KR100557729B1 - The organic electro-luminescence device and method for fabricating of the same - Google Patents

Abstract

The present invention relates to an organic light emitting device, and more particularly, to a double-sided light emitting organic light emitting device.

The double-sided light emitting organic light emitting device according to the present invention is characterized in that the organic light emitting layer and the anode electrode (top and bottom) are formed around the cathode electrode (cathode electrode), respectively.

In this way, compared with the structure of implementing double-sided light emission using only one light emitting layer as in the prior art, even if a large amount of current is applied, it is dispersed in the light emitting layers formed up and down, so that the problem of deterioration of the light emitting layer does not occur.

Furthermore, the present invention proposes a dual-plate light emitting device having a dual plate structure in which the light emitting part and the thin film transistor array part of the double-sided light emitting structure are formed on separate substrates and formed by bonding them.

Description

The organic electroluminescent device and method for manufacturing the same {The organic electro-luminescence device and method for fabricating of the same}             

1 is a cross-sectional view schematically illustrating a configuration of a passive matrix organic light emitting device according to a first example of the related art.

2 is a cross-sectional view showing the configuration of a conventional double-sided emission type organic light emitting device,

3 is a cross-sectional view showing the configuration of a double-sided emission type organic light emitting device according to the first embodiment of the present invention,

4 is an enlarged plan view showing the configuration of a double-sided light emitting organic light emitting device according to the present invention;

5 is an enlarged plan view illustrating a structure of a thin film transistor array unit corresponding to one pixel of the double-sided light emitting organic light emitting diode according to the present invention;

6A and 6B are cross-sectional views taken along lines IV-IV and V-V of FIG. 5, respectively.

7 is a cross-sectional view illustrating a process of forming a double-sided light emitting organic light emitting part according to the present invention in a process sequence;

FIG. 8 is a cross-sectional view schematically illustrating a configuration of an organic light emitting device having a dual plate structure according to a second embodiment of the present invention.

<Brief description of the main parts of the drawing>

100: substrate 130: power wiring

136: first anode electrode 138: first light emitting layer

140 cathode electrode 142 second light emitting layer

144: second anode electrode

The present invention relates to an organic light emitting device, and more particularly, to a constitution and a method of manufacturing the double-sided light emitting organic light emitting device.

In general, organic light emitting diodes inject electrons and holes into the light emitting layer from the electron injection electrodes and the hole injection electrodes, respectively, to inject the injected electrons. ) Is a device that emits light when the exciton, which is a combination of holes and holes, drops from the excited state to the ground state.

Due to this principle, unlike the conventional thin film liquid crystal display device, since a separate light source is not required, the volume and weight of the device can be reduced.

In addition, the organic EL device exhibits high quality panel characteristics (low power, high brightness, high reaction rate, low weight). Due to these characteristics, OLED is considered to be a powerful next generation display that can be used in most consumer electronic applications such as mobile communication terminal, CNS, PDA, Camcorder, Palm PC.

In addition, since the manufacturing process is simple, there is an advantage that can reduce the production cost more than conventional LCD.

The method of driving the organic light emitting diode can be classified into a passive matrix type and an active matrix type.

The passive matrix type organic light emitting device has a simple structure and a simple manufacturing method. However, the passive matrix type organic light emitting device has a high power consumption and a large area of the display device, and the opening ratio decreases as the number of wirings increases.

On the other hand, an active matrix organic light emitting diode has an advantage of providing high luminous efficiency and high image quality.

Hereinafter, the configuration of the active matrix organic light emitting device will be described schematically.

1 is a view schematically showing a configuration of a conventional active matrix organic light emitting device.

As illustrated, the organic light emitting diode 30 has a thin film transistor (T) array portion 34 on the transparent first substrate 32, and a first electrode on the thin film transistor array portion 34. An anode electrode 36, an organic light emitting layer 38, and a second electrode 40 are formed.

In this case, the light emitting layer 38 expresses the colors of red (R), green (G), and blue (B). In general, each of the pixels P emits red, green, and blue light. A separate organic material is patterned and used.

The first substrate 32 is bonded to the second substrate 48 having the moisture absorbent 41 and the sealant 47 to complete the encapsulated organic light emitting device 30.

At this time, the moisture absorbent 41 is for removing moisture and oxygen that can penetrate into the capsule, and a part of the substrate 48 is etched and the moisture absorbent 41 is filled in the etched portion and fixed with a tape 45. .

In the above configuration, the first electrode 36 is an anode electrode, and the second electrode 40 is a cathode electrode.

In general, the anode electrode uses a conductive metal having a high work function, and the metal may include indium tin oxide (ITO), and the cathode electrode may be calcium (Ca) or aluminum (Al). In this case, an opaque conductive metal having a low work function such as magnesium (Mg) is used.

Therefore, the above-described configuration is referred to as a bottom emission type because the light emitted from the organic light emitting layer 38 comes out in the direction of the lower thin film transistor array portion 34.

In recent years, researches have been conducted on the organic light emitting diodes having the top emitting structure rather than the bottom emitting type, and further, studies on the double-sided organic light emitting diodes have been conducted.

2 is a cross-sectional view schematically showing the configuration of a conventional double-sided light emitting organic light emitting device.

As illustrated, the double-sided organic light emitting diode 50 may include a thin film transistor (T) array portion 34 on the transparent first substrate 32 and a top portion of the thin film transistor array portion 34. An anode electrode 36, an organic emission layer 38, and a second electrode 40 are formed.

In this case, the light emitting layer 38 expresses the colors of red (R), green (G), and blue (B). In general, a separate method of emitting red, green, and blue colors for each pixel (P) is performed. Organic materials are patterned and used.

In the above configuration, the first electrode 36 is an anode electrode, and the second electrode 40 is a cathode electrode.

In general, the anode electrode uses a conductive metal having a high work function, and the metal may include indium tin oxide (ITO), and the cathode may be calcium (Ca) or aluminum (Al). In this case, an opaque conductive metal having a low work function such as magnesium (Mg) is used.

Therefore, in order to use the double-sided light emission type, when the second electrode 40 is formed, it is generally formed to a thickness thin enough to transmit light.

A transparent protective film 45 is formed on the entire surface of the substrate 32 on which the second electrode 40 is formed.

By the way, the double-sided organic light emitting device configured as described above is actually a structure that divides the brightness of light into both.

Since the structure has to emit the same luminance in both directions as in the case of emitting only one direction, for example, if the brightness of about 200 nits of light in one direction is required, the conventional double-sided emission type must emit 400 nits of luminance.

Therefore, in order to use the double-sided light emission type, the amount of current applied to the light emitting material should be increased by almost twice. In this case, the lifespan of the light emitting device is also reduced.

Therefore, there is a problem in manufacturing as a product since the life, which is pointed out as a problem in the organic light emitting device, is further reduced.

The present invention has been proposed for the purpose of solving the above-mentioned problem, the double-sided light emitting organic light emitting device according to the present invention is characterized in that the organic light emitting layer and the anode electrode are configured respectively up and down around the cathode electrode.

In such a case, since the organic light emitting layers are separately formed on both surfaces, the organic light emitting layers are dispersed in the organic light emitting layers on both sides even if the amount of current is twice as large as before. Therefore, the lifetime of a light emitting layer can be prevented from falling.

An organic light emitting display device according to a first aspect of the present invention for achieving the above object includes a substrate having a plurality of pixel regions defined; A gate wiring and a data wiring formed on one surface of the substrate corresponding to one side of the pixel region and the other side perpendicular thereto; A switching element composed of a gate electrode, an active layer, a source electrode and a drain electrode, and a driving element connected to the gate line and the data line, respectively; A first anode electrode in contact with the drain electrode of the driving element; A first light emitting layer formed on the first anode electrode; A cathode electrode formed on the first light emitting layer; A second light emitting layer formed on the cathode electrode; And a second anode electrode disposed on the second emission layer and in contact with the first anode electrode.

The source electrode of the switching element is connected to the data line, the drain electrode is configured to be connected to the gate electrode of the driving element, and the power line is further connected to the source electrode of the driving element.

An electron transport layer is further configured between the first and second light emitting layers and the cathode electrode, and a hole transport layer is further configured between the first and second light emitting layers and the first and second anode electrodes.

The cathode electrode may be configured to have a smaller width than the first and second light emitting layers, and the cathode electrode may be configured in one direction in a plurality of pixel regions adjacent to one direction, and the plurality of cathode electrodes may be formed on the substrate. It is composed of one connected around.

The anode electrode is formed by selecting a material group having a large work function such as indium tin oxide (ITO), and the cathode electrode is made of aluminum (Al), calcium (Ca), magnesium (Mg), and lithium. A work function comprising a double metal of fluorine / aluminum (LIF / Al) forms as one of the small group of conductive metals.

A method of manufacturing a double-sided light emitting organic light emitting device according to a first aspect of the present invention includes the steps of defining a plurality of pixel regions on a substrate; Forming a gate line and a data line on one surface of the substrate in correspondence with one side of the pixel area and the other side perpendicular thereto;

Forming a switching element composed of a gate electrode, an active layer, a source electrode and a drain electrode, and a driving element connected to the gate line and the data line, respectively; Forming a first anode electrode in contact with the drain electrode of the driving device; Forming a first light emitting layer formed on the first anode electrode; Forming a cathode electrode formed on the first light emitting layer; Forming a second light emitting layer formed on the cathode; And forming a second anode electrode formed on the second emission layer and in contact with the first anode electrode.

A double-sided light emitting organic light emitting diode according to a second aspect of the present invention includes a first substrate and a second substrate having a plurality of pixel regions defined therein; A gate line and a data line formed on one surface of the first substrate facing one side of the pixel area and the other side perpendicular to the pixel area; A switching element composed of a gate electrode, an active layer, a source electrode and a drain electrode, and a driving element connected to the gate line and the data line, respectively; A first anode electrode formed on one surface of the second substrate facing each other; A first light emitting layer formed on the first anode electrode; A cathode electrode formed on the first light emitting layer; A second light emitting layer formed on the cathode electrode; And a second anode electrode formed on the second emission layer and connected to the first anode electrode and the drain electrode of the driving device.

According to a second aspect of the present invention, there is provided a method of manufacturing an organic light emitting display device, the method comprising: defining a plurality of pixel areas on a first substrate and a second substrate; Forming a gate line and a data line on one surface of the first substrate facing one side of the pixel area and the other side perpendicular to the pixel area; Forming a switching element composed of a gate electrode, an active layer, a source electrode and a drain electrode, and a driving element connected to the gate line and the data line, respectively; Forming a first anode electrode formed on an opposite surface of the second substrate; Forming a first light emitting layer on the first anode electrode; Forming a cathode electrode on the first light emitting layer; Forming a second light emitting layer on the cathode; And forming a second anode electrode disposed on the second emission layer and connected to the first anode electrode and the drain electrode of the driving device.

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

First Embodiment

A feature of the first embodiment of the present invention is characterized in that the organic light emitting layer and the anode electrode are respectively formed above and below the cathode electrode.

3 is a cross-sectional view schematically showing the configuration of a double-sided light emitting organic light emitting device according to the present invention.

As shown, a thin film transistor array unit AL including a plurality of pixel regions P on the substrate 100 and including a driving element T _D and a switching element T _{S for} each pixel region P. ).

An organic light emitting unit EL is formed on the thin film transistor array unit 102. The organic light emitting unit EL includes a first anode electrode 136 connected to the driving device T _D , and the first light emitting unit EL. The first organic light emitting layer 138 on the first anode electrode 136, the cathode electrode 140 on the first organic light emitting layer 136, the second organic light emitting layer 142 on the cathode electrode 140, The second anode electrode 144 is formed on the second organic emission layer 142.

In this case, the first positive electrode 136 and the second positive electrode 144 are in contact with each other (F) up and down to allow the same signal to flow, and the negative electrode 140 is connected to both outside the substrate 100. Configure.

In addition, the cathode electrode 140 may be formed to have a smaller width than the first and second organic light emitting layers 138 and 142 so as not to be in side contact with the upper and lower first and second anode electrodes 136 and 144.

As described above, after forming the organic light emitting part EL, a transparent protective film 180 capable of protecting the organic light emitting part EL is formed on the entire surface of the substrate 100.

The cross-sectional configuration described above will be described below with reference to a plan view for easier understanding.

Figure 4 is a plan view schematically showing the configuration of a double-sided light emitting organic light emitting device according to the present invention. (Switching elements and driving elements are omitted for simplicity of the drawings.)

As illustrated, the gate line GL is formed in the horizontal direction on the substrate 100, and the data line DL and the power line 130 spaced apart from the data line DL are formed in the vertical direction.

The gate lines GL, the data lines DL, and the power lines 130 vertically intersect to define a plurality of pixel regions P. FIG.

A cathode electrode 140 and a first emission layer 138 and a first anode electrode 136 are sequentially formed in the pixel region P, and a lower portion of the cathode electrode 140 is disposed on the cathode region 140. The second organic light emitting layer 142 and the second anode electrode 144 are sequentially formed.

In this case, the upper and lower first and second anode electrodes 136 and 144 are configured to be in contact with each other through a contact hole CH at one side of the pixel region P, and the first and second anode electrodes 136 and 144 are each pixel. Each area P is configured independently.

The cathode electrode 140 is applied with the same signal to the entire surface of the substrate 100, and for convenience, a plurality of cathode electrodes 140 formed in common in neighboring pixel regions P in one direction are bundled together at the outside of the substrate. Form.

The first and second light emitting layers 138 and 142 may also be formed by independently patterning the pixel regions P. FIG.

5 and 6, a planar configuration and a cross-sectional configuration of a thin film transistor array unit configured under the organic electroluminescent unit described above will be described.

(Examples using amorphous thin film transistors as driving elements and switching elements will be described.)

FIG. 5 is a plan view illustrating a thin film transistor array unit corresponding to one pixel of the organic light emitting diode of the present invention, and FIGS. 6A and 6B are cross-sectional views taken along line IV-IV and V-V of FIG. 5.

As illustrated, the switching region S, the driving region D, and the pixel region P are defined on one side of the pixel region P and the pixel region P on the substrate 100.

 A gate line GL is formed along one side of the pixel region P, and a data line DL is formed in a direction perpendicular to the gate line GL.

Gate electrodes 102 and 104, active layers 110 and 114, source electrodes 118 and 122, and drain electrodes 120 and 124 in the switching region S and the driving region D at the intersection of the gate line GL and the data line DL. The switching element T _S and the driving element T _D are formed.

The source electrode 118 of the switching element T _S is connected to the data line DL and the drain electrode 120 is connected to the gate electrode 104 of the driving element T _D.

And configuring the power supply wiring 130 in parallel spaced apart from the data line (DL), the power supply wiring 130 is a drive element connected to the source electrode 122 of the (T _D), and the driving device (T _D) The drain electrode 124 is configured to be connected to the first electrode 136 (anode electrode) of the organic light emitting unit.

Hereinafter, the manufacturing process of the organic light emitting part formed on the above-mentioned thin film transistor array part is demonstrated with reference to process sectional drawing.

7A to 7C are cross-sectional views illustrating a method of manufacturing a light emitting unit of a double-sided light emitting organic light emitting diode according to the present invention in a process sequence.

As shown in FIG. 7A, a first anode electrode 136 is formed on the substrate 100 in which the pixel region P is defined, in contact with the drain electrode of the driving device.

One selected from the group of inorganic insulating materials including silicon nitride (SiN _X ) and silicon oxide (SiO ₂ ) is deposited on the first anode electrode 136 to form an insulating layer and pattern the pixel region P A buffer layer BF covering one side of the first anode electrode 136 is formed corresponding to the boundary of the.

Next, a first emission layer 138 is formed on the exposed first anode electrode 136.

The first light emitting layer 138 may be configured as a single layer or a multi-layer, and in the case of a multi-layered structure, hole transport layers 138b and HTL may be further formed between the first anode electrode 136 and the light emitting layer 138a. The electron transport layers 138c and ETL are further formed on the emission layer 138a.

When the hole transport layer 138b and the electron transport layer 138c are further configured, the holes and the electrons are easily moved to the light emitting layer.

In the above-described configuration, the first light emitting layer 138 is formed at a distance K on one side of the first anode electrode 136.

As shown in FIG. 7B, a cathode electrode 140 is formed on the first emission layer 138 with a smaller width.

The cathode electrode 140 is an electron injection electrode, and is formed of one selected from aluminum (Al), calcium (Ca), and magnesium (Mg) or a double metal layer of lithium fluorine / aluminum (LIF / Al).

Next, a second organic light emitting layer 142 having a single layer or a multilayer same as the first light emitting layer 138 is formed before the cathode electrode 140.

Next, a contact hole CH exposing one side of the first electrode 136 is formed.

As shown in FIG. 7C, a second electrode anode electrode 144 is formed on the second organic emission layer 142. The second positive electrode 144 is configured to contact the exposed first positive electrode 144.

In the above-described configuration, since the cathode electrode 140 has a width smaller than that of the first and second light emitting layers 138 and 142, the cathode electrode 140 may not be in side contact with the second anode electrode 144.

The organic light emitting part having the above-described configuration includes the first light emitting layer 138, the first positive electrode 136, the second light emitting layer 142, and the second positive electrode 144, respectively, above and below the cathode electrode 140. Since the light emitting device is configured to emit light on both sides, even when a large amount of current flows for luminance, the first and second light emitting layers 138 and 142 are dispersed on both sides, thereby preventing shortening of the surface of the light emitting layer due to excessive current.

In this case, the anode electrode is formed by selecting a material group having a large work function such as indium tin oxide (ITO), and the cathode electrode is made of aluminum (Al), calcium (Ca), and magnesium (Mg). The work function comprising a double metal of lithium fluorine / aluminum (LIF / Al) is formed into one selected from the group of small conductive metals.

Hereinafter, an organic light emitting device in which the organic light emitting unit and the thin film transistor array unit according to the present invention are configured on a separate substrate will be described.

-Second Example-

A second embodiment of the present invention proposes a dual plate structure organic light emitting device in which an organic light emitting unit and a thin film transistor array unit of a double-sided light emitting organic light emitting device are fabricated and bonded to separate substrates.

8 is a cross-sectional view illustrating a configuration of a dual plate structure organic light emitting diode according to a second exemplary embodiment of the present invention.

As shown, the double-sided light emitting dual plate structure organic light emitting device 199 according to the present invention has a thin film transistor array unit AL on a separate first substrate 200 and a second substrate 300, respectively. ) And the organic light emitting unit EL are bonded to each other through the sealant 400.

In this case, the first substrate 200 and the second substrate 300 are defined as a plurality of pixel regions P, and the driving elements T _D described above are included in the pixel regions P of the first substrate 200. And the thin film transistor array part AL including the switching element T _D.

The first anode electrode 300 is formed on one surface of the second substrate 300, and the cathode electrode 306 is disposed on the first emission layer 304 and the first emission layer 304 on the first anode electrode 300. The second anode electrode 310 is formed on the cathode electrode 306.

In this case, the first and second anode electrodes 302 and 310 are configured to be in contact with each other, and the two electrodes 302 and 310 are formed by independently patterning the pixel regions P. FIG.

The anode electrode is formed by selecting a material group having a large work function such as indium tin oxide (ITO), and the cathode electrode is made of aluminum (Al), calcium (Ca), magnesium (Mg), and lithium. A work function comprising a double metal of fluorine / aluminum (LIF / Al) forms as one of the small group of conductive metals.

In the above-described configuration, the second anode electrode 310 and the driving element of the array unit of the thin film transistor contact each other, and the second anode electrode 310 and the driving element T _D in consideration of the gap between the two substrates 200 and 300. To form a connection electrode 500 for connecting at the same time.

Since the organic light emitting diode of the double-sided light emitting dual plate structure includes a thin film transistor array unit and a light emitting unit separately, when a defect occurs in any one substrate, only the defective portion is discarded and the defective rate is also very low.

The organic light emitting device according to the present invention has the following effects.

First, since the organic light emitting layer and the anode electrode are respectively formed at the top and the bottom of the cathode electrode, respectively, even though a large amount of current is input for luminance, the light emitting layer is dispersed in both emitting layers. There is an effect of preventing this from falling.

Second, since it is a double-sided light emission type, it can be used for multipurpose.

Third, in the case of the dual plate structure, the defect rate is significantly lowered, and it is convenient to manage the defective products, thereby improving productivity.

Claims (30)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A first substrate and a second substrate on which a plurality of pixel regions are defined; A gate line and a data line formed on one surface of the first substrate facing one side of the pixel area and the other side perpendicular to the pixel area; A switching element composed of a gate electrode, an active layer, a source electrode and a drain electrode, and a driving element connected to the gate line and the data line, respectively; A first anode electrode formed on one surface of the second substrate facing each other; A first light emitting layer formed on the first anode electrode; A cathode electrode formed on the first light emitting layer; A second light emitting layer formed on the cathode electrode; A second anode electrode formed on the second emission layer and connected to the first anode electrode and the drain electrode of the driving device; Double-sided light emitting organic electroluminescent device comprising a. The method of claim 16, And a source electrode connected to the data line and a drain electrode connected to the gate electrode of the driving device. The method of claim 16, The organic light emitting device further comprises a power line connected to the source electrode of the driving device. The method of claim 16, And an electron transporting layer between the first and second light emitting layers and the cathode electrode, and further comprising a hole transporting layer between the first and second light emitting layers and the first and second anode electrodes. The method of claim 16, The cathode electrode is an organic light emitting device having a width smaller than the first and second light emitting layer. The method of claim 16, The cathode electrode is configured in one direction in a plurality of pixel areas neighboring in one direction. And a plurality of cathode electrodes are connected to one at the periphery of the substrate and configured as a double-sided organic light emitting diode. The method of claim 16, The anode electrode is formed by selecting a material group having a large work function such as indium tin oxide (ITO), and the cathode electrode is made of aluminum (Al), calcium (Ca), magnesium (Mg), and lithium. An organic electroluminescent device formed of one selected from the group of conductive metals having a small work function including a double metal of fluorine / aluminum (LIF / Al). The method of claim 16, And the first and second anode electrodes and the light emitting layer are independently patterned for each pixel area. Defining a plurality of pixel regions in the first and second substrates; Forming a gate line and a data line on one surface of the first substrate facing one side of the pixel area and the other side perpendicular to the pixel area; Forming a switching element composed of a gate electrode, an active layer, a source electrode and a drain electrode, and a driving element connected to the gate line and the data line, respectively; Forming a first anode electrode formed on an opposite surface of the second substrate; Forming a first light emitting layer on the first anode electrode; Forming a cathode electrode on the first light emitting layer; Forming a second light emitting layer on the cathode; Forming a second anode electrode on the second emission layer and connected to the first anode electrode and the drain electrode of the driving device; Method for manufacturing a double-sided light emitting organic electroluminescent device comprising a. The method of claim 24, And a source electrode of the switching element is connected to the data line and a drain electrode of the switching element is connected to the gate electrode of the driving element. The method of claim 24, And a power line connected to the source electrode of the driving device. The method of claim 24, An electron transport layer is further configured between the first and second light emitting layers and the cathode electrode, and a hole transport layer is further provided between the first and second light emitting layers and the first and second anode electrodes. The method of claim 24, The cathode electrode manufacturing method of an organic light emitting device having a smaller width than the first and second light emitting layer. The method of claim 24, The cathode electrode is configured in one direction in a plurality of pixel areas neighboring in one direction. And, the plurality of cathode electrodes are connected to one in the periphery of the substrate is composed of a double-sided organic light emitting device manufacturing method. The method of claim 24, The anode electrode is formed by selecting a material group having a large work function such as indium tin oxide (ITO), and the cathode electrode is made of aluminum (Al), calcium (Ca), magnesium (Mg), and lithium. A method of manufacturing an organic light emitting device, wherein the work function including a double metal of fluorine / aluminum (LIF / Al) is formed as one selected from a group of small conductive metals.

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