KR101680705B1 - Organic electroluminescent device and method of fabricating the same - Google Patents

Abstract

The present invention provides a liquid crystal display comprising: a first substrate; A first electrode formed on the first substrate; A light emitting layer formed on the first electrode; A second electrode formed on the light emitting layer and having a work function lower than that of the first electrode; A capping layer formed on the second electrode and made of a conductive organic material; And a second substrate disposed on the capping layer and bonded to the first substrate.

Description

Technical Field [0001] The present invention relates to an organic electroluminescent device and a method of manufacturing the same,

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

2. Description of the Related Art In the field of flat panel display (FPD), a liquid crystal display device (LCD device) which is light and consumes little power has been widely used up to now, but a liquid crystal display device has a light receiving element (non-emissive device), which has disadvantages such as brightness, contrast ratio, viewing angle, and large area.

Accordingly, a new flat panel display device which can overcome the disadvantages of such a liquid crystal display device has been actively developed, and an organic electroluminescent display device or an organic light emitting diode display (OLED) device is an emissive device that generates light by itself. Therefore, the OLED device has excellent luminance, viewing angle, and contrast ratio as compared with a liquid crystal display device, and since it does not require a backlight, It is advantageous.

Also, since it can be driven by DC low voltage and its response speed is fast and it is made of solid, it is strong against external impact, has a wide temperature range, and is especially advantageous in terms of manufacturing cost.

The organic electroluminescent display device displays an image using light emitted from an organic electroluminescent device, that is, a light emitting diode, connected to a thin film transistor of each pixel region. The organic electroluminescent device includes an anode and a cathode It is a device that emits light by forming an organic light emitting layer and applying an electric field. It can be driven at a low voltage, has relatively low power consumption, and is light and can be fabricated on a flexible substrate.

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

FIG. 1 is a cross-sectional view of a conventional organic electroluminescent device, and FIG. 2 is a schematic view of an energy band diagram of a conventional organic electroluminescent device.

1 and 2, a conventional organic electroluminescent device 10 includes a substrate 20, a first electrode 30 formed on the substrate 20, a first electrode 30, And a second electrode 50 formed on the light emitting layer 40. The light emitting layer 40 is formed on the light emitting layer 40,

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

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

The hole injection layer 41 and the hole transport layer 43 are formed in such a manner that the hole 62 of the first electrode 30 is smoothly injected to be transferred to the light emitting material layer 45, The second electrode 49 allows the electrons 64 of the second electrode 50 to be injected smoothly and to be transmitted to the light emitting material layer 45.

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

Such an organic electroluminescent device may have a problem that the lifetime and the luminous efficiency are lowered depending on materials to be used and a laminated structure.

For example, in the top emission type organic electroluminescent device 10 for emitting the light of the light emitting material layer 45 to the second electrode 50, the second electrode 50 may be formed of magnesium: The second electrode 50 is formed to have a relatively high resistance by using an alloy such as Mg (Ag) or Ca (Ag) or the like. In this case, the second electrode 50 has a relatively high resistance, ) Is degraded and the lifetime is reduced.

That is, due to the characteristics of the organic electroluminescent device 10, a large amount of current continuously flows in the common wiring (not shown) connected to the second electrode 50 and the second electrode 50, A large amount of heat is generated in the second electrode 50 and the common wiring, which have a relatively high resistance due to the current, and the second electrode 50 and the common wiring are short-circuited or oxidized by the generated heat, As a result, the reliability of the organic electroluminescent device 10 is lowered and the lifetime thereof is reduced.

Particularly, when the second electrode 50 includes silver (Ag), hillock may be generated due to migration of Ag atoms to the second electrode 50 and the common wiring. Clustering causes a possibility of shorting of the second electrode 50 and the common wiring.

Of course, the thickness of the second electrode 50 may be increased in order to reduce the resistance of the second electrode 50. However, in this case, the transmittance of the second electrode 50 may be drastically reduced to lower the luminous efficiency of the organic electroluminescent device 10 Lt; / RTI >

In the top emission type organic electroluminescent device 10, the light of the light emitting material layer 45 may be totally reflected from the upper surface of the second electrode 50, Emitting efficiency of the light-emitting device 10 is reduced.

An object of the present invention is to provide an organic electroluminescent device having improved electrical characteristics and thermal stability and thus having a longer lifetime by forming a capping layer containing a conductive organic material on a second electrode, and a manufacturing method thereof .

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

According to an aspect of the present invention, there is provided a plasma display panel comprising: a first substrate; A first electrode formed on the first substrate; A light emitting layer formed on the first electrode; A second electrode formed on the light emitting layer and having a work function lower than that of the first electrode; A capping layer formed on the second electrode and made of a conductive organic material; And 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 electroluminescent device may further include a bank layer formed on the first electrode and exposing a center portion of the first electrode and covering an edge portion of the first electrode.

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

The organic electroluminescent device may further include a reflective layer formed between the first substrate and the first electrode.

The conductive organic material may have a refractive index ranging from 1.6 to 1.8.

According to another aspect of the present invention, there is provided a method of manufacturing a plasma display panel, comprising: forming a first electrode on a 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 work function lower than that of the first electrode; Forming a capping layer made of a conductive organic material on the second electrode; And bonding the second substrate to the first substrate having the capping layer formed thereon.

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

The method of fabricating the organic electroluminescent device may further include treating the surface of the first electrode with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

In the organic electroluminescent device and the method of manufacturing the same according to the present invention, by forming the capping layer of the conductive organic material on the second electrode used as the cathode, the electrical characteristics and the thermal stability of the second electrode are improved, The lifetime of the device can be increased.

Further, by forming a capping layer of a conductive organic material having a refractive index in a range to prevent total reflection on the second electrode used as a cathode, the luminous efficiency of the organic electroluminescent device can be improved.

1 is a sectional view of a conventional organic electroluminescent device.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic electroluminescent device,
3 is a cross-sectional view of an organic electroluminescent device of a top emission type according to a first embodiment of the present invention.
4 is a sectional view of an organic light emitting device of a bottom emission type according to a second embodiment of the present invention.
FIGS. 5A, 5B, and 5C are diagrams showing luminous efficiency, current density, and intensity of the organic electroluminescent device according to the first and second embodiments of the present invention, respectively. FIG.
6 is a cross-sectional view of an organic light emitting display device including an organic electroluminescent device according to an 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 device of a top emission type according to a first embodiment of the present invention.

3, the organic light emitting device 110 of the top emission type according to the first embodiment of the present invention includes a first substrate 120, a first substrate 120 formed on the first substrate 120, A light emitting layer 140 formed on the first electrode 130, a second electrode 150 formed on the light emitting layer 140, and a capping layer 140 formed on the second electrode 150. [ a capping layer 160 and a second substrate 170 disposed on the capping layer 160. [

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

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

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

A reflection layer 134 is formed under the first electrode 130 in order to reflect light of the light emitting material layer 145 emitted toward the first electrode 130 in the direction of the second electrode 150 However, in another embodiment, the first electrode 130 may be formed as a single layer using a conductive material having a relatively high reflectance, so that the reflective layer 134 may be omitted.

An insulating material is deposited on the first electrode 130 and patterned to form a bank layer 132 that exposes a center portion of the first electrode 130 and covers the edge portion.

The bank layer 132 is formed to separate the first electrodes 130 by regions and to prevent short-circuiting with other conductive wirings. By making the bank layer 132 cover the edge portions of the first electrodes 130, It is possible to prevent defects such as peeling of the edge portions of the first electrode 130.

A hole injection layer (HIL) 141, a hole transport layer (HIL) 141, a hole transport layer (HIL) 141, and a hole transport layer (HIL) are sequentially formed on the first electrode 130 exposed through the bank layer 132 through thermal evaporation. (HTL) 143, an emitting material layer (EML) 145, an electron transport layer (ETL) 147, and an electron injection layer (EIL) Thereby forming a light emitting layer 140. [

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

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

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

A second electrode 150 is formed on the light emitting layer 140 by depositing a metal material having a relatively small work function value.

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, or Al: Li.

A capping layer 160 is formed on the second electrode 150 by depositing or coating a conductive organic material having a refractive index capable of preventing total reflection on the surface of the second electrode 150.

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

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).

The second substrate 170 is bonded to the first substrate 120 on which the capping layer 160 is formed by using a bonding agent.

Here, the bonding agent may be a photo-curing resin or a thermosetting resin, and the spacing space 165 between the bonded first and second substrates 120 and 170 may be filled with air, nitrogen, or a bonding agent.

Further, by disposing the moisture absorbent in the spacing space 165, it is possible to protect the organic EL device 110 from moisture or oxygen (O ₂ ) in the air.

In the organic electroluminescent device 110 of the upper emission type according to the first embodiment of the present invention, the first electrode 130 has a lower Fermi level than the second electrode 150, 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 supply holes and electrons to the light emitting layer 140, respectively, and 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 in the light emitting material layer 145 is transmitted in the direction of the first and second electrodes 130 and 150. Light transmitted in the direction of the first electrode 130 passes through the reflective layer 134 And is transmitted to the second electrode 150 again.

Accordingly, the light generated in 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 is formed to have a relatively thin thickness, for example, a thickness ranging from about 1 nm to about 5 nm, so that light generated in the light emitting material layer 145 can be transmitted. As a result, A common wiring (not shown) connected to the second electrode 150 and the second electrode 150 has a relatively high resistance by itself.

The electrical characteristics and thermal stability of the second electrode 150 and the common wiring due to such a high resistance may be degraded. In the organic electroluminescent device 110 according to the first embodiment of the present invention, 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.

Thus, defects such as short-circuiting, oxidation, and bunching of the second electrode 150 and the common wiring are prevented to improve electrical characteristics and thermal stability, and reliability and lifetime of the organic electroluminescent device 110 are improved.

In addition, light generated in the light emitting material layer 145 may be totally reflected on the upper surface of the second electrode 150 to decrease the light emitting efficiency of the organic light emitting device 110. In the first exemplary embodiment of the present invention, In the organic electroluminescent device 110, a capping layer 160 of a conductive organic material having a refractive index capable of preventing total internal reflection, for example, a refractive index ranging from about 1.6 to about 1.8, is formed on the second electrode 150 The total reflection on the upper surface of the second electrode 150 is prevented, and the luminous efficiency of the organic electroluminescent device 110 is improved.

On the other hand, the capping layer of the conductive organic material can be applied to the organic light emitting device of the lower emission type, which will be described with reference to the drawings.

4 is a cross-sectional view of a bottom emission organic electroluminescent device according to a second embodiment of the present invention.

4, the organic electroluminescent device 210 of the lower emission type according to the second embodiment of the present invention includes a first substrate 220, a first substrate 220 formed on the first substrate 220, A light emitting layer 240 formed on the first electrode 230, a second electrode 250 formed on the light emitting layer 240, and a capping layer 250 formed on the second electrode 250. [ a capping layer 260 and a second substrate 270 disposed on the capping layer 260. [

Specifically, a transparent conductive material having a relatively large work function value is deposited on the first substrate 220 made of glass or plastic and patterned to form the first electrode 230.

For example, the first electrode 230 may be formed to 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 first electrode 230 is formed, the surface of the first electrode 230 may be treated with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

An insulating material is deposited on the first electrode 230 and patterned to form a bank layer 232 that exposes a center portion of the first electrode 230 and covers the edge portion.

The bank layer 232 is formed to separate the first electrodes 230 by regions and to prevent short-circuiting with other conductive wirings. By making the bank layer 232 cover the edge portions of the first electrodes 230, It is possible to prevent defects such as peeling of the edge portion of the first electrode 230.

A hole injection layer (HIL) 241, a hole transport layer (HIL) 244, and a hole transport layer (HIL) 241 are formed on the first electrode 230 exposed through the bank layer 232 through a thermal evaporation method or the like. (HTL) layer 243, an emitting material layer (EML) 245, an electron transport layer (ETL) 247, and an electron injection layer (EIL) Thereby forming a light emitting layer 240. [

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

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

Electron transport layer 247 is Alq3, such as (tris (8-hydroxyquinoline) aluminum) using a material, such as approximately 20nm ~ can be formed to a thickness of about 40nm range, the electron injection layer 249 is LiF or Li ₂ O Or may be formed to a thickness ranging from about 10 nm to about 20 nm by using an alkali metal or an alkaline earth metal such as Li, Ca, Mg, Sm, or the like.

A second electrode 250 is formed on the light emitting layer 240 by depositing a metal material having a relatively high reflectivity and a relatively small work function value.

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

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

For example, the capping layer 260 may be formed to a thickness ranging from 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).

The second substrate 270 is bonded to the first substrate 220 on which the capping layer 260 is formed by using a bonding agent.

Here, the bonding agent may be a photo-curing resin or a thermosetting resin, and the spacing space 265 between the first and second substrates 220 and 270 may be filled with air, nitrogen, or a bonding agent.

Further, by disposing the moisture absorbent in the spacing space 265, it is possible to protect the organic electroluminescent element 210 from moisture or oxygen (O ₂ ) in the air or the like.

In the organic electroluminescent device 210 of the lower emission type according to the second embodiment of the present invention, the first electrode 230 has a lower Fermi level than the second electrode 250, and the first electrode 230 and the second electrode 250 operate as an anode and a cathode, respectively.

Accordingly, the first and second electrodes 230 and 250 supply holes and electrons to the light emitting layer 240, respectively, and 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.

Light generated in the light emitting material layer 245 is transmitted in the direction of the first and second electrodes 230 and 250. The light transmitted in the direction of the second electrode 250 is reflected by the second electrode 250, 1 electrode 230, as shown in FIG.

Accordingly, the 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 wiring (not shown) connected to the second electrode 250 and the second electrode 250 is formed to a thickness ranging from about 10 nm to about 20 nm by using a metal material. The second electrode 250, By forming the capping layer 260 of the conductive organic material on the upper portion, the resistance of the second electrode 250 and the common wiring can be further reduced, and thereby the short circuit, oxidation, And the like are improved, the electrical characteristics and the thermal stability are improved, and the reliability and lifetime of the organic electroluminescent device 210 are improved.

The luminous efficiency, electrical characteristics and lifetime of such an organic electroluminescent device will be described with reference to the drawings.

FIGS. 5A, 5B, and 5C are diagrams showing luminous efficiency, current density, and intensity of the organic electroluminescent device according to the first and second embodiments of the present invention, respectively.

Herein, the organic electroluminescent device according to the embodiment of the present invention is compared with the organic electroluminescent device according to the comparative example, and the cross-sectional structure of the organic electroluminescent device according to the embodiments 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 injecting layer / hole transporting layer / light emitting material layer / electron transporting layer / electron injecting layer / second electrode (Mg: Ag) / capping layer (non-

As shown in FIG. 5A, the luminous efficiency characteristics with respect to the ideal illuminance that can be generated by the organic electroluminescent device in proportion to the applied driving voltage can be obtained by adjusting the organic electroluminescent device according to the comparative example It is understood that the organic electroluminescent device is better than the organic electroluminescent device.

As shown in FIG. 5B, the current density characteristics with respect to the applied driving voltage are similar to those of the organic electroluminescent device according to the comparative example.

In addition, as shown in FIG. 5C, it is found that the light intensity reduction characteristic with respect to the operation time is better than that of the organic electroluminescent device according to the comparative example.

That is, the intensity of the organic electroluminescent device according to the comparative example is reduced more rapidly than the intensity of the organic electroluminescent device according to the embodiment. This is because the lifetime of the organic electroluminescent device according to the embodiment is shorter than that of the organic electroluminescent device according to the comparative example. It is longer than the lifetime.

For example, the organic electroluminescent device according to the present invention is about 165 hours, while the organic electroluminescent device according to the comparative example has about 115 hours. Therefore, about 30% Or more.

Table 1 shows the results of the driving voltage, the luminous efficiency, the color coordinate value and the lifetime of the organic electroluminescent device according to Examples and Comparative Examples.

The driving voltage (V) Efficiency (cd / A) EQE (%) CIE_x CIE_y Lifetime (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, it can be seen that the organic electroluminescent device according to the embodiment is similar to the organic electroluminescent device according to the comparative example in color characteristics, but improved in luminous efficiency and lifetime characteristics compared with the organic electroluminescent device according to the comparative example have.

That is, in the organic electroluminescent device and the method of manufacturing the same according to the first and second embodiments of the present invention, by forming the capping layer of the conductive organic material on the second electrode, The electrical properties and thermal stability thereof are improved, and as a result, reliability, luminous efficiency and lifetime of the organic electroluminescent device are improved.

An organic electroluminescent display device including such an organic electroluminescent device will now be described with reference to the drawings.

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

6, the organic light emitting display 300 includes a first substrate 320, a thin film transistor T in each pixel region on the first substrate 320, and an organic light emitting diode 310 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 the 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 312 corresponding to the active layer 311 is formed. A gate electrode 313 is formed on the gate insulating layer 312 and an interlayer insulating layer 314 is formed on the gate electrode 313. A source electrode 314 connected to the active layer 311 is formed on the interlayer insulating layer 314, The active layer 311, the gate electrode 313, the source electrode 315 and the drain electrode 316 constitute a thin film transistor T. The active layer 311, the gate electrode 313, the source electrode 315,

Although not shown, gate wiring made of the same layer and the same material as the gate electrode 313 is formed on the gate insulating layer 312. A source electrode 315 and a drain electrode 316 are formed on the interlayer insulating layer 314, And a thin film transistor T in each pixel region may be connected to a gate wiring and a data wiring line. In this case, .

A protective layer 317 covering the thin film transistor T is formed on the source electrode 315 and the drain electrode 316 and a first electrode 310 connected to the drain electrode 316 is formed on the protective layer 317. [ 330 are formed.

A bank layer 332 covering the edges of the first electrode 330 and exposing the first electrode 330 is formed on the first electrode 330 and the exposed first electrode 330 and the bank layer 332 A light emitting layer 340 is formed.

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 light emitting layer 340. [ The second electrode 350, and the capping layer 360 constitute the organic electroluminescent device 310.

Here, the light emitting layer 340, the second electrode 350, and the capping layer 360 may be formed as a single unit, and the second electrode 350 may be formed as a common wiring (not shown) The capping layer 360 may be 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 a space 365 is formed between the first and second substrates 320 and 370, Can be defined.

The spacing space 365 may be filled with air, nitrogen, or a bonding agent, and a moisture absorbent may be disposed in the spacing space 365 to protect the organic electroluminescent device 310 from moisture or oxygen (O ₂ ) .

In this 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, The electrical characteristics and thermal stability of the organic light emitting display device 300 and the organic light emitting display device 300 are improved. As a result, the reliability, luminous efficiency, and lifetime of the organic light emitting display device 300 and the organic light emitting display device 300 are improved.

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

110, 210: organic electroluminescent device 120, 220: first substrate
130, 230: first electrode 140, 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;
A light emitting layer formed on the first electrode;
A second electrode formed on the light emitting layer and having a work function lower than that of 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 attached to the first substrate,
/ RTI >
Wherein the conductive organic material is an organic material doped with a conductive inorganic material or an organic material doped with a metal complex.
delete The method according to claim 1,
Wherein the conductive organic material is 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 Liq (lithium-quinolate).
The method according to claim 1,
And a bank layer formed on the first electrode, the bank layer exposing a center portion of the first electrode and covering an edge portion of the first electrode.
The method according to claim 1,
Wherein the light emitting layer includes a hole injecting layer, a hole transporting layer, a light emitting material layer, an electron transporting layer, and an electron injecting layer sequentially formed on the first electrode.
The method according to claim 1,
And a reflective layer formed between the first substrate and the first electrode.
The method according to claim 6,
Wherein the conductive organic material has a refractive index in a range of 1.6 to 1.8.
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 work function lower than that of the first electrode;
Forming a capping layer made of a conductive organic material on the second electrode;
Attaching a second substrate to the first substrate on which the capping layer is formed
Lt; / RTI >
Wherein the conductive organic material is an organic material doped with a conductive inorganic material or an organic material doped with a metal complex.
9. The method of claim 8,
Wherein the light emitting layer is formed by a thermal evaporation method, and the capping layer is formed by a vapor deposition method or a coating method.
9. The method of claim 8,
Further comprising the step of treating the surface of the first electrode with oxygen (O ₂ ) plasma or UV-ozone (O ₃ ).

Images