KR101889020B1 - Organic electro-luminescent device - Google Patents

Abstract

The present invention provides a display device comprising: a first substrate on which a display region having a plurality of pixel regions is defined; A buffer layer formed on the entire surface of the first substrate; A bottom gate type switching thin film transistor and a driving thin film transistor formed in the respective pixel regions on the buffer layer; A first electrode formed in each pixel region in contact with a drain electrode of the driving thin film transistor; An organic light emitting layer formed on the first electrode; And a second electrode formed on the entire surface of the display region above the organic light emitting layer.

Description

[0001] The present invention relates to an organic electroluminescent device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device that can be applied to a large-area display device and can reduce the reflectance.

An organic electroluminescent device, which is one of flat panel displays (FPDs), has high luminance and low operating voltage characteristics. In addition, since it is a self-luminous type that emits light by itself, it has a large contrast ratio, can realize an ultra-thin display, can realize a moving image with a response time of several microseconds (μs), has no viewing angle limit, And it is driven with a low voltage of 5 V to 15 V direct current, so that it is easy to manufacture and design a driving circuit.

Accordingly, the organic electroluminescent device having the above-described advantages has recently been used in various IT devices such as a TV, a monitor, and a mobile phone.

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

1 is a schematic cross-sectional view of a portion of a display region of a conventional organic light emitting device.

As shown in the figure, in the conventional organic electroluminescent device 1, the first and second substrates 10 and 70 are arranged so as to face each other.

In the first substrate 10, a display area AA and a non-display area (not shown) are defined outside the display area AA. In the display area AA, a gate wiring (not shown) A plurality of pixel regions P defined as regions captured by data lines (not shown) are provided, and power lines (not shown) are provided in parallel with the data lines (not shown). A switching and driving thin film transistor (not shown) DTr is formed in each of the plurality of pixel regions P and a first electrode 47 is formed to be connected to the driving thin film transistor DTr.

At this time, the switching and driving thin film transistor is mainly composed of a thin film transistor having a top gate type having a semiconductor layer of polysilicon.

An organic light emitting layer 55 including light emitting material patterns 55a, 55b and 55c for emitting red, green and blue colors is formed on the first electrode 47 And a second electrode 58 is formed on the entire surface of the display region on the organic light emitting layer 55.

The second substrate 70 is opposed to the first substrate 10 having the above-described components in order to encapsulate the first and second substrates 10 and 70, The first substrate 10 and the second substrate 70 are bonded together by providing a face seal (not shown) on the front surface or a seal pattern (not shown) State.

In the organic electroluminescent device 1 having such a configuration, light generated from the organic light emitting layer 55 is emitted toward the first electrode 47 or the second electrode 58 to display an image.

On the other hand, in recent years, a flat panel display device for displaying an image has a large area of 20 inches or more, especially when used in a TV or the like.

Therefore, in order to meet such a trend, the organic electroluminescent device 1 must have a large area of 20 inches or more. In order to form the organic electroluminescent device 1 having a large area of 20 inches or more, In the conventional organic electroluminescent device 1 having the thin film transistor DTr which uses polysilicon as the semiconductor layer 113 which requires a crystallization process to be used, there is a problem that display unevenness or the like occurs and the display quality is lowered .

In the case of the thin film transistor DTr made of polysilicon as the semiconductor layer 113, the polysilicon semiconductor layer 13 / the gate insulating film 14 / the gate electrode 17 / the semiconductor layer 13 on the first substrate 10, An interlayer insulating film 18 having layer contact holes 19a and 19b, and source and drain electrodes 33 and 36 spaced apart from each other.

Therefore, the top gate type thin film transistor DTr having such a configuration is relatively complicated compared to the manufacturing process of the bottom gate type thin film transistor (not shown) in which amorphous silicon is used as the semiconductor layer, The crystallization of the semiconductor layer 13 and the doping of the impurities must be performed. Therefore, the time for forming the semiconductor layer 13 is increased and the productivity per unit time is lowered, thereby increasing the manufacturing cost.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide a method of manufacturing a semiconductor device, which has a large area of 20 inches or more, but fundamentally prevents display quality deterioration due to laser beam irradiation, And an object of the present invention is to provide an organic electroluminescent device.

According to an aspect of the present invention, there is provided an organic electroluminescent device including a first substrate on which a display region having a plurality of pixel regions is defined; A buffer layer formed on the entire surface of the first substrate; A bottom gate type switching thin film transistor and a driving thin film transistor formed in the respective pixel regions on the buffer layer; A first electrode formed in each pixel region in contact with a drain electrode of the driving thin film transistor; An organic light emitting layer formed on the first electrode; And a second electrode formed on the entire surface of the display region above the organic light emitting layer.

At this time, the buffer layer is formed of silicon oxide (SiO ₂ ) or silicon nitride (SiN x).

Each of the bottom gate type switching thin film transistor and the driving thin film transistor is composed of a source electrode and a drain electrode spaced apart from each other by a gate electrode, a gate insulating film, and a semiconductor layer sequentially stacked on the buffer layer. Layer structure of the ohmic contact layer which is made of the active layer of pure amorphous silicon and the impurity amorphous silicon, or has a single layer structure made of an oxide semiconductor material.

When the semiconductor layer is a single-layered semiconductor layer made of the oxide semiconductor material, an etch stopper made of an insulating material is provided at a central portion of the upper portion of the semiconductor layer, and the source electrode and the drain electrode are connected to each other And is in contact with the semiconductor layer exposed to the outside of the etch stopper.

The oxide semiconductor material is one of indium gallium zinc oxide (IGZO), zinc tin oxide (ZTO), and zinc oxide (ZIO), which is an oxide of zinc oxide (ZnO).

The first electrode is made of indium-tin-oxide, which is a transparent conductive material, and the second electrode is made of aluminum (Al), aluminum alloy (AlNd), silver (Ag), magnesium (Mg) And a magnesium alloy (AlMg).

The organic electroluminescent device is a bottom emission type in which light is emitted toward the first substrate.

Further, a hole injection layer and a hole transporting layer may be further disposed between the organic light emitting layer and the first electrode, and an electron transport layer may be interposed between the organic light emitting layer and the second electrode. At least one layer selected from the group consisting of an electron transporting layer and an electron injection layer is further provided.

In addition, a gate wiring extending in one direction is formed on the buffer layer, and the gate wiring is connected to a gate electrode of the switching thin film transistor. A gate electrode of the switching thin film transistor is connected to the source electrode of the switching thin film transistor, A data line for defining a region, and a power line extending in parallel to the data line.

In addition, a second substrate facing the first substrate is provided, or a capping film serving as a second substrate in contact with the second electrode is provided.

The second substrate is made of glass or plastic and is sealed with an adhesive along the edges of the first and second substrates. The first substrate and the second substrate are in a state of vacuum or inert A gas atmosphere is formed, or a front adhesive is provided between the first substrate and the second substrate to be cemented.

An organic electroluminescent device according to an embodiment and a modified example of the present invention having such a structure includes a bottom gate type thin film transistor using amorphous silicon or an oxide semiconductor material as a semiconductor layer and constituting it as a driving and switching thin film transistor, Since a crystallization step of irradiating a laser beam for forming a semiconductor layer of polysilicon is not required compared with a conventional organic electroluminescent device having a thin film transistor having a semiconductor layer, It is advantageous to provide a large-area organic electroluminescent device because defects can be prevented originally.

Furthermore, the organic electroluminescent device according to the embodiments and modifications of the present invention simplifies the manufacturing process of the thin film transistor compared to the conventional organic electroluminescent device having the top gate type switching and driving thin film transistor having the semiconductor layer of polysilicon The productivity per unit time can be improved, and further, the manufacturing cost can be reduced.

In addition, in the organic electroluminescent device according to the embodiment and the modified example of the present invention, when a buffer layer is provided on the inner surface of the first substrate to take a lower light emitting mode to emit light toward the first substrate, The reflectance of the external light is reduced and the external contrast ratio is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a portion of a display area of a conventional organic electroluminescent device. FIG.
2 is a circuit diagram of one pixel region of a general organic electroluminescent device.
3 is a cross-sectional view of a portion of a display region of an organic electroluminescent device according to a first embodiment of the present invention.
4 is a cross-sectional view of a portion of a display region of an organic electroluminescent device according to a second embodiment of the present invention.

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

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

As shown, a switching thin film transistor STr, a driving thin film transistor DTr, a storage capacitor StgC, and an organic light emitting diode E are provided in each pixel region of the organic electroluminescent device have.

That is, the gate line GL is formed in the first direction and the data line DL is formed in the second direction intersecting the first direction to form the data line DL surrounded by the gate line GL and the data line DL. And a power supply line PL for applying a power source voltage is formed in the pixel region P spaced apart from the data line DL.

A switching thin film transistor STr is formed at the intersection of the data line DL and the gate line GL 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 electroluminescent 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 supply voltage transmitted through the power supply line PL is transmitted to the organic light emitting diode E through the driving peak transistor DTr. A storage capacitor StgC is formed between the gate electrode and the source electrode of the driving thin film transistor DTr.

Therefore, 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, The thin film transistor DTr is turned on so that 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 a current flowing from the power supply line PL to the organic light emitting diode E is determined, The storage capacitor StgC is capable of maintaining a constant gate voltage of the driving thin film transistor DTr when the switching thin film transistor STr is turned off, The level of the current flowing through the organic light emitting diode E can be kept constant until the next frame even if the switching thin film transistor STr is turned off.

3 is a cross-sectional view of a portion of a display region of an organic electroluminescent device according to a first embodiment of the present invention. In this case, for convenience of description, a region where the driving thin film transistor DTr is formed is referred to as a driving region DA, and a region where a switching thin film transistor is formed in each pixel region P (not shown) .

The organic light emitting device 101 according to the first embodiment of the present invention includes a first substrate 102 on which a driving and switching thin film transistor DTr (not shown) and an organic light emitting diode E are formed, And a second substrate 170 for encapsulation. At this time, the second substrate 170 may be omitted by being replaced with an inorganic film, an organic film, a film, or the like.

First, the structure of the first substrate 102 provided with the driving and switching thin film transistor DTr (not shown) and the organic electroluminescent diode E will be described.

A buffer layer 103 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first substrate 102 made of a transparent material such as a glass material or a flexible plastic to be.

The formation of the buffer layer 103 on the first substrate 102 thus reduces the reflectance under the external light by the gate electrode 105 made of a low-resistance metal material and the gate wiring (not shown) (ambient contrast ratio).

The switching and driving thin film transistor (not shown) (DTr) is a bottom gate type in which the gate electrode 105 is located at the bottom layer, and the gate electrode Gate lines (not shown) are formed on the same layer on which the switching and driving thin film transistors (not shown) are formed, and when the buffer layer 103 is not formed, A gate electrode 105 and a gate wiring (not shown) are formed in direct contact with the first substrate 102.

In this case, when the organic electroluminescent device 101 is driven by the bottom emission type in which light is emitted to the first substrate 102, the user looks at the first substrate 102, External light is reflected by the gate electrode 105 and the gate wiring (not shown), which is mixed with light emitted from the organic electroluminescent device 101, thereby deteriorating display quality.

Therefore, a buffer layer 103 is formed on the first substrate 102 to suppress deterioration of display quality due to reflection of external light.

When external light is incident on the buffer layer 103 and is reflected by the gate wiring (not shown) and the gate electrode 105, the buffer layer 103 induces destructive interference, and thereby the gate wiring (not shown) and the gate electrode 105 It is possible to reduce the reflectance due to the reflection.

 Next, the buffer layer 103 is formed of a low resistance metal material such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum (Mo) or molybdenum alloy (MoTi) (Not shown) having a multi-layer structure and having a layer structure or two or more materials and extending in one direction are formed in the driving region DA and the gate electrode 105 are formed. At this time, the gate electrode 105 formed in the switching region (not shown) is connected to the gate wiring (not shown).

An inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN x) is formed on the entire surface of the gate electrode 105 formed in the gate wiring (not shown) and the switching and driving regions A gate insulating film 110 is formed.

A data line (not shown) is formed on the gate insulating layer 110 to define the pixel region P having a single layer or a multi-layer structure with the low resistance metal material and intersecting the gate line (not shown) And a power wiring (not shown) are formed in parallel to each other.

An active layer 120a made of pure amorphous silicon and an ohmic contact layer 120b made of impurity amorphous silicon are formed on the gate insulating layer 110 in each switching region (not shown) and the driving region DA And a semiconductor layer 120 are provided. At this time, the ohmic contact layer 120b is formed apart from the active layer 120a.

A source electrode and a drain electrode 133 and 136, which are in contact with the ohmic contact layer 120b spaced apart from each other and separated from each other, are formed on the semiconductor layer 120 in the respective switching and driving regions (not shown) Is formed. At this time, a source electrode (not shown) formed in the switching region (not shown) is connected to the data line (not shown).

The gate electrode 105, the gate insulating film 110, and the source and drain electrodes 133 and 136, which are sequentially stacked in the switching and driving regions (not shown), are spaced apart from each other by switching and driving Thereby forming a thin film transistor (not shown).

In the first embodiment of the present invention, as described above, the semiconductor layer 120 having a bilayer structure composed of the active layer 120a of pure amorphous silicon and the ohmic contact layer 120b of the impurity amorphous silicon is provided (Not shown, DTr) are provided in the organic EL device according to the second embodiment of the present invention. However, in the organic EL device according to the second embodiment of the present invention, The semiconductor layer 119 of the switching and driving thin film transistor (not shown) may be formed of an amorphous silicon or an oxide semiconductor material such as indium gallium zinc oxide (IGZO), which is an oxide of zinc oxide (ZnO) , ZTO (Zinc Tin Oxide), and ZIO (Zinc Indium Oxide). The oxide semiconductor layer 119 may have a single layer structure.

At this time, in the case of a switching and driving thin film transistor (DTr) including the oxide semiconductor layer 119, an etch stopper 125 made of an insulating material is further provided at the center of the oxide semiconductor layer 119 And the source and drain electrodes 133 and 136 are spaced from each other on the etch stopper 125 and are in contact with the ends of the respective oxide semiconductor layers 119 exposed to the outside of the etch stopper 125 .

In the case of the organic electroluminescent device 101 according to the second embodiment of the present invention, only the configuration of the switching and driving thin film transistors (not shown) is different from that of the first embodiment, Since the elements have the same configuration as that of the first embodiment, the configuration of the organic EL device 101 according to the first embodiment will be described below with reference to FIG.

 A passivation layer 140 having a drain contact hole 143 exposing the drain electrode 136 of the driving thin film transistor DTr is formed on the switching and driving thin film transistor (not shown) (DTr).

The protective layer 140 is in contact with the drain electrode 136 of the driving thin film transistor DTr through the drain contact hole 143 and has a relatively large work function value , A first electrode 147 having a single layer structure made of a transparent conductive material having a work function value of about 4.8 eV to 5.2 eV, for example, indium-tin-oxide (ITO) is formed.

In addition, as described above, the first electrode 147 is formed of a transparent conductive material having a relatively high work function value and overlaps the edge of the first electrode 147 serving as an anode electrode, A bank 150 is formed at the boundary.

An organic light emitting layer 155 is formed on the first electrode 147 in each pixel region P surrounded by the bank 150. At this time, the organic light emitting layer 155 may be a single layer made of an organic light emitting material, or may have a multi-layer structure to enhance the light emitting efficiency.

When the organic light emitting layer 155 has a multilayer structure, a hole injection layer 155a, a hole transporting layer 155b, and a hole transporting layer 155b are sequentially formed from above the first electrode 147 serving as the anode electrode, Layer structure of an electron injection layer 155b, an emitting material layer 155c, an electron transporting layer 155d and an electron injection layer 155e, Or a hole transporting layer 155b, an emitting material layer 155c, an electron transporting layer 155d and an electron injection layer 155e, Layer structure of a hole transporting layer 155b, an emitting material layer 155c, and an electron transporting layer 155d. In the drawing, for example, the organic light emitting layer 155 has a five-layer structure.

At this time, the hole injection layer 155a functions to smoothly inject holes from the first electrode 147 serving as an anode electrode into the organic light emitting material layer 155c, and CuPc (cupper phthalocyanine ), PEDOT (poly (3,4) -ethylenedioxythiophene), PANI (polyaniline) and NPD (N, N-dinaphthyl-N, N'-diphenyl benzidine).

Also, the hole transport layer 155b serves to smoothly transport holes, and can be formed by using NPD (N-dinaphthyl-N, N'-diphenylbenzidine), TPD (N, N'- N, N'-bis- (phenyl) -benzidine), s-TAD and MTDATA (4,4 ', 4 "-tris Two or more materials may be mixed.

The electron transport layer 155d serves to smooth the transport of electrons and may be formed of one or more materials selected from Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq and SAlq Lt; / RTI >

Finally, the electron injection layer 155e serves to smooth the injection of electrons, and one or two or more materials selected from Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq, Can be made in a mixed state.

Next, the organic luminescent layer 155 and the bank 150 serve as a cathode electrode on the entire surface of the display region, and an average work function value of the first electrode 147 serves as an anode electrode. (Al), an aluminum alloy (AlNd), silver (Ag), magnesium (Mg), gold (Au), or the like having a work function value of about 4.2 eV to 4.9 eV and having opaque properties, (Au), and an aluminum magnesium alloy (AlMg).

At this time, the first and second electrodes 147 and 158 and the organic light emitting layer 155 formed therebetween form an organic light emitting diode (E).

A second substrate 170 for encapsulation corresponding to the first substrate 102 provided with the organic electroluminescent diode E according to the first and second embodiments of the present invention having the above- And is spaced apart from the substrate 102.

The first substrate 102 and the second substrate 170 are provided with an adhesive agent (not shown) made of a sealant or a frit along the edges thereof. The first substrate 102 and the second substrate 170 are adhered to each other to maintain a panel state. At this time, a vacuum state is formed between the first substrate 102 and the second substrate 170 which are spaced apart from each other, or an inert gas atmosphere may be obtained by being filled with an inert gas.

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

In addition, the first substrate 102 and the second substrate 170 are bonded together by the adhesive (not shown), and a face seal is provided on the entire surface of the first substrate 102, The second substrate 170 and the second substrate 170 may be joined together.

Meanwhile, the organic electroluminescent device 101 according to the first embodiment of the present invention has a second substrate 170 for encapsulation spaced apart from the first substrate 102 However, as a modification, the second substrate 170 may be configured to contact the second electrode 158 provided on the uppermost layer of the first substrate 102 in the form of a film including an adhesive layer.

Although not shown in the drawing, according to another embodiment of the present invention, an organic insulating film (not shown) or an inorganic insulating film 162 is further provided on the second electrode 158 to form a capping film (not shown) And the organic insulating film (not shown) or the inorganic insulating film 162 may be used as an encapsulation film. In this case, the second substrate 170 may be omitted.

The organic electroluminescent device 101 according to the first and second embodiments of the present invention having the above-described structure and the modified example thereof may be a bottom gate type (FIG. 4) using the amorphous silicon or the oxide semiconductor material as the semiconductor layer 120 (DTr in Fig. 1) having polysilicon as a semiconductor layer (13 in Fig. 1) by using a thin film transistor and constituting it as a switching and driving thin film transistor (not shown, DTr) Contrast (1 in FIG. 1) Since the crystallization process of irradiating the laser beam for forming the semiconductor layer of the polysilicon (13 in FIG. 1) is not required, the defective stain due to the laser beam irradiation at the large- It is possible to provide an organic electroluminescent device having a large area.

Furthermore, the organic electroluminescent device 101 according to the first and second embodiments of the present invention includes a top gate type switching and driving thin film transistor (not shown in FIG. 1 The manufacturing process of the thin film transistor can be simplified in comparison with the conventional organic electroluminescent device (1 in FIG. 1) having the DTr of FIG. 1, thereby improving the productivity per unit time and further reducing the manufacturing cost.

The organic electroluminescent device 101 according to the first and second embodiments of the present invention includes a buffer layer 103 provided on the inner surface of the first substrate 102 to emit light toward the first substrate 102 In the case of adopting the bottom emission type, the reflectance of the external light by the gate wiring (not shown) and the gate electrode 105 is reduced to improve the ambient contrast ratio.

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

101: organic electroluminescent device 102: first substrate
103: buffer layer 105: gate electrode
110: gate insulating film 120: semiconductor layer (of amorphous silicon)
120a: active layer 120b: ohmic contact layer
133: source electrode 136: drain electrode
140: protective layer 143: drain contact hole
147: first electrode 150: bank
155: organic light emitting layer 155a: hole injection layer
155b: hole transport layer 155c: organic light emitting material layer
155d: electron transport layer 155e: electron injection layer
158: second electrode 170: second substrate
DA: driving region DTr: driving thin film transistor
P: pixel area

Claims (12)

A first substrate on which a display region having a plurality of pixel regions is defined;
A buffer layer formed on the entire surface of the first substrate;
A bottom gate type switching thin film transistor and a driving thin film transistor formed in the respective pixel regions on the buffer layer;
A first electrode formed in each pixel region in contact with a drain electrode of the driving thin film transistor;
An organic light emitting layer formed on the first electrode;
And a second electrode formed on the entire surface of the display region above the organic light emitting layer,
Wherein the buffer layer comprises silicon oxide (SiO2) alone or silicon nitride (SiNx) only, and each of the switching thin film transistor and the driving thin film transistor includes a gate electrode directly above the buffer layer,
Wherein the organic light emitting device is a bottom emission type in which light is emitted toward the first substrate side and external light reflected by the gate electrodes of the switching TFT and the driving TFT is canceled by the buffer layer, .


delete The method according to claim 1,
Wherein the bottom gate type switching thin film transistor and the driving thin film transistor are composed of a gate electrode, a gate insulating film, and a semiconductor layer, which are sequentially stacked on the buffer layer, and are separated from each other by a source electrode and a drain electrode.
The method of claim 3,
The semiconductor layer is made of an active layer of pure amorphous silicon and impurity amorphous silicon and has a double layer structure of spaced apart ohmic contact layers,
Or an oxide semiconductor material.
5. The method of claim 4,
In the case where the semiconductor layer is a single-layered semiconductor layer made of the oxide semiconductor material, an etch stopper made of an insulating material is provided at a central portion of the upper portion of the semiconductor layer, and the source electrode and the drain electrode are spaced apart from each other at an upper portion of the etch stopper Wherein the contact hole is in contact with the semiconductor layer exposed outside the etch stopper.
5. The method of claim 4,
Wherein the oxide semiconductor material is any one of indium gallium zinc oxide (IGZO), zinc tin oxide (ZTO), and zinc oxide (ZIO), which is an oxide of zinc oxide (ZnO).
The method according to claim 1,
The first electrode is made of indium-tin-oxide, which is a transparent conductive material,
Wherein the second electrode is made of at least one of aluminum (Al), an aluminum alloy (AlNd), silver (Ag), magnesium (Mg), gold (Au), aluminum magnesium alloy (AlMg) Light emitting element.


delete The method according to claim 1,
And at least one layer of a hole injection layer and a hole transporting layer is further provided between the organic light emitting layer and the first electrode,
Wherein at least one layer of an electron transporting layer and an electron injection layer is further provided between the organic light emitting layer and the second electrode.
The method of claim 3,
And a gate wiring connected to the gate electrode of the switching thin film transistor and extending in one direction is provided on the buffer layer,
And a power supply line connected to the source electrode of the switching thin film transistor and extending in parallel to the data line, the power line extending in parallel to the gate line and defining the pixel region, An electroluminescent device.
The method according to claim 1,
A second substrate facing the first substrate, or a capping film serving as a second substrate in contact with the second electrode.
12. The method of claim 11,
The second substrate may be made of glass or plastic,
And an adhesive is provided along the rim of the first and second substrates to form a sealed state and a vacuum state or an inert gas atmosphere is formed between the first substrate and the second substrate,
Wherein a front adhesive is provided between the first substrate and the second substrate and the first and second substrates are bonded together.

Images