KR20170020634A - Organic light emitting diode display - Google Patents

Abstract

The present invention provides an organic light emitting diode display. The organic light emitting diode display includes a substrate, a first transistor which is arranged on one surface of the substrate and includes a first control electrode, a first source electrode and a first drain electrode, an organic light emitting diode which is arranged on one surface of the substrate and is electrically connected to the first drain electrode of the first thin film transistor, and a storage capacitor which is arranged on the other surface of the substrate and includes a first electrode which is electrically connected to the first control electrode and a second electrode which is electrically connected to the first source electrode. Accordingly, the present invention can increase a charging capacity and an aperture ratio.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light-

The present invention relates to an organic light emitting display.

2. Description of the Related Art In recent years, a display device has been replaced by a thin flat panel display device such as a liquid crystal display (LCD) or an organic light emitting diode (OLED).

Among the flat panel display devices, the organic light emitting display device emits light as it goes down from the organic light emitting layer to the base state after the formation of the excitons, and the light can be emitted to the outside through the organic and inorganic layers.

However, as the organic electroluminescent display device becomes larger, the aperture ratio may be further lowered due to the capacitor formed in each pixel. In particular, although it is important to increase the electrostatic capacity for stable driving, it is necessary to develop a structure capable of increasing the aperture ratio and increasing the charging capacity because the aperture ratio is lowered due to the arrangement of the capacitor electrodes It is true.

An object of the present invention is to provide an organic light emitting display capable of increasing the aperture ratio while increasing the charging capacity.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method of manufacturing the same.

According to an aspect of the present invention, there is provided an organic light emitting display including a substrate, a first electrode disposed on one surface of the substrate, the first electrode including a first control electrode, a first source electrode, An organic light emitting diode disposed on one side of the substrate and electrically connected to a first drain electrode of the first thin film transistor and a first electrode disposed on the other side of the substrate and electrically connected to the first control electrode, And a storage capacitor including a first electrode electrically connected to the first source electrode and a second electrode electrically connected to the first source electrode.

Wherein the first electrode of the storage capacitor is electrically connected to the first control electrode through the first through hole and the first electrode of the storage capacitor is electrically connected to the first control electrode, And the second electrode of the capacitor may be electrically connected to the first source electrode through the second through hole.

The storage capacitor may further include an insulating layer interposed between the first electrode and the second electrode, and the first electrode may include a first insulating layer disposed between the substrate and the second electrode.

And a second thin film transistor disposed on one side of the substrate and including a second control electrode, a second source electrode, and a second drain electrode, wherein the second drain electrode is electrically connected to the first control electrode .

Further comprising a gate line disposed on one side of the substrate, a data line disposed on one side of the substrate, and a power supply line disposed on one side of the substrate, wherein the gate line is electrically connected to the second control electrode The data line may be electrically connected to the second source electrode, and the power supply line may be electrically connected to the first source electrode.

The storage capacitor may be arranged such that at least one of the first thin film transistor and the second thin film transistor is overlapped.

The second thin film transistor includes a second control electrode electrically connected to the gate line, a second active pattern overlapped with the second control electrode, a second active pattern electrically connected to the data line and being in contact with the second active pattern, 2 source electrode and a second drain electrode in contact with the second active pattern and electrically connected to the first electrode of the storage capacitor.

The driving thin film transistor includes a first gate electrode connected to the second drain electrode, a first active pattern overlapping the first gate electrode, and a second active pattern electrically connected to the power source signal line, A first source electrode and a first drain electrode in contact with the first active pattern and electrically connected to the pixel.

The pixel includes a pixel electrode disposed on one side of the first substrate and electrically connected to the second transistor, and the organic light emitting layer may be disposed on the pixel electrode.

A second insulating layer disposed on one side of the substrate and insulating the first and second active patterns and a third insulating layer disposed on the first and second control electrodes disposed on the second insulating layer, And a first insulating layer disposed on the other surface of the substrate and insulating the first and second electrodes of the storage capacitor and covering the storage capacitor.

The first contact hole and the second contact hole may be arranged to penetrate the substrate by laser drilling so as to penetrate at least any one of the first insulating layer, the second insulating layer, and the third insulating layer .

And a second thin film transistor disposed on the other surface of the substrate and including a second control electrode, a second source electrode, and a second drain electrode, wherein the second drain electrode is electrically connected to the first control electrode .

The first electrode of the storage capacitor is electrically connected to the first control electrode through the first through hole and the second electrode of the storage capacitor is electrically connected to the second control electrode through the first through hole, The electrode may be electrically connected to the first source electrode through a contact hole.

A first control electrode and a first electrode of the storage capacitor are disposed on the first-first insulation layer disposed on the other surface of the substrate, and a first-second insulation layer is formed on the second control electrode and the first electrode, Wherein the second source electrode, the second drain electrode, and the second electrode of the storage capacitor are disposed on the first and second insulating layers, and the second source electrode, the second drain electrode, An insulating layer 1-3 may be disposed.

The second control electrode and the first electrode of the storage capacitor may be disposed of the same material, and the second source electrode, the second drain electrode, and the second electrode of the storage capacitor may be disposed of the same material.

The first contact hole may be disposed through the substrate by laser drilling, and may be disposed to penetrate at least one of the first insulating layer, the second insulating layer, and the third insulating layer.

And a second thin film transistor including a second control electrode disposed on the other surface of the substrate, a second source electrode disposed on one surface of the substrate, and a second drain electrode, And can be electrically connected to the electrode.

Wherein the substrate includes a first through hole, a second through hole, a third through hole, and a fourth through hole penetrating in the thickness direction, and the first electrode of the storage capacitor is connected to the first through hole And the second electrode of the storage capacitor may be electrically connected to the first source electrode through the second through hole.

Wherein the substrate includes a third through hole and a fourth through hole penetrating in the thickness direction and the second drain electrode is electrically connected to the second active pattern through the third through hole, May be electrically connected to the second active pattern through the fourth through hole.

Wherein the first contact hole, the second through hole, the third through hole, and the fourth through hole are disposed by penetrating the substrate by laser drilling, wherein the first insulating layer, the second insulating layer, Or at least one of them may be arranged to penetrate.

The details of other embodiments are included in the detailed description and drawings.

The embodiments of the present invention have at least the following effects.

According to embodiments of the present invention, the capacitance of the organic light emitting display device can be increased to increase the amount of light output from the organic light emitting display device, thereby improving the display quality of the organic light emitting display device.

In addition, according to the embodiments of the present invention, the aperture ratio of the organic light emitting display device can be improved.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

1 is a plan view of an organic light emitting display according to an embodiment of the present invention.
2 is a circuit diagram of an organic light emitting display according to an embodiment of the present invention.
3 is a cross-sectional view taken along line I-I 'of FIG.
4 is a cross-sectional view taken along line II-II 'of FIG.
5 is a cross-sectional view taken along line III-III 'of FIG.
6 is a cross-sectional view of an organic light emitting display according to another embodiment of the present invention.
7 is a cross-sectional view of an organic light emitting display according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The dimensions and relative sizes of layers and regions in the figures may be exaggerated for clarity of illustration.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It is also to be understood that the terms " comprises "or" having ", when used in this specification, specify a feature, a number, a step, an operation, an element, a part, or a combination thereof, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figure, an element described as " below or beneath "of another element may be placed" above "another element. Thus, the exemplary term "below" can include both downward and upward directions. The elements can also be oriented in different directions, in which case spatially relative terms can be interpreted according to orientation.

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

FIG. 1 is a plan view of an organic light emitting display according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of an organic light emitting display according to an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line I-I 'of FIG. 1, FIG. 4 is a cross-sectional view taken along line II-II' of FIG. 1, and FIG. 5 is a cross-sectional view taken along line III-III 'of FIG.

1 and 2, an organic light emitting display device 1 according to an embodiment of the present invention includes a substrate 5, a first control electrode GE1 disposed on one surface of a substrate 5, A first thin film transistor TR1 including a first source electrode SE1 and a first drain electrode DE1 and a second thin film transistor TR2 disposed on one side of the substrate 5 and having a first drain electrode DE1 And an organic light emitting diode (EML) electrically connected to the organic light emitting diode (OLED). And a second electrode CE2 disposed on the other surface of the substrate 5 and electrically connected to the first electrode CE1 and the first source electrode SE1 electrically connected to the first control electrode GE1 And a storage capacitor Cst.

The pixel PXL may include a pixel PXL connected to the first thin film transistor TR1 and the pixel PXL may include a pixel electrode PE and an organic light emitting diode EML.

And a second thin film transistor TR2 disposed on one surface of the substrate 5 and including a second control electrode GE2, a second source electrode SE2 and a second drain electrode DE2, And the second drain electrode DE2 may be electrically connected to the first control electrode GE1.

Here, the first transistor TR1 may be a driving transistor, and the second transistor TR2 may be a switching transistor.

On one side of the substrate 5, the gate line GL may be connected to the second control electrode GE2 and the data line DL may be connected to the second source electrode SE2. And the second source electrode SE2 may be electrically connected to the second drain electrode DE2. And the power supply line DVL may be connected to the first source electrode SE1.

First, the substrate 5 may be made of a transparent glass or quartz material containing SiO ₂ as a main component. The substrate 5 is not necessarily limited to this, and may be formed of a transparent polymer material. Polymeric materials are composed of insulating organic materials such as polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelenenaphthalate (PEN), polyethylene terephthalate (PET) polyethlyeneterephthalate, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate CAP) or a combination thereof. In some embodiments, the first and second substrates S1 and S2 may be a flexible substrate made of a flexible material such as polyimide (PI).

The buffer layer 10 can be selectively disposed on one surface or the other surface of the substrate 5. [ The buffer layer 10 may form a smooth surface on the substrate 5 and block the penetration of the impurity element. The buffer layer 10 may be formed of a single layer or a plurality of layers such as silicon nitride and / or silicon oxide. In the present embodiment, the buffer layer 10 is disposed on one surface of the substrate 5, but the present invention is not limited thereto. The buffer layer 10 may be disposed on both surfaces of the substrate 5 as well as on one surface or the other surface.

The first insulating layer L1 may be disposed on the other surface of the substrate 5. [ A storage capacitor Cst may be disposed on the first insulating layer L1. The storage capacitor Cst includes a first electrode CE1 and a second electrode CE2 and has an insulating layer having a high dielectric constant between the first electrode CE1 and the second electrode CE2 in order to increase capacitance .

Specifically, the first insulating layer L1 may be formed of a plurality of layers. The first layer may be disposed with the first insulating layer L1, the second layer may be disposed on the first layer, and the third layer may be disposed on the second layer. Here, the second layer is an insulating layer disposed between the first electrode CE1 and the second electrode CE2, and an insulating material capable of increasing the electrostatic capacity can be disposed. And materials with organic materials or silicon nitride (SiNx), isolated with a dielectric constant, silicon oxide (SiO _2), alumina oxynitride silicon _{(SiON), (Al 2 O} 3), titanium oxide (TiO _2), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), zirconium oxide (ZrO ₂ ), BST and PZT.

Accordingly, the first insulating layer L1 is formed of a plurality of layers, and the capacitance of the storage capacitor Cst is increased through the insulating layer having a high dielectric constant between the first electrode CE1 and the second electrode CE2 .

In another embodiment, the first insulating layer L1 may be formed of the same material or may be formed of the same material as the first insulating layer L1, polyimide (PI), or the like. It is not. The first and second electrodes CE1 and CE2 can be insulated from each other with the first insulating layer L1 interposed between the first and second electrodes CE1 and CE2.

The first electrode CE1 and the second electrode CE2 of the storage capacitor Cst disposed on the other surface of the substrate 5 are electrically connected to the first through hole CH1 and the second through- (TR1) and a second thin film transistor (TR2) disposed on one side of the substrate (5) through a hole (CH2). The first contact hole CH1 and the second contact hole CH2 can be formed by penetrating the substrate 5 using laser drilling in the thickness direction of the substrate 5. [

Specifically, the first electrode CE1 is electrically connected to the first control electrode GE1 through the first through hole CH1, and the second electrode CE2 is electrically connected to the first control electrode GE1 through the second through hole CH2. And may be electrically connected to the source electrode SE1. Here, the first source electrode SE1 may be disposed in an integrated manner with the power supply line DVL.

The connection relationship between the electrodes CE1 and CE2 of the storage capacitor disposed on the other surface of the substrate 5 and the first thin film transistor TR1 and the second thin film transistor TR2 disposed on one surface of the substrate 5, .

First, the second thin film transistor TR2 will be described. The third insulating film L3 is interposed between the gate line GL and the data line DL to be insulated from each other. In this embodiment, the gate line GL and the data line DL, (DL) may extend in different directions and intersect with each other.

A gate signal may flow through the gate line GL and a data signal may flow through the data line DL and the gate line GL and the data line DL may be electrically connected to the second thin film transistor TR2.

The second thin film transistor TR2 is electrically connected to the gate line GL and the data line DL while the second thin film transistor TR2 is supplied with a gate signal through the gate line GL, And the data signal is supplied via the data bus. The switching transistor TR2 may include a second active pattern AP2, a second gate electrode GE2, a second source electrode SE2, and a second drain electrode DE2.

The second active pattern AP2 may be disposed on the buffer layer 10 on one side of the substrate 5 and the second active pattern AP2 may comprise a semiconductor material. The second active pattern AP2 may include, but is not limited to, amorphous silicon and polysilicon.

The second active pattern (AP2) As another embodiment may include an oxide semiconductor (oxide semiconductor), for oxide lifting semiconductor _{example, IGZO, ZnO, SnO 2,} In 2 O 3, Zn 2 SnO 4, Ge 2 O ₃ , HfO ₂ , and the like. The second active pattern AP2 may be a compound semiconductor. For example, the compound semiconductor may include GsAs, GaP, InP, and the like.

Although not shown, the second active pattern AP2 may include a channel region and a source region and a drain region doped with ionic impurities outside the channel region.

A second insulating layer L2 may be disposed on the second active pattern AP2. And the second insulating layer L2 can insulate the second active pattern AP2. And the second control electrode GE2 may be disposed on the second insulation layer L2. The second control electrode GE2 may be electrically connected to the gate line GL to receive the gate signal from the gate line GL.

Specifically, the second control electrode GE2 may be disposed on a region where the second thin film transistor TR2 of the second insulating layer L2 is formed. The second control electrode GE2 is arranged to overlap at least part of the second active pattern AP2 and may serve to transmit an electrical signal. The second gate electrode GE2 may be formed of a material selected from the group consisting of Al, Pt, Pd, Ag, Mg, Au, Ni, May be formed as a single layer or multiple layers of at least one metal selected from the group consisting of Ir, Cr, Ni, Ca, Mo, Ti, W and Cu. have. For example, the gate electrode 220 may include a first layer of molybdenum (Mo), a second layer of aluminum (Al) formed on the first layer, and a second layer of molybdenum (Mo) And a second layer of a second layer. When the second control electrode GE2 is made of Mo / Al / Mo, aluminum (Al) serves as a wiring or an electrode, and molybdenum (Mo) can serve as a barrier layer.

A third insulating layer L3 may be disposed on the substrate 5 on which the second control electrode GE2 is formed. A third insulating layer (L3) can be used an insulating material with silicon-based, including SiO _2, SiNx, SiON.

A second source electrode SE2 and a second drain electrode DE2 may be disposed on the third insulating layer L3. The second source electrode SE2 is electrically connected to the data line DL to receive the data signal from the data line DL and the second drain electrode DE2 is disposed apart from the second source electrode SE2 .

Each of the second source electrode and the second drain electrode SE2 and DE2 is in contact with the second active pattern AP2 by a contact hole formed through the second insulating layer L2 and the third insulating layer L3 . The second drain electrode DE2 and the second source electrode SE2 may be connected to the drain region and the source region of the second active pattern AP2, respectively.

The second drain electrode DE2 in contact with the second active pattern AP2 is electrically connected to the first electrode CE1 or the second electrode CE2 of the storage capacitor Cst through the first through hole CH1 . The second drain electrode DE2 may be connected to the first control electrode GE1 through a contact hole. The first through hole CH1 may be connected to the first control electrode GE1 and the first electrode CE1 of the storage capacitor Cst. Or each hole may be formed and connected. In this embodiment, they are connected through the same hole.

Therefore, when the gate signal is supplied to the second control electrode GE2 via the gate line GL to turn on the second thin film transistor TR2, the data signal is supplied through the data line DL The data signal may be sequentially supplied to the storage capacitor Cst and the first thin film transistor TR1 through the second source electrode SE2, the second active pattern AP2 and the second drain electrode DE2.

The first thin film transistor TR1 includes a first control electrode GE1 connected to the second drain electrode DE2, a third insulating layer L3 disposed on the first control electrode GE1, And a first source electrode SE1 and a first drain electrode DE1 disposed in the first and second pixel regions L3 and L3.

A first active pattern AP1 may be disposed under the first control electrode GE1 and partially overlapping the first control electrode GE1 with a second insulating layer L2 therebetween.

The first source electrode may be connected to a power supply line to multiply power the pixel. Here, the power supply line DVL or the first source electrode SE1 may be connected to the first electrode CE1 or the second electrode CE2 of the storage capacitor Cst through the second through hole CH2.

The first and second electrodes of the storage capacitor Cst may be electrically connected to the second drain electrode DE2 of the second thin film transistor TR2 and the power supply line DVL of the first thin film transistor TR1 have.

Therefore, the storage capacitor Cst charges the voltage corresponding to the data signal received from the second thin film transistor TR2 and the charge corresponding to the voltage difference corresponding to the power supply signal received from the power supply line DVL, The amount of charge can be provided to the first thin film transistor TR1 side while the second thin film transistor TR2 is turned off.

The first electrode CE1 may be connected to the second drain electrode DE2 of the second thin film transistor TR2 and the second electrode CE2 may be electrically connected to the power supply line DVL. have.

A first contact hole CH1 for penetrating the first insulating layer L1, the second insulating layer L2 and the third insulating layer L3 is disposed so that the second insulating layer L3 is formed on the second drain electrode DE2, The first electrode CE1 of the storage capacitor Cst is connected to the first insulating layer L1 disposed under the second insulating layer L1 and the first electrode CE1 of the storage capacitor Cst is connected to the first insulating layer L1, A second contact hole CH2 for passing through the insulating layer L3 is disposed and the second electrode CE2 of the storage capacitor Cst is connected to the power supply signal line DVL to increase the capacitance of the storage capacitor Cst .

This is because when the storage capacitor Cst is designed, the storage capacitor Cst is arranged on the other surface of the substrate on which the first thin film transistor TR1 or the second thin film transistor TR2 is arranged, The size of the first and second electrodes CE1 and CE2 can be freely set large regardless of the size of the storage capacitor Cst and the capacitance of the storage capacitor cst can be increased. It is possible to arrange the storage capacitor cst irrespective of the size of the pixel PXL, thereby sufficiently securing the electrostatic capacity and to increase the amount of light output from the pixel PXL.

Referring again to FIG. 5, the first thin film transistor TR1 may be electrically connected to the second thin film transistor TR2, the power supply line DVL, and the pixel PXL. The first thin film transistor TR1 can switch the power supply signal provided from the power supply line DVL to the pixel PXL side. The first thin film transistor TR1 may include a first active pattern AP1, a first gate electrode GE1, a first source electrode SE1, and a first drain electrode DE1.

The first gate electrode GE1 may be electrically connected to the second drain electrode DE2 of the second thin film transistor TR2 through the second electrode CE2. Therefore, when the second thin film transistor TR2 is turned on and the data signal is supplied to the first gate electrode GE1 side through the second thin film transistor TR2, the first thin film transistor TR1 is turned on .

The first source electrode SE1 is electrically connected to the power source signal line DVL to receive the power source signal from the power source supply line DVL and the first drain electrode DE1 is connected to the first source electrode SE1, It can be arranged so as to be spaced apart. Each of the first source and the first drain electrodes SE1 and DE1 is in contact with the first active pattern AP1 by the contact holes passing through the second insulating layer L2 and the third insulating layer L3, . Therefore, when the first thin film transistor TR1 is turned on, the power source signal sequentially flows through the first source electrode SE1, the first active pattern AP1, and the first drain electrode DE1, PXL) side.

The pixel PXL may include a pixel electrode PE and an organic light emitting diode (EML). The pixel electrode PE can act as an anode electrode of the pixel PXL and the common electrode (not shown) can act as a cathode electrode of the pixel PXL.

The pixel electrode PE may include a conductive material having a relatively large work function as compared with the common electrode. The pixel electrode PE formed of a conductive material having a large work function may include a transparent conductive oxide. For example, the pixel electrode PE may be formed of indium tin oxide (ITO), tin oxide (SnO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide at least one selected from the group consisting of indium oxide (In ₂ O ₃ ), indium gallium oxide (IGO), aluminum zinc oxide (AZO) and zinc gallium oxide (GZO) . ≪ / RTI > Such a pixel electrode PE can reduce a difference in work function between the organic light emitting diodes (EML) disposed on the pixel electrode PE.

The pixel electrode PE is disposed on the fourth insulating layer L4 covering the first thin film transistor TR1 and the second thin film transistor TR2 and the pixel electrode PE is disposed on the fourth insulating layer L4. And may be electrically connected to the first drain electrode DE1 through a contact hole formed in the first electrode. The fourth insulating layer L4 may be a planarizing film.

The organic light emitting diode (EML) may be a low molecular organic material or a high molecular organic material. The organic light emitting diode (EML) includes a hole transport layer (HTL), a hole injection layer (HIL), an electron transport layer (ETL), and an electron injection layer (EIL) Can be stacked. In addition, various layers can be stacked as needed.

For example, a first charge transfer region may be disposed between the pixel electrode PE and the organic light emitting diode (EML). In addition, a second charge transfer region may be disposed between the organic light emitting diode (EML) and the common electrode. Either the first charge transfer region or the second charge transfer region may be responsible for the transfer of holes and the other may be responsible for the transfer of electrons. Therefore, the first charge transfer region adjacent to the pixel electrode PE, which is the anode electrode, is the hole transfer region, and the second charge transfer region adjacent to the common electrode which is the cathode electrode is the electron transfer region.

A first charge transfer region may be disposed on the pixel electrode PE. The first charge transport region may have a single layer of a single material, a single layer of a plurality of different materials, or a multi-layer structure having a plurality of layers of a plurality of different materials. In addition, the first charge transfer region may further include a buffer layer and a first charge blocking layer as needed. Either the first charge injecting layer or the first charge transporting layer may be omitted or they may be composed of one layer.

The first charge injecting layer is disposed on the pixel electrode PE and serves to enhance hole injection efficiency from the pixel electrode PE to the organic light emitting layer side. Specifically, the first charge injecting layer can lower the energy barrier to allow holes to be injected more effectively.

The first charge transporting layer is disposed on the first charge injection layer and may transport holes injected into the first charge injection layer to the organic light emitting layer. The first charge transporting layer is formed so that the highest occupied molecular energy HOMO is substantially lower than the work function of the material constituting the pixel electrode PE and the highest occupied molecular orbital energy HOMO of the organic light- The hole transport efficiency can be optimized.

In addition to the above-mentioned materials, the first charge transfer region may further include a charge generating material for improving conductivity. The charge generating material may be uniformly or non-uniformly dispersed within the first charge transport region.

As mentioned above, the first charge transfer region may further include at least one of a buffer layer and a first charge blocking layer. The buffer layer may compensate the resonance distance according to the wavelength of the light emitted from the organic light emitting layer, thereby increasing the light emission efficiency. As the material contained in the buffer layer, a material that can be contained in the first charge transfer region can be used. The first charge blocking layer may serve to prevent charge injection from the second charge transfer region to the first charge transfer region.

A light emitting layer may be disposed on the first charge transfer region. The material is not particularly limited as long as it is a material commonly used as a light emitting layer, but may be made of a material emitting red, green, and blue light, for example. The light emitting layer may include a fluorescent material or a phosphorescent material.

A second charge transfer region may be disposed on the organic light emitting layer. The second charge transport region may have a single layer of a single material, a single layer of a plurality of different materials, or a multi-layer structure having a plurality of layers of a plurality of different materials. In addition, the second charge transfer region may further include a second charge blocking layer as needed. Although the second charge transporting layer includes the second charge transporting layer and the second charge injecting layer in the drawing, any one of the second charge transporting layer and the second charge injecting layer may be omitted or they may be composed of one layer It is possible.

The second charge transporting layer is disposed on the light emitting layer and can serve to transport electrons injected from the second charge injection layer to the light emitting layer.

The second charge injecting layer is disposed on the second charge transporting layer and serves to increase electron injection efficiency from the second electrode to the light emitting layer side.

A common electrode may be disposed on the second charge transfer region. The second electrode may be a front electrode or a common electrode formed without dividing a pixel. The common electrode may include a conductive material having a relatively small work function as compared with the pixel electrode.

As described above, the organic light emitting display device 1 according to the embodiment of the present invention has the structure in which the second thin film transistor TR2 and the first thin film transistor TR1 are arranged on the other surface of the substrate 5 with respect to one surface of the substrate 5 on which the first thin film transistor TR1 is disposed It is possible to freely adjust the formation area of the storage capacitor Cst by disposing the storage capacitor Cst so that a sufficient capacitance can be secured and the stable light emission can be maintained with the increased capacitance.

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

In the following description, duplicate description will be avoided and the description will be made with reference to Figs. 1 to 5 for ease of explanation.

Referring to FIG. 6, the first thin film transistor TR1 may be disposed on one surface of the substrate 5. FIG. The second thin film transistor TR2 and the storage capacitor Cst may be disposed on the other surface of the substrate 5. [

Here, the second drain electrode DE2 of the second thin film transistor TR2 may be connected to the first electrode CE1 or the second electrode CE2 of the storage capacitor Cst through the wp2 through hole. The second electrode CE2 of the storage capacitor Cst may be electrically connected to the first source electrode SE1 through the contact hole H. [

The first electrode CE1 of the storage capacitor Cst includes a first through hole CH1 through the first through hole CH1 and a second through hole CH1 through the first through hole CH1, RTI ID = 0.0 > GE1. ≪ / RTI >

The first electrode CE1 of the second control electrode GE2 and the storage capacitor Cst is disposed on the first insulation layer L1-1 disposed on the other surface of the substrate 5, The first and second electrodes GE1 and CE2 are disposed on the second electrode layer GE2 and the first electrode CE1 and the second source electrode SE2, The second electrode CE2 of the storage capacitor Cst and the first and second source electrodes SE1 and DE2 and the storage capacitor Cst are disposed on the first source electrode SE1 and the second electrode CE2, L1-3) may be disposed.

Here, the second control electrode GE2 and the first electrode CE1 of the storage capacitor Cst may be disposed of the same material, and the second source electrode SE2, the second drain electrode DE2, and the storage capacitor Cst May be disposed of the same material. Alternatively, the second drain electrode DE2 and the first electrode CE1 may be integrally formed.

By disposing the second source electrode SE2 and the second drain electrode DE2 on the other surface of the substrate 5 as described above, the second source electrode SE2 and the second drain electrode DE2 are connected to the substrate The light emitting region can be further increased by disposing it on the other surface of the substrate 5.

7 is a cross-sectional view of an organic light emitting display according to another embodiment of the present invention.

In the following description, duplicate description will be avoided and the description will be made with reference to Figs. 1 to 6 for ease of explanation.

Referring to FIG. 7, a first thin film transistor TR1 may be disposed on one side of the substrate 5, and a second control electrode GE2 may be disposed on the other side of the substrate 5. FIG. And a second thin film transistor TR2 including a second source electrode SE2 and a second drain electrode DE2 disposed on one surface of the substrate 5 may be disposed. Here, the second drain electrode DE2 may be electrically connected to the first control electrode GE1.

In order to connect the electrodes, the substrate 5 has a first through-hole CH1, a second through-hole CH2, a third through-hole CH3, and a fourth through- .

The first electrode CE1 of the storage capacitor Cst is electrically connected to the first control electrode GE1 through the first through hole CH1 and the second electrode CE2 of the storage capacitor Cst is electrically connected to the first control electrode GE1 through the first through hole CH1, May be electrically connected to the first source electrode SE1 through the second through hole CH2.

The second drain electrode DE2 is electrically connected to the second active pattern AP2 through the third through hole CH3 and the second source electrode SE2 is electrically connected to the second active electrode AP2 through the fourth through hole CH4. 2 active pattern AP2.

As described above, the first thin film transistor TR1 may be disposed on one surface of the substrate 5, and the storage capacitor Cst may be disposed on the other surface to increase the light emitting area. In addition, the formation area of the storage capacitor Cst can be freely adjusted, so that a sufficient capacitance can be secured, and stable light emission can be maintained with an increased capacitance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be appreciated that many variations and applications not illustrated above are possible. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

1: organic electroluminescence display device
5: substrate 10: buffer layer
TR1: first thin film transistor TR2: second thin film transistor
Cst: storage capacitor GE1: first control electrode
GE2: second control electrode DE1: first drain electrode
DE2: second drain electrode SE1: first source electrode
SE2: second source electrode AP1: first active pattern
AP2: second active pattern CE1: first electrode
CE2: Second electrode

Claims (20)

Board;
A first thin film transistor disposed on one surface of the substrate and including a first control electrode, a first source electrode, and a first drain electrode;
An organic light emitting diode disposed on one surface of the substrate and electrically connected to a first drain electrode of the first thin film transistor; And
And a storage capacitor disposed on the other surface of the substrate and including a first electrode electrically connected to the first control electrode and a second electrode electrically connected to the first source electrode. The method according to claim 1,
Wherein the substrate includes a first through hole and a second through hole penetrating in the thickness direction,
The first electrode of the storage capacitor is electrically connected to the first control electrode through the first through hole,
And the second electrode of the storage capacitor is electrically connected to the first source electrode through the second through hole. 3. The method of claim 2,
Wherein the storage capacitor further comprises an insulating layer interposed between the first electrode and the second electrode,
Wherein the first electrode includes a first insulating layer disposed between the substrate and the second electrode. The method according to claim 1,
And a second thin film transistor disposed on one side of the substrate and including a second control electrode, a second source electrode, and a second drain electrode,
And the second drain electrode is electrically connected to the first control electrode. 5. The method of claim 4,
A gate line disposed on one surface of the substrate;
A data line disposed on one side of the substrate; And
Further comprising a power supply line disposed on one side of the substrate,
The gate line is electrically connected to the second control electrode,
The data line is electrically connected to the second source electrode,
And the power supply line is electrically connected to the first source electrode. 5. The method of claim 4,
Wherein the storage capacitor is disposed such that at least one of the first thin film transistor and the second thin film transistor overlaps the storage capacitor. 5. The method of claim 4,
The second thin film transistor
A second control electrode electrically connected to the gate line;
A second active pattern overlapped with the second control electrode;
A second source electrode electrically connected to the data line and in contact with the second active pattern; And
And a second drain electrode that is in contact with the second active pattern and is electrically connected to the first electrode of the storage capacitor. 5. The method of claim 4,
The driving thin film transistor
A first gate electrode connected to the second drain electrode;
A first active pattern overlapped with the first gate electrode;
A first source electrode electrically connected to the power source signal line and in contact with the first active pattern; And
And a first drain electrode in contact with the first active pattern and electrically connected to the pixel. 9. The method of claim 8,
The pixel includes:
And a pixel electrode disposed on one surface of the first substrate and electrically connected to the second transistor,
And the organic light emitting layer is disposed on the pixel electrode. The method of claim 3,
A second insulating layer disposed on one surface of the substrate and insulating the first and second active patterns;
And a third insulating layer disposed on the first and second control electrodes disposed on the second insulating layer,
And a first insulating layer disposed on the other surface of the substrate and insulating the first and second electrodes of the storage capacitor and covering the storage capacitor. 11. The method of claim 10,
Wherein the first contact hole and the second contact hole are formed by penetrating the substrate by laser drilling so that an organic electric field is generated by passing through at least one of the first insulating layer, Emitting display device. The method according to claim 1,
And a second thin film transistor disposed on the other surface of the substrate and including a second control electrode, a second source electrode, and a second drain electrode,
And the second drain electrode is electrically connected to the first control electrode. 13. The method of claim 12,
Wherein the substrate includes a first through hole penetrating in the thickness direction,
The first electrode of the storage capacitor is electrically connected to the first control electrode through the first through hole,
And the second electrode of the storage capacitor is electrically connected to the first source electrode through a contact hole. 13. The method of claim 12,
The first control electrode and the first electrode of the storage capacitor are disposed on the first-first insulation layer disposed on the other surface of the substrate,
And a second insulation layer is disposed on the second control electrode and the first electrode,
The second source electrode, the second drain electrode, and the second electrode of the storage capacitor are disposed on the first and second insulating layers,
And a first-third insulating layer is disposed on the second source electrode, the second drain electrode, and the second electrode. 15. The method of claim 14,
Wherein the second control electrode and the first electrode of the storage capacitor are disposed in the same material, and the second source electrode, the second drain electrode, and the second electrode of the storage capacitor are disposed of the same material. 13. The method of claim 12,
Wherein the first contact hole is disposed through the substrate by laser drilling so as to penetrate through at least one of the first insulating layer, the second insulating layer, and the third insulating layer. The method according to claim 1,
And a second thin film transistor including a second control electrode disposed on the other surface of the substrate, a second source electrode disposed on one surface of the substrate, and a second drain electrode,
And the second drain electrode is electrically connected to the first control electrode. 18. The method of claim 17,
Wherein the substrate includes a first through hole and a second through hole penetrating in the thickness direction,
The first electrode of the storage capacitor is electrically connected to the first control electrode through the first through hole,
And the second electrode of the storage capacitor is electrically connected to the first source electrode through the second through hole. 18. The method of claim 17,
Wherein the substrate includes a third through hole and a fourth through hole penetrating in the thickness direction,
The second drain electrode is electrically connected to the second active pattern through the third through hole,
And the second source electrode is electrically connected to the second active pattern through the fourth through hole. 18. The method of claim 17,
Wherein the first contact hole, the second through hole, the third through hole, and the fourth through hole are disposed by penetrating the substrate by laser drilling, wherein the first insulating layer, the second insulating layer, And at least one of the plurality of organic light emitting display devices is arranged to pass through the organic light emitting display device.

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