KR20140025750A - Organic electro luminescent device and method of fabricating array substrate for the same - Google Patents

Abstract

The present invention relates to an organic electroluminescent device including an anode electrode with a relatively large work function value and a method for manufacturing an array substrate thereof. The organic electroluminescent device according to the present invention includes: a first electrode which includes a first layer and a second layer which are made of transparent conducive materials; a light emitting material layer which is located on the upper side of the first electrode; and a second electrode which is located on the upper side of the light emitting material layer. The second layer is located between the first layer and the light emitting material layer. The surface resistance of the first layer is smaller than the surface resistance of the second layer. The work function of the second layer is larger than the work function of the first layer. Thereby, the work function of the first electrode functioning as an anode electrode is increased.

Description

Organic electroluminescent device and method of manufacturing the array substrate {organic electro luminescent device and method of fabricating array substrate for the same}

The present invention relates to an organic electroluminescent device, and to an organic electroluminescent device comprising an anode electrode having a relatively large work function value and a method for manufacturing the array substrate thereof.

In recent years, the display field for processing and displaying a large amount of information has been rapidly developed as society has entered into a full-fledged information age. In recent years, flat panel display devices having excellent performance such as thinning, light weight, Has been proposed.

Among them, an organic electroluminescent device or an organic electroluminescent display, also called an organic light emitting diode (OLED), injects electric charge into a light emitting layer formed between a cathode, which is an electron injection electrode, and an anode, which is a hole injection electrode. This is a device that emits light while disappearing after pairing electrons and holes. Such organic electroluminescent devices can be formed not only on a flexible substrate such as a plastic but also because they are excellent in color due to self-luminescence and are low in plasma display panel (Plasma Display Panel) and inorganic electroluminescence It has the advantage of being able to drive (less than 10V) voltage and relatively low power consumption.

1 is a diagram illustrating a structure of a general organic electroluminescent device using a band diagram.

As shown in FIG. 1, the organic electroluminescent device has an emitting material layer (EML) 14 between an anode electrode 11 serving as an anode and a cathode electrode 17 serving as a cathode. Located. To inject holes from the anode electrode 11 and electrons from the cathode electrode 17 into the light emitting material layer 14, between the anode electrode 11 and the light emitting material layer 14 and between the cathode electrode 17 and the light emission. A hole transporting layer (HTL) 13 and an electron transporting layer (ETL) 15 are positioned between the material layers 14, respectively. At this time, to inject holes and electrons more efficiently, a hole injecting layer (HIL) between the anode electrode 11 and the hole transport layer 13 and between the electron transport layer 15 and the cathode electrode 17 ( 12) and an electron injecting layer (EIL) 16.

In the band diagram of FIG. 1, the lower line is the highest energy level of the valence band, called the highest occupied molecular orbital, and the upper line is the lowest of the conduction band. As the energy level, it is called LUMO (lowest unoccupied molecular orbital), and the energy difference between HOMO level and LUMO level is called band gap.

In the organic electroluminescent device having such a structure, holes (+) and cathode electrodes 17 injected from the anode electrode 11 into the light emitting material layer 14 through the hole injection layer 12 and the hole transport layer 13. Electrons (−) injected from the electron injection layer 16 and the electron transport layer 15 through the electron injection layer 16 form an exciton through recombination, and from the exciton The light of color corresponding to the band gap of (14) is emitted.

In general, indium tin oxide (ITO) is widely used as the anode electrode 11, and a work function in the deposition state of ITO is about 4.7 eV, and the light emitting material layer 14 Has a LUMO level of about 5.7 to 6.0 eV, and an energy barrier of about 1.0 to 1.3 eV exists between the anode electrode 11 made of ITO and the light emitting material layer 14. A large energy barrier not only reduces the hole injection efficiency, but also provides a relatively large driving voltage in case the energy barrier is not felt.

Therefore, in order to lower the energy barrier between the anode electrode 11 of the ITO and the light emitting material layer 14 to facilitate the injection of holes, various attempts have been made to increase the work function of the ITO, and oxygen plasma (O ₂ Although the work function of ITO was increased to about 5.1 eV level through plasma treatment, there is still a limit in reducing the energy barrier with the light emitting material layer 14. Accordingly, in order to alleviate the energy barrier difference, a hole injection layer 12 and a hole transport layer 13 are formed between the anode electrode 11 and the light emitting material layer 14. Holes are injected into the light emitting material layer 14, and the hole injection efficiency decreases while contacting different interfaces.

Power consumption (P) is expressed as the product of current (I) and voltage (V), and current has a relationship between luminance and I = L / η (η is the efficiency of the device). The current increases, which in turn increases the power consumption.

In addition, as mentioned above, when the work function of the anode is low, a relatively large driving voltage must be provided, thereby increasing power consumption.

In order to solve the above problems, the present invention increases the work function of the anode electrode to lower the hole injection barrier to increase the luminous efficiency, reduce the driving voltage, and to simplify the device structure and an organic electroluminescent device that can be manufactured The purpose is to provide.

The organic electroluminescent device of the present invention comprises: a first electrode comprising a first layer and a second layer of a transparent conductive material; A light emitting material layer on the first electrode; And a second electrode on the light emitting material layer, wherein the second layer is positioned between the first layer and the light emitting material layer, and the first layer has a sheet resistance smaller than that of the second layer. The layer has a larger work function than the first layer.

The first electrode is subjected to plasma treatment or heat treatment or both plasma treatment and heat treatment.

The first layer has a thickness of about 500 mm 3 and the second layer has a thickness of about 300 mm 3 to about 1500 mm 3.

The first layer is made of indium tin oxide, and the second layer is made of indium tin zinc oxide or indium gallium zinc oxide.

An electron transport layer and an electron injection layer are further included between the light emitting material layer and the second electrode.

A hole transport layer is further included between the first electrode and the light emitting material layer.

The method of manufacturing an array substrate for an organic electroluminescent device of the present invention comprises the steps of forming a thin film transistor on the substrate; Forming a protective layer covering the thin film transistor; A first electrode including a first layer and a second layer disposed on the passivation layer, the first transparent conductive material and the second transparent conductive material being sequentially deposited and patterned to be connected to the drain electrode of the thin film transistor; Forming a; Forming a light emitting material layer on the first electrode; And forming a second electrode on the light emitting material layer, wherein the first layer has a sheet resistance smaller than that of the second layer, and the second layer has a larger work function than the first layer.

Between the forming of the first electrode and the forming of the light emitting material layer, forming a bank layer having an opening that exposes the first electrode, and heat-treating the substrate including the bank layer It includes more.

The heat treatment is performed at about 230 degrees Celsius for about 1 hour.

And helium plasma treating the first electrode after the forming of the first electrode.

The first transparent conductive material is indium tin oxide, and the second transparent conductive material is indium tin zinc oxide or indium gallium zinc oxide.

The method may further include forming an electron transport layer and forming an electron injection layer between the forming of the light emitting material layer and the forming of the second electrode.

The method may further include forming a hole transport layer between the forming of the first electrode and the forming of the light emitting material layer.

According to the present invention, the anode electrode is formed of a double layer of a transparent conductive material having a relatively low sheet resistance at the bottom and a transparent conductive material having a relatively high work function at the upper portion, and subjected to plasma treatment or heat treatment to raise the sheet resistance of the anode electrode to a predetermined level. Increase work function while maintaining Accordingly, the device structure can be simplified by lowering the energy barrier between the anode electrode and the light emitting material layer to increase the hole injection efficiency and omitting the hole transport layer and the hole injection layer. In addition, power consumption can be reduced by increasing the luminous efficiency and reducing the driving voltage.

1 is a diagram illustrating a structure of a general organic electroluminescent device using a band diagram.
2 is a cross-sectional view schematically showing the structure of an organic electroluminescent device according to an embodiment of the present invention.
3 is a diagram showing the structure of the organic electroluminescent device according to an embodiment of the present invention in a band diagram.
4A and 4B are graphs showing work function and sheet resistance characteristics of post-treatment conditions of a bilayer structure of ITO and ITZO according to an embodiment of the present invention, respectively.
5 is a cross-sectional view illustrating an array substrate for an organic electroluminescent device according to an embodiment of the present invention.
6A to 6K are cross-sectional views illustrating the array substrates of each stage in the manufacturing process of the array substrate for the organic light emitting diode according to the embodiment of the present invention.

Hereinafter, an organic electroluminescent device according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view schematically showing the structure of an organic electroluminescent device according to an embodiment of the present invention, Figure 3 is a diagram showing the structure of the organic electroluminescent device according to an embodiment of the present invention in a band diagram.

As shown in FIG. 2 and FIG. 3, an organic electroluminescent device according to an embodiment of the present invention includes a light emitting material layer between an anode electrode 110 serving as an anode and a cathode electrode 120 serving as a cathode. emitting material layer (EML) 132, and between the cathode electrode 120 and the light emitting material layer 132 to inject electrons from the cathode electrode 120 into the light emitting material layer 132. An electron transporting layer (ETL) 134 is located. In this case, an electron injection layer (EIL) 136 may be further included between the electron transport layer 134 and the cathode electrode 120 to inject electrons more efficiently.

Here, the anode electrode 110 includes a first layer 112 and a second layer 114 made of a transparent conductive material, the second layer 114 is the first layer 112 and the light emitting material layer 132. Located in between.

Here, it is preferable that the material of the first layer 112 has a relatively small sheet resistance, and the material of the second layer 114 has a relatively large work function. That is, the material of the first layer 112 has a sheet resistance smaller than the material of the second layer 114, and serves to function as an electrode by controlling the sheet resistance of the anode electrode 110 by the first layer 112. The material of the second layer 114 has a larger work function than the material of the first layer 112, thereby increasing the work function of the anode electrode 110 by the second layer 114.

For example, the first layer 112 is made of indium tin oxide (ITO), and the second layer 114 is made of indium tin zinc oxide (ITZO) and indium. It may be made of any one of-gallium-zinc-oxide (IGZO).

The first layer 112 preferably has a thickness of about 500 GPa in order to secure a sheet resistance of the anode electrode 110 to a predetermined level, and the second layer 114 has a work function of the anode electrode 110. It is desirable to have a thickness of about 300 kPa to about 1500 kPa to ensure a constant level.

At this time, in order to further increase the work function, the surface of the second layer 114 adjacent to the light emitting material layer 132 is preferably plasma-treated or heat-treated.

4A and 4B are graphs showing work function and sheet resistance characteristics of post-treatment conditions of a double layer structure of ITO and ITZO according to an embodiment of the present invention.

4A and 4B, after deposition of ITO and ITZO, the work function value is about 5.27 eV and the sheet resistance value is about 171 ohm / sq. In comparison, when the heat treatment is performed, the work function value is about 5.50. It increases to eV and the sheet resistance decreases to about 45 ohm / sq. In case of hydrogen plasma treatment, the work function decreases to about 4.21 eV and the sheet resistance increases to about 211 ohm / sq. He plasma) treatment increases the work function to about 5.72 eV and the sheet resistance to about 273 ohm / sq.

Here, similar results can be obtained when IGZO is used instead of ITZO.

Therefore, the dual function structure of ITO and ITZO or ITO and IGZO is subjected to heat treatment or plasma treatment, or both heat treatment and plasma treatment to maintain the surface resistance of the anode electrode 110 at a level of about 55 ohm / sq or less. It can increase to about 5.5 ~ 5.8eV, and lower the energy barrier between the anode electrode 110 and the light emitting material layer 132 to about 0.2 ~ 0.5eV to increase the hole injection efficiency and omit the hole transport layer and hole injection layer. have. Accordingly, the device structure can be simplified, and the power consumption can be reduced by increasing the luminous efficiency and reducing the driving voltage.

An array substrate for an organic electroluminescent device having such a structure will be described in more detail with reference to the drawings.

5 is a cross-sectional view illustrating an array substrate for an organic electroluminescent device according to an embodiment of the present invention.

As shown in FIG. 5, a buffer layer 112 of an inorganic insulating material is formed on the insulating substrate 110. A semiconductor layer 122 made of polysilicon and a first capacitor electrode 124 are formed on the buffer layer 112. The first capacitor electrode 124 is doped with a high concentration impurity and the semiconductor layer 122 is doped with a high concentration of impurities on both sides of the active region 122a and the active region 122a, And source and drain regions 122b and 122c.

A gate insulating film 130 is formed on the semiconductor layer 122 and the first capacitor electrode 124 and covers the gate insulating film 130. A gate electrode 132 and a second capacitor electrode 134 are formed on the gate insulating film 130 . The gate electrode 132 is located corresponding to the active region 122a and the second capacitor electrode 134 is located corresponding to the first capacitor electrode 124. [

An interlayer insulating layer 140 is formed on the gate electrode 132 and the second capacitor electrode 134 to cover the gate electrode 132 and the second capacitor electrode 134. The interlayer insulating layer 140 has first and second contact holes 140a and 140b which expose the source and drain regions 122b and 122c, respectively, together with the gate insulating layer 130. [

Next, source and drain electrodes 142 and 144 and a third capacitor electrode 146 are formed on the interlayer insulating layer 140. The source and drain electrodes 142 and 144 are respectively in contact with the source and drain regions 122b and 122c through the first and second contact holes 140a and 140b and the third capacitor electrode 146 is connected to the source and drain regions 122b and 122c, (134).

Here, the semiconductor layer 122, the gate electrode 132, and the source and drain electrodes 142 and 144 form a thin film transistor.

A first passivation layer 150 and a second passivation layer 160 are sequentially formed on the source and drain electrodes 142 and 144 and the third capacitor electrode 146. The first and second passivation layers 150 and 160 have a drain contact hole 160a exposing the drain electrode 144.

A first electrode 162 made of a transparent conductive material is formed on the second protective layer 160 to contact the drain electrode 144 through the drain contact hole 160a. Here, the first electrode 162 includes a lower first layer 162a and an upper second layer 162b. The first layer 162a is made of a material having a relatively low sheet resistance, and the second layer ( 162b) consists of a material having a relatively large work function. For example, the first layer 162a may be formed of indium tin oxide (ITO), and the second layer 162b may be indium tin zinc oxide (ITZO) or indium. It may be made of indium gallium zinc oxide (IGZO).

The bank layer 172 is formed on the first electrode 162. The bank layer 172 covers the edge of the first electrode 162 and has an opening 172a exposing the first electrode 162.

A light emitting material layer 182 is formed on the bank layer 172 to contact the first electrode 162 exposed through the opening 172a, and a second light emitting material layer 182 is formed on the entire surface of the substrate 110 above the light emitting material layer 182. An electrode 184 is formed. The second electrode 184 is preferably formed of a metal material having a work function smaller than that of the first electrode 162.

The first electrode 162, the light emitting material layer 182, and the second electrode 184 form a light emitting diode, the first electrode 162 serves as an anode electrode of the light emitting diode, and the second electrode 184. Silver serves as a cathode of the light emitting diode.

Although not shown, an electron transport layer and an electron injection layer are sequentially formed between the light emitting material layer 182 and the second electrode 184 to efficiently inject electrons. In addition, a hole injection layer and a hole transport layer may be omitted between the first electrode 162 and the light emitting material layer 182, but only a hole transport layer may be formed without a hole injection layer.

Here, the first electrode 162 may be plasma-treated or heat-treated, or both plasma and heat-treated may be performed.

The manufacturing process of the array substrate for an organic electroluminescent device according to the embodiment of the present invention will be described in detail with reference to FIGS. 6A to 6K.

6A to 6K are cross-sectional views illustrating the array substrates of each stage in the manufacturing process of the array substrate for the organic light emitting diode according to the embodiment of the present invention.

First, as shown in FIG. 6A, a buffer layer 112 is formed by depositing silicon nitride (SiNx) or silicon oxide (SiO ₂ ), which is an inorganic insulating material, on the insulating substrate 110. When the amorphous silicon layer is crystallized into the polycrystalline silicon layer in a subsequent process, the buffer layer 112 is formed of alkali ions existing in the substrate 110, for example, potassium ions K +) or sodium ions (Na +) into the polycrystalline silicon layer. Here, the buffer layer 112 may be omitted depending on the material of the substrate 110.

Next, amorphous silicon is deposited on the buffer layer 112 to form an amorphous silicon layer (not shown) on the entire surface, and a crystallization process is performed to crystallize the amorphous silicon layer to form a polycrystalline silicon layer (not shown).

At this time, the crystallization process may be a solid phase crystallization (SPC) process or a laser crystallization process.

Here, the solid phase crystallization (SPC) process may be performed by, for example, thermal crystallization through heat treatment in an atmosphere of 600 to 800 degrees Celsius, alternating crystallization in a temperature atmosphere of 600 to 700 degrees Celsius using an alternating magnetic field crystallization apparatus Magnetic Field Crystallization) process. Preferably, the crystallization using a laser is an excimer laser annealing (ELA) method using an excimer laser or a sequential lateral solidification (SLS) method.

Next, a mask process including a step of application of a photoresist, a step of exposure using a photomask, development of an exposed photoresist, etching of a thin film, and stripping of a photoresist is carried out to pattern the polycrystalline silicon layer, The first semiconductor pattern 120a and the second semiconductor pattern 120b are formed.

Next, as shown in FIG. 6B, an inorganic insulating material, for example, silicon nitride (SiNx) or silicon oxide (SiO ₂ ), is formed on the entire surface of the first semiconductor pattern 120a and the second semiconductor pattern 120b of FIG. 6A. To form a gate insulating film 130 by depositing the photoresist through a mask process, and then exposing and developing the photoresist, thereby forming a photoresist pattern 192 covering the first semiconductor pattern 120a on the gate insulating film 130. Form. Subsequently, a high concentration of impurities are injected into the second semiconductor pattern 120b of FIG. 6A by performing a doping process to form the first capacitor electrode 124.

Thereafter, the photoresist pattern 192 is removed.

Next, as illustrated in FIG. 6C, a metal material having a relatively low resistivity is deposited on the gate insulating layer 130 and patterned through a mask process to form the gate electrode 132 and the second capacitor electrode 134. The gate electrode 132 is positioned corresponding to the center of the first semiconductor pattern 120a of FIG. 6B. The second capacitor electrode 134 is located above the first capacitor electrode 124. The metal material may be formed by depositing any one or two or more of aluminum (Al), an aluminum alloy such as aluminum-nedium (AlNd), copper (Cu), copper alloy, molybdenum (Mo), and molybdenum (MoTi). Can be formed.

On the other hand, although not shown in the drawing, a gate wiring connected to the gate electrode 132 and extending in one direction is also formed on the gate insulating film 130.

Subsequently, a doping process is performed using the gate electrode 132 and the second capacitor electrode 134 as a doping mask, thereby providing high concentrations on both sides of the first semiconductor pattern (120a of FIG. 6B) not covered with the gate electrode 132. Impurities are implanted to form the semiconductor layer 122. The semiconductor layer 122 includes an active region 122a in which a central impurity is not doped and source and drain regions 122b and 122c doped with impurities on both sides of the active region 122a. Here, the impurity may be a p-type impurity of boron (B), indium (In), gallium (Ga) or an n-type impurity of phosphorus (P), arsenic (As) or antimony (Sb).

On the other hand, between the active region 122a and the source region 122b of the semiconductor layer 122 and between the active region 122a and the drain region 122c, an impurity-doped region having a low concentration to reduce off- lightly-doped drain (LDD) may be further formed.

Next, as shown in FIG. 6D, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the gate electrode 132 and the second capacitor electrode 134 to form the interlayer insulating layer 140. And first and second contact holes 140a and 140b are formed by patterning through a mask process. At this time, the first and second contact holes 140a and 140b are formed in the gate insulating layer 130 to expose the lower source and drain regions 122b and 122c, respectively.

Next, as shown in FIG. 6E, a metal material having a relatively small specific resistance on the interlayer insulating layer 140, for example, aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, and titanium (Ti). ), Or at least one of molybdenum (Mo) and molybdenum (MoTi) is deposited and patterned through a mask process to form the source and drain electrodes 142 and 144 and the third capacitor electrode 146. The source and drain electrodes 142 and 144 are respectively in contact with the source and drain regions 122b and 122c through the first and second contact holes 140a and 140b while the third capacitor electrode 146 is in contact with the source and drain regions 122b and 122c, (134).

A storage capacitor is formed by using the gate insulating film 130 and the interlayer insulating film 140 as a dielectric between the first capacitor electrode 124 and the second capacitor electrode 134 and the third capacitor electrode 147 .

Although not shown, a data line connected to the source electrode 142 and extending in one direction to cross the gate line (not shown) to define the pixel area is also formed on the interlayer insulating layer 140.

Next, as illustrated in FIG. 6F, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the source and drain electrodes 142 and 144 and the third capacitor electrode 146. The first protective layer 150 is formed and patterned through a mask process to form a first drain contact hole 150a exposing the drain electrode 144.

Subsequently, as illustrated in FIG. 6G, the second protective layer 160 having a flat surface by applying an organic insulating material such as photo acryl or benzocyclobutene on the first protective layer 150 is formed. ) And patterned through a mask process to form a second drain contact hole 160a. The second drain contact hole 160a exposes the drain electrode 144 together with the first drain contact hole 150a of FIG. 6F.

In the present invention, the first and second drain contact holes 150a and 160a are formed in the first passivation layer 150 and the second passivation layer 160 through two mask processes, respectively. However, 1 and the second passivation layers 150 and 160 are sequentially deposited and the first and second passivation layers 150 and 160 are patterned through a single mask process to form a drain contact hole May be formed.

Here, the case where the first and second protective layers 150 and 160 are formed has been described. However, any one of the first and second protective layers 150 and 160 may be omitted.

Next, as shown in FIG. 6H, the first transparent conductive material and the second transparent conductive material are sequentially deposited on the second protective layer 150 and patterned through a mask process to form the lower first layer 162a and the upper part. The first electrode 162 including the second layer 162b is formed in each pixel area. The first electrode 162 contacts the drain electrode 144 through the second and first drain contact holes 160a (150a in FIG. 6F).

Here, the first transparent conductive material is a material having a relatively small sheet resistance, for example, may be indium tin oxide (ITO), and the second transparent conductive material is a material having a relatively large work function. For example, it may be indium tin zinc oxide (ITZO) or indium gallium zinc oxide (IGZO).

In order to secure the sheet resistance of the first electrode 162 to a predetermined level, the first layer 162a preferably has a thickness of about 500 GPa, and the second layer 162b has a predetermined work function of the first electrode 162. In order to ensure that it has a thickness of about 300 kPa to about 1500 kPa.

Next, as shown in FIG. 6I, the substrate 110 on which the first electrode 162 is formed is exposed to plasma to expose the surface of the first electrode 162, more specifically, the second layer 162b. The surface of the plasma is treated. In this case, helium plasma may be used. Through the plasma treatment, the work function and the sheet resistance of the second layer 162b may be further increased.

Next, as shown in FIG. 6J, a bank layer 172 having an opening 172a exposing the first electrode 162 by forming an insulating material on the first electrode 162 and patterning the same through a mask process. Form. The bank layer 172 may be formed of a photosensitive organic insulating material.

Subsequently, the substrate 110 on which the bank layer 172 is formed is heat-treated at a temperature of about 230 degrees Celsius for about one hour. In this case, since the first electrode 162 is also heat treated together, the work function and the sheet resistance of the second layer 162b may be further improved without a separate heat treatment process.

Although not shown, a spacer may be further formed on the bank layer 172.

Next, as illustrated in FIG. 6K, the light emitting material layer 182 is formed in the pixel area on the substrate 110 including the bank layer 172. The light emitting material layer 182 contacts the first electrode 162 exposed through the opening 172a. Next, a second electrode 184 is formed on the entire surface of the substrate 110 including the light emitting material layer 182. The second electrode 184 is made of a metal material having a lower work function than the first electrode 162.

The first electrode 162, the light emitting material layer 182, and the second electrode 184 form a light emitting diode, the first electrode 162 serves as an anode electrode of the light emitting diode, and the second electrode 184. Silver serves as a cathode of the light emitting diode.

Although not shown, an electron transport layer and an electron injection layer are sequentially formed between the light emitting material layer 182 and the second electrode 184 to efficiently inject electrons. In addition, a hole injection layer and a hole transport layer may be omitted between the first electrode 162 and the light emitting material layer 182, and only a hole transport layer may be further formed as necessary.

As described above, in the present invention, the first electrode 162 serving as the anode electrode is formed of a double layer of ITO and ITZO or ITO and IGZO, followed by plasma treatment, and then a heat treatment is performed after the bank layer 172 is formed. The work function may be increased while maintaining the sheet resistance of the first electrode 162 at a predetermined level. Therefore, the device structure may be simplified by omitting the hole injection layer and the hole transport layer, and the efficiency of the device may be increased by improving the hole injection efficiency, and the driving voltage may be reduced to reduce power consumption.

On the other hand, the plasma treatment may be omitted. That is, the first electrode 162 is formed, the bank layer 172 is formed on the first electrode 162, and then heat treated, thereby increasing the work function of the first electrode 162 by heat treatment alone without plasma treatment. You can also

The structure of the thin film transistor and the array substrate is not limited to the above embodiment.

The present invention is not limited to the above-described embodiments, and various changes and modifications may be made without departing from the spirit of the present invention.

110: anode electrode 112: first layer
114: second layer 132: light emitting material layer
134: electron transport layer 136: electron injection layer
120: cathode electrode

Claims (13)

A first electrode comprising a first layer and a second layer of a transparent conductive material;
A light emitting material layer on the first electrode;
A second electrode on the light emitting material layer
/ RTI >
The second layer is located between the first layer and the light emitting material layer, the first layer has a sheet resistance less than the second layer, the second layer has a larger work function than the first layer An organic electroluminescent device characterized by.
The method of claim 1,
And the first electrode is subjected to a plasma treatment, a heat treatment, or a plasma treatment.
3. The method of claim 2,
And the first layer has a thickness of about 500 mW and the second layer has a thickness of about 300 mW to about 1500 mW.
4. The method according to any one of claims 1 to 3,
The first layer is made of indium tin oxide, and the second layer is made of indium tin oxide or indium gallium zinc oxide.
The method of claim 1,
An organic electroluminescence device further comprising an electron transport layer and an electron injection layer between the light emitting material layer and the second electrode.
6. The method of claim 5,
An organic electroluminescence device further comprising a hole transport layer between the first electrode and the light emitting material layer.
Forming a thin film transistor on the substrate;
Forming a protective layer covering the thin film transistor;
A first electrode including a first layer and a second layer disposed on the passivation layer, the first transparent conductive material and the second transparent conductive material being sequentially deposited and patterned to be connected to the drain electrode of the thin film transistor; Forming a;
Forming a light emitting material layer on the first electrode;
Forming a second electrode on the light emitting material layer
Lt; / RTI >
And the first layer has a sheet resistance smaller than that of the second layer, and the second layer has a work function larger than that of the first layer.
8. The method of claim 7,
Between the forming of the first electrode and the forming of the light emitting material layer, forming a bank layer having an opening that exposes the first electrode, and heat treating a substrate including the bank layer. A method of manufacturing an array substrate for an organic electroluminescent device, further comprising.
9. The method of claim 8,
The heat treatment is a method of manufacturing an array substrate for an organic electroluminescent device, characterized in that performed for about 1 hour at about 230 degrees Celsius.
10. The method according to any one of claims 7 to 9,
The method of manufacturing an array substrate for an organic electroluminescent device further comprising the step of helium plasma treatment of the first electrode after the forming of the first electrode.
11. The method of claim 10,
The first transparent conductive material is indium tin oxide, and the second transparent conductive material is indium tin oxide or indium gallium zinc oxide manufacturing of the array substrate for an organic light emitting device Way.
8. The method of claim 7,
Forming an electron transport layer and forming an electron injection layer between the step of forming the light emitting material layer and the step of forming the second electrode further comprises manufacturing an array substrate for an organic light emitting device Way.
The method of claim 12,
And forming a hole transport layer between the step of forming the first electrode and the step of forming the light emitting material layer.

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