at least one fluorescent host material selected from the group consisting of an anthracene derivative, a pyrene derivative, and a perylene derivative. may, but is not necessarily limited thereto.

Such a light emitting layer (EML) is a patterning process in a solution state, for example, after preparing a light emitting layer composition in a solution state, the red (R) pixel and the green (R) pixel through a spin-coating or inkjet printing process G) A pattern may be formed for each pixel and each blue (B) pixel.

The electron transport layer ETL is formed on the emission layer EML in the red (R) pixel, the green (G) pixel, and the blue (B) pixel. The electron transport layer (ETL) may be made of oxadiazole, triazole, phenanthroline, benzoxazole or benzthiazole, but is not necessarily limited thereto. not. The electron transport layer ETL may be formed on the emission layer EML by a patterning process or a deposition process in a solution state.

The electron injection layer EIL is formed on the charge transport layer ETL in the red (R) pixel, the green (G) pixel, and the blue (B) pixel. The electron injection layer EIL may be formed of LIF or lithium quinolate (LiQ), but is not limited thereto. Such an electron injection layer (EIL) may be formed by a deposition process.

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 Such a cathode may also be formed through a deposition process.

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

As can be seen from FIG. 3 , an organic light emitting diode according to another exemplary embodiment of the present invention includes a substrate 1 , and a red (R) pixel, a green (G) pixel, and a blue (B) pixel formed on the substrate 1 . ) including pixels.

The red (R) pixel and the green (G) pixel are formed in the same pattern, and the blue (B) pixel is formed in a different pattern from the red (R) pixel and the green (G) pixel.

Specifically, the red (R) pixel and the green (G) pixel are sequentially formed an anode, an interfacial layer, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), and a common blue color It includes a layer (Blue Common Layer: BCL), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode.

On the other hand, in the blue (B) pixel, an anode, an interfacial layer, a hole injection layer (HIL), a hole transport layer (HTL), a blue common layer (BCL), and an electron transport layer are sequentially formed. (ETL), an electron injection layer (EIL), and a cathode (Cathode) is formed.

Although not shown in the drawings, a bank layer is patterned in a matrix structure to distinguish each pixel area on the substrate 100 , so that the interfacial layer, the hole injection layer (HIL), the hole transport layer (HTL), and the light emitting layer are formed. (EML) and the like may be formed in the pixel area divided by the bank layer.

Since the interfacil layer formed on the anode is formed in the same manner as in the organic light emitting diode according to the embodiment of the present invention, a repeated description thereof will be omitted.

In the organic light emitting device according to another embodiment of the present invention, the hole injection layer (HIL), the hole transport layer (HTL), and the light emitting layer (EML) are formed by a solution process, and the blue common layer (BCL), The electron transport layer (ETL) and the electron injection layer (EIL) are formed through a deposition process.

In the description of the organic light emitting diode according to another embodiment of the present invention, a repeated description of the same configuration as that of the organic light emitting diode according to the embodiment of the present invention of FIG. 2 described above may be omitted, and a different configuration may be omitted. will be mainly explained.

The emission layer EML is patterned on the hole transport layer HTL in the red (R) pixel and the green (G) pixel, respectively. The blue common layer BCL is commonly formed in the red (R) pixel, the green (G) pixel, and the blue (B) pixel. Specifically, the blue common layer BCL is formed on the emission layer EML in the red (R) pixel and the green (G) pixel, and is formed on the hole transport layer HTL in the blue (B) pixel. do. In particular, in the blue (B) pixel, the blue common layer BCL serves as an emission layer.

The blue common layer BCL basically functions as an emission layer for blue light in a blue (B) pixel. Accordingly, the blue common layer BCL includes a host material for emitting blue light and a light emitting dopant. More specifically, the blue common layer (BCL) comprises at least one fluorescence host material selected from the group consisting of an anthracene derivative, a carbazole derivative, a pyrene derivative and a perylene derivative, and a fluorescence layer. The blue (B) light emitting dopant may be included, but is not necessarily limited thereto. The blue common layer BCL of the blue (B) pixel may emit blue light having a peak wavelength of 430 nm to 490 nm.

The electron transport layer ETL is formed on the blue common layer BCL in the red (R) pixel, the green (G) pixel, and the blue (B) pixel. The electron transport layer (ETL) may be made of oxadiazole, triazole, phenanthroline, benzoxazole or benzthiazole, but is not necessarily limited thereto. not. Like the blue common layer BCL, the electron transport layer ETL may be formed on the blue common layer BCL by a deposition process without a separate shadow mask.

The electron injection layer EIL is formed on the electron transport layer ETL in the red (R) pixel, the green (G) pixel, and the blue (B) pixel. The electron injection layer EIL may be formed of LIF or lithium quinolate (LiQ), but is not limited thereto. The electron injection layer EIL may also be formed on the electron transport layer ETL by a deposition process without a separate shadow mask.

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

Such a cathode is also formed on the entire surface of the substrate 100 , and thus may be formed through a deposition process without a separate shadow mask.

4A to 4D are manufacturing process diagrams illustrating a method of manufacturing 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. 3 . Hereinafter, repeated descriptions of the same components as those described above, such as materials of components, may be omitted.

First, as shown in FIG. 4A , an anode is patterned on each of the red (R) pixel, the green (B) pixel, and the blue (B) pixel on the substrate 1 .

Specifically, the anode is patterned on the substrate 1 by a combination of a Metal Organic Chemical Vapor Deposition (MOCVD) process and a photolithography process. Although not shown in the drawings, a bank layer is patterned in a matrix structure to separate each pixel area on the substrate 100 , and the Interfacial Layer, the hole injection layer (HIL), and the hole transport layer (HTL) to be described later. , an emission layer EML, and the like may be formed in the pixel area divided by the bank layer.

Thereafter, an interfacial layer is formed on the anode by using fluorinated phosphonic acid represented by the following formula (3).

<Formula 3>

(In Formula 3, m is one of integers from 1 to 9, and n is one of integers from 1 to 3)

A reaction formula for forming an interfacial layer on the anode is as follows.

는 전술한 화학식3으로 표현되는 플루오르화 포스포늄산(Fluorinated Phosphonic Acid)이며, 따라서 R은 하기 화학식2로 표현되는 화합물로 이루어지고, 화학식2 중 m은 1 내지 9의 정수 중 하나이고, n은 1 내지 3의 정수 중 하나이다.in the above reaction

is a fluorinated phosphonic acid represented by the above-mentioned Chemical Formula 3, and thus R is composed of a compound represented by the following Chemical Formula 2, in which m is one of integers of 1 to 9, and n is One of integers from 1 to 3.

<Formula 2>

는 양극(Anode)을 구성하는 물질을 나타내며, 상기 M1, M2, 및 M3는 각각 독립적으로 인듐(In), 주석(Sn), 아연(Zn), 및 그들의 2종 이상의 합금으로 이루어진 군에서 선택될 수 있지만, 반드시 그에 한정되는 것은 아니다.in the above reaction

represents a material constituting the anode, and M1, M2, and M3 are each independently selected from the group consisting of indium (In), tin (Sn), zinc (Zn), and alloys of two or more thereof. may, but is not necessarily limited thereto.

When describing the process represented by the reaction scheme in detail, first, the compound represented by Chemical Formula 3 in a solution state is applied on the anode through inkjet printing or the like. Thereafter, the anode and the compound represented by Chemical Formula 3 in a solution state applied on the anode are heated for a predetermined time through a hot plate or an oven. In this process, hydrogen ions are added, and through a condensation reaction, an interfacial layer including the compound represented by Chemical Formula 1 is finally formed on the anode.

As such, since the interfacial layer can be patterned on the anode for each pixel through a solution process, although not shown in the drawing, it affects the upper part of the bank layer patterned in a matrix structure to separate each pixel area. It is possible to reduce the energy level difference between the anode and the hole injection layer (HIL). That is, in the prior art, gas plasma treatment was performed on the entire surface of the substrate 100 in order to adjust the work function of the anode, but the present invention does not require gas plasma treatment, and thus the upper portion of the bank layer is not damaged.

Therefore, when the solution of the organic layer formed by a solution process (herein, the organic layer refers to each functional layer constituting the organic light emitting device) is hydrophilic, the upper surface of the bank layer is formed with a hydrophobic layer so that the organic layer solution does not overflow the bank layer. In addition, since the hydrophobic layer is not damaged, the organic layer is prevented from overflowing out of the bank layer, and the pattern can be formed by a solution process.

Next, as shown in FIG. 4B, a hole injection layer (HIL) and a hole transport layer (HTL) are formed on each of the red (R) pixel, the green (B) pixel, and the blue (B) pixel on the interfacial layer. pattern is formed in turn.

Specifically, a patterning process in a solution state, for example, a hole injection layer composition in a solution state, is prepared on the interfacial layer, and then holes are formed through an inkjet printing or spin-coating process. After forming a pattern on the injection layer (HIL), and preparing a patterning process in a solution state, for example, a hole transport layer composition in a solution state on the hole injection layer (HIL), inkjet printing or spin-coating ) to pattern-form the hole transport layer (HTL) through the process.

Since the interface layer (Interfacial Layer) has hydrophobicity, it is preferable to use a hydrophobic material for the hole injection layer composition in the solution state so that the hole injection layer composition in the solution state spreads well and contacts the interface layer (Interfacial Layer).

Next, as shown in FIG. 4C , a light emitting layer EML is patterned on each of the red (R) pixel and the green (G) pixel on the hole transport layer HTL.

Specifically, after preparing a solution-state patterning process, for example, a solution-state light emitting layer composition on the hole transport layer (HTL), inkjet printing or spin-coating process to red (R) The light emitting layer EML and the green (G) light emitting layer EML are patterned.

Next, as can be seen from FIG. 4D , a blue common layer (BCL), an electron transport layer (ETL), a blue common layer (BCL), an electron transport layer (ETL), on the entire surface of the substrate 100 including a red (R) pixel, a green (G) pixel, and a blue (B) pixel An electron injection layer (EIL) and a cathode (Cathode) are sequentially formed.

Specifically, the blue common layer (EML) of the red (R) pixel and the green (G) pixel and the upper surface of the hole transport layer (HTL) of the blue (B) pixel are vacuum deposited without a shadow mask. BCL) is formed.

In addition, the electron transport layer ETL is formed on the blue common layer BCL by a deposition process without a shadow mask, and the electron injection layer EIL is formed on the electron transport layer ETL by a deposition process without a shadow mask. and forming the cathode on the electron injection layer EIL through a deposition process without a shadow mask.

5A is a graph showing a change in driving voltage-current density characteristics of the organic light-emitting device according to the present invention, FIG. 5B is a graph showing a change in driving voltage-luminance characteristics of the organic light-emitting device according to the present invention, and FIG. It is a graph showing the change in current density-luminance characteristics of the organic light emitting diode according to the

5a to 5c, a graph according to the present invention shows the characteristics of an organic light emitting device in which an interfacial layer is formed using the above-described fluorinated phosphonic acid on the anode, and the graph according to the comparative example is It shows the characteristics of an organic light emitting diode formed on the anode without any treatment.

As can be seen from FIG. 5A , the organic light-emitting device according to the present invention shows improvement in high current density and efficiency with a lower driving voltage compared to the organic light-emitting device according to the comparative example, and as can be seen in FIG. 5B, the present invention The organic light-emitting device according to , shows that the luminance is increased at a lower driving voltage than the organic light-emitting device according to the comparative example. In addition, as can be seen from FIG. 5C , the organic light-emitting device according to the present invention has improved luminous efficiency compared to the organic light-emitting device according to the comparative example.

In the case of the organic light emitting device according to the present invention, an interface layer having an energy level in a range between the work function value of the anode and the Highest Occupied Molecular Orbital (HOMO) value of the hole injection layer (HIL) is formed. By doing so, it is effective in improving the driving voltage and efficiency of the organic light emitting diode.

The organic light emitting diode 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.

6 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 or FIG. 3 described above.

As can be seen from FIG. 6 , 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 , an anode, a bank layer 500 , and an interface. A layer (Interfacial Layer), an organic layer (600), and is made to include a cathode (Cathode).

The substrate 100 may be made of glass or a transparent plastic that can be bent or bent, for example, polyimide, but is not necessarily 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 1 , 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 500 is formed on the planarization layer 300 or the anode, and is patterned in a matrix structure to define a pixel area. When the organic layer 600 is formed by a solution process, the upper surface of the bank layer 500 may be made hydrophobic in order to prevent the organic layer composition having hydrophilicity from overflowing the bank layer 500 . That is, the bank layer 500 may include a base layer 500a made of a hydrophilic material and a hydrophobic layer 500b made of a hydrophobic material on the base layer 500a.

The interfacil layer is formed on the anode and comes in contact with the organic layer 600 to be formed thereafter. Since the interfacil layer is the same as in FIG. 2 described above, a repeated description will be omitted.

The organic layer 600 is formed on the interfacil layer, and in particular, is formed in a pixel area defined by the bank layer 500 . The organic layer 600 is not specifically illustrated, but as in FIG. 2 described above, 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) ) can be included. In addition, as in FIG. 3 , in the organic layer 600 , the red (R) pixel and the green (G) pixel have a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), and a blue common layer (Blue). Common Layer: BCL), electron transport layer (ETL), and includes an electron injection layer (EIL), the blue (B) pixel is a hole injection layer (HIL), a hole transport layer (HTL), a blue common layer (Blue Common) Layer: BCL), an electron transport layer (ETL), and an electron injection layer (EIL) may be included.

The cathode is formed on the organic layer 600 . A common voltage may be applied to the cathode, and thus, the cathode may be formed on the entire surface of the substrate without being patterned for each pixel. That is, the cathode may be formed on the bank layer 500 as well as the organic layer 600 in the pixel.

Meanwhile, although not shown, an encapsulation layer is formed on the cathode to prevent oxygen or moisture from penetrating into the organic layer 600 . 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 light emitted from the organic layer 600 is emitted in an upward direction, and in the organic layer 600 , A so-called bottom emission method in which the emitted light is emitted in the direction of the lower substrate 100 may be used.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes are possible within the scope of the present invention. It will be clear to those who have the knowledge of Therefore, the scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

100: substrate Anode: anode
Interfacial Layer: HIL: hole injection layer
HTL: hole transport layer EML: light emitting layer
ETL: electron transport layer EIL: electron injection layer
Cathode: cathode 200: thin film transistor layer
300: planarization layer 500: bank layer
600: organic layer

Claims (12)

In the organic light emitting device in which a red pixel, a green pixel, and a blue pixel are defined,
positive and negative poles;
an organic layer provided between the anode and the cathode; and
An interface layer provided between the anode and the organic layer,
The interfacial layer contains fluorine,
The organic layer includes a hole injection layer on the anode, a hole transport layer on the hole injection layer, a light emitting layer on the hole transport layer, an electron transport layer on the light emitting layer, and an electron injection layer on the electron transport layer,
The emission layer includes a red emission layer overlapping the red pixel, a green emission layer overlapping the green pixel, and a blue emission layer overlapping the red pixel, the green pixel, and the blue pixel;
The blue light emitting layer is formed as a common layer in the red pixel, the green pixel, and the blue pixel;
The electron transport layer and the electron injection layer are formed as a common layer in the red pixel, the green pixel, and the blue pixel. The method of claim 1,
The interface layer is an organic light emitting device in contact with the upper surface of the anode and the lower surface of the organic layer. According to claim 1,
The interfacial layer is of Formula 1:
<Formula 1>

(In Formula 1, M1, M2, and M3 are each independently selected from a metal component included in the positive electrode, and R is composed of a compound represented by Formula 2 below)
<Formula 2>

(In Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3)
An organic light emitting device comprising a compound represented by The method of claim 1,
The interfacial layer has an energy level in a range between a work function value of the anode and a Highest Occupied Molecular Orbital (HOMO) value of the organic layer in contact with the upper surface of the interfacial layer. The method of claim 1,
The anode is one selected from Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Indium Oxide, Tin Oxide, and Zinc Oxide (ZnO) An organic light emitting device comprising the above metal oxide. delete 4. The method of claim 3,
Wherein M1, M2, and M3 are each independently selected from the group consisting of indium (In), tin (Sn), zinc (Zn), and alloys of two or more thereof. In the method of manufacturing an organic light emitting device in which a red pixel, a green pixel, and a blue pixel are defined,
Formula 1: on the positive electrode:
<Formula 1>

(In Formula 1, M1, M2, and M3 are each independently selected from a metal component included in the positive electrode, and R is composed of a compound represented by Formula 2 below)
<Formula 2>

(in Formula 2, m is one of integers from 1 to 9, and n is one of integers from 1 to 3) forming an interface layer including a compound represented by the formula;
forming a hole injection layer on the interface layer;
forming a hole transport layer on the hole injection layer;
forming a light emitting layer on the hole transport layer;
forming an electron transport layer on the light emitting layer; and
and forming an electron injection layer on the electron transport layer;
The emission layer includes a red emission layer overlapping the red pixel, a green emission layer overlapping the green pixel, and a blue emission layer overlapping the red pixel, the green pixel, and the blue pixel;
The blue light emitting layer is formed as a common layer in the red pixel, the green pixel, and the blue pixel;
The electron transport layer and the electron injection layer are formed as a common layer in the red pixel, the green pixel, and the blue pixel. 9. The method of claim 8,
The process of forming the interface layer,
The following formula 3: in solution:
<Formula 3>

(in Formula 3, m is one of integers from 1 to 9, and n is one of integers from 1 to 3) applying a compound represented by the formula on the positive electrode; and
and heating the anode and the compound represented by Formula 3 in a solution state applied on the anode. 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 to 5 and 7. 11. The method of claim 10,
Further comprising a bank layer for dividing the organic light emitting device for each pixel area,
The upper surface of the bank layer is made of a hydrophobic material. 11. The method of claim 10,
Further comprising a bank layer for dividing the organic light emitting device for each pixel area,
and the bank layer includes a base layer made of a hydrophilic material and a hydrophobic layer made of a hydrophobic material on the base layer.

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