KR20160050905A - Organic light emitting device - Google Patents

Abstract

According to an embodiment of the present invention, an organic light emitting device includes: first and second electrodes; first and second red light emitting units placed between the first and second electrodes, including first and second red light emitting layers, respectively, in a red sub pixel area, and formed by being laminated; first and second green light emitting units placed between the first and second electrodes, including first and second green light emitting layers, respectively, in a red sub pixel area, and formed as laminated; and first and second blue light emitting units placed between the first and second electrodes, including first and second green light emitting layers, respectively, in a red sub pixel area, and formed as laminated. The sum of the thicknesses of the first and second blue light emitting units is bigger than the sum of the thicknesses of the first and second red light emitting units and the sum of the thicknesses of the first and second green light emitting units. Therefore, the present invention is capable of reducing device defects and dark spot defects, caused by foreign substances.

Description

ORGANIC LIGHT EMITTING DEVICE

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device capable of reducing the occurrence of defects caused by foreign matter in an organic light emitting device.

The organic light emitting diode (OLED) is a self-luminous display device in which electrons and holes are injected into the light emitting layer from an anode for injecting electrons and an anode for injecting holes, And emits light when an exciton in which injected electrons and holes are coupled falls from an excited state to a ground state.

The organic light emitting display device includes a top emission type, a bottom emission type, and a dual emission type depending on a direction in which light is emitted, and a passive matrix type ) And active matrix (Active Matrix).

Unlike a liquid crystal display (LCD), an organic light emitting display does not require a separate light source, and can be manufactured in a light and thin shape. Further, the organic light emitting display device is not only advantageous from the viewpoint of power consumption by low voltage driving, but also excellent in color implementation, response speed, viewing angle, and contrast ratio (CR), and is being studied as a next generation display.

The number of pixels per unit area increases and a high luminance is required. However, since the unit area current (A) is limited by the light emitting structure of the organic light emitting display device, There is a problem that reliability is lowered and power consumption is increased.

Therefore, it is necessary to overcome the technical limitations of the luminous efficiency, life span and power consumption reduction of the organic light emitting device, which are factors that hinder the quality and productivity of the organic light emitting display device. Various studies have been conducted to develop organic light emitting devices capable of improving the viewing angle characteristics.

Various organic light emitting device structures have been proposed for improving the efficiency, lifetime, and power consumption of the organic light emitting device in order to improve the quality and productivity of the organic light emitting display device.

Accordingly, in order to realize not only an organic light emitting device structure in which one stack (one stack), that is, an electroluminescence unit (EL unit) is applied, but also an improved efficiency and lifetime characteristic, a plurality of stacks, That is, an organic light emitting device having a tandem structure using a stack of a plurality of light emitting units has been proposed.

1 is a view schematically showing the structure of a conventional organic light emitting diode 1000. As shown in FIG.

A conventional organic light emitting device 1000 shown in Fig. 1 comprises a first light emitting unit (1100, 1 ^st EL Unit) including a first organic light emitting layer between the first electrode 110 and second electrode 190 and the the organic light emitting device having a first light emitting unit 2 (1200, 2 ^nd EL unit) is laminated a second stack (stack) structure configured to include a second organic light emitting layer.

Referring to FIG. 1, a conventional organic light emitting diode 1000 includes a first electrode (not shown) formed on a substrate having a red sub pixel region Rp, a green sub pixel region Gp, and a blue sub pixel region Bp (110, anode) and a hole injection layer (115, hole injection layer: HIL ), a first hole transport layer ^{(120, 1 st hole transporting layer} : 1 st HTL), the first red light emitting layer ^{(130, 1 st red emission layer} : the first organic light emitting layer formed of a ^{1 st blue EML),: 1} st Red EML), a first green light-emitting layer ^{(131, 1 st green emission layer} : 1 st green EML) and the first blue light emitting layer (132, 1 ^st blue emission layer a first electron transport layer ^{(140, 1 st electron transporting layer} : 1 st ETL), a first charge generating layer ^{(150, 1 st charge generation layer} : N-CGL), a second charge generation layer (155, 2 ^nd charge generation layer : P-CGL), a second hole transport layer (160, 2 ^nd hole transporting layer: 2 ^nd HTL), the second red light emitting layer (170, 2 ^nd red emission layer: 2 ^nd red EML), a second green light-emitting layer (171, 2 ^nd Green emission layer: 2 ^nd Green EML) and the second blue light emitting layer ^{(172, 2 nd Blue emission layer} : 2 nd Blue EML) a second organic light emitting layer, a second electron transport layer (180, 2 ^nd electron transporting layer made of: 2 ^nd ETL A second electrode 190, and a capping layer 200 (CPL).

The organic light emitting device 1000 according to one embodiment of the present invention includes a first charge generation layer 150 that is an n-type charge generation layer located between the first light emitting unit 1100 and the second light emitting unit 1200, and a second charge generation layer 155 which is a p-type charge generation layer.

The conventional organic light emitting diode 1000 has a structure having an optical distance of 2 ^nd order in the red sub pixel region Rp, the green sub pixel region Gp and the blue sub pixel region Bp, The first subpixel region Bp including the first blue emission layer 132 in the blue subpixel region Bp emitting the shortest wavelength among the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp, The thickness of the blue light emitting unit should be low and the thickness of the hole transport layer 120 of the common layer should be low.

However, in the case where the thickness of the hole transport layer 120 is low, as the size of a particle that can be generated during the manufacturing process of the organic light emitting device becomes larger, the hole injection layer 115, the hole transport layer 120, The electron transport layer 140, the first charge generation layer 150, and the second charge generation layer 155, which are formed of the first green light emitting layer 130, the first green light emitting layer 131, and the first blue light emitting layer 132, The organic material layer including the organic material layer may invade foreign matter generated during the manufacturing process, and thus, the defective device or the progressive defect of the defect has occurred due to the deterioration of the organic material layer damaged by the foreign matter.

The inventors of the present invention have invented a novel organic light emitting device structure having improved durability against foreign substances that may occur during the manufacturing process in an organic light emitting device structure using a plurality of light emitting units stacked.

The object of the present invention is to provide an organic light emitting diode capable of reducing the occurrence of defects in a dark point due to foreign matter that may occur during a manufacturing process in an organic light emitting device.

The solutions according to the embodiments of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In the organic light emitting device structure using the stacking of a plurality of light emitting units according to an embodiment of the present invention, an organic light emitting device capable of lowering occurrence of a defect in a dark spot due to foreign matter that may occur during a manufacturing process is provided.

An organic light emitting diode according to an exemplary embodiment of the present invention includes a first electrode, a second electrode, a first electrode, and a second electrode, which are disposed between the first electrode and the second electrode and include first and second red light- 1 and the second red light emitting unit and the first and second green light emitting units and the first and second green light emitting units which are located between the first and second electrodes and which include first and second green light emitting layers in the green sub pixel region, And a second blue light emitting unit which is disposed between the first electrode and the second electrode and includes first and second blue light emitting layers in the blue sub pixel region and is stacked, and the sum of thicknesses of the first and second blue light emitting layers is Emitting layer is larger than the sum of the thicknesses of the first and second red light-emitting layers and larger than the sum of the thicknesses of the first and second green light-emitting layers.

The sum of the thicknesses of the first and second red luminescent layers may be greater than the sum of the thicknesses of the first and second green luminescent layers.

The distance between the first electrode and the second electrode in the blue sub pixel region is 3? / 2n,? Is the wavelength of light emitted in each sub pixel, and n is a position between the first electrode and the second electrode The average refractive index of the plurality of organic material layers.

And a hole transport layer disposed between the first electrode and the second electrode and disposed in common in the red, green, and blue sub pixel regions, and the thickness of the hole transport layer may be 400 to 1600 ANGSTROM.

A first charge generation layer and a second charge generation layer disposed between the first and second red light emitting units and between the first and second green light emitting units and between the first and second blue light emitting units .

An organic light emitting diode according to another embodiment of the present invention includes a first electrode, a second electrode, a first electrode and a second electrode, and the first and second red light emitting layers, The first and second green light emitting units and first and second green light emitting units which are located between the first and second red light emitting units and the first and second electrodes and which include first and second green light emitting layers in the green sub pixel region, And a first blue light emitting unit and a second blue light emitting unit located between the electrode and the second electrode and including first and second blue light emitting layers in a blue sub pixel area, And the sum is larger than the sum of the thicknesses of the first and second red luminescent layers and larger than the sum of the thicknesses of the first and second blue luminescent layers.

The sum of the thicknesses of the first and second blue light-emitting layers may be greater than the sum of the thicknesses of the first and second red light-emitting layers.

The distance between the first electrode and the second electrode in the green sub pixel area and the blue sub pixel area is 3? / 2n,? Is the wavelength of light emitted in each sub pixel, And the average refractive index of the plurality of organic material layers located between the two electrodes.

And a hole transport layer disposed between the first electrode and the second electrode and disposed in common in the red, green, and blue sub pixel regions, and the thickness of the hole transport layer may be 400 to 1600 ANGSTROM.

A first charge generation layer and a second charge generation layer disposed between the first and second red light emitting units and between the first and second green light emitting units and between the first and second blue light emitting units .

In a two stack structure organic light emitting device using a plurality of light emitting units according to an embodiment of the present invention, at least one of red (Rp), green (Gp) and blue (3 ^rd order) in the sub-pixel region of the organic light emitting device and the thickness of the hole transporting layer formed of the common layer is made high, 1 organic luminescent layer and the organic material layer containing the organic luminescent layer can be further spaced apart from each other, so that the occurrence of element defects and defects in a dark spot caused by foreign matter can be reduced.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

The scope of the claims is not limited by the matters described in the contents of the invention, as the contents of the invention described in the problems, the solutions to the problems and the effects to be solved do not specify essential features of the claims.

1 is a view schematically showing the structure of a conventional organic light emitting device.
2 is a view schematically showing the structure of an organic light emitting diode according to an embodiment of the present invention.
3 is a view schematically showing the structure of an organic light emitting diode according to another embodiment of the present invention.
4 is a diagram showing a result of evaluation of a defect of a dark spot in an organic light emitting device according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may be added unless "only" is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description. In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

Also, the first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

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

2 is a view schematically showing a structure of an organic light emitting diode 2000 according to an embodiment of the present invention.

2, an organic light emitting diode 2000 according to an exemplary embodiment of the present invention includes a substrate 200 on which a red subpixel region Rp, a green subpixel region Gp, and a blue subpixel region Bp are defined a first electrode (210, anode) is formed with a hole injection layer (215, hole injection layer: HIL), a first hole transport layer (220, 1 ^st hole transporting layer: 1 ^st HTL), the first red light emitting layer (230, 1 including ^{1 st blue EML): st Red} emission layer: 1 st Red EML), a first green light-emitting layer ^{(231, 1 st green emission layer} : 1 st green EML) and the first blue light emitting layer (232, 1 ^st blue emission layer the first organic light emitting layer, a first electron transport layer (240, 1 ^st electron transporting layer: 1 ^st ETL), a first charge generating layer ^{(250, 1 st charge generation layer} : N-CGL), a second charge generation layer (255 ^{, 2 nd charge generation layer: P} -CGL), a second hole transport layer ^{(260, 2 nd hole transporting layer} : 2 nd HTL), the second red light emitting layer ^{(270, 2 nd red emission layer} : 2 nd red EML), the 2 green light ^{(271, 2 nd Green emission layer} : 2 nd Green EML) and the second blue light emitting layer ^{(272, 2 nd Blue emission layer} : 2 nd Blue EML) a second organic light emitting layer, a second electron transport layer (280, 2 ^nd, including is configured to include the CPL): electron transporting layer: 2 nd ETL), a second electrode (290, cathode) and capping layers (300, capping layer.

2, an organic light emitting diode 2000 according to an exemplary embodiment of the present invention includes a hole injection layer 215, a first hole transport layer 220, and a second hole transport layer 220 between the first electrode 210 and the second electrode 290, A first organic light emitting layer including a first red light emitting layer 230, a first green light emitting layer 231 and a first blue light emitting layer 232, and a first electron transport layer 240, 1 ^st EL Unit).

The organic light emitting diode 2000 according to the exemplary embodiment of the present invention includes a second hole transport layer 260, a second red light emitting layer 270, a second green light emitting layer 270, and a second green light emitting layer 270 between the first electrode 210 and the second electrode 290. [ It is configured to include a second light emitting unit (2200, 2 ^nd EL unit) consisting of the luminescent layer 271 and the second blue light emitting layer 272, the second organic emission layer and a second electron transport layer 280 comprising a.

That is, the organic light emitting device 2000 according to the embodiment of the present invention is an organic light emitting device having a stack structure in which a first light emitting unit 2100 and a second light emitting unit 2200 are stacked.

The organic light emitting device 2000 according to the embodiment of the present invention further includes a first charge generation layer 250 which is an n-type charge generation layer and a second charge generation layer 250 which is a p-type charge generation layer between the first light emitting unit 2100 and the second light emitting unit 2200. [ And a second charge generation layer 255 which is a charge generation layer.

The organic light emitting device 2000 according to the exemplary embodiment of the present invention includes a hole injection layer 215, a first hole transport layer 220, a first red light emitting layer 230, and a first electron transport layer Rp in a red sub pixel region Rp. And a second red light emitting unit including a second red light emitting unit and a second hole transporting layer 260, a second red light emitting layer 270, and a second electron transporting layer 280.

The organic light emitting device 2000 according to an embodiment of the present invention may include a hole injection layer 215, a first hole transport layer 220, a first green light emitting layer 231, and a first electron transport layer And a second green light emitting unit including a second green light emitting unit and a second hole transporting layer 260, a second green light emitting layer 271, and a second electron transporting layer 280.

The organic light emitting device 2000 according to the embodiment of the present invention may include a hole injection layer 215, a first hole transport layer 220, a first blue light emitting layer 232, and a first electron transport layer And a second blue light emitting unit including a first blue light emitting unit and a second hole transporting layer 260, a second blue light emitting layer 272, and a second electron transporting layer 280.

In addition, in the organic light emitting display device including the organic light emitting diode according to the embodiment of the present invention, a gate wiring line and a data line crossing each other and defining pixel regions, And a switching thin film transistor connected to the gate wiring and the data wiring and a driving thin film transistor connected to the switching thin film transistor are disposed in each pixel region. A driving thin film transistor is connected to the first electrode 210 (anode).

Hereinafter, the structure of the organic light emitting diode 2000 according to the embodiment of the present invention will be described in more detail with reference to FIG.

The first electrode 210 is positioned on the substrate so as to correspond to both the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp defined on the substrate, have.

For example, a layer of a transparent conductive material having a high work function such as indium-tin-oxide (ITO) and a layer of a reflective material such as silver (Ag) or silver alloy .

The hole injection layer 215 is positioned on the first electrode 210 to correspond to both the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp.

The hole injecting layer 215 may function to smooth the injection of holes and may be formed of HATCN (1,4,5,8,9,11-hexaazatriphenylene-hexanitrile), CuPc (cupper phthalocyanine), PEDOT (poly , 4) -ethylenedioxythiophene, PANI (polyaniline) and NPD (N, N-dinaphthyl-N, N'-diphenylbenzidine).

The hole injection layer 215 may be formed by adding a p-type dopant to the material of the first hole transport layer 220. In this case, the hole injection layer 215 And the first hole transport layer 220 can be formed.

The first hole transport layer 220 and the second hole transport layer 260 are formed to correspond to both the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp, The second hole transport layer 260 is located on the hole injection layer 215 and the second hole transport layer 260 is located on the second charge generation layer 255.

The first hole transporting layer 220 and the second hole transporting layer 260 serve to smooth the transport of holes and may be made of NPD (N, N-dinaphthyl-N, N'-diphenylbenzidine), TPD (N, bis- (3-methylphenyl) -N, N'-bis- (phenyl) -benzidine, s-TAD and MTDATA (4,4 ' -triphenylamine), but the present invention is not limited thereto.

The first red light emitting layer 230 is located on the first hole transport layer 220 of the red sub pixel region Rp and the second red light emitting layer 270 is located on the second hole transport layer 260 of the red sub pixel region Rp ). The first red light emitting layer 230 and the second red light emitting layer 270 may include a light emitting material that emits red light, and the light emitting material may be formed using a phosphor or a fluorescent material.

More specifically, the first red light emitting layer 230 and the second red light emitting layer 270 include a host material including carbazole biphenyl (CBP) or mCP (1,3-bis (carbazol-9-yl) (1-phenylquinoline) acetylacetonate iridium), PQIr (acac) (bis (1-phenylquinoline) acetylacetonate iridium), PQIr (t-phenylquinoline) iridium) and PtOEP (octaethylporphyrin platinum) (DBM) 3 (Phen) or perylene, but the present invention is not limited thereto.

The first green light emitting layer 231 is located on the first hole transport layer 220 of the green sub pixel region Gp and the second green light emitting layer 271 is located on the second hole transport layer 260 of the green sub pixel region Gp ). The first green light emitting layer 231 and the second green light emitting layer 271 may include a light emitting material that emits green light, and the light emitting material may be formed using a phosphor or a fluorescent material.

More specifically, the first green light emitting layer 231 and the second green light emitting layer 271 include a host material including CBP or mCP and include Ir (ppy) 3 (fac tris (2-phenylpyridine) iridium) complex, and the phosphorescent material may include Alq3 (tris (8-hydroxyquinolino) aluminum), but not limited thereto.

The first blue light emitting layer 232 is located on the first hole transport layer 220 of the blue sub pixel region Bp and the second blue light emitting layer 272 is located on the second hole transport layer 260 of the blue sub pixel region Bp ). The first blue light emitting layer 232 and the second blue light emitting layer 272 may include a light emitting material that emits blue light, and the light emitting material may be formed using a phosphor or a fluorescent material.

More specifically, the first blue light-emitting layer 232 and the second blue light-emitting layer 272 include a host material including CBP or mCP, and a phosphorescent material containing a dopant material including (4,6-F2ppy) 2Irpic Lt; / RTI > The fluorescent material may include any one selected from the group consisting of spiro-DPVBi, spiro-6P, distyrylbenzene (DSB), distyrylarylene (DSA), PFO polymer and PPV polymer. It does not.

The first electron transport layer 240 is formed to correspond to both the red subpixel region Rp, the green subpixel region Gp and the blue subpixel region Bp and the first red emission layer 230 on the first green light emitting layer 231 of the green sub pixel region Gp and on the first blue light emitting layer 232 of the blue sub pixel region Bp.

The second electron transport layer 280 is formed to correspond to both the red subpixel region Rp, the green subpixel region Gp and the blue subpixel region Bp, Is located on the second green light emitting layer 271 of the green sub pixel region Gp and on the second blue light emitting layer 272 of the blue sub pixel region Bp.

The first electron transport layer 240 and the second electron transport layer 280 may serve as transport and injection electrons and the first electron transport layer 240 and the second electron transport layer 280 may have electron transport properties . ≪ / RTI >

The first electron transporting layer 240 and the second electron transporting layer 280 serve to smooth the transport of electrons and include Alq3 (tris (8-hydroxyquinolino) aluminum), PBD (2- (4-biphenylyl) (4-tert-butylpheny) -1,3,4oxadiazole), TAZ, spiro-PBD, BAlq, and SAlq. However, the present invention is not limited thereto.

Further, an electron injection layer (EIL) may be additionally formed on the second electron transport layer 280 separately.

The electron injection layer (EIL) is composed of Alq3 (tris (8-hydroxyquinolino) aluminum), PBD (2- (4-biphenylyl) -5- , BAlq, or SAlq, but is not limited thereto. In addition, the electron injection layer (EIL) can be omitted.

Here, the structure is not limited according to the embodiment of the present invention, and the hole injection layer 215, the first and second hole transporting layers 220 and 260, the first and second electron transporting layers 240 and 280, At least one of the electron injection layers (EIL) may be omitted. The formation of the hole injection layer 215, the first and second hole transporting layers 220 and 260, the first and second electron transporting layers 240 and 280, and the electron injection layer (EIL) It is possible.

The first charge generation layer 250 is located on the first electron transport layer 240 to correspond to both the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp.

The second charge generation layer 255 is located on the first charge generation layer 250 to correspond to both the red subpixel region Rp, the green subpixel region Gp and the blue subpixel region Bp.

The first charge generation layer 250 and the second charge generation layer 255 are formed on the first hole injection layer 215, the first hole transport layer 220, the first red emission layer 230, the first green emission layer 231, The first light emitting unit 2100 and the second hole transporting layer 260, the second red light emitting layer 270, and the second red light emitting layer 270, which are composed of the first organic light emitting layer including the first blue light emitting layer 232 and the first electron transporting layer 240, The first light emitting unit 2100 is positioned between the second light emitting unit 2200 composed of the second organic light emitting layer including the green light emitting layer 271 and the second blue light emitting layer 272 and the second electron transporting layer 280, And the second light emitting unit 2200. The first light emitting unit 2200 and the second light emitting unit 2200 are connected to each other.

The first charge generating layer 250 includes an n-type charge generating layer (n-CGL) for assisting injection of electrons into the first red light emitting unit, the first green light emitting unit and the first blue light emitting unit of the first light emitting unit 2100, And the second charge generating layer 265 serves as a second red light emitting unit, a second green light emitting unit and a second blue light emitting unit of the second light emitting unit 2200, (p-CGL).

More specifically, the first charge generating layer 250 serves as an n-type charge generating layer (n-CGL) serving as an electron injecting layer, and may be formed of an alkali metal, an alkali metal compound, It is possible to form a compound. For example, it is formed of n-type (n-type) doped mixed dopant (dopant), such as lithium (Li) in the material, such as anthracene derivatives, but not limited to these.

The second charge generating layer 255 serves as a p-type charge generating layer (p-CGL) serving as a hole injecting layer and is a single layer of a p-type material such as HATCN or F4-TCNQ But is not limited thereto.

The second electrode 290 is located on the second electron transport layer 280. For example, the second electrode 290 may be formed of an alloy of magnesium and silver (Mg: Ag) and may have a transflective property. That is, the light emitted from the organic light emitting layer is displayed to the outside through the second electrode 290. Since the second electrode 290 has a transflective property, a part of the light is directed toward the first electrode 210 do.

The first electrode 210 and the second electrode 290 are formed by a micro cavity effect in which repetitive reflection occurs between the first electrode 210 and the second electrode 290 serving as a reflective layer, The light is repeatedly reflected in the cavity of the light emitting device, thereby increasing the light efficiency.

In addition, it is also possible that the first electrode 210 is formed as a transmissive electrode, the second electrode 290 is formed as a reflective electrode, and light from the organic light emitting layer is displayed externally through the first electrode 210.

The capping layer 300 is located on the second electrode 290. The capping layer 300 is formed to increase the light extracting effect of the organic light emitting device. The capping layer 300 includes first and second hole transporting layers 220 and 260, first and second electron transporting layers 240 and 280, And the host material of the second red light emitting layers 230 and 270, the first and second green light emitting layers 231 and 271, and the first and second blue light emitting layers 232 and 272. Further, the capping layer 300 can be omitted.

In the structure of the organic light emitting device, in order for each light generated in the sub-pixels having different wavelengths constituting one pixel to generate a micro-cavity effect, the organic light emitting device having the different light emitting wavelength Light generated when the micro cavity length or depth becomes an integer multiple of the wavelength of light emitted can be amplified within the micro cavity distance and the luminous efficiency can be improved.

In order to obtain the above-mentioned micro-cavity effect in the organic light emitting device, the condition of m? = 2nd must be satisfied. In other words, in order to obtain the micro-cavity effect, the distance between the first electrode and the second electrode, that is, the micro-cavity distance d, should be set to an integral multiple (m) of? / 2n. Where m is the order,? Is the wavelength of the light emitted by each sub-pixel, n is the average refractive index of a plurality of organic material layers located between the first and second electrodes in each sub-pixel, and d is Means the distance between the first electrode and the second electrode, that is, the micro-cavity distance. The plurality of organic material layers disposed between the first electrode and the second electrode may include a hole injecting layer (HIL), a hole transporting layer (HTL), a light emitting layer (EML), a charge generating layer (CGL), an electron transporting layer But not limited to, an injection layer (EIL).

When the micro-cavity distance d is one times the wavelength of light emitted (that is, m = 1), it is referred to as an organic light-emitting device having an optical distance of 1 ^st order, and the micro- (I.e., m = 2), the organic light emitting device is referred to as an organic light emitting device having an optical distance of 2 ^nd order. In addition, when the micro cavity distance is three times the wavelength of the light emitted (that is, m = 3) Is referred to as an organic light emitting element having an optical distance of 3 ^rd order.

1, the first red light emitting layer 130 and the second red light emitting layer 130 are formed in the red sub pixel region Rp between the first electrode 110 and the second electrode 190, The first green light emitting layer 131 and the second green light emitting layer 171 are formed in the green sub pixel region Gp and the first blue light emitting layer 132 and the second blue light emitting layer (I.e., m = 2) of the light emitted by the first electrode 110 and the second electrode 190 in all the sub pixel regions, that is, has a second organic light emitting device structure having an optical distance ^nd order (order) is set so as to satisfy n.

However, in the case of the conventional organic light emitting diode 1000, a structure having a 2 ^nd order optical distance in both the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp has a structure The thickness of the first blue light emitting unit including the first blue light emitting layer 132 must be reduced in the blue sub pixel region Bp emitting the shortest wavelength. Therefore, the thickness of the hole transport layer 120, which is a common layer, Should be low.

However, when the thickness of the hole transport layer 120 is low, the larger the particle size that can be generated during the manufacturing process of the organic light emitting device, the more the hole injection layer 115, the hole transport layer 120, , The electron transport layer 140, the first charge generating layer 150, and the second charge generating layer 155 can be invaded by the organic material layer during the manufacturing process, A device failure or a progressive defect of a dark spot is caused by a decrease in the performance of the organic material layer.

On the other hand, the organic light emitting device 2000 according to the embodiment of the present invention, when compared with the conventional organic light emitting device 1000, has a structure in which the first blue light emitting layer 2000 is formed to have an optical distance of 3 ^rd order in the blue sub- The thickness of the hole transport layer 220 and the thickness of the second blue light emitting layer 272 may be increased and the thickness of the hole transport layer 220 may be increased.

More specifically, in the organic light emitting device 2000 according to the embodiment of the present invention, the thicknesses of the first blue light emitting layer 232 and the second blue light emitting layer 272 in the blue sub pixel region Bp are different from that of the conventional structure, The first red light emitting layer 230 and the second red light emitting layer 270 of the green subpixel region Gp and the first green light emitting layer 231 and the second green light emitting layer 271 of the green subpixel region Gp are formed higher, The hole transport layer 220 is formed to have a high thickness so that the distance d between the first electrode 210 and the second electrode 290 in the blue sub pixel area Bp is three times the wavelength of light emitted = 3), that is, an optical distance of order 3 ^rd set to satisfy 3? / 2n.

The sum of the thicknesses of the first blue light emitting layer 232 and the second blue light emitting layer 272 in the organic light emitting device 2000 according to the exemplary embodiment of the present invention is the sum of the thicknesses of the first red light emitting layer 230 and the second red light emitting layer 270, The thickness of the first green light emitting layer 231 and the thickness of the second green light emitting layer 271 may be larger than the sum of the thicknesses of the first green light emitting layer 231 and the second green light emitting layer 271. [

In the case of the organic light emitting device 2000 according to the embodiment of the present invention, the sum of the thicknesses of the first red light emitting layer 230 and the second red light emitting layer 270 is the sum of the thicknesses of the first green light emitting layer 231 and the second green light emitting layer 271 ) Of the thickness of the film.

In the case of the organic light emitting diode 2000 according to the embodiment of the present invention, the hole transport layer 220 has a thickness of 400 to 1600 angstroms, which is larger than that of the conventional art, so as to have an optical distance of 3 ^rd order in the blue sub- Lt; / RTI >

In other words, in the organic light emitting device 2000 according to the embodiment of the present invention, 3 ^rd (3 ^rd ) in the blue sub-pixel region Bp of the red sub pixel region Rp, the green sub pixel region Gp, And the thickness of the hole transport layer 220 formed as a common layer is increased to increase the thickness of the first red light emission layer 220 formed on the hole transport layer 220 from the foreign matter that may be generated during the manufacturing process of the organic light emitting device 220. [ The first organic light emitting layer composed of the first green light emitting layer 230, the first green light emitting layer 231 and the first blue light emitting layer 232 and the organic material layer including the first organic light emitting layer can be further separated, The occurrence of defects can be reduced.

3 is a view schematically showing the structure of an organic light emitting diode 3000 according to another embodiment of the present invention.

In the description of the organic light emitting device 3000 according to another embodiment of the present invention, description of the same or corresponding components to those of the organic light emitting device 2000 according to the embodiment of the present invention described above will be omitted.

3, an organic light emitting diode 3000 according to another embodiment of the present invention includes a substrate 300 on which a red subpixel region Rp, a green subpixel region Gp, and a blue subpixel region Bp are defined a first electrode (310, anode) and the hole injection layer formed on the (315, hole injection layer: HIL), a first hole transport layer (320, 1 ^st hole transporting layer: 1 ^st HTL), the first red light emitting layer (330, ^{1 st Red emission layer: 1 st} Red EML), a first green light-emitting layer ^{(331, 1 st green emission layer} : 1 st green EML) and the first blue light emitting layer ^{(332, 1 st blue emission layer} : 1 st blue EML) the the first organic light emitting layer, a first electron transport layer comprising (340, 1 ^st electron transporting layer: 1 ^st ETL), a first charge generating layer ^{(350, 1 st charge generation layer} : N-CGL), a second charge generation layer ( ^{355, 2 nd charge generation layer:} P-CGL), a second hole transport layer ^{(360, 2 nd hole transporting layer} : 2 nd HTL), the second red light emitting layer ^{(370, 2 nd red emission layer} : 2 nd red EML), Second green Gwangcheung (371, 2 ^nd Green emission layer: 2 ^nd Green EML) and the second blue light emitting layer (372, 2 ^nd Blue emission layer: 2 ^nd Blue EML) a second organic light emitting layer, a second electron transport layer (380, 2, including is configured to include the ^{CPL): nd electron transporting layer:} 2 nd ETL), a second electrode (390, cathode) and capping layers (400, capping layer.

3, an organic light emitting diode 3000 according to another exemplary embodiment of the present invention includes a first electrode 310 and a second electrode 390, and a hole injection layer 315, a first hole transport layer A first organic emission layer 3100 including a first red emission layer 320, a first red emission layer 330, a first green emission layer 331, and a first blue emission layer 332, and a first electron transport layer 340. , 1 ^st EL Unit).

The organic light emitting diode 3000 according to another embodiment of the present invention may further include a second hole transport layer 360, a second red light emitting layer 370, a second red light emitting layer 370, and a second red light emitting layer 370 between the first electrode 310 and the second electrode 390, It is configured to include a second light emitting unit (3200, 2 ^nd EL unit) consisting of a second organic emission layer and a second electron transport layer 380 comprises the green luminescent layer 371 and the second blue light emitting layer (372).

That is, the organic light emitting device 3000 according to another embodiment of the present invention is an organic light emitting device having a stack structure in which a first light emitting unit 3100 and a second light emitting unit 3200 are stacked.

The organic light emitting device 3000 according to another embodiment of the present invention may further include a first charge generation layer 350 and an n < th > charge generation layer 350 between the first light emitting unit 3100 and the second light emitting unit 3200, And a second charge generation layer 355 which is a charge generation layer.

The organic light emitting diode 3000 according to another embodiment of the present invention may include a hole injection layer 315, a first hole transport layer 320, a first red light emitting layer 330, and a first electron transport layer 320 in a red sub pixel region Rp. And a second red light emitting unit including a first red light emitting unit and a second hole transporting layer 360, a second red light emitting layer 370, and a second electron transporting layer 380 including a light emitting layer 340,

The organic light emitting device 3000 according to another embodiment of the present invention may include a hole injection layer 315, a first hole transport layer 320, a first green light emitting layer 331, and a first electron And a second green light emitting unit including a first green light emitting unit and a second hole transporting layer 360, a second green light emitting layer 371, and a second electron transporting layer 380 including a light emitting layer 340,

The organic light emitting device 3000 according to another embodiment of the present invention may include a hole injection layer 315, a first hole transport layer 320, a first blue light emitting layer 332, and a first electron transport layer 320 in a blue sub pixel region Bp. And a second blue light emitting unit including a first blue light emitting unit and a second hole transporting layer 360, a second blue light emitting layer 372, and a second electron transporting layer 380 including a light emitting layer 340,

The organic light emitting device 3000 according to another embodiment of the present invention may have a structure of a 3 ^rd order in the green subpixel region Gp and the blue subpixel region Bp, The thicknesses of the first green light emitting layer 331 and the second green light emitting layer 371 and the thicknesses of the first blue light emitting layer 332 and the second blue light emitting layer 372 are increased to have an optical distance, The thickness can be increased.

More specifically, the organic light emitting diode 3000 according to another embodiment of the present invention includes a first green light emitting layer 331 and a second green light emitting layer 371 in a red sub pixel region (green pixel region) The thicknesses of the first blue light emitting layer 332 and the second blue light emitting layer 372 in the blue sub pixel region Bp are set to be higher than that of the first red light emitting layer 330 and the second red light emitting layer 370 of the red sub- Is formed higher than the first red light emitting layer 330 and the second red light emitting layer 370 of the sub pixel region Rp and the thickness of the hole transport layer 320 is formed to be higher than that of the green sub pixel region Gp, A distance d between the first electrode 310 and the second electrode 390 in the pixel region Bp is set to 3 ^rd (3 m), which is set to satisfy three times (3) Order optical distance.

The sum of the thicknesses of the first green light emitting layer 331 and the second green light emitting layer 371 in the organic light emitting device 3000 according to another embodiment of the present invention is the sum of the thicknesses of the first blue light emitting layer 332 and the second blue light emitting layer 372 And the thickness of the first red light emitting layer 330 and the thickness of the second red light emitting layer 370 may be greater than the sum of the thicknesses of the first red light emitting layer 330 and the second red light emitting layer 370.

In the organic light emitting device 3000 according to another embodiment of the present invention, the sum of the thicknesses of the first blue light emitting layer 332 and the second blue light emitting layer 372 is equal to the sum of the thicknesses of the first red light emitting layer 330 and the second red light emitting layer 370). ≪ / RTI >

In the case of the organic light emitting diode 3000 according to another embodiment of the present invention, the hole transport layer 320 may be formed to have an optical distance of 3 ^rd order in the green subpixel region Gp and the blue subpixel region Bp. The thickness may be in the range of 400 to 1600 angstroms.

That is, in the organic light emitting device 3000 according to another embodiment of the present invention, the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp among the green subpixel region Gp and the blue subpixel region Bp, By increasing the thickness of the hole transport layer 320 formed by the common layer so as to have an optical distance of 3 ^rd order in the sub pixel area Bp, the hole transport layer 320 The first organic light emitting layer including the first red light emitting layer 330, the first green light emitting layer 331, and the first blue light emitting layer 332 and the organic material layer including the first organic light emitting layer may be separated from each other, It is possible to reduce the occurrence of element defects and defective pixel defects caused by the defects.

4 is a diagram showing a result of evaluation of a defect of a dark spot in an organic light emitting device according to an embodiment of the present invention.

In the comparative example of FIG. 4, the results of the evaluation of the defect of a dark spot in the conventional organic light emitting device 1000 structure described above with reference to FIG. 1 are shown.

In the case of the first embodiment shown in Fig. 4, the results of the defect evaluation of the dark point in the structure of the organic light emitting diode 2000 according to the embodiment of the present invention described with reference to Fig. 2 are shown.

In the case of the second embodiment shown in FIG. 4, the results of the defect evaluation of the dark point in the structure of the organic light emitting diode 3000 according to another embodiment of the present invention described with reference to FIG. 3 are shown.

As can be seen from FIG. 4, in the comparative example, the dark point defect of about 4.3 levels in the red sub pixel region Rp, the dark point defect of 16.5 levels in the green sub pixel region Gp, , Which was about 52.5 points.

On the other hand, in the case of the embodiment 1, about 5.0 defective pixel points in the red sub pixel region Rp, 4.0 defective pixel points in the green sub pixel region Gp, about 15.0 defective pixels in the blue sub pixel region Bp And the occurrence of the defect of the dark spot in the green sub pixel area (Gp) and the blue sub pixel area (Bp) was reduced when compared with the comparative example.

Further, in the case of the second embodiment, the defect of the black dot of about 0.67 level in the red sub pixel area Rp, the defect of the black spot of the black sub pixel area Gp in the green sub pixel area Gp, The dark spot defect of the red subpixel region Rp, the green subpixel region Gp and the blue subpixel region Bp was further reduced in comparison with the comparative example and the first embodiment.

That is, in the organic light emitting device having the two stack structure using the stacking of the plurality of light emitting units according to the embodiment of the present invention, among the red subpixel region Rp, the green subpixel region Gp, and the blue subpixel region Bp (3 ^rd order) in the at least one sub-pixel region and the thickness of the hole transporting layer formed of the common layer is increased to form an organic light emitting layer formed on the upper portion of the hole transporting layer The first organic light emitting layer and the organic material layer including the first organic light emitting layer can be further separated from each other. Therefore, the occurrence of element defects and defect of a dark spot caused by foreign matter can be reduced.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

2000: Organic light emitting device
210: first electrode
215: Hole injection layer
220: First hole transport layer
230: first red light emitting layer
231: first green light emitting layer
232: first blue light emitting layer
240: first electron transporting layer
250: first charge generating layer
255: second charge generating layer
260: Second hole transport layer
270: second red light emitting layer
271: second green light emitting layer
272: second blue light emitting layer
280: second electron transport layer
290: second electrode
300: capping layer
2100: first light emitting unit
2200: second light emitting unit
Rp: Red sub pixel area
Gp: green sub pixel area
Bp: blue sub pixel area

Claims (10)

A first electrode and a second electrode;
First and second red light emitting units disposed between the first electrode and the second electrode, the first and second red light emitting units being formed by stacking first and second red light emitting layers in a red sub pixel region;
First and second green light emitting units which are disposed between the first electrode and the second electrode and are formed by stacking first and second green light emitting layers in a green sub pixel region, respectively; And
And a first blue light emitting unit and a second blue light emitting unit which are disposed between the first electrode and the second electrode and include first and second blue light emitting layers in a blue sub pixel region,
Wherein the sum of the thicknesses of the first and second blue light emitting layers is greater than the sum of the thicknesses of the first and second red light emitting layers and greater than the sum of the thicknesses of the first and second green light emitting layers.
The method according to claim 1,
Wherein a sum of thicknesses of the first and second red light emitting layers is greater than a sum of thicknesses of the first and second green light emitting layers.
3. The method of claim 2,
The distance between the first electrode and the second electrode of the blue sub pixel region is 3? / 2n, the? Is a wavelength of light emitted from each sub pixel, And the average refractive index of the plurality of organic material layers located between the second electrodes.
The method of claim 3,
And a hole transport layer disposed between the first electrode and the second electrode and disposed in common to the red, green, and blue sub-pixel regions, wherein the thickness of the hole transport layer is 400 to 1600 ANGSTROM.
The method according to claim 1,
A first charge generation layer and a second charge generation layer disposed between the first and second red light emission units and between the first and second green light emission units and between the first and second blue light emission units, Emitting layer.
A first electrode and a second electrode;
First and second red light emitting units disposed between the first electrode and the second electrode, the first and second red light emitting units being formed by stacking first and second red light emitting layers in a red sub pixel region;
First and second green light emitting units which are disposed between the first electrode and the second electrode and are formed by stacking first and second green light emitting layers in a green sub pixel region, respectively; And
And a first blue light emitting unit and a second blue light emitting unit which are disposed between the first electrode and the second electrode and include first and second blue light emitting layers in a blue sub pixel region,
Wherein the sum of the thicknesses of the first and second green light emitting layers is larger than the sum of the thicknesses of the first and second red light emitting layers and larger than the sum of the thicknesses of the first and second blue light emitting layers.
The method according to claim 6,
Wherein a sum of thicknesses of the first and second blue light-emitting layers is greater than a sum of thicknesses of the first and second red light-emitting layers.
8. The method of claim 7,
Wherein a distance between the first electrode and the second electrode in the green sub pixel region and the blue sub pixel region is 3? / 2n,? Is a wavelength of light emitted in each sub pixel, Is an average refractive index of a plurality of organic material layers located between the first electrode and the second electrode.
9. The method of claim 8,
And a hole transport layer disposed between the first electrode and the second electrode and disposed in common to the red, green, and blue sub-pixel regions, wherein the thickness of the hole transport layer is 400 to 1600 ANGSTROM.
The method according to claim 6,
A first charge generation layer and a second charge generation layer disposed between the first and second red light emission units and between the first and second green light emission units and between the first and second blue light emission units, Emitting layer.

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