KR102278535B1 - Organic electro-luminescent device and method of fabricating the same - Google Patents

Abstract

The present invention reduces the pile-up phenomenon in which the organic light emitting layer increases in thickness around the bank rather than at the center of the light emitting area, thereby reducing the thickness difference between the edge and the center in each pixel area when the liquid organic light emitting layer is formed. It relates to an organic electroluminescent device capable of suppressing a decrease in the aperture ratio and consequent decrease in lifespan, comprising: a first substrate provided with a display area in which a plurality of light-emitting areas are defined; a first electrode provided for each of the plurality of light-emitting areas; An auxiliary layer provided on the entire surface of the display area over the first electrode and made of a material having hydrophilic properties and hole injection capability, overlapping the edge of the first electrode on the auxiliary layer and surrounding each of the plurality of light emitting areas An organic light emitting device including a bank, an organic light emitting layer provided on the auxiliary layer in each of the plurality of light emitting areas surrounded by the bank, and a second electrode provided on the entire surface of the display area over the organic light emitting layer, and a method for manufacturing the same provides
The organic electroluminescent device according to the present invention has excellent hydrophilic properties for the entire surface of the display area on the upper part of the first electrode and excellent hole injection ability into the organic light emitting material layer or hole transport layer, so that it can serve as a hole injection layer. As an auxiliary layer made of a stun (WO ₃ ) material is provided, the pile-up phenomenon of the organic light emitting layer around the bank is reduced, and the area of the portion having a flat surface of the organic light emitting layer in each light emitting area increases as the area of the organic light emitting layer increases. This has the effect of improving the aperture ratio.

Description

Organic electro-luminescent device and method of fabricating the same

The present invention relates to an organic electro-luminescent device, and in particular, a liquid organic light emitting layer is formed by reducing a pile up phenomenon in which the organic light emitting layer increases in thickness around a bank rather than at the center of the light emitting region. The present invention relates to an organic electroluminescent device capable of suppressing a decrease in the aperture ratio caused by a difference in thickness between an edge portion and a central portion within each pixel region and a decrease in lifespan thereof.

An organic light emitting diode, which is one of flat panel displays, has high luminance and low operating voltage characteristics.

And, since the organic light emitting device is a self-emitting device that emits light by itself, it has a large contrast ratio and does not require a separate additional light source, so that an ultra-thin display can be realized.

In addition, the organic electroluminescent device has a small response time of several microseconds (㎲), so it does not generate afterimages even in realizing moving images, so it has excellent display quality, has no viewing angle limitation, is stable even at low temperatures, and has a low voltage of 5V to 15V DC As it is driven by the , it has the advantage of easy manufacturing and designing of the driving circuit.

Accordingly, the organic electroluminescent device having the above-described advantages has recently been used in various IT devices such as TVs, monitors, and mobile phones.

Hereinafter, the basic structure of the organic EL device will be described in more detail.

The organic light emitting diode is largely composed of an array element and an organic light emitting diode. The array element includes a switching thin film transistor connected to a gate and a data line, and a driving thin film transistor connected to the organic light emitting diode, and the organic light emitting diode includes a first electrode connected to the driving thin film transistor, an organic light emitting layer and a second made up of electrodes.

In the organic light emitting device having such a configuration, the light generated from the organic light emitting layer is emitted toward the first electrode or the second electrode to display an image. Considering the aperture ratio, etc., in recent years, it is usually directed toward the second electrode. It is manufactured in a top emission method that displays an image using emitted light.

Meanwhile, in such a general organic light emitting display device, the organic light emitting layer is usually formed by thermal evaporation using a shadow mask.

However, in recent years, a larger shadow mask is required due to the enlargement of the display device or the enlargement of the area, and the enlarged shadow mask has severe sagging and self-warping, resulting in increased deposition defects, so that it is difficult to apply to large-area substrates. It is becoming increasingly difficult.

In addition, in the case of thermal deposition using a shadow mask, a shadow effect is generated, so it is difficult to manufacture an organic electroluminescent device having a high resolution of 250 PPI or more with current technology.

Therefore, a method of forming an organic light emitting layer has been proposed as an alternative to the thermal deposition process using a shadow mask for manufacturing a large-area organic light emitting device.

The proposed method of forming the organic light emitting layer is to spray or drop a liquid organic light emitting material onto the area surrounded by the bank through an inkjet device or a nozzle device, and then harden it.

1 is a cross-sectional view of a portion of a display area of an organic light emitting device in which an organic light emitting layer is formed using a conventional ink jet apparatus, except for an array device, and only a planarization layer, a bank and an organic light emitting diode provided thereon are simplified. the drawing shown.

In order to spray the liquid organic light emitting material for each light emitting area through an inkjet device (not shown) or drop it through a nozzle device, it is necessary to prevent the liquid organic light emitting material from flowing around in each light emitting area EA1. In order to prevent this, a bank 53 in the form of enclosing each light emitting area EA1 in which the first electrode 50 is formed is essentially required.

Therefore, as shown, after the first electrode is formed on the planarization layer, before the organic light emitting layer 55 is provided for each light emitting area, a bank 53 having a dam shape is provided along the boundary of each light emitting area EA1. is becoming For convenience of description, an area surrounded by the bank is defined as a first light emitting area EA1.

In this case, the bank 53 is made of an organic material having a hydrophobic property. The reason that the bank 53 has hydrophobic properties is that when the liquid organic light emitting material is sprayed or dropped through an ink jet device or a nozzle device, the first light emitting region ( Even if a predetermined amount is sprayed on the bank 53 because it is not sprayed at the center of EA1), it flows down from the bank 53 to be located in each of the first light emitting areas EA1, and furthermore, the amount of liquid organic light emitting material injected This is to suppress overflow to the upper part of the bank 53 even when this is done a little excessively.

When the head of the inkjet device or the nozzle of the nozzle device is positioned in each first light emitting area EA1 surrounded by the bank 53 to spray or drop the liquid material, the liquid material in each of the first light emitting areas EA1 is filled, and heat treatment is performed in this state to dry and harden the liquid material, thereby forming the organic light emitting layer 55 .

At this time, in the drawings, the organic light emitting layer 55 has a single layer structure as an example, but the organic light emitting layer 55 has a quadruple layer structure of a hole injection layer, a hole transport layer, an organic light emitting material layer, and an electron transport layer or the above. It has a five-layer structure by further providing an electron injection layer over the electron transport layer. All of these quadruple and quintuple organic light emitting layers 55 are formed by spraying or dropping a liquid material using an inkjet device or a nozzle device.

However, as described above, when a liquid organic material is sprayed and dropped through an ink jet device or a nozzle device and dried to form the organic light emitting layer 55 having a multilayer structure, the first light emission surrounded by each bank 53 A pile up phenomenon in which the thickness of the edge portion adjacent to the bank 53 is thicker than the central portion in the area EA1 is occurring.

On the other hand, when the organic light emitting layer 55 has a different thickness in each light emitting area EA1 , a difference in light emitting efficiency occurs due to the application of current of the same size, which causes the organic light emitting layer 55 to surround the bank 53 . ) does not have a flat surface, and the thickly formed part appears darker than other regions, and the darkly displayed part feels like a stain when the user looks at it. It is not included in EA2).

In the case of the conventional organic light emitting device 1 having such a configuration, the area in which light is emitted toward the user side is not the entire surface of the first light emitting area EA1 surrounded by the bank 53 , but the surface of the organic light emitting layer 55 on a flat surface. The second light emitting area EA2 is formed to have a uniform luminance and to emit light, whereby the aperture ratio of the conventional organic light emitting device is greatly reduced.

Recently, in order to alleviate the pile-up phenomenon of the organic light emitting layer 55 that occurs when the liquid organic light emitting material is sprayed or dropped through an ink jet device or a nozzle device, an organic electroluminescent device having a double bank structure has been proposed. became

In the case of the organic electroluminescent device having such a double bank structure, the lower bank is formed to have a first width with a hydrophilic material, and has a second width smaller than the first width with a material having a hydrophobic property above the lower bank to expose the lower bank By constructing the upper bank in the form of a lower bank, it was possible to alleviate to some extent the pile-up phenomenon of the organic light emitting layer around the bank by the hydrophilic property of the lower bank.

However, in the case of an organic electroluminescent device (not shown) having such a two-stage bank, an additional mask process is required for the implementation of the two-stage bank, and the productivity per unit time is lowered due to the increase of the manufacturing process. .

The present invention has been devised to solve the above problem, and by forming a single-layered bank, an additional mask process is not required, and organic electroluminescence can reduce a pile-up phenomenon in which the thickness of the organic light emitting layer becomes thick around the bank. An object of the present invention is to provide a device and a method for manufacturing the same.

An organic electroluminescent device according to an embodiment of the present invention for achieving the above object includes a first substrate provided with a display area in which a plurality of light-emitting areas are defined, a first electrode provided for each of the plurality of light-emitting areas; An auxiliary layer formed on the entire surface of the display area over the first electrode and made of a material having hydrophilic properties and hole injection capability, overlapping an edge of the first electrode on the auxiliary layer, and surrounding each of the plurality of light emitting areas a bank, an organic light emitting layer provided on the auxiliary layer in each of the plurality of light emitting areas surrounded by the banks, and a second electrode provided on the entire surface of the display area above the organic light emitting layer.

_{At this time, the auxiliary layer is preferably made of tungsten oxide (WO 3} ), and further, the auxiliary layer is formed of a first crystallized portion corresponding to each of the light emitting regions, and a second portion corresponding to the bank is in an amorphous state. It is characterized by parts.

In addition, the organic light emitting layer has a triple-layer structure of a hole transport layer, an organic light emitting material layer, and an electron transport layer, or a hole transport layer, an organic light emitting material layer, an electron transport layer, and an electron injection layer. The organic light emitting layer may further include a hole injection layer between the auxiliary layer and the hole transport layer.

In addition, a plurality of switching thin film transistors and driving thin film transistors, a planarization layer formed while covering the switching and driving thin film transistors and exposing the drain electrode of the driving thin film transistor is provided under the first electrode on the first substrate, The first electrode is formed in contact with the drain electrode of the driving thin film transistor on the planarization layer.

A method of manufacturing an organic light emitting device according to an embodiment of the present invention comprises the steps of: forming a first electrode for each of the plurality of light emitting areas on a first substrate provided with a display area in which a plurality of light emitting areas are defined; forming an auxiliary layer on the entire surface of the display area by depositing a material having hydrophilic properties and hole injection capability on the first electrode; overlapping the edge of the first electrode on the auxiliary layer and surrounding each of the plurality of light emitting areas Forming a bank in the shape of a, and forming an organic light emitting layer by spraying or dropping a liquid material through an ink jet device or a nozzle device onto the auxiliary layer in each of the plurality of light emitting regions surrounded by the bank. and forming a second electrode on the entire surface of the display area over the organic light emitting layer.

In this case, the material having the hydrophilic property and the hole injection ability _{is preferably tungsten oxide (WO 3} ), and the deposition is preferably vacuum thermal evaporation or sputtering.

In addition, the organic light emitting layer is formed to form a triple layer structure of the hole transport layer, the organic light emitting material layer, and the electron transport layer, or to form a quadruple layer structure of the hole transport layer, the organic light emitting material layer, the electron transport layer, and the electron injection layer. , In this case, before forming the hole transport layer, a hole injection layer may be further formed on the auxiliary layer.

And before forming the organic light emitting layer, by irradiating a laser beam on the auxiliary layer exposed to the outside of the bank to form a crystallized first portion and a portion corresponding to the bank to form a second portion in an amorphous state. Another feature that In this case, the laser beam is preferably a pulse wave type laser beam having a wavelength range of 248 nm to 1060 nm.

_{The organic electroluminescent device according to the embodiment of the present invention and its modifications is tungsten oxide (WO 3)} having excellent hydrophilic properties for the entire surface of the display area on the upper part of the first electrode and hole injection ability into the organic light emitting material layer or hole transport layer. ) by providing an auxiliary layer made of a material, the pile-up phenomenon around the bank of the organic light emitting layer formed using a liquid material is reduced compared to the conventional organic electroluminescent device having a two-stage bank. As the area of the portion having the flat surface increases, the actual light emitting area EA3 expands, thereby improving the aperture ratio.

Furthermore, the organic electroluminescent device according to the embodiment of the present invention and its modifications has a uniform luminance characteristic as well as an improvement in luminance by increasing the portion of the organic light emitting layer having a flat surface in each light emitting region, so that the face caused by luminance non-uniformity Defects are suppressed and the display quality is improved.

In addition, the organic electroluminescent device according to the embodiment of the present invention and its modifications has the effect of reducing the pile-up phenomenon in each light emitting region and improving the thickness uniformity of the organic light emitting layer), thereby suppressing deterioration of the organic light emitting layer and extending the lifespan. have.

Furthermore, the organic electroluminescent device according to the modified example of the embodiment of the present invention is provided with a single-layered bank unlike the conventional organic electroluminescent device having a two-stage bank, so there is no need to form a two-stage bank, so a one-time mask process By omitting, productivity per unit time is improved through the simplification of the manufacturing process, and furthermore, there is an effect of reducing material cost.

1 is a cross-sectional view of a portion of a display area of an organic light emitting device in which an organic light emitting layer is formed using a conventional ink jet apparatus, except for an array device, and only a planarization layer, a bank and an organic light emitting diode provided thereon are simplified. the drawing shown.
2 is a circuit diagram of one pixel region of an organic light emitting diode.
3 is a cross-sectional view of a portion of a display area of an organic light emitting diode according to an embodiment of the present invention;
4 is a cross-sectional view of a portion of a display area of an organic light emitting diode according to a modified example of an embodiment of the present invention;
5A to 5J are cross-sectional views of the manufacturing steps of an organic light emitting diode according to an embodiment of the present invention.
6A to 6D are cross-sectional views illustrating a step-by-step process for manufacturing an organic light emitting device according to a modified example of an embodiment of the present invention, including a step of forming an organic light emitting layer and a second electrode on an auxiliary layer and a second substrate for encapsulation. A cross section of the manufacturing process showing the steps.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the drawings.

First, the configuration and operation of the organic light emitting device will be briefly described with reference to FIG. 2 which is a circuit diagram for one pixel region of the organic light emitting device.

As shown, in each pixel region (P) of the organic light emitting device, a switching thin film transistor (STr), a driving thin film transistor (DTr), a storage capacitor (StgC), and an organic light emitting diode (E) is being prepared.

That is, the gate line GL is formed in a first direction, and the data line DL is formed in a second direction intersecting the first direction, and thus is surrounded by the gate line GL and the data line DL. A pixel area P defined as an area is provided, and a power line PL for applying a power voltage is formed to be spaced apart from the data line DL.

In addition, a switching thin film transistor STr is formed in a portion where the data line DL and the gate line GL intersect, and a driving thin film transistor DTr electrically connected to the switching thin film transistor STr is formed. have.

The first electrode, which is one terminal of the organic light emitting diode (E), is connected to the drain electrode of the driving thin film transistor (DTr), and the second electrode, which is the other terminal, is grounded. At this time, the power voltage transmitted through the power supply line PL is transmitted to the organic light emitting diode E through the driving thin film transistor DTr. Also, a storage capacitor StgC is formed between the gate electrode and the source electrode of the driving thin film transistor DTr.

Accordingly, when a signal is applied through the gate line GL, the switching thin film transistor STr is turned on, and the signal of the data line DL is transmitted to the gate electrode of the driving thin film transistor DTr and the driving thin film transistor STr is turned on. Since the transistor DTr is turned on, light is output through the organic light emitting diode E.

At this time, when the driving thin film transistor DTr is turned on, the level of the current flowing from the power supply wiring PL to the organic light emitting diode E is determined, and thus the organic light emitting diode E can implement gray scale.

In addition, the storage capacitor StgC serves to maintain a constant gate voltage of the driving thin film transistor DTr when the switching thin film transistor STr is turned off, so that the switching thin film transistor STr is turned off ( off) state, it is possible to maintain a constant level of current flowing through the organic light emitting diode E until the next frame.

3 is a cross-sectional view of a portion of a display area of an organic light emitting diode according to an embodiment of the present invention. At this time, for convenience of explanation, the driving area DA is a region where the driving thin film transistor DTr is formed in each pixel region, and the switching region is the switching region where the switching thin film transistor is formed in each pixel region P, although not shown in the drawing. (not shown) was defined.

As shown, the organic light emitting diode 101 according to an embodiment of the present invention includes a first substrate 110 on which a driving and switching thin film transistor (DTr, not shown) and an organic light emitting diode E are formed, and It is composed of a second substrate 170 for encapsulation. In this case, in the second substrate 170 for encapsulation, an inorganic insulating film or/or an organic insulating film is formed on the second electrode 160 to suppress moisture penetration, or the extraction efficiency of emitted light is increased. It may be omitted when a capping layer is formed for this purpose.

First, the configuration of the first substrate 110 provided with the driving and switching thin film transistor (DTr, not shown) and the organic light emitting diode (E) will be described.

Each of the driving area DA and the switching area (not shown) on the first substrate 110 is made of pure polysilicon, and the central portions thereof include a first area 113a forming a channel passage and the first area ( 113a) A semiconductor layer 113 including a second region 113b doped with a high concentration of impurities is formed on both sides thereof.

At this time, a buffer layer (not shown) made of an inorganic insulating material, for example, silicon oxide (SiO ₂ ) or silicon nitride (SiNx), is further provided on the entire surface between the semiconductor layer 113 and the first substrate 110 . may be The buffer layer (not shown) is to prevent deterioration of properties of the semiconductor layer 113 due to the release of alkali ions from the inside of the first substrate 110 when the semiconductor layer 113 is crystallized.

In addition, a gate insulating layer 116 is formed on the entire surface of the semiconductor layer 113 to cover the semiconductor layer 113 , and each of the semiconductor layers 113 is provided in the driving area DA and the switching area (not shown) above the gate insulating layer 116 . ), a gate electrode 120 is formed corresponding to the first region 113a, respectively. A gate line (not shown) is formed on the gate insulating layer 116 , which is connected to a gate electrode (not shown) formed in the switching region (not shown) and extends in one direction.

_{Next, an interlayer insulating layer 123 made of an inorganic insulating material, for example, silicon oxide (SiO 2} ) or silicon nitride (SiNx) is formed on the gate electrode 120 and the gate wiring (not shown). In this case, semiconductor layer contact holes 125 exposing the second regions 113b positioned on both sides of the first region 113a are provided in the interlayer insulating film 123 and the gate insulating film 116 thereunder. .

Next, on the upper portion of the interlayer insulating layer 123 provided with the semiconductor layer contact hole 125 , a data line (not shown) crossing the gate line (not shown) and a power line (not shown) are spaced apart and parallel to each other. this is being formed

In addition, each driving region DA and a switching region (not shown) on the interlayer insulating layer 123 are spaced apart from each other and in contact with the second region 113b exposed through the semiconductor layer contact hole 125 , respectively, and include a source and Drain electrodes 133 and 136 are formed.

Meanwhile, the semiconductor layer 113, the gate insulating layer 116, the gate electrode 120, the interlayer insulating layer 123, and the source and drain electrodes 133 and 136 spaced apart from each other are sequentially stacked in the driving area DA. A driving thin film transistor (DTr) is formed.

At this time, a switching thin film transistor (not shown) having the same stacked structure as the driving thin film transistor DTr formed in the driving area DA is also formed in the switching area (not shown).

The switching thin film transistor (not shown) is electrically connected to a gate line (not shown) and a data line (not shown), and further is also connected to the driving thin film transistor (DTr).

On the other hand, in the organic electroluminescent device 101 according to the embodiment of the present invention, the driving thin film transistor (DTr) and the switching thin film transistor (not shown) has a semiconductor layer 113 of polysilicon and a top gate type (Top gate) type) is shown as an example.

However, the driving and switching thin film transistor (DTr, not shown) may be configured as a bottom gate type having a semiconductor layer made of an amorphous silicon semiconductor layer or an oxide semiconductor material.

When the driving and switching thin film transistor (DTr, not shown) is configured as a bottom gate type, the gate electrode, the gate insulating layer, and the active layer of pure amorphous silicon are spaced apart from each other from the bottom to the top, and the ohmic contact of impurity amorphous silicon It has a stacked structure in which a semiconductor layer composed of layers, and source and drain electrodes spaced apart from each other are stacked, or a gate electrode, a gate insulating film, an oxide semiconductor layer, an etch stopper, and spaced apart from each other on the etch stopper, respectively It has a stacked structure of source and drain electrodes in contact with the oxide semiconductor layer.

In the case of the first substrate 110 on which the bottom gate type driving and switching thin film transistor (DTr, not shown) is formed, the gate wiring (not shown) is formed on the same layer on which the gate electrode 120 is formed. It is formed to be connected to a gate electrode (not shown) of (not shown), and the data line (not shown) is formed on the same layer on which the source electrode 133 of the driving thin film transistor DTr is formed and the switching thin film transistor (not shown). ) is configured to be connected to the source electrode (not shown).

On the other hand, the upper portion of the driving and switching thin film transistor (DTr, not shown) is made of an organic insulating material, for example, photoacrylic to form a flat surface, and a drain contact hole exposing the drain electrode 136 of the driving thin film transistor (DTr). A planarization layer 140 having 143 is formed.

At this time, although not shown in the drawings, a protective layer (not shown) made of an inorganic insulating material is formed between the driving and switching thin film transistor (DTr, not shown) and the planarization layer 140 having a flat surface made of an organic insulating material. It may be further formed. In this case, the drain contact hole 143 is formed for the planarization layer 400 and the passivation layer (not shown).

Next, on the planarization layer 140 having a flat surface, the first electrode 150 is in contact with the drain electrode 136 of the driving thin film transistor DTr through the drain contact hole 143 and for each light emitting area EA. ) is formed.

The first electrode 150 has a substantially larger area than the light emitting area EA and is formed for each pixel area P. As shown in FIG. Each of the pixel areas P includes a driving and switching area DA (not shown) in which an array element such as a driving and switching thin film transistor (DTr, not shown) is provided and a light emitting area EA surrounded by a bank 153 . do.

At this time, the first electrode 150 is made of a transparent conductive material having a relatively large work function value, that is, a work function value of about 4.8 eV to 5.2 eV, for example, indium-tin-oxide (ITO). plays a role

On the other hand, when the first electrode 150 is made of indium-tin-oxide (ITO), which is a transparent conductive material having a large work function value, when the organic light emitting diode 101 operates in a top emission mode, an organic light emitting diode A reflective layer (not shown) made of any one of aluminum (Al), an aluminum alloy (AlNd), which is a metal material having excellent reflectivity, is further provided under the first electrode 150 in order to increase the luminous efficiency to the upper part of (E). can

When such a reflective layer (not shown) is provided under the first electrode 150 , light emitted from the organic light emitting layer 155 formed on the first electrode 150 passes through the reflective layer (not shown). By being reflected and reflected upward, the efficiency of use of the emitted light is increased, and finally, the luminance characteristic is improved.

At this time, the reflective layer (not shown) is not separately constituted under the first electrode 150, and the first electrode 150 itself forms a double-layer structure, that is, the lower layer 150a made of a metal having excellent reflective efficiency. and indium-tin-oxide (ITO) to form a double-layer structure of the upper layer 150b, the organic light emitting device 101 may be driven in a top light emission method.

In the drawing, as an example, the first electrode 150 has a double-layer structure of a lower layer 150a made of a metal material having excellent reflectivity and an upper layer 150b made of indium-tin-oxide (ITO) having a high work function value. It was.

And as the most characteristic configuration of the organic electroluminescent device 101 according to the embodiment of the present invention, it has a hydrophilic property corresponding to the entire surface of the display area above the first electrode 150 and at the same time the first electrode 150 The auxiliary layer 152 is formed of _{tungsten oxide (WO 3} ), which is a material having excellent ability to inject holes generated from the organic light emitting material into the organic light emitting material layer 150b.

The auxiliary layer 152 is a component constituting the organic light emitting layer and is formed on the entire surface of the display area on the first substrate 110 by a deposition method on the first electrode 150 and on the outside of the first electrode 150 . It is characterized in that it is formed on the exposed planarization layer 140 .

In addition, the auxiliary layer 152 includes a crystallized first portion 152a corresponding to the emission area EA, and a portion overlapping the bank 153 is a second portion 152b having an amorphous state. is becoming another characteristic.

The auxiliary layer 152 has a flat surface on top of the first electrode 150 due to the material properties constituting it and the mechanism properties of deposition, and has an even thickness without a difference in thickness for each location, and furthermore has a hydrophilic tendency. It is characterized in that it serves to suppress a pile-up phenomenon of the organic light emitting layer 155 formed by dropping a liquid organic material through an ink jet device or a nozzle device on the top thereof.

The suppression of the pile-up phenomenon of the organic emission layer 152 by the formation of the auxiliary layer 152 will be described later in detail.

On the other hand, the auxiliary layer 152 overlaps the edge of the first electrode 150 at the boundary of the light emitting area EA in which the organic light emitting layer 155 is provided and surrounds the light emitting area EA3 by a predetermined width. A bank 153 having a single-layer structure exposing a central portion of the first electrode 150 is formed.

The bank 153 of the single layer structure is formed of a polymer material having hydrophobic properties, for example, polyimide containing fluorine (F), styrene, methyl mathacrylate, polytetraflow. It is made of any one or a mixture of two or more of tylene (polytetrafluoroethylene).

Also, the bank 153 has a trapezoidal cross-sectional shape, so that the side of the bank 153 is not perpendicular to the surface of the auxiliary layer 152 with a tapered side, but is inclined at an angle.

This is to ensure that the second electrode 160 provided on the organic light emitting layer 155 provided inside surrounded by the bank 153 is continuously formed later.

On the other hand, inside each light emitting area EA surrounded by the single-layered bank 153 having the above-described shape, a liquid material is dropped onto the auxiliary layer 152 by a jetting method using an ink jet device or a nozzle device by using a nozzle device. An organic light emitting layer 155 having a multi-layered structure is provided.

At this time, the organic light emitting layer 155 has a relatively even thickness in each light emitting area EA by reducing a pile-up phenomenon formed thicker than the central portion, for example, in other areas within the light emitting area EA generated around the bank 153 . It is characterized by being formed with

Since the bank 153 has a hydrophobic property, it tries to push the liquid organic light emitting layer around the bank 153. At this time, since the auxiliary layer 152 has a strong hydrophilic property, the liquid organic light emitting layer is relatively applied on its surface. It gives the characteristic of spreading over a wide area.

Accordingly, the organic light emitting layer to be gathered around the bank 153 is deteriorated by the hydrophilic property of the auxiliary layer 152 , and at the same time, the property to spread on the surface of the auxiliary layer 152 is strongly expressed in the light emitting area EA. The organic light emitting layer 155 may be formed to have a relatively even thickness.

In the case of the conventional organic electroluminescent device (1 in FIG. 1) having a single-layer bank (53 in FIG. 1), referring to FIG. 1 , the separation distance between the light emitting area EA1 and the actual light emitting area EA2 is the first On the other hand, in the case of the organic light emitting diode 101 according to the embodiment of the present invention, referring to FIG. 3 , the separation distance between the light emitting area EA and the actual light emitting area EA3 is the first width ( It can be seen that the actual light emitting area EA3 in the light emitting area EA is increased as the second width w2 (< w1 of FIG. 1 ) is greatly reduced compared to w1 of FIG. 1 .

This suppresses the pile-up phenomenon implemented in the conventional organic electroluminescent device (not shown) having a bank (not shown) having a two-stage structure of a lower layer (not shown) having a hydrophilic property and an upper layer (not shown) having a hydrophobic property. It works similarly to

However, in the organic electroluminescent device 101 according to the embodiment of the present invention, the effect of reducing the pile-up phenomenon of the organic light emitting layer 155 in each light emitting area EA is conventionally provided with two-stage banks (not shown). It will be more effective than the organic electroluminescent device (not shown) of

Furthermore, the organic electroluminescent device 101 according to an embodiment of the present invention is different from the conventional organic electroluminescent device (not shown) that requires a separate additional mask process for implementing a two-stage bank (not shown). Since it does not require a mask process, it will be superior to an organic electroluminescent device (not shown) having a conventional double bank (not shown) in terms of manufacturing process, productivity, and material cost reduction.

In the case of the organic electroluminescent device 101 according to the embodiment of the present invention _{, an auxiliary layer 152 made of tungsten oxide (WO 3} ), which is a material having excellent hydrophilic properties, is provided on the entire surface of the display area.

Accordingly, each light emitting area EA is provided with an auxiliary layer 152 having a hydrophilic property with respect to its entire surface, so that a force to spread the organic light emitting layer 155 formed on the upper bank 153 has a hydrophobic property from the surface. ) is larger than the conventional organic electroluminescent device (not shown) having a lower bank (not shown) partially made of a hydrophilic material around the periphery.

Accordingly, in the organic light emitting device 101 according to the embodiment of the present invention, the organic light emitting layer 155 is relatively better spread within each light emitting area EA, so that the thickness is finally uniform for each light emitting area EA. to form the organic light emitting layer 155 having a planarized surface.

In order to improve light emission efficiency, the organic light emitting layer 155 does not usually have a single layer structure, but a multilayer structure, that is, a hole injection layer 155e, a hole transport layer 155a, an organic light emitting material layer 155b, and an electron transport layer 155c. ) and optionally the electron injection layer 155d.

Accordingly, in order to improve the luminous efficiency of the organic light emitting diode 101 and the organic light emitting layer 155 according to the embodiment of the present invention, the organic light emitting layer 155 includes a hole injection layer 154, a hole transport layer 155a, and an organic light emitting layer 155 . The light emitting material layer 155b and the electron transport layer 155c are configured to form a quadruple-layer structure, or to form a 5-layer structure in which an electron injection layer 155d is further provided on the electron transport layer 155c.

In this case, the auxiliary layer 152 serves to increase the area of a portion having a flat surface in each light emitting region by suppressing a pile-up phenomenon when the organic light emitting layer is formed, and at the same time as the hole injection layer 155e and In addition, it serves to better inject holes into the electron transport layer 155a or the organic light emitting material layer 155b.

When the pile-up phenomenon of the organic light emitting layer 155 is reduced in this way, the area of the organic light emitting layer 155 having a flat surface in the light emitting area EA surrounded by the bank 153 is increased, and thus the actual light emitting area ( As EA3) is expanded, the aperture ratio and luminance characteristics are improved, and at the same time, the lifespan is improved.

On the other hand, the auxiliary layer 152 has a hydrophilic property due to the material properties and also has excellent hole injection ability, so that it can replace the hole injection layer 155e, which is a component constituting the organic light emitting layer 155. can

A configuration in which the auxiliary layer takes over the role of the hole injection layer is presented as an organic electroluminescent device according to a modified example of the embodiment of the present invention.

4 is a cross-sectional view of a portion of a display area of an organic light emitting diode according to a modified example of an embodiment of the present invention. At this time, the organic light emitting device according to the modified example of the embodiment of the present invention differs only in the stacked structure of the organic light emitting layer provided above the auxiliary layer compared to the organic light emitting device according to the modified example of the exemplary embodiment of the present invention. Since the components are all the same, only the configuration of the organic light emitting layer that is different will be described.

In the case of the organic electroluminescent device according to the modified example of the embodiment of the present invention, the auxiliary layer 152 having excellent hydrophilic properties and hole injection capability is provided on the entire display area over the first electrode, so that the organic light emitting layer ( The hole injection layer 154, the hole transport layer 155a, the organic light emitting material layer 155b, and the electron transport layer 155c form a quadruple-layer structure, or an electron injection layer 155d over the electron transport layer 155c. ) is not formed, and the electron injection layer is omitted to form a triple-layer structure of the hole transport layer 155a, the organic light emitting material layer 155b, and the electron transport layer 155c, or the electron transport layer 155c ) is characterized in that it forms a quadruple-layer structure with an electron injection layer 155d above it.

That is, in the organic light emitting device 102 according to the modified example of the embodiment of the present invention, the organic light emitting layer 155 is an organic light emitting layer provided in the organic light emitting device (101 in FIG. 3) according to the embodiment of the present invention. 155 of FIG. 3) or the organic light emitting layer (55 of FIG. 1) of the conventional organic electroluminescent device (1 of FIG. 1), the auxiliary layer 152 is a hole injection layer (155e of FIG. 3 or FIG. 1) It is characterized in that the hole injection layer (155e in FIG. 3 or 55a in FIG. 1) is omitted by replacing 55a of FIG.

In the organic electroluminescent device 102 according to a modification of the embodiment of the present invention having such a configuration, the auxiliary layer 152 is added compared to the conventional organic light emitting device (1 in FIG. 1), but this auxiliary layer 152 ) suppresses the pile-up phenomenon of the organic light emitting layer 155 due to its hydrophilic properties, and at the same time has excellent hole injection ability, so as to replace the hole injection layer (55a in FIG. 1), which is a component of the organic light emitting layer 155, and its In this case, the hole injection layer (55a in FIG. 1), which is a component constituting the organic light emitting layer 155, may be omitted, and the conventional single-layered bank (53 in FIG. 1) and There is no substantial additional process compared to the organic electroluminescent device (1 in FIG. 1) having the organic light emitting layer (55 in FIG. 1) of a five-layer or quadruple-layer structure.

Therefore, it has the effect of suppressing the pile-up phenomenon of the organic light emitting layer 155 compared to the conventional organic electroluminescent device ( 1 in FIG. 1 ) having a single-layer bank without adding a process.

And the organic light emitting device 102 according to a modified example of the embodiment of the present invention is an embodiment of the present invention or a conventional organic light emitting device (101 and FIG. 3 in FIG. 3) in the laminated configuration of the organic light emitting layer 155 as described above. 1) compared to the organic emission layer (155 in FIG. 3 or 55 in FIG. 1) provided in 1), the hole injection layer (155e in FIG. 3 or 55a in FIG. 1) is omitted, so that the organic emission layer (155 in FIG. 3 or 55 in FIG. 1) is omitted. 55) is reduced by the thickness of the hole injection layer (155e in FIG. 3 or 55a in FIG. 1), thereby achieving the effect of further reducing the pile-up phenomenon.

The pile-up phenomenon occurs when the organic light emitting layer 155 is formed by ink jetting or nozzle dropping of a liquid material, and is generated in proportion to the thickness of the organic light emitting layer 155 .

When the thickness of the organic light emitting layer 155 is reduced, the pile-up phenomenon can be reduced. Each layer constituting the organic light emitting layer 155 having a multi-layer structure has a minimum thickness required to perform its role, and each material layer has at least Even if it is formed to a thickness of , the organic light emitting layer (55 in FIG. 1) of the conventional organic light emitting device (1 in FIG. 1) includes a hole injection layer (55a in FIG. 1), a hole transport layer (55b in FIG. 1), an organic light emitting material A layer (55c in FIG. 1), a quadruple layer of the electron transport layer (55d in FIG. 1), or a five-layer structure including an electron injection layer (55e in FIG. 1) above the electron transport layer (55d in FIG. 1) should be formed.

However, in the organic electroluminescent device 102 according to a modified example of the embodiment of the present invention, the auxiliary layer 152 provided on the entire surface of the display area is a hole injection layer (55a in FIG. 1 ), which is a component of the organic light emitting layer 155 . ), the hole injection layer (55a in FIG. 1 ) provided for each light emitting area EA may be omitted.

In this case, in the organic electroluminescent device 102 according to a modification of the embodiment of the present invention having a configuration in which the hole injection layer (not shown) is omitted, the organic light emitting layer 155 is formed by ink jetting or nozzle dropping. Since the hole transport layer 155a, the organic light emitting material layer 155b, and the electron transport layer 155c form a triple layer structure, or a quadruple layer structure with an electron injection layer 155d over the electron transport layer 155c is formed. Since the thickness is reduced by omitting the hole injection layer, the pile-up phenomenon of the organic light emitting layer 155 is relatively more reduced compared to the embodiment of the present invention or the conventional organic electroluminescent device (101 in FIG. 3 or 1 in FIG. 1) effect can be implemented.

In addition, when the pile-up phenomenon of the organic light emitting layer 155 is reduced in this way, the area of the organic light emitting layer 155 having a flat surface in the light emitting area EA surrounded by the bank 153 is increased, thereby causing actual light emission. As the area EA3 is expanded, the aperture ratio and luminance characteristics are improved, and at the same time, the lifespan is improved.

However, the hole injection layer (not shown) is not necessarily omitted, and may be formed like the organic electroluminescent device (101 in FIG. 3) according to an embodiment of the present invention, in this case, the auxiliary layer 152 ) serves to inject holes into the electron transport layer 155a or the organic light emitting material layer 155b together with the hole injection layer (155e in FIG. 3).

The organic light emitting device 102 according to a modified example of the embodiment of the present invention having such a configuration is provided on the organic light emitting layer 155 in the organic light emitting device according to an embodiment of the present invention (101 in FIG. 3). ), the configuration of the organic electroluminescent device 101 according to an embodiment of the present invention will be described below with reference to FIG. 3 .

On the other hand, in the organic light emitting device 101 according to the embodiment of the present invention having such a configuration, the organic light emitting layer 155 emits red, green, and blue light in a form that is sequentially repeated for each light emitting area EA, respectively. may be configured, or may be configured to emit white light for each of the light emitting areas EA. This is due to the material properties of the organic light emitting material layer 155b of the organic light emitting layer 155 having a multilayer structure.

The organic light emitting layer 155 is characterized in that it is formed by spraying or dropping a liquid organic material through an inkjet device or a nozzle device, followed by drying and curing.

Next, a second electrode 160 is formed on the entire surface of the display area on the organic emission layer 155 .

At this time, the second electrode 160 is a metal material having a relatively low work function value compared to the first electrode 150, for example, aluminum (Al), aluminum alloy (AlNd), silver (Ag), magnesium (Mg), As it is made of one of gold (Au) and aluminum magnesium alloy (AlMg), it serves as a cathode electrode.

In this case, the first electrode 150 , the auxiliary layer 1520 , the organic light emitting layer 155 , and the second electrode 160 sequentially stacked in the light emitting area EA form an organic light emitting diode E .

On the other hand, the second substrate 170 for encapsulation is provided corresponding to the first substrate 110 of the organic light emitting device 101 according to the embodiment of the present invention having the above-described configuration.

An adhesive (not shown) made of a sealant or a frit is provided along the edges of the first substrate 110 and the second substrate 170, and the first substrate 110 and the second substrate 170 are formed by the adhesive (not shown). The second substrate 170 is bonded to maintain the panel state. At this time, the space between the first substrate 110 and the second substrate 170 spaced apart from each other may have a vacuum state or an inert gas atmosphere by filling it with an inert gas.

In this case, the second substrate 170 for the encapsulation may be made of plastic having a flexible characteristic, or may be made of a glass substrate.

On the other hand, although the organic electroluminescent device 101 according to the above-described embodiment shows that the second substrate 170 for encapsulation is provided in a form facing and spaced apart from the first substrate 110 , the second The substrate 170 may be configured to be in contact with the second electrode 160 provided on the uppermost layer of the first substrate 110 in the form of a film including an adhesive layer, or to the upper portion of the second electrode 160 . An organic insulating layer (not shown) or an inorganic insulating layer (not shown) may be further provided to form a capping layer (not shown), and the organic insulating layer (not shown) or inorganic insulating layer (not shown) encapsulates itself. It may be used as a film (not shown), and in this case, the second substrate 170 may be omitted.

The organic electroluminescent device 101 (102 of FIG. 4) according to the embodiment of the present invention and its modifications having the above-described configuration has hydrophilic properties and organic light emitting material with respect to the entire surface of the display area with the upper portion of the first electrode 150 Organic electroluminescence having a conventional two-stage bank (not shown) by providing an auxiliary layer 152 made of a _{tungsten oxide (WO 3} ) material having excellent hole injection capability into the layer 155b or the hole transport layer 155a The pile-up phenomenon around the bank 153 of the organic light emitting layer 155 formed using a liquid material compared to the device (not shown) is reduced, so that the flat surface of the organic light emitting layer 155 in each light emitting area EA is reduced. As the area of the portion increases, the aperture ratio is improved by the expansion of the actual light emitting area EA3.

Furthermore, in the organic light emitting device 101 ( 102 in FIG. 4 ) according to the embodiment of the present invention and its modifications, the luminance is improved by increasing the portion of the organic light emitting layer 155 having a flat surface in each light emitting area EA. In addition, since it has uniform luminance characteristics, face defects due to luminance non-uniformity are suppressed, thereby improving display quality.

And in the organic light emitting diode 101 (102 in FIG. 4) according to the embodiment of the present invention and its modifications, the pile-up phenomenon is reduced in each light emitting area EA, and the thickness uniformity of the organic light emitting layer 155 is improved. There is an effect of suppressing deterioration of the organic light emitting layer 155 to extend the lifespan.

Furthermore, the organic electroluminescent device (102 in FIG. 4) according to a modification of the embodiment of the present invention has a single-layered bank unlike the conventional organic electroluminescent device (not shown) having a two-stage bank (not shown). Therefore, since there is no need to form a two-stage bank, productivity per unit time is improved by simplifying the manufacturing process by omitting one mask process, and furthermore, there is an effect of reducing material cost.

Hereinafter, a method of manufacturing an organic electroluminescent device according to an embodiment of the present invention having the above-described configuration and a modification thereof will be described. In this case, the organic light emitting device according to the embodiment of the present invention and its modifications is characterized in an auxiliary layer, a bank, and an organic light emitting layer provided above the first electrode of the organic light emitting diode, and located below the first electrode. Since the switching and driving thin film transistors are manufactured by a general method, the description thereof will be omitted or simplified. And for convenience of explanation, the manufacturing method of the organic electroluminescent device according to the modified example of the embodiment of the present invention is the same as the manufacturing method of the organic electroluminescent device according to the embodiment of the present invention, except for the configuration in which the hole injection layer is omitted. The manufacturing method of the organic electroluminescent device according to the embodiment of the present invention will be mainly described, and only the parts with differences will be briefly described.

5A to 5J are cross-sectional views illustrating steps of manufacturing an organic light emitting diode according to an embodiment of the present invention.

First, as shown in FIG. 5A, a gate wiring (not shown) and a data wiring (not shown) intersecting each other by performing a general method on the first substrate 110 made of a transparent insulating material, for example, glass or plastic. ) and a power wiring (not shown) in parallel with the data wiring (not shown), and further forming a switching thin film transistor (not shown) connected to the gate and the data wiring (not shown), and at the same time forming the switching thin film transistor (not shown) and a driving thin film transistor (DTr) connected to a power wiring (not shown) are formed. At this time, since the structure of the switching and driving thin film transistor (not shown, DTr) has been described in detail with reference to FIG. 3 above, a detailed description of the stacked structure thereof will be omitted.

Thereafter, as shown in FIG. 5B , a planarization layer 140 having a flat surface is formed by coating an organic insulating material, for example, photoacrylic, on the switching and driving thin film transistor (not shown, DTr), and a mask is applied thereto. A drain contact hole 143 exposing the drain electrode 136 of the driving thin film transistor DTr is formed by patterning through the process.

On the other hand, prior to forming the planarization layer 140, an inorganic insulating material, for example, silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is preferentially deposited on the switching and driving thin film transistor (not shown, DTr) to protect it. After further forming a layer (not shown), the planarization layer 140 is formed over the passivation layer (not shown), and the driving thin film transistor (DTr) is formed with respect to the planarization layer 140 and the passivation layer (not shown). A drain contact hole 143 exposing the drain electrode 136 may be formed.

Next, as shown in FIG. 5C , the driving thin film transistor DTr and the drain contact hole 143 are formed on the planarization layer 143 having the drain contact hole 143 for each light emitting area EA. The first electrode 150 in contact with each other is formed.

In this case, the first electrode 150 includes a lower layer 150a made of a highly reflective metal material, for example, aluminum (Al) or aluminum alloy (AlNd), and indium-tin-oxide (indium-tin-oxide) ( Although the double-layer structure of the upper layer 150b made of ITO is shown as an example, the first electrode 150 is a single layer made of indium-tin-oxide (ITO), which is a transparent conductive material having a large work function value. structure can be achieved.

Next, as shown in FIG. 5D, it has hydrophilic properties using any one deposition method of vacuum thermal evaporation and sputtering on the first electrode 150 and at the same time the first electrode ( _{An auxiliary layer by depositing tungsten oxide (WO 3} ), which is a material having excellent hole injection capability for well injecting holes generated from 150 ) onto the organic light emitting material layer 155b, on the entire surface of the display area of the first substrate 110 . (152).

At this time, since the auxiliary layer 152 does not need to be patterned for each light emitting area EA, a separate shadow mask is not required even if it is deposited using the thermal evaporation method. Since there is no room for pattern defects to occur, there is no problem even if deposition is performed through the thermal evaporation method.

The auxiliary layer 152 is characterized in that it is formed by a vapor deposition method. Unlike forming a liquid crystal material by spraying or dropping a liquid crystal material using an ink jet apparatus or a nozzle apparatus, the first electrode 150 does not have a pile-up phenomenon. ) It is characterized in that it is formed to have an even thickness and a flat surface at the top.

On the other hand, since the auxiliary layer 152 deposited on the entire surface of the display area has a hydrophilic tendency due to the material properties constituting it, a liquid organic material is sprayed or dropped on the upper part of the auxiliary layer 152 later through an ink jet device or a nozzle device. The auxiliary layer 152 serves to suppress the pile-up phenomenon of the formed organic light emitting layer 155 and at the same time, the auxiliary layer 152 has excellent hole injection ability, so that the hole transport layer 155a or In the case of the organic electroluminescent device (102 in FIG. 4) according to a modification of the embodiment of the present invention by serving to inject holes into the organic light emitting material layer 155b, or by replacing the hole injection layer 155e, the holes The injection layer 155e serves as itself.

Next, as shown in FIG. 5E , a photosensitive material is included on the auxiliary layer 152 to have photosensitive properties, and further, a polymer material having hydrophobic properties, for example, polyimide containing fluorine (F). , styrene, methyl mathacrylate, and polytetrafluoroethylene are applied to form a bank material layer (not shown) by applying a material in which one or a mixture of two or more thereof is mixed.

In this case, the bank material layer (not shown) may be formed to have a black color itself by further including a black pigment or a black-based resin.

Thereafter, by patterning the bank material layer (not shown) having such a photosensitive characteristic to surround each light emitting area EA at the boundary of each light emitting area EA, and at the same time, the first first positioned under the auxiliary layer 152 . A bank 153 having a single-layer structure overlapping the edge of the electrode 150 by a predetermined width and having a trapezoidal cross-sectional shape is formed.

Next, as shown in FIG. 5F, the bank 153 in the state in which the bank 153 of the single-layer structure is formed as a manufacturing method feature of the organic electroluminescent device (101 of FIG. 5J) according to an embodiment of the present invention ), the auxiliary layer 152 is crystallized by selectively irradiating a laser beam LB using a laser irradiation device (not shown).

In this case, the laser irradiator (not shown) is an excimer laser beam irradiator, and it is preferable that the laser beam LB in the form of a pulse wave having a relatively short wavelength of 248 nm to 1060 nm is irradiated. This is because the laser beam LB having a high energy density is irradiated within a relatively short time, which is advantageous in minimizing the laser process time.

The laser beam LB may have a line beam shape or a pattern beam shape.

Meanwhile, the laser beam LB is preferably applied only to the auxiliary layer 152 exposed to the outside of the bank 153 in each light emitting area EA surrounded by the bank 153, and thus the auxiliary layer ( A portion 152 irradiated with the laser beam LB forms a crystallized first portion 152a, and a portion not irradiated with the laser beam LB forms a second portion 152b in an amorphous state.

When the auxiliary layer 152 is crystallized, it tends to become conductive due to improved hole mobility. This auxiliary layer 152 is formed on the entire surface of the display area, so that adjacent light emitting areas EA are in contact with each other. In this case, since each light emitting area EA in the display area is shorted, a full-color image cannot be smoothly implemented.

Therefore, in the auxiliary layer 152 , it is preferable that the crystallization process through the laser beam LB is performed only on the auxiliary layer 152 exposed to the outside of the bank 153 .

On the other hand, when the bank 153 is made of a black material, even if the laser beam LB is irradiated to the bank 153 , the laser beam LB cannot reach the portion where the auxiliary layer 152 is located. It is not affected by the irradiation of the laser beam LB. Therefore, in this case, it does not matter whether the laser beam LB is a patterned laser beam LB or a line-type laser beam LB for each light emitting area EA.

In this way, when the auxiliary layer 152 is irradiated with a laser beam LB for crystallization, in a state in which the auxiliary layer 152 is deposited, the molecules therein are in a disordered amorphous state. In this case, the mobility of holes As the characteristic is relatively deteriorated, the hole injection capability into the hole transport layer 155a or the organic light emitting material layer 155b becomes weak, and the hole mobility characteristic is improved to finally improve the hole injection capability. .

Next, after the crystallization process of the auxiliary layer 152 is completed to form the first and second parts 152a and 152b, as shown in FIG. 5G, an ink jet device 195 or a nozzle device ( By spraying or dropping a liquid hole transport material by using (not shown), a liquid hole transport material layer (not shown) is formed in each light emitting area (EA), and a heat treatment process is performed on this to dry and harden. A hole injection layer 155e is formed.

In this case, the hole injection layer 155e has an improved spreading ability by the hydrophilic property of the auxiliary layer 152 in each light emitting area EA, so that the pile-up phenomenon in which the thickness increases around the bank 153 is conventional. Compared to an organic electroluminescent device (not shown) having a two-stage bank (not shown) of

Next, as shown in FIG. 5H , the same method as in forming the hole injection layer 155e is performed in each light emitting area EA surrounded by the single-layered bank 153 over the hole injection layer 155e. A hole transport layer 155a, an organic light emitting material layer 155b, an electron transport layer 155c, and optionally an electron injection layer 155d are sequentially formed.

At this time, the hole injection layer 155e, the hole transport layer 155a, the organic light emitting material layer 155b, and the electron transport layer 155c are sequentially stacked in each light emitting area EA to form a quadruple layer structure, or electron injection When the layer 155d is further formed, the organic emission layer 155 having a five-layer structure is formed.

In the organic light emitting layer 155 formed by spraying or dropping through an ink jet device or a nozzle device as described above, a predetermined pile-up phenomenon occurs around the bank, but a conventional single layer is formed by forming the auxiliary layer 152 having hydrophilicity. It is characterized in that the width of the portion where the pile-up phenomenon occurs is greatly reduced compared to the organic EL device having a bank of the structure (1 in FIG. 1).

On the other hand, according to a modified example of the embodiment of the present invention having a difference in the stacked structure of the organic light emitting layer 155 compared to the organic light emitting device according to the embodiment of the present invention having the structure of the organic light emitting layer as described above (101 in FIG. 5J) 6a to 6d (Fig. 6d is a step-by-step process cross-sectional view of the organic light emitting device according to a modified example of the embodiment of the present invention for forming the organic light emitting layer of the organic light emitting device (102 of Fig. 6b) as a cross-sectional view of the organic light emitting layer on the auxiliary layer A cross-sectional view of the manufacturing process showing the steps of forming the second electrode and providing the second substrate for encapsulation.).

As shown in FIG. 6A , after the crystallization process of the auxiliary layer 152 is completed to form the first and second portions 152a and 152b, the ink jet device 195 is applied over the auxiliary layer 152. Alternatively, a liquid hole transport material layer (not shown) is formed in each light emitting area EA by spraying or dropping a liquid hole transport material using a nozzle device (not shown), and a heat treatment process is performed thereon. By drying and curing, the hole transport layer 155a is formed.

In this case, the hole transport layer 155a has an improved spreading ability by the hydrophilic property of the auxiliary layer 152 in each light emitting area EA, so that the pile-up phenomenon in which the thickness increases around the bank 153 is conventional. Compared to an organic electroluminescent device (not shown) having a two-stage bank (not shown) of

Next, as shown in FIG. 6B , the hole transport layer 155a is sequentially formed in each light emitting area EA surrounded by the single-layered bank 153 by the same method as the hole transport layer 155a is formed over the hole transport layer 155a. An organic light emitting material layer 155b, an electron transport layer 155c, and optionally an electron injection layer 155d are formed.

The hole transport layer 155a, the organic light emitting material layer 155b, the electron transport layer 155c, and the electron injection layer 155d sequentially stacked in each light emitting area EA form an organic light emitting layer 155 having a quadruple layer structure. . In this case, the electron injection layer 155d may be omitted, and in this case, the organic emission layer 155 has a triple or quadruple layer structure.

Although a predetermined pile-up phenomenon occurs around the bank 153 in the organic light emitting layer 155 formed by spraying or dropping through an ink jet device or a nozzle device as described above, the auxiliary layer 152 having hydrophilicity is formed and the organic light emitting layer 155 is formed. It is characterized in that the width of the portion where the pile-up phenomenon occurs is greatly reduced compared to the conventional organic light emitting device by reducing the number of stacked light emitting layers 155 itself.

That is, the organic light emitting layer 155 includes a conventional hole transport layer (55a in FIG. 1) by forming the auxiliary layer 152 serving as a hole injection layer (55a in FIG. 1) with a flat surface. 4 or 5 of the hole transport layer (55b in FIG. 1), the organic light emitting material layer (55c in FIG. 1), the electron transport layer (55d in FIG. 1) and/or the electron injection layer (55e in FIG. 1) provided on the upper part The pile-up phenomenon can be further reduced due to fewer layers formed by jetting or dropping than when all of the layers are formed by jetting or dropping through an inkjet or nozzle device.

The subsequent process, that is, the process of completing the organic EL device 102 by forming the second electrode 160 shown in FIGS. 6C and 6D and providing the second substrate 170 for encapsulation is the process of the present invention. Since the manufacturing method of the organic electroluminescent device (101 of FIG. 5J) according to the embodiment is the same, the manufacturing method of the organic electroluminescent device (101 of FIG. 5J) according to the embodiment of the present invention will be described.

As shown in FIG. 5I , the second electrode 160 is formed on the entire surface of the display area over the organic light emitting layer 155 through vacuum thermal evaporation.

In this case, the first electrode 150 , the auxiliary layer 152 , the organic light emitting layer 155 , and the second electrode 160 sequentially stacked on each of the light emitting regions E form an organic light emitting diode E .

Next, as shown in FIG. 5J, a film (not shown) or a capping film (not shown) is formed on the second electrode 160, or a second substrate 170 made of a transparent glass material or plastic material is formed. Organic according to an embodiment of the present invention and its modifications by bonding a front seal (not shown) or a seal pattern (not shown) to a predetermined width of the edge of the first substrate 110 in an inert gas atmosphere or an atmosphere of vacuum The electroluminescent device 101 is completed.

The present invention is not limited to the above-described embodiments and modifications thereof, and can be implemented with various modifications without departing from the spirit and spirit of the present invention.

101: organic electroluminescent device
110: first substrate
113: semiconductor layer (113a: first region, 113b: second region)
116: gate insulating film
120: gate electrode
123: interlayer insulating film
125: semiconductor layer contact hole
133: source electrode
136: drain electrode
140: planarization layer
143: drain contact hole
150: first electrode (150a: lower layer, 150b: upper layer)
152: auxiliary layer (152a: first portion, 152b: second portion)
153 : bank
155: organic light emitting layer (155e hole injection layer, 155a: hole transport layer, 155b: organic light emitting material layer, 155c: electron transport layer, 155d: electron injection layer)
160: second electrode
170: second substrate
DTr: driving thin film transistor
E: organic light emitting diode
EA: light emitting area
EA3 : Actual light emitting area
w2: second width (size of the spaced area between the light emitting area and the actual light emitting area)

Claims (15)

a first substrate having a display area in which a plurality of light emitting areas are defined;
a first electrode provided for each of the plurality of light emitting regions and having a double layer structure;
an auxiliary layer provided on the entire surface of the display area over the first electrode as the front surface of the display area and made of a material having hydrophilic properties and hole injection capability;
a bank overlapping an edge of the first electrode on the auxiliary layer and surrounding each of the plurality of light emitting regions, the bank having a hydrophobic property of a single layer structure;
an organic light emitting layer provided on the auxiliary layer in each of the plurality of light emitting regions surrounded by the bank;
and a second electrode provided on the entire surface of the display area above the organic light emitting layer,
The organic light emitting layer has a structure of a hole transport layer, an organic light emitting material layer, and an electron transport layer,
The auxiliary layer is an organic light emitting formed of a second portion consisting of an amorphous state of the tungsten oxide (WO ₃₎ corresponding made of a crystallized tungsten oxide (WO ₃₎ the first portion and, in the bank corresponding to the respective light-emitting region device.

The method of claim 1,
The first portion is a conductive organic electroluminescent device.
delete The method of claim 1,
The organic light emitting layer is an organic electroluminescent device further comprising an electron injection layer.
The method of claim 1,
The organic light emitting layer is an organic electroluminescent device further comprising a hole injection layer between the auxiliary layer and the hole transport layer.
The method of claim 1,
A plurality of switching thin film transistors and driving thin film transistors are provided under the first electrode on the first substrate, and a planarization layer formed by covering the switching and driving thin film transistors and exposing the drain electrode of the driving thin film transistor is provided; One electrode is an organic electroluminescent device characterized in that it is formed on the planarization layer in contact with the drain electrode of the driving thin film transistor.
forming a first electrode having a double layer structure for each of the plurality of light emitting areas on a first substrate having a display area in which a plurality of light emitting areas are defined;
forming an auxiliary layer on the entire surface of the display region by depositing a material having hydrophilic properties and hole injection capability on the first electrode on the entire surface of the display region;
forming a bank having a hydrophobic property of a single layer structure on the auxiliary layer, overlapping an edge of the first electrode and enclosing each of the plurality of light emitting regions;
forming an organic light emitting layer by spraying or dropping a liquid material through an ink jet device or a nozzle device onto the auxiliary layer in each of the plurality of light emitting regions surrounded by the bank;
forming a second electrode on the entire surface of the display area over the organic light emitting layer
includes,
The organic light emitting layer has a structure of a hole transport layer, an organic light emitting material layer, and an electron transport layer,
The auxiliary layer is an organic light emitting formed of a second portion consisting of an amorphous state of the tungsten oxide (WO ₃₎ corresponding made of a crystallized tungsten oxide (WO ₃₎ the first portion and, in the bank corresponding to the respective light-emitting region A method of manufacturing a device.
8. The method of claim 7,
The deposition is a vacuum thermal deposition or sputtering method of manufacturing an organic light emitting device.
8. The method of claim 7,
The organic light emitting layer is a method of manufacturing an organic light emitting device is formed to further include an electron injection layer.
8. The method of claim 7,
A method of manufacturing an organic electroluminescent device for forming a hole injection layer on the auxiliary layer before forming the hole transport layer.
8. The method of claim 7,
Before forming the organic light emitting layer, by irradiating a laser beam on the auxiliary layer exposed to the outside of the bank to form the crystallized first portion and the portion corresponding to the bank to form the second portion in an amorphous state A method of manufacturing an organic electroluminescent device in progress.
12. The method of claim 11,
The method of manufacturing an organic electroluminescent device, wherein the laser beam is a pulse wave type laser beam having a wavelength of 248 nm to 1060 nm.
7. The method of claim 6,
The driving thin film transistor has a polysilicon semiconductor layer, a gate insulating film, a gate electrode and an interlayer insulating film, spaced apart from each other and forming a stacked structure of the source electrode and the drain electrode in contact with the polysilicon semiconductor layer, respectively.
The method of claim 1,
The first electrode consists of a lower layer made of a metal having a reflectance, and an upper layer made of indium-tin-oxide (ITO),
The light emitted from the organic light emitting layer passes through the second electrode.
8. The method of claim 7,
The first electrode consists of a lower layer made of a metal having a reflectance, and an upper layer made of indium-tin-oxide (ITO),
Light emitted from the organic light emitting layer is a method of manufacturing an organic light emitting device that passes through the second electrode.

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