KR20120042435A - Organic electroluminescent device and method of fabricating the same - Google Patents

Abstract

PURPOSE: An organic electroluminescence device and a manufacturing method thereof are provided to improve light emitting efficiency of the organic electroluminescence device by forming a capping layer of a conductive organic material which has a refractive index in a range for preventing total reflection of the upper part of a second electrode. CONSTITUTION: A first electrode(130) is formed on a first substrate(120). A light emitting layer(140) is formed on the upper part of the first electrode. A second electrode(150) which has a work function value lower than the first electrode is formed on the upper part of the light emitting layer. A capping layer(160) which is comprised of a conductive organic material is formed on the upper part of the second electrode. A second substrate(170) which is attached on the first substrate is located on the upper part of the capping layer.

Description

Organic electroluminescent device and manufacturing method thereof {ORGANIC ELECTROLUMINESCENT DEVICE AND METHOD OF FABRICATING THE SAME}

The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device including a capping layer made of a conductive organic material on the second electrode and a method of manufacturing the same.

In the field of flat panel display (FPD), light crystal and low power consumption liquid crystal display device (LCD device) have been widely used so far, but the liquid crystal display device does not generate light by itself. As a non-emissive device, there are disadvantages in brightness, contrast ratio, viewing angle, and large area.

Accordingly, development of a new flat panel display device capable of overcoming the disadvantages of the liquid crystal display device is being actively developed. One of the new flat panel display devices is an organic electroluminescent display device or an organic light emitting diode display. device: OLED device is a light emitting device that generates light by itself, which has better brightness, viewing angle, and contrast ratio than liquid crystal display devices, and is lightweight and thinner because it does not require a backlight. It is advantageous.

In addition, since it is possible to drive a DC low voltage, fast response speed, and all made of solid, it is resistant to external shock, wide use temperature range, and in particular, in terms of manufacturing cost.

An organic light emitting display device displays an image using an organic light emitting device connected to a thin film transistor of each pixel region, that is, light emitted from a light emitting diode, and the organic light emitting display device is disposed between an anode and a cathode. A device that emits light by forming an emission layer made of an organic material and applying an electric field, can be driven at a low voltage, has a relatively low power consumption, and can be manufactured on a light and flexible substrate.

Such an organic light emitting device will be described with reference to the drawings.

1 is a cross-sectional view of a conventional organic light emitting diode, and FIG. 2 is a view schematically showing an energy band diagram of a conventional organic light emitting diode.

As shown in FIG. 1 and FIG. 2, the conventional organic EL device 10 includes a substrate 20, a first electrode 30 formed on the substrate 20, and a first electrode 30. The light emitting layer 40 is formed on the upper portion, and the second electrode 50 is formed on the light emitting layer 40.

The first electrode 30 supplies holes 62 to the light emitting layer 40 as an anode, and the second electrode 50 serves as electrons to the light emitting layer 40 as a cathode. 64, the first electrode 30 has a Fermi level (E _F ) that is lower than the second electrode 50, that is, a large work function value.

The light emitting layer 40 may include a hole injection layer (HIL) 41, a hole transport layer (HTL) 43, an emitting material layer (EML) 45, and an electron transport layer ( and an electron transport layer (ETL) 47 and an electron injection layer (EIL) 49.

The hole injection layer 41 and the hole transport layer 43 allow the holes 62 of the first electrode 30 to be smoothly injected and transferred to the light emitting material layer 45, and the electron transport layer 47 and the electron injection layer. 49 allows electrons 64 of the second electrode 50 to be smoothly injected and transferred to the light emitting material layer 45.

The holes 62 and electrons 64 supplied from the first and second electrodes 30 and 50, respectively, are coupled to each other in the light emitting material layer 45 to form an exciton 66 in an excited state. Is generated, and light is emitted while the generated excitons 66 transition to a stable state.

Such an organic light emitting device may have a problem in that its lifespan and luminous efficiency are lowered depending on the material and the laminated structure used.

For example, in the organic light emitting device 10 of the top emission type emitting light of the light emitting material layer 45 to the second electrode 50, the second electrode 50 may be magnesium: silver. (Mg: Ag) or calcium: silver (Ca: Ag) or the like, and a relatively thin thickness is formed. In this case, the second electrode 50 has a relatively high resistance so that the organic light emitting device 10 ), The electrical characteristics are reduced, and the life is reduced.

That is, in the organic electroluminescent device 10, a large amount of current continuously flows through the second electrode 50 and a common wiring (not shown) connected to the second electrode 50. A large amount of heat is generated in the second electrode 50 and the common wiring having a relatively high resistance by the current, and the second electrode 50 and the common wiring are shorted or oxidized with the adjacent wiring by the generated heat. As a result, the reliability of the organic light emitting diode 10 is reduced and the lifespan is reduced.

In particular, when the second electrode 50 includes silver, agglomeration may occur due to the migration of silver atoms in the second electrode 50 and the common wiring. The aggregation causes a possibility of short circuit of the second electrode 50 and the common wiring.

Of course, the thickness may be increased in order to reduce the resistance of the second electrode 50, but in this case, the transmittance of the second electrode 50 decreases rapidly, thereby lowering the luminous efficiency of the organic light emitting diode 10. Occurs.

In the organic light emitting device 10 of the top emission type, the light of the light emitting material layer 45 may be totally reflected on the upper surface of the second electrode 50, and accordingly, the organic light emitting device There is also a problem that the luminous efficiency of (10) is reduced.

An object of the present invention is to provide an organic electroluminescent device and a method of manufacturing the same, by forming a capping layer including a conductive organic material on the second electrode, thereby improving electrical characteristics and thermal stability and thereby increasing lifetime. .

In addition, another object of the present invention is to provide an organic electroluminescent device having improved luminous efficiency and a method of manufacturing the same, by forming a capping layer including a conductive organic material having a refractive index that prevents total reflection on the second electrode. .

In order to achieve the above object, the present invention, the first substrate; A first electrode formed on the first substrate; An emission layer formed on the first electrode; A second electrode formed on the emission layer and having a lower work function value than the first electrode; A capping layer formed on the second electrode and made of a conductive organic material; The organic light emitting device includes a second substrate disposed on the capping layer and bonded to the first substrate.

Here, the conductive organic material may be an organic material doped with a conductive inorganic material or an organic material doped with a metal complex.

The conductive organic material may be one of an organic material doped with a P-type dopant or an N-type dopant, an organic material doped with a metal, and an organic material doped with lithium-quinolate (Liq).

The organic light emitting diode may further include a bank layer formed on the first electrode and exposing a central portion of the first electrode and covering an edge portion of the first electrode.

The light emitting layer may include a hole injection layer, a hole transport layer, a light emitting material layer, an electron transport layer, and an electron injection layer sequentially formed on the first electrode.

In addition, the organic light emitting device may further include a reflective layer formed between the first substrate and the first electrode.

In addition, the conductive organic material may have a refractive index in the range of 1.6 to 1.8.

On the other hand, the present invention comprises the steps of forming a first electrode on the first substrate; Forming a light emitting layer on the first electrode; Forming a second electrode on the light emitting layer, the second electrode having a lower work function than the first electrode; Forming a capping layer made of a conductive organic material on the second electrode; It provides a method of manufacturing an organic light emitting device comprising the step of bonding the second substrate to the first substrate on which the capping layer is formed.

The light emitting layer may be formed by a thermal evaporation method, and the capping layer may be formed by a deposition method or a coating method.

The method of manufacturing the organic light emitting diode may further include treating the surface of the first electrode with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

In the organic light emitting device according to the present invention and a method of manufacturing the same, by forming a capping layer of a conductive organic material on the second electrode used as a cathode, the electrical characteristics and thermal stability of the second electrode is improved and thereby the organic electroluminescence The life of the device can be increased.

In addition, by forming a capping layer of a conductive organic material having a refractive index in the range of preventing total reflection on the second electrode used as a cathode, it is possible to improve the luminous efficiency of the organic light emitting device.

1 is a cross-sectional view of a conventional organic light emitting device.
2 is a view schematically showing an energy band diagram of a conventional organic light emitting diode.
3 is a cross-sectional view of an organic light emitting display device of the top light emitting method according to the first embodiment of the present invention.
4 is a cross-sectional view of an organic light emitting diode of a bottom emission type according to a second embodiment of the present invention.
5A, 5B, and 5C are diagrams illustrating luminous efficiency, current density, and intensity of the organic light emitting diodes according to the first and second embodiments of the present invention, respectively.
6 is a cross-sectional view of an organic light emitting display device including an organic light emitting display device according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

3 is a cross-sectional view of an organic light emitting display device of the top light emitting method according to the first embodiment of the present invention.

As shown in FIG. 3, the organic light emitting device 110 of the top emission type according to the first embodiment of the present invention may include a first substrate 120 and a first formed on the first substrate 120. The electrode 130, the light emitting layer 140 formed on the first electrode 130, the second electrode 150 formed on the light emitting layer 140, and the capping layer formed on the second electrode 150. and a second substrate 170 disposed on the capping layer 160.

Specifically, the reflective layer 134 and the first layer are sequentially deposited and patterned on the first substrate 120 made of glass or plastic by sequentially depositing and patterning a material having a relatively large reflectance and a transparent conductive material having a relatively large work function value. The electrode 130 is formed.

For example, the reflective layer 134 may be formed using a material such as aluminum (Al), and the first electrode 130 may be formed of indium-tin-oxide (ITO) or indium-zinc-oxide (IZO). The material may be formed to a thickness in the range of about 100 nm to 400 nm.

After the formation of the first electrode 130, the surface of the first electrode 130 may be treated with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

In the first embodiment, the reflective layer 134 is formed under the first electrode 130 to reflect the light of the light emitting material layer 145 emitted toward the first electrode 130 toward the second electrode 150. In another embodiment, the reflective layer 134 may be omitted by forming the first electrode 130 as a single layer using a conductive material having a relatively high reflectance.

In addition, an insulating material is deposited and patterned on the first electrode 130 to form a bank layer 132 exposing the center portion of the first electrode 130 and covering the edge portion.

The bank layer 132 is formed to separate the first electrode 130 for each region and to prevent a short circuit with another conductive wiring. The bank layer 132 covers the edge portion of the first electrode 130, Defects such as lifting of the edges of the first electrode 130 may be prevented.

In addition, a hole injection layer (HIL) 141 and a hole transport layer are formed on the first electrode 130 exposed through the bank layer 132 through a thermal evaporation method. : HTL) 143, emitting material layer (EML) 145, electron transport layer (ETL) 147, and electron injection layer (EIL) 149 in sequence Deposition is performed to form the emission layer 140.

For example, the hole injection layer 141 may be formed to have a thickness in a range of about 10 nm to about 50 nm, and the hole transport layer 143 may include NPD (4,4'-bis [N- (1-naphthyl) -N-). phenyl-amino] biphenyl]) may be formed to a thickness ranging from about 30 nm to about 60 nm.

The light emitting material layer 145 may be formed to have a thickness ranging from about 5 nm to about 100 nm using an organic material, and a dopant may be added as needed.

The electron transport layer 147 may be formed to a thickness of about 20 nm to about 40 nm using a material such as Alq3 (tris (8-hydroxyquinoline) aluminum), and the electron injection layer 149 may be formed of LiF or Li ₂ O. The material may be formed to a thickness in a range of about 0.5 nm to about 1 nm, or may be formed in a thickness of about 10 nm to about 20 nm using an alkali metal or alkaline earth metal such as Li, Ca, Mg, Sm, or the like.

The second electrode 150 is formed by depositing a metal material having a relatively small work function on the emission layer 140.

For example, the second electrode 150 may be formed to a thickness of about 1 nm to about 5 nm using a material such as Mg: Ag, Ca: Ag, Ca, Al: Li, or the like.

The capping layer 160 is formed on the second electrode 150 by depositing or coating a conductive organic material having a refractive index that can prevent total reflection on the surface of the second electrode 150.

For example, the capping layer 160 has a refractive index in the range of about 1.6 to about 1.8, and is formed to a thickness in the range of about 10 nm to about 100 nm using an organic material doped with a conductive inorganic material or an organic material doped with a metal complex. Can be.

Specifically, the conductive organic material may be one of an organic material doped with a P-type dopant or an N-type dopant, an organic material doped with a metal, and an organic material doped with lithium-quinolate (Liq).

Then, the second substrate 170 is bonded to the first substrate 120 on which the capping layer 160 is formed using the bonding agent.

Here, the binder may be a photocurable resin or a thermosetting resin, and the separation space 165 between the bonded first and second substrates 120 and 170 may be filled with air, nitrogen, or a binder.

In addition, by disposing the hygroscopic agent in the space 165, the organic EL device 110 can be protected from moisture or oxygen (O ₂ ) in the air.

In the organic light emitting diode device 110 according to the first embodiment of the present invention as described above, the first electrode 130 has a Fermi level lower than the second electrode 150, that is, a large work function. It is formed to have a (work function) value, and the first and second electrodes 130 and 150 operate as an anode and a cathode, respectively.

Accordingly, the first and second electrodes 130 and 150 respectively supply holes and electrons to the emission layer 140, and the holes and electrons supplied from the first and second electrodes 130 and 150, respectively. The electrons combine with each other in the light emitting material layer 145 to generate light.

Light generated from the light emitting material layer 145 is transmitted toward the first and second electrodes 130 and 150, and the light transmitted toward the first electrode 130 is reflected layer 134 under the first electrode 130. ) Is reflected by the light source and transferred to the second electrode 150.

Therefore, the light generated by the light emitting material layer 145 is emitted from the organic light emitting diode 110 through the second electrode 150.

Here, the second electrode 150 forms a metal material in a relatively thin thickness, for example, in a range of about 1 nm to about 5 nm, so that the light generated by the light emitting material layer 145 can be transmitted. The common wiring (not shown) connected to the second electrode 150 and the second electrode 150 has a relatively high resistance by itself.

Due to such a high resistance, the electrical characteristics and thermal stability of the second electrode 150 and the common wiring may be degraded. In the organic light emitting device 110 according to the first embodiment of the present invention, the second electrode 150 is disposed on the second electrode 150. Since the capping layer 160 of the conductive organic material is formed, the resistance of the second electrode 150 and the common wiring is reduced.

Therefore, defects such as short-circuit, oxidation, agglomeration, etc. of the second electrode 150 and the common wiring are prevented, thereby improving electrical characteristics and thermal stability, and improving reliability and lifespan of the organic light emitting diode 110.

In addition, the light generated by the light emitting material layer 145 is totally reflected on the upper surface of the second electrode 150 may reduce the luminous efficiency of the organic light emitting device 110, according to the first embodiment of the present invention In the organic light emitting diode 110, a capping layer 160 of a conductive organic material having a refractive index that prevents total reflection is formed on the second electrode 150, for example, about 1.6 to about 1.8. The total reflection at the upper surface of the second electrode 150 is prevented, and the luminous efficiency of the organic light emitting diode 110 is improved.

Meanwhile, the capping layer of the conductive organic material may be applied to the organic light emitting device of the bottom emission type, which will be described with reference to the drawings.

4 is a cross-sectional view of an organic light emitting diode of a bottom emission type according to a second embodiment of the present invention.

As shown in FIG. 4, the organic light emitting diode 210 of the bottom emission type according to the second embodiment of the present invention may include a first substrate 220 and a first formed on the first substrate 220. The electrode 230, the light emitting layer 240 formed on the first electrode 230, the second electrode 250 formed on the light emitting layer 240, and the capping layer formed on the second electrode 250. a capping layer 260 and a second substrate 270 disposed on the capping layer 260.

Specifically, the first electrode 230 is formed by depositing and patterning a transparent conductive material having a relatively large work function value on the first substrate 220 made of glass or plastic.

For example, the first electrode 230 may be formed to have a thickness of about 100 nm to 400 nm using a material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

After the formation of the first electrode 230, the surface of the first electrode 230 may be treated with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

In addition, an insulating material is deposited and patterned on the first electrode 230 to form a bank layer 232 exposing the center portion of the first electrode 230 and covering the edge portion.

The bank layer 232 is formed to separate the first electrode 230 for each region and prevent short circuits with other conductive wirings. The bank layer 232 covers the edge portion of the first electrode 230. Defects such as lifting of the edges of the first electrode 230 may be prevented.

In addition, a hole injection layer (HIL) 241 and a hole transport layer are formed on the first electrode 230 exposed through the bank layer 232 through a thermal evaporation method. : HTL) 243, emitting material layer (EML) 245, electron transport layer (ETL) 247, and electron injection layer (EIL) 249 are sequentially The vapor deposition is performed to form the emission layer 240.

For example, the hole injection layer 241 may be formed to have a thickness in a range of about 10 nm to about 50 nm, and the hole transport layer 243 may be formed of NPD (4,4'-bis [N- (1-naphthyl) -N-). phenyl-amino] biphenyl]) may be formed to a thickness ranging from about 30 nm to about 60 nm.

The light emitting material layer 245 may be formed to have a thickness ranging from about 5 nm to about 100 nm, and a dopant may be added as needed.

The electron transport layer 247 may be formed to a thickness of about 20 nm to about 40 nm using a material such as Alq3 (tris (8-hydroxyquinoline) aluminum), and the electron injection layer 249 may be formed of LiF or Li ₂ O. The material may be formed to a thickness in a range of about 0.5 nm to about 1 nm, or may be formed to a thickness in a range of about 10 nm to about 20 nm using an alkali metal or alkaline earth metal such as Li, Ca, Mg, Sm, or the like.

In addition, a second electrode 250 is formed by depositing a metal material having a relatively high reflectance and a relatively small work function value on the emission layer 240.

For example, the second electrode 250 may be formed to have a thickness of about 10 nm to about 20 nm using materials such as Mg: Ag, Ca: Ag, Ca, and Al: Li.

The capping layer 260 is formed by depositing or coating a conductive organic material on the second electrode 250.

For example, the capping layer 260 may be formed to a thickness of about 10 nm to about 100 nm using an organic material doped with a conductive inorganic material or an organic material doped with a metal complex.

Specifically, the conductive organic material may be one of an organic material doped with a P-type dopant or an N-type dopant, an organic material doped with a metal, and an organic material doped with lithium-quinolate (Liq).

Then, the second substrate 270 is bonded to the first substrate 220 on which the capping layer 260 is formed using the bonding agent.

Here, the bonding agent may be a photocurable resin or a thermosetting resin, and the separation space 265 between the bonded first and second substrates 220 and 270 may be filled with air, nitrogen, or a binder.

In addition, the moisture absorbent may be disposed in the space 265 to protect the organic light emitting diode 210 from moisture or oxygen (O ₂ ) in the air.

In the organic light emitting diode 210 according to the second embodiment of the present invention as described above, the first electrode 230 has a Fermi level lower than the second electrode 250, that is, a large work function. It is formed to have a (work function) value, and the first and second electrodes 230 and 250 operate as an anode and a cathode, respectively.

Accordingly, the first and second electrodes 230 and 250 respectively supply holes and electrons to the emission layer 240, and the holes and electrons supplied from the first and second electrodes 230 and 250, respectively. The electrons combine with each other in the light emitting material layer 245 to generate light.

The light generated from the light emitting material layer 245 is transmitted toward the first and second electrodes 230 and 250, and the light transmitted toward the second electrode 250 is reflected by the second electrode 250 and then regenerated. It is transmitted in the direction of one electrode 230.

Therefore, light generated in the light emitting material layer 245 is emitted from the organic light emitting diode 210 through the first electrode 230.

Here, the common electrode (not shown) connected to the second electrode 250 and the second electrode 250 is formed to have a thickness of about 10 nm to about 20 nm using a metal material, and the second electrode 250 and the common wiring are formed. By forming the capping layer 260 of the conductive organic material thereon, the resistance of the second electrode 250 and the common wiring can be further reduced. Accordingly, the short circuit, oxidation, and aggregation of the second electrode 250 and the common wiring can be reduced. Such defects are prevented to improve electrical characteristics and thermal stability, and improve reliability and lifespan of the organic light emitting diode 210.

The luminous efficiency, electrical characteristics, and lifespan of the organic light emitting diode will be described with reference to the drawings.

5A, 5B, and 5C are diagrams illustrating luminous efficiency, current density, and intensity of the organic light emitting diodes according to the first and second embodiments of the present invention, respectively.

Here, the organic light emitting diode according to the embodiment of the present invention was compared with the organic light emitting diode according to the comparative example, and the cross-sectional structure of the organic light emitting diode according to the example and the comparative example is as follows.

Example: First electrode ITO / hole injection layer / hole transport layer / light emitting material layer / electron transport layer / electron injection layer / second electrode (Mg: Ag) / capping layer (conductive organic material)

Comparative Example: First electrode ITO / hole injection layer / hole transport layer / light emitting material layer / electron transport layer / electron injection layer / second electrode (Mg: Ag) / capping layer (non-conductive organic material) CPL

As shown in FIG. 5A, the luminous efficiency characteristic of the ideal illuminance that the organic light emitting diode can generate in proportion to the applied driving voltage is higher than the specific illuminance. It can be seen that it is better than the organic EL device.

And, as shown in Figure 5b, it can be seen that the current density characteristics with respect to the applied driving voltage, the organic EL device according to the embodiment is similar to the organic EL device according to the comparative example.

In addition, as shown in Figure 5c, it can be seen that the organic light emitting device according to the embodiment is better than the organic light emitting device according to the comparative example, the light intensity (intensity) reduction characteristics with respect to the operation time.

That is, the intensity of the organic light emitting device according to the comparative example decreases faster than the intensity of the organic light emitting device according to the embodiment, which means that the lifespan of the organic light emitting device according to the embodiment decreases. It means longer than lifespan.

For example, in comparison with the time taken to decrease to 95% of the initial intensity, the organic light emitting device according to the embodiment is about 165 hours, while the organic light emitting device according to the comparative example is about 115 hours, so about 30% It shows the effect of longer life.

Table 1 summarizes the results of driving voltage, luminous efficiency, color coordinate value, and lifetime of the organic light emitting diode according to the Examples and Comparative Examples.

Driving voltage (V) Efficiency (cd / A) EQE (%) CIE_x CIE_y Life (T95) Example 4.2 5.4 8.6 0.133 0.076 165 Comparative example 4.2 5.2 8.4 0.134 0.074 115

In Table 1, the organic light emitting device according to the embodiment is similar to the organic light emitting device according to the comparative example in terms of color characteristics, while the light emitting efficiency and life characteristics are improved compared to the organic light emitting device according to the comparative example. have.

That is, in the organic light emitting diode according to the first and second embodiments of the present invention and a method of manufacturing the same, a common wiring connected to the second electrode and the second electrode is formed by forming a capping layer of a conductive organic material on the second electrode. The resistance of the is reduced, thereby improving the electrical characteristics and thermal stability, and as a result improve the reliability, luminous efficiency and lifetime of the organic light emitting device.

An organic light emitting display device including the organic light emitting display device will be described with reference to the accompanying drawings.

6 is a cross-sectional view of an organic light emitting display device including an organic light emitting display device according to an exemplary embodiment of the present invention.

As illustrated in FIG. 6, the organic light emitting display device 300 includes a first substrate 320, a thin film transistor T, and an organic light emitting diode 310 in each pixel area on the first substrate 320. ) And a second substrate 370 spaced apart from the first substrate 320.

The first and second substrates 320 and 370 may be made of a transparent material such as glass or plastic.

An active layer 311 is formed on an upper surface (inner surface) of the first substrate 320, a gate insulating layer 312 is formed on the active layer 311, and a gate insulating layer corresponding to the active layer 311. A gate electrode 313 is formed on the upper portion 312, an interlayer insulating layer 314 is formed on the gate electrode 313, and a source electrode connected to the active layer 311 on the interlayer insulating layer 314. The 315 and the drain electrode 316 are formed, and the active layer 311, the gate electrode 313, the source electrode 315, and the drain electrode 316 constitute a thin film transistor T.

Although not shown, a gate wiring formed of the same layer and the same material as the gate electrode 313 is formed on the gate insulating layer 312, and the source electrode 315 and the drain electrode 316 are disposed on the interlayer insulating layer 314. The data wiring layer may be formed of the same layer and the same material, and the pixel region may be defined by the intersection of the gate wiring and the data wiring, and the thin film transistor T of each pixel region may be connected to the gate wiring and the data wiring. .

In addition, a passivation layer 317 is formed on the source electrode 315 and the drain electrode 316 to cover the thin film transistor T, and a first electrode connected to the drain electrode 316 is formed on the passivation layer 317. 330 is formed.

A bank layer 332 is formed on the first electrode 330 to cover the edge of the first electrode 330 and expose the first electrode 330. The exposed first electrode 330 and the bank layer 332 are formed. The light emitting layer 340 is formed on the top.

In addition, a second electrode 350 is formed on the light emitting layer 340, and a capping layer 360 of a conductive organic material is formed on the second electrode 350, and the first electrode 330 and the light emitting layer 340 are formed on the second electrode 350. The second electrode 350 and the capping layer 360 constitute an organic light emitting diode 310.

Here, each of the light emitting layer 340, the second electrode 350, and the capping layer 360 formed in the plurality of pixel areas may be integrally connected to each other. In particular, the second electrode 350 may have a common wiring (not shown). The common voltage may be applied from the outside through the capping layer 360. The capping layer 360 is also formed on the common wiring.

The second substrate 370 is bonded to the first substrate 320 on which the capping layer 360 is formed by the bonding agent, and the separation space 365 is formed between the first and second substrates 320 and 370. Can be defined.

The separation space 365 may be filled with air, nitrogen, or a binder, and may be disposed in the separation space 365 to protect the organic light emitting device 310 from moisture or oxygen (O ₂ ) in the air. .

In the organic light emitting display device 300, since the capping layer 360 of the conductive organic material is formed on the second electrode 350 and the common wiring, the resistance of the second electrode 350 and the common wiring is reduced, and As a result, electrical characteristics and thermal stability are improved, and as a result, reliability, luminous efficiency, and lifespan of the organic light emitting diode 310 and the organic light emitting display 300 are improved.

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

110 and 210: organic light emitting diodes 120 and 220: first substrate
130 and 230: first electrode 140 and 240: light emitting layer
150, 250: second electrode 160, 260: capping layer
170, 270: second substrate

Claims (10)

A first substrate;
A first electrode formed on the first substrate;
An emission layer formed on the first electrode;
A second electrode formed on the emission layer and having a lower work function value than the first electrode;
A capping layer formed on the second electrode and made of a conductive organic material;
A second substrate disposed on the capping layer and bonded to the first substrate;
An organic light emitting device comprising a.
The method of claim 1,
The conductive organic material may be an organic material doped with a conductive inorganic material or an organic material doped with a metal complex.
The method of claim 2,
The conductive organic material may be one of an organic material doped with a P-type dopant or an N-type dopant, an organic material doped with a metal, and an organic material doped with lithium-quinolate (Liq).
The method of claim 1,
And a bank layer formed on the first electrode and exposing a central portion of the first electrode and covering an edge of the first electrode.
The method of claim 1,
The light emitting layer is an organic light emitting device including a hole injection layer, a hole transport layer, a light emitting material layer, an electron transport layer and an electron injection layer sequentially formed on the first electrode.
The method of claim 1,
The organic light emitting device of claim 1, further comprising a reflective layer formed between the first substrate and the first electrode.
The method according to claim 6,
The conductive organic material is an organic light emitting device having a refractive index of 1.6 ~ 1.8 range.
Forming a first electrode on the first substrate;
Forming a light emitting layer on the first electrode;
Forming a second electrode on the light emitting layer, the second electrode having a lower work function than the first electrode;
Forming a capping layer made of a conductive organic material on the second electrode;
Bonding a second substrate to the first substrate having the capping layer formed thereon;
Method for manufacturing an organic light emitting device comprising a.
The method of claim 8,
The light emitting layer is formed by a thermal evaporation method, the capping layer is a manufacturing method of an organic light emitting device is formed by a deposition method or a coating method.
The method of claim 8,
The method of manufacturing an organic light emitting device further comprising the step of treating the surface of the first electrode with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

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