KR20170065727A - Organic Light Emitting Diode Device - Google Patents

Abstract

The organic electroluminescent device according to the present invention includes at least two light emitting portions including a light emitting layer and a charge generating layer located between the light emitting portions, And compounds represented by formulas (3) and (4).

Description

[0001] The present invention relates to an organic light emitting diode (OLED)

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device capable of lowering a driving voltage of an organic electroluminescent device and improving efficiency and lifetime.

The image display device that realizes various information on the screen is a core technology of the information communication age and it is becoming thinner, lighter, more portable and higher performance. (LCD), a plasma display panel (PDP), an electro luminescent display (ELD), a field emission display (FED), and an organic light emitting diode (OLED) display device, Organic Light Emitting Diode) have been actively studied.

Among these organic electroluminescent devices, electrons and holes are paired when an electric charge is injected into the organic light emitting layer formed between the anode and the cathode, and then the light is emitted while disappearing. The organic electroluminescent device can be formed not only on a flexible transparent substrate such as a plastic but also can be driven at a lower voltage than a plasma display panel (plasma display panel) or an inorganic electroluminescence (EL) display, It has the advantage of being excellent in color. In particular, an organic electroluminescent device that implements white light is used for various purposes such as a thin light source, a backlight of a liquid crystal display device, or a full color display device employing a color filter.

In developing white organic electroluminescent devices, research and development are proceeding according to each method because it is important not only high efficiency and long life but also color stability due to color purity, current and voltage change, and ease of device manufacturing. There are various structures of white organic electroluminescent devices, and they can be largely divided into a single layer light emitting structure and a multilayer light emitting structure. Of these, a multilayered light-emitting structure in which a fluorescent blue light-emitting layer and a phosphorescent yellow light-emitting layer are tandemized for a long-life white device is mainly adopted.

Specifically, a phosphorescent light-emitting portion laminate structure in which a first light-emitting portion using a blue fluorescent element as a light-emitting layer and a second light-emitting portion structure using a yellow-green phosphor element as a light-emitting layer are laminated is used have. In such a white organic electroluminescent device, white light is realized by the mixing effect of the blue light emitted from the blue fluorescent element and the yellow light emitted from the yellow green phosphor element. Between the first light emitting portion and the second light emitting portion, a charge generation layer is provided which doubles the current efficiency generated in the light emitting layer and smoothes charge distribution. The charge generation layer is a layer for generating charges, that is, electrons and holes, in the inside, doubles the current efficiency generated in the light emitting layer, and smoothly distributes the charge, thereby preventing the drive voltage from rising.

However, the charge generation layer has a PN junction structure in which the N-type charge generation layer and the P-type charge generation layer have a PN junction structure. Due to the LUMO energy level difference between the N-type charge generation layer and the P- There is a problem that electrons are injected into the N-type charge generation layer and the driving voltage is increased. Further, when the N-type charge generation layer is doped with a dopant such as an alkali metal or an alkaline earth metal, the dopant diffuses into the P-type charge generation layer, thereby deteriorating the lifetime of the device.

The present invention provides an organic electroluminescent device capable of lowering a driving voltage and improving efficiency and lifetime.

In order to achieve the above object, an organic electroluminescent device according to the present invention includes at least two light emitting portions including a light emitting layer, and a charge generating layer located between the light emitting portions, 1 and 2, or compounds represented by the following formulas (3) and (4).

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

R ₁ , R ₂ , L ₁ , A ₁ and A ₂ are each independently selected from the group consisting of hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, , A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted C1 to C60 alkoxy group, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms; R ₁ and L _{1 each} independently represent hydrogen, deuterium, a halogen atom, Hydlock A carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, m and n are each 1 or 2, and the alkyl group,

In Formula 3 or 4, R ₁ , R ₂ , L ₁ , L ₂ , A ₁ , A ₂ , A ₃ and A ₄ each independently represent hydrogen, deuterium, a halogen atom, a hydroxyl group, A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted 6 to 6 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms, and R ₁ , R _2, L ₁ and L ₂ is selected from hydrogen, deuterium, Can not be selected from a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine, a hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, 1 or 2.

Each of R ₁ , R ₂ , L ₁ and L ₂ may independently be one of the compounds shown below.

Each of A ₁ , A ₂ , A ₃ and A ₄ may independently be one of the compounds shown below.

The charge generation layer includes a P-type charge generation layer and an N-type charge generation layer, and the compounds may be included in the N-type charge generation layer.

The N-type charge generation layer may further include a dopant, and the dopant may be one of an alkali metal, an alkaline earth metal, an alkali metal compound, an alkaline earth metal compound, an organic complex of an alkali metal, or an organic complex of an alkaline earth metal.

One of the at least two light emitting portions may be a light emitting portion emitting blue light and the other may be a light emitting portion emitting yellow green.

Also, an organic electroluminescent device according to an embodiment of the present invention includes at least two light emitting portions including a light emitting layer, and a charge generation layer located between the light emitting portions, 6 or compounds represented by the following formulas (7) and (8).

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

In Formula 5 or 6, R ₁ , R ₂ , L ₁ , A ₁ and A ₂ are each independently selected from the group consisting of hydrogen, deuterium, halogen atoms, hydroxyl groups, cyano groups, nitro groups, amino groups, , A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted C1 to C60 alkoxy group, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms; R ₁ and L _{1 each} independently represent hydrogen, deuterium, a halogen atom, Hydlock Group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, there can be selected from a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a non-salt, wherein m and n are each 1 or 2;

In Formula 7 or 8, R ₁ , R ₂ , L ₁ , L ₂ , A ₁ , A ₂ , A ₃ and A ₄ each independently represent hydrogen, deuterium, a halogen atom, a hydroxyl group, A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted 6 to 6 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms, and R ₁ , R _2, L ₁ and L ₂ is selected from hydrogen, deuterium, Can not be selected from a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine, a hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, 1 or 2.

Each of R ₁ , R ₂ , L ₁ and L ₂ may independently be one of the compounds shown below.

Each of A ₁ , A ₂ , A ₃ and A ₄ may independently be one of the compounds shown below.

The charge generation layer includes a P-type charge generation layer and an N-type charge generation layer, and the compounds may be included in the N-type charge generation layer.

The N-type charge generation layer may further include a dopant, and the dopant may be one of an alkali metal, an alkaline earth metal, an alkali metal compound, an alkaline earth metal compound, an organic complex of an alkali metal, or an organic complex of an alkaline earth metal.

One of the at least two light emitting portions may be a light emitting portion emitting blue light and the other may be a light emitting portion emitting yellow green.

The compounds of the present invention include compounds containing two or more electron-rich nitrogen (N) atoms, so that they have a high electron mobility and facilitate the injection of electrons. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

1 is a view illustrating an organic electroluminescent device according to a first embodiment of the present invention.
2 is an energy band diagram of an organic electroluminescent device.
3 is a view illustrating an organic electroluminescent device according to a second embodiment of the present invention.
FIG. 4 is a graph showing current densities according to drive voltages of devices manufactured according to Comparative Examples 1, 2, and 1 and 2. FIG.
5 is a graph showing efficiency according to luminance of devices manufactured according to Comparative Example 1, Comparative Example 2, Example 1 and Example 2 of the present invention.
6 is a graph showing the external quantum efficiency according to the luminance of the device manufactured according to Comparative Example 1, Comparative Example 2, Example 1 and Example 2 of the present invention.
FIG. 7 is a graph showing the luminance decreasing rate with time of the device manufactured according to Comparative Example 1, Comparative Example 2, Example 1 and Example 2 of the present invention. FIG.
8 is a graph showing current densities according to driving voltages of devices manufactured according to Comparative Example 3, Comparative Example 4, and Example 3 of the present invention.
9 is a graph showing efficiency according to luminance of the device manufactured according to Comparative Example 3, Comparative Example 4, and Example 3 of the present invention.
10 is a graph showing the external quantum efficiency according to the luminance of the device manufactured according to Comparative Example 3, Comparative Example 4, and Example 3 of the present invention.
11 is a graph showing the rate of decrease in luminance over time of the device manufactured according to Comparative Example 3, Comparative Example 4, and Example 3 of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

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. In the case where the word 'includes', 'having', 'done', etc. are used in this specification, other parts can 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.

In the case of a description of a temporal relationship, for example, if the temporal relationship is described by 'after', 'after', 'after', 'before', etc., May not be continuous unless they are not used.

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, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view illustrating an organic electroluminescent device according to a first embodiment of the present invention.

1, an organic electroluminescent device 100 according to the present invention includes a plurality of light emitting units ST1 and ST2 disposed between an anode 110 and a cathode 220 and a plurality of light emitting units ST1 and ST2 disposed between the light emitting units ST1 and ST2. And a formation layer 160.

The anode 110 may be one of indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO), which has high work function as an electrode for injecting holes. When the anode 110 is a reflective electrode, the anode 110 may further include a reflective layer formed of one of aluminum (Al), silver (Ag), and nickel (Ni) under the layer of one of ITO, IZO, or ZnO can do.

The first light emitting portion ST1 includes a first light emitting layer 140. The first light emitting layer 140 may emit red (R), green (G), or blue (B) light, and may be formed of a fluorescent material or a phosphorescent material. In this embodiment, it may be a blue light emitting layer emitting blue light. The blue light emitting layer includes one of a blue light emitting layer, a dark blue light emitting layer, and a sky blue light emitting layer. Alternatively, the first light emitting layer 140 may include a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a green light emitting layer.

The first light emitting portion ST1 includes a hole injection layer 120 and a first hole transport layer 130 between the anode 110 and the first light emitting layer 140, And a transport layer 150.

The hole injecting layer 120 may function to smoothly inject holes from the anode 110 into the first light emitting layer 140 and may be formed of cupper phthalocyanine (CuPc), poly (3,4) -ethylenedioxythiophene (PEDOT) , PANI (polyaniline) and NPD (N, N'-bis (naphthalene-1-yl) -N, N'-bis (phenyl) -2,2'-dimethylbenzidine) . The thickness of the hole injection layer 120 may be 1 to 150 nm. If the thickness of the hole injection layer 120 is 1 nm or more, hole injection characteristics can be improved. If the thickness of the hole injection layer 120 is 150 nm or less, an increase in the thickness of the hole injection layer 120 can be prevented. The hole injection layer 120 may not be included in the organic electroluminescent device depending on the structure and characteristics of the organic electroluminescent device.

The first hole transport layer 130 serves to smooth the transport of holes, and NPD (N, N'-bis (naphthalene-1-yl) -N, N'- -dimethylbenzidine), TPD (N, N'-bis (3-methylphenyl) -N, N'-bis -diphenylamino) -9,9'-spirofluorene and MTDATA (4,4 ', 4 "-Tris (N-3-methylphenyl-N-phenylamino) -triphenylamine). The thickness of the first hole transporting layer 130 may be 1 to 150 nm. If the thickness of the first hole transporting layer 130 is 1 nm or more, the hole transporting property may be improved. If the thickness of the first hole transporting layer 130 is 150 nm or less, 130 can be prevented from increasing and the rise of the driving voltage can be prevented.

The first electron transport layer 150 plays a role of facilitating the transport of electrons and includes Alq ₃ (tris (8-hydroxy quinolinato) aluminum), PBD (2- (4-biphenyl) -5- -butylphenyl) -1,3,4-oxadiazole), TAZ (3- (4-biphenyl) -4-phenyl-5-tert- 4-yl) - [1,3,5] triazine) and BAlq (Bis (2-methyl-8-quinolinolate) -4- (phenylphenolato) aluminum), but the present invention is not limited thereto. The first electron transport layer 150 may have a thickness of 1 to 150 nm. If the thickness of the first electron transporting layer 150 is 1 nm or more, the electron transporting property can be prevented from being lowered. If the thickness of the first electron transporting layer 150 is 150 nm or less, It is possible to prevent an increase in the thickness of the driving voltage and to prevent an increase in the driving voltage.

The first light emitting portion ST1 including the hole injection layer 120, the first hole transport layer 130, the first light emitting layer 140, and the first electron transport layer 150 is formed on the anode 110 . The hole injection layer 120 may not be included in the structure of the first light emitting portion ST1 depending on the structure and characteristics of the device.

A charge generation layer (CGL) 160 is disposed between the first light emitting portion ST1 and the second light emitting portion ST2. The first light emitting portion ST1 and the second light emitting portion ST2 are connected to each other by the charge generation layer 160. The charge generation layer 160 may be a PN junction charge generation layer in which an N-type charge generation layer 160N and a P-type charge generation layer 160P are bonded. At this time, the PN junction charge generation layer 160 generates charges or separates them into holes and electrons, and injects holes and electrons into the light emitting layer. That is, the N-type charge generation layer 160N transfers electrons to the first electron transporting layer 150, the first electron transporting layer 150 supplies electrons to the first light emitting layer 140 adjacent to the anode, The charge generation layer 160P transfers holes to the second hole transport layer 180 and supplies holes to the second light emitting layer 190 of the second light emitting portion ST2 to form the first light emitting layer 140, The light emitting efficiency of the light emitting device 190 can be further increased, and the driving voltage can also be lowered. Therefore, the charge generating layer 160 has a significant influence on the luminous efficiency and the driving voltage, which are characteristics of the organic electroluminescent device.

Therefore, the present inventors have conducted various experiments to improve the electron injection characteristics of the N-type charge generation layer. Through this experiment, it was recognized that the driving voltage increases when electrons injected into the N-type charge generation layer move to the electron transport layer due to the LUMO energy level difference between the electron transport layer and the N-type charge generation layer. Also, it was recognized that the driving voltage increases when the electrons injected into the P-type charge generation layer move to the N-type charge generation layer due to the LUMO energy level difference between the P-type charge generation layer and the N-type charge generation layer. Further, when the N-type charge generation layer is doped with a dopant of an alkali metal or an alkaline earth metal, the alkali metal or alkaline earth metal is diffused into the P-type charge generation layer to deteriorate the lifetime of the device. Therefore, the present inventors have introduced an N-type charge generation layer compound which can reduce the driving voltage and improve the lifetime through various experiments.

The present inventors have found that the energy barrier in the N-type charge generation layer can be reduced through various experiments of materials without affecting the lifetime or efficiency of the organic electroluminescent device and without increasing the driving voltage, And a compound capable of preventing diffusion of the dopant contained in the N-type charge generation layer has been developed. Therefore, in order to reduce the energy barrier of the N-type charge generating layer, the inventive compounds composed of structural isomers of electron mobility fast material have been introduced.

The compounds of the present invention include a core containing two or more electron-rich nitrogen (N) atoms, thereby facilitating electron injection with fast electron mobility. A core containing two or more electron-rich nitrogen (N) atoms introduced triazine or phenanthroline. In addition, the compounds of the present invention can be synthesized by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer, whereby the highest occupied molecular orbital (HOMO) energy level and lowest unoccupied molecular orbital energy levels can be used to reduce the energy barrier in the N-type charge generating layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Accordingly, the N-type charge generation layer 160N of the present invention includes the compounds represented by the following formulas (1) and (2) or the compounds represented by the following formulas (3) and (4)

[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

R ₁ , R ₂ , L ₁ , A ₁ and A ₂ are each independently selected from the group consisting of hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, , A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted C1 to C60 alkoxy group, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms. R ₁ and L ₁ are independently selected from the group consisting of hydrogen, deuterium, halogen atom, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazine, hydrazone, carboxyl group or salt thereof, sulfonic acid group or salt thereof, It can not be selected from salts. And m and n may be 1 or 2, respectively.

In Formula 3 or 4, R ₁ , R ₂ , L ₁ , L ₂ , A ₁ , A ₂ , A ₃ and A ₄ each independently represent hydrogen, deuterium, a halogen atom, a hydroxyl group, A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted 6 to 6 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, Substituted or unsubstituted aryloxy groups, substituted or unsubstituted arylthio groups having 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl groups having 2 to 60 carbon atoms. In this case, R _1, R _2, L ₁ and L ₂ is hydrogen, heavy hydrogen, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or Its salt, phosphate group or other salt. And m and n may be 1 or 2, respectively.

Each of R ₁ , R ₂ , L ₁ and L ₂ may independently be one of the compounds shown below.

Each of A ₁ , A ₂ , A ₃ and A ₄ may independently be one of the compounds shown below.

The N-type charge generation layer 160N may include the compounds represented by the following formulas (5) and (6) or the compounds represented by the following formulas (7) and (8).

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

In Formula 5 or 6, R ₁ , R ₂ , L ₁ , A ₁ and A ₂ are each independently selected from the group consisting of hydrogen, deuterium, halogen atoms, hydroxyl groups, cyano groups, nitro groups, amino groups, , A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted C1 to C60 alkoxy group, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms. R ₁ and L ₁ are independently selected from the group consisting of hydrogen, deuterium, halogen atom, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazine, hydrazone, carboxyl group or salt thereof, sulfonic acid group or salt thereof, It can not be selected from salts. And n and m may be 1 or 2, respectively.

In Formula 7 or 8, R ₁ , R ₂ , L ₁ , L ₂ , A ₁ , A ₂ , A ₃ and A ₄ each independently represent hydrogen, deuterium, a halogen atom, a hydroxyl group, A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted 6 to 6 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, Substituted or unsubstituted aryloxy groups, substituted or unsubstituted arylthio groups having 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl groups having 2 to 60 carbon atoms. In this case, R _1, R _2, L ₁ and L ₂ is hydrogen, heavy hydrogen, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or Its salt, phosphate group or other salt. And m and n may be 1 or 2, respectively.

Each of R ₁ , R ₂ , L ₁ and L ₂ may independently be one of the compounds shown below.

Each of A ₁ , A ₂ , A ₃ and A ₄ may independently be one of the compounds shown below.

The N-type charge generation layer 160N of the present invention may be a mixture of the compounds of the above-mentioned formulas 1 and 2, the compounds of the formulas 3 and 4, the compounds of the formulas 5 and 6, or the compounds of the formulas 7 and 8 have. That is, the structural isomers of the triazine compound may be mixed with each other or the structural isomers of the phenanthroline may be mixed with each other. The structural isomers have the same molecular formula but different chemical structures. In the present invention, the metatriazine compound and the paratriazine compound or the metaphenanthroline compound and the paraphenanthroline compound may be mixed. Compounds with a para structure have a large number of double bonds capable of resonance structure, resulting in a decrease in the π-π * spacing, thereby reducing the energy bandgap. The energy bandgap is smaller in the para-structure than in the meta-structure in compounds of the same molecular formula. A compound with a meta structure has the same or higher HOMO energy level and a higher LUMO energy level than a compound with a para structure. Thus, the present invention utilizes the HOMO and LUMO energy levels of the meta and para structures to form a step-like energy barrier in the N-type charge generation layer.

Referring to FIG. 2, the organic electroluminescent device of the present invention includes a hole transport layer, a P-type charge generation layer, an N-type charge generation layer, and an electron transport layer. The N-type charge generation layer supplies electrons to the adjacent electron transport layer and the P-type charge generation layer supplies holes to the adjacent hole transport layer. Generally, when electrons are transferred from the N-type charge generating layer to the electron transporting layer, the electron injection barrier is large and the driving voltage is increased. In addition, when electrons are transferred from the P-type charge generation layer to the N-type charge generation layer, the electron injection barrier is large and the driving voltage is increased. In the present invention, a meta-triazine and para-triazine compound or metaphenanthroline and a paraphenanthroline compound are mixed to form an N-type charge generation layer, whereby a step-like energy barrier can be formed in the N-type charge generation layer. The compound having a meta structure in the N-type charge generation layer is formed to have a higher LUMO energy level and a higher HOMO energy level than a compound having a para structure, and the para-structure compound is formed to have a lower LUMO energy level and a lower HOMO energy level than a meta structure compound . When electrons move from the LUMO energy level of the P-type charge generation layer to the LUMO energy level of the N-type charge generation layer, they can easily move to the N-type charge generation layer through the LUMO energy level of the low para structure. Further, when electrons move from the LUMO energy level of the N-type charge generation layer to the LUMO energy level of the electron transport layer, it is possible to easily move to the electron transport layer through the LUMO energy level of the high meta structure compound.

The present invention is not capable of mixing compounds of different molecular formulas, for example, compounds of formulas 1 and 3, formulas 1 and 4, formulas 2 and 3, or formulas 2 and 4. When materials having different molecular formulas, for example, different cores, are mixed together, grains of the same core are aggregated to form grains. Between the grain and the grain, traps that can trap electrons are generated, which hinders the movement of electrons, and the driving voltage can be raised. Accordingly, in the present invention, structural isomers of triazine compounds or structural isomers of phenanthroline are mixed with each other to form an N-type charge generation layer.

Further, in the N-type charge generation layer 160N, mixed compounds are formed at a constant volume ratio. For example, the N-type charge generating layer 160N may be formed in the same volume ratio or in different volume ratios of the mixed compounds. In the N-type charge generation layer 160N, the volume ratio of the compound having the meta structure to the compound having the para structure may be 0.1: 99.9 to 99.9: 0.1. That is, when the volume ratio of any one compound is increased from 0.1 to 99.9, the volume ratio of the other compound can be reduced from 99.9 to 0.1. Here, the volume ratio refers to the volume of a substance occupied by a substance in a certain layer, and the volume ratio is based on the sum of the volumes occupying the substance. In the present invention, the triazine compound having a meta structure has a higher electron mobility than that of a para-structure triazine compound, and the phenanthroline compound having a meta structure is faster than the phenanthrolone compound having a para structure, Structure compound. ≪ / RTI > Therefore, in the N-type charge generation layer 160N, the volume ratio of the compound of the meta structure is larger than the volume ratio of the compound of the para structure, so that the driving voltage of the N-type charge generation layer 160N can be lowered.

The above-mentioned compounds of the present invention include compounds containing two or more electron-rich nitrogen (N) atoms, so that they have a high electron mobility and facilitate the injection of electrons. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

The N-type charge generation layer 160N further includes a dopant. The dopant may further include any one of an alkali metal, an alkaline earth metal, an alkali metal compound, an alkaline earth metal compound, an organic complex of an alkali metal, or an organic complex of an alkaline earth metal.

The P-type charge generation layer 160P may be formed of a metal or a P-type doped organic material. The metal may be one or more of Al, Cu, Fe, Pb, Zn, Au, Pt, W, In, Mo, Ni and Ti. The P-type dopant used for the P-type doped organic material and the host material may use the following materials. For example, the P-type dopant may be F ₄ -TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanl-quinodemethane), derivatives of tetracyanoquinodimethane, iodine, FeCl ₃ , FeF _3, and SbCl ₅ . In addition, the host may be selected from the group consisting of NPB (N, N'-bis (naphthaen-1-yl) -N, N'- N'-bis (phenyl) -benzidine) and TNB (N, N, N ', N'-tetra-naphthalenyl-benzidine).

A second light emitting portion ST2 including a second hole transport layer 180, a second light emitting layer 190, a second electron transport layer 200, and an electron injection layer 210 is formed on the charge generation layer 160, .

The second light emitting portion ST2 includes a second light emitting layer 190. The second light emitting layer 190 may emit red (R), green (G), blue (B), or yellow (YG) light. In the present embodiment, it may be a light-emitting layer that emits yellow-green. The second light emitting layer 190 may have a single layer structure of a yellow-green light emitting layer or a green light emitting layer, or a multi-layer structure of a yellow light emitting layer and a green light emitting layer. The second light emitting layer 190 may include a yellow light emitting layer or a green light emitting layer or a yellow light emitting layer and a green light emitting layer or a yellow light emitting layer and a red light emitting layer, , Or a multilayer structure of a yellow-emitting layer and a red-emitting layer.

In this embodiment, a single layer structure of the second light emitting layer 190 that emits yellow green is described as an example. The second light emitting layer 190 may include at least one of CBP (4,4'-bis (carbazol-9-yl) biphenyl) or BAlq (Bis (2-methyl-8-quinolinolate) -4- And a phosphorescent yellow green dopant which emits yellow green. However, the present invention is not limited thereto.

The second light emitting portion ST2 includes a second hole transporting layer 180 between the charge generating layer 160 and the second light emitting layer 190 and a second electron transporting layer 200 And an electron injection layer 210. The second hole transport layer 180 and the second electron transport layer 200 may be the same as or different from the first hole transport layer 120 and the first electron transport layer 150 of the first light emitting portion ST1.

Therefore, the second light emitting portion ST2 including the second hole transport layer 180, the second light emitting layer 190, the second electron transport layer 200, and the electron injection layer 210 is formed on the charge generation layer 160 . A cathode 220 is provided on the second light emitting portion ST2 to constitute an organic electroluminescent device according to the first embodiment of the present invention.

As described above, the compounds of the present invention include a compound containing two or more electron-rich nitrogen (N) atoms, thereby facilitating the electron injection with high electron mobility. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

3 is a view illustrating an organic electroluminescent device according to a second embodiment of the present invention. In the following description, the same constituent elements as those of the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

3, the organic electroluminescent device 100 of the present invention includes a plurality of light emitting units ST1, ST2, and ST3 positioned between an anode 110 and a cathode 220, and a plurality of light emitting units ST1 and ST2 (ST3), and a second charge generation layer (230) located between the first charge generation layer (ST3) and the second charge generation layer (ST3). In the present embodiment, three light emitting portions are positioned between the anode 110 and the cathode 220. However, the present invention is not limited to this, and four or more light emitting portions may be provided between the anode 110 and the cathode 220 .

The first light emitting portion ST1 of the plurality of light emitting portions includes a first light emitting layer 140. The first light emitting layer 140 may emit light of any one of red, green, and blue. In this embodiment, the first light emitting layer 140 may be a blue light emitting layer emitting blue light. The blue light emitting layer includes one of a blue light emitting layer, a dark blue light emitting layer, and a sky blue light emitting layer. Alternatively, the first light emitting layer 140 may include a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a green light emitting layer.

The first light emitting portion ST1 includes a hole injection layer 120 and a first hole transport layer 130 between the anode 110 and the first light emitting layer 140, And an electron transporting layer (150). The first light emitting portion ST1 including the hole injection layer 120, the first hole transport layer 130, the first light emitting layer 140, and the first electron transport layer 150 is formed on the anode 110 . The hole injection layer 120 may not be included in the structure of the first light emitting portion ST1 depending on the structure and characteristics of the device.

The second light emitting portion ST2 including the second light emitting layer 190 is located on the first light emitting portion ST1. The second light-emitting layer 190 may emit light of one of red, green, blue, and yellow green. For example, the second light-emitting layer 190 may be a light-emitting layer that emits yellow-green in this embodiment. The second light emitting layer 190 may include a yellow-green light emitting layer or a green light emitting layer or a yellow-green light emitting layer and a green light emitting layer or a yellow light emitting layer and a red light emitting layer, A green light emitting layer and a red light emitting layer, or a multi-layered structure of a yellow light emitting layer and a red light emitting layer. The second light emitting portion ST2 further includes a second hole transport layer 180 on the first light emitting portion ST1 and a second electron transport layer 200 on the second light emitting layer 190. [ Accordingly, the second light emitting portion ST2 including the second hole transport layer 180, the second light emitting layer 190, and the second electron transport layer 200 is formed on the first light emitting portion ST2.

A first charge generation layer 160 is positioned between the first light emitting portion ST1 and the second light emitting portion ST2. The first charge generation layer 160 is a PN junction charge generation layer in which an N-type charge generation layer 160N and a P-type charge generation layer 160P are bonded to each other to generate charges or separate them into holes and electrons, Holes and electrons are injected into the second light emitting layer 140 and the second light emitting layer 190.

The N-type charge generation layer 160N is formed in the same manner as the N-type charge generation layer 160N of the first embodiment described above. The compounds of the present invention contained in the N-type charge generating layer 160N include compounds containing two or more electron-rich nitrogen (N) atoms, thereby facilitating electron injection with high electron mobility. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

And a third light emitting portion ST3 including a third light emitting layer 250 is disposed on the second light emitting portion ST2. The third light emitting layer 250 may emit light of one of red, green, and blue, and is made of a fluorescent material. For example, in this embodiment, it may be a blue light emitting layer emitting blue light. The blue light emitting layer includes one of a blue light emitting layer, a dark blue light emitting layer, and a sky blue light emitting layer. Alternatively, the third light emitting layer 250 may include a blue light emitting layer and a red light emitting layer, or a blue light emitting layer and a yellow-green light emitting layer, or a blue light emitting layer and a green light emitting layer.

The third light emitting portion ST3 includes a third hole transport layer 240 on the second light emitting portion ST2 and a third electron transport layer 260 and an electron injection layer 210 ).

A second charge generating layer 230 is positioned between the second light emitting portion ST2 and the third light emitting portion ST3. The second charge generating layer 230 is a PN junction charge generating layer in which an N-type charge generating layer 230N and a P-type charge generating layer 230P are bonded to each other to generate charges or separate them into holes and electrons, Holes and electrons are injected into the first light emitting layer 190 and the third light emitting layer 250.

The N-type charge generation layer 230N is formed in the same manner as the N-type charge generation layer 160N of the first charge generation layer 160 described above. The compounds of the present invention contained in the N-type charge generation layer 230N include a compound containing two or more electron-rich nitrogen (N) atoms, thereby facilitating the electron injection with high electron mobility. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

And a cathode 220 is provided on the third light emitting portion ST3 to constitute an organic electroluminescent device according to the second embodiment of the present invention.

In the second embodiment of the present invention described above, the N-type charge generation layer 160N of the first charge generation layer 160 and the N-type charge generation layer 230N of the second charge generation layer 230 are coated with the compound ≪ / RTI > However, the present invention includes the compound of the present invention in at least one of the N-type charge generation layer 160N of the first charge generation layer 160 and the N-type charge generation layer 230N of the second charge generation layer 230 You may.

The OLED display according to the second embodiment of the present invention can be applied to a top emission display device, a bottom emission display device, a dual emission display device, a vehicle lighting device . The vehicle lighting device may be, but is not limited to, one of headlights, high beams, taillights, brake lights, and back-up lights. Further, the organic light emitting diode display employing the organic electroluminescent device according to the second embodiment of the present invention may be applied to mobile, monitor, TV, and the like. In addition, the organic light emitting display device to which the organic electroluminescent device according to the second embodiment of the present invention is applied can be applied to a display device in which at least two light emitting layers of the first light emitting layer, the second light emitting layer and the third light emitting layer emit light of the same color have.

As described above, the compounds of the present invention include a compound containing two or more electron-rich nitrogen (N) atoms, thereby facilitating the electron injection with high electron mobility. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

Hereinafter, synthesis examples of the compounds of the present invention will be described in detail in the following examples. However, the following examples are illustrative of the present invention, but the present invention is not limited to the following examples.

1) Synthesis of compound TA_A01

(4,4,5,5-tetramethyl-1,3,2-dioxoborolen-2-yl) -4,6-diphenyl-1,3,5-triazine (2- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -4,6-diphenyl-1,3,5-triazine (5.00 g, 13.9 mmol), Intermediate B g, 11.6 mmol), tetrakistriphenylphosphine palladium (0) (Pd (PPh ₃ ) ₄ ) (0.53 g 0.46 mmol), 4 M potassium carbonate aqueous solution (10 ml) 30 ml of toluene and 10 ml of ethanol were added, and the mixture was stirred under reflux for 12 hours. After completion of the reaction, 50 ml of water (H ₂ O) was added and the mixture was stirred for 3 hours. The mixture was subjected to filtration under reduced pressure and separated by column chromatography using methylene chloride and hexane as an eluent MC recrystallization yielded 5.2 g of TA_A01.

2) Synthesis of compound TA_A02

(4,4,5,5-tetramethyl-1,3,2-dioxoborolen-2-yl) -4,6-diphenyl-1,3,5-triazine (2- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -4,6-diphenyl-1,3,5-triazine) (5.00 g, 13.9 mmol), Intermediate C g, 11.6mmol), tetrakis (triphenylphosphine) palladium (0) (tetrakistriphenylphosphine palladium (0 )) (Pd (PPh 3) 4) (0.53g, 0.46mmol), 4M potassium carbonate (potassium carbonate) solution (10ml) , Toluene (30 ml) and ethanol (10 ml) were added, and the mixture was stirred under reflux for 12 hours. After completion of the reaction, 50 ml of water (H ₂ O) was added and the mixture was stirred for 3 hours. The mixture was subjected to filtration under reduced pressure and separated by column chromatography using methylene chloride and hexane as an eluent MC recrystallization yielded 5.6 g of TA_A02 as a compound.

3) Synthesis of intermediate A

To a round bottom flask was added 1- (4-bromophenyl) ethanone (11.5 g, 0.058 mol), 8-aminoquinoline-7-carbaldehyde ), 800 mL of ABS ethanol (Absolute EtOH), and 13 g of potassium hydroxide (KOH) were charged, and the mixture was heated to reflux and stirred for 15 hours. The reaction solution is cooled to room temperature, extracted with dichloromethane (CH ₂ Cl ₂ , MC) / water, and the organic layer is recovered. The organic layer was concentrated under reduced pressure, and then dichloromethane was developed using aluminum oxide (Al ₂ O ₃ ), followed by column separation to obtain 9.5 g of intermediate A.

4) Synthesis of compound PN_A01

To a round bottom flask was added Intermediate A (2.68 g, 8 mmol), 9- (3- (pyrimidin-2-yl) phenyl) anthracene-10- yl) phenyl) anthracen-10- yl-10-boronic acid) (3.38g, 9mmol), tetrakis (triphenylphosphine) palladium (0) (tetrakistriphenylphosphine palladium (0 )) (Pd (PPh 3) 4) (0.4g , 60 mL of toluene, 15 mL of ethanol, and 8 mL of 2M potassium carbonate were added, and the mixture was stirred under reflux for 12 hours. After completion of the reaction, the reaction solution is filtered to obtain a product in a crude state. The filtered crude product was dissolved in chloroform (CHCl ₃ ) to dissolve it. The solution was filtered under reduced pressure on aluminum oxide (Al ₂ O ₃ ), concentrated and recrystallized to obtain 2.4 g of compound PN_A01.

5) Synthesis of compound PN_A02

To a round bottom flask was added Intermediate A (2.68 g, 8 mmol), 9- (4- (pyrimidin-2yl) phenyl) anthracene-10- phenyl) anthracen-10-yl- 10-boronic acid) (3.38g, 9mmol), tetrakis (triphenylphosphine) palladium (0) (tetrakistriphenylphosphine palladium (0 )) (Pd (PPh 3) 4) (0.4g, 0.3 mmol), toluene (60 mL), ethanol (15 mL) and 2M potassium carbonate (8 mL) were added, and the mixture was refluxed with stirring for 12 hours. After completion of the reaction, the reaction solution is filtered to obtain a product in a crude state. The filtered crude product was dissolved in chloroform (CHCl ₃ ) by heating and then filtered through aluminum oxide (Al ₂ O ₃ ) under reduced pressure, followed by concentration and recrystallization to obtain 3.6 g of compound PN_A02.

Hereinafter, embodiments in which the organic electroluminescent device of the present invention is manufactured are disclosed. The material of the N-type charge generation layer below does not limit the scope of the present invention.

Experiment 1: Mixture of triazine compounds

≪ Comparative Example 1 &

A first light emitting portion including a hole injection layer, a first hole transporting layer, a fluorescent blue light emitting layer and a first electron transporting layer on a substrate; a charge generation layer including an N-type charge generation layer and a P-type charge generation layer; A second light emitting portion including a hole transporting layer, a phosphorescent yellow emitting layer, and a second electron transporting layer, and a cathode were formed to prepare an organic electroluminescent device. Here, the N-type charge generation layer was formed from the compound TA_A02.

≪ Comparative Example 2 &

With the same structure as that of Comparative Example 1 described above, the N-type charge generation layer was formed of the compound TA_A01.

≪ Example 1 >

The N-type charge generation layer was formed by mixing the compounds TA_A01 and TA_A02 at a ratio of 5: 5, with the same constitution as that of Comparative Example 1 described above.

≪ Example 2 >

The N-type charge generation layer was formed by mixing the compounds TA_A01 and TA_A02 in a ratio of 3: 7, with the same constitution as that of Comparative Example 1 described above.

The driving voltage, the luminous efficiency, the external quantum efficiency and the lifetime of the device manufactured according to the above-described Comparative Example 1, Comparative Example 2, and Embodiments 1 and 2 of the present invention were measured and shown in Table 1 below. (The device was driven at a driving current of 10 mA / cm 2, and the lifetime T 95 represents the white lifetime, which is the time required to achieve a luminance of 95% based on the initial luminance of 100%.)

The current density according to the driving voltage of the device manufactured according to the above-described Comparative Example 1, Comparative Example 2, Example 1 and Example 2 of the present invention is shown in FIG. 4, FIG. 6 shows the external quantum efficiency according to the luminance, and FIG. 7 shows the luminance decreasing rate with time.

The driving voltage (V) The luminous efficiency (cd / A) External quantum efficiency (%) Lifetime (T95, hour) Comparative Example 1 9.0 59.6 23.7 28.30 Comparative Example 2 13.3 58.9 22.4 43.09 Example 1 8.7 58.8 23.7 40.23 Example 2 8.3 59.2 23.7 30.46

Referring to the above Table 1, Example 1 including the compounds TA_A01 and TA_A02 of the present invention in a ratio of 5: 5, as compared with Comparative Example 1 in which the compound TA_A02 was formed in the N-type charge generation layer, , The luminous efficiency decreased by about 0.8 cd / A, the external quantum efficiency was the same, and the lifetime increased by about 11.93 hours. Compared with Comparative Example 2 in which the compound TA_A02 was formed in the N-type charge generation layer, Example 1 including the compounds TA_A01 and TA_A02 of the present invention at a ratio of 5: 5 decreased the driving voltage by about 4.6 V, 0.1 cd / A, the external quantum efficiency increased about 1.3%, and the lifetime decreased by about 2.86 hours.

 Compared with Comparative Example 1 in which the compound TA_A01 was formed in the N-type charge generation layer, Example 2 including the compounds TA_A01 and TA_A02 of the present invention at a ratio of 3: 7 decreased the driving voltage by about 0.7 V, 0.4 cd / A, the external quantum efficiency was the same, and the lifetime increased by about 2.16 hours. Compared with Comparative Example 2 in which the compound TA_A02 was formed on the N-type charge generation layer, Example 2 including the compound TA_A01 and TA_A02 of the present invention in a ratio of 3: 7 decreased the driving voltage by about 5 V, The external quantum efficiency increased about 1.3% and the lifetime decreased about 12.63 hours.

4, the driving voltage of the device according to the first and second embodiments of the present invention is lower than that of the device according to the first comparative example, and compared with the device according to the second comparative example, The driving voltage of the device according to Example 2 was significantly lowered. Referring to FIG. 5, the luminous efficiencies of the devices according to Comparative Example 1, Comparative Example 2, and Embodiments 1 and 2 of the present invention were substantially the same. Referring to FIG. 6, the external quantum efficiency of the devices according to Comparative Example 1, Example 1 and Example 2 of the present invention were substantially the same, and compared with the device according to Comparative Example 2, The external quantum efficiency of the device according to Example 2 was increased. Referring to FIG. 7, in the device according to Example 1 of the present invention, the time required from the initial luminance of 100% to reach 95% was increased compared with the device according to Comparative Example 1, Respectively. In the device according to Example 1 of the present invention, compared to the device according to Comparative Example 2, the time required for reaching 95% from the initial luminance of 100% was almost the same level. Respectively.

Experiment 2: Mixing Phenanthroline Compound

≪ Comparative Example 3 &

A first light emitting portion including a hole injection layer, a first hole transporting layer, a fluorescent blue light emitting layer and a first electron transporting layer on a substrate; a charge generation layer including an N-type charge generation layer and a P-type charge generation layer; A second light emitting portion including a hole transporting layer, a phosphorescent yellow emitting layer, and a second electron transporting layer, and a cathode were formed to prepare an organic electroluminescent device. Here, the N-type charge generation layer was formed of the compound PN_A01.

≪ Comparative Example 4 &

With the same structure as that of Comparative Example 3, the N-type charge generation layer was formed of the compound PN_A02.

≪ Example 3 >

In the same structure as that of Comparative Example 3, the N-type charge generation layer was formed by mixing the compound PN_A01 and PN_A02 at a ratio of 5: 5.

The driving voltage, the luminous efficiency, the external quantum efficiency and the lifetime of the device manufactured according to the above-described Comparative Example 3, Comparative Example 4, and Example 3 of the present invention were measured and are shown in Table 2 below. (The device was driven at a driving current of 10 mA / cm 2, and the lifetime T 95 represents the white lifetime, which is the time required to achieve a luminance of 95% based on the initial luminance of 100%.)

8 shows the current density according to the driving voltage of the device manufactured according to Comparative Example 3, Comparative Example 4, and Example 3 of the present invention. The efficiency according to the luminance is shown in FIG. 9, FIG. 10 shows the external quantum efficiency according to the present invention, and FIG. 11 shows the luminance decreasing rate with time.

The driving voltage (V) The luminous efficiency (cd / A) External quantum efficiency (%) Lifetime (T95, hour) Comparative Example 3 7.5 62.5 25.9 51.04 Comparative Example 4 7.5 61.7 25.6 51.02 Example 3 7.4 64.0 27.0 53.09

Referring to Table 2, in Example 3 in which the compounds PN_A01 and PN_A02 of the present invention were contained at a ratio of 5: 5 as compared with Comparative Example 3 in which the compound PN_A01 was formed in the N-type charge generation layer, , The luminous efficiency increased by about 2.5 cd / A, the external quantum efficiency increased by about 1.1%, and the lifetime increased by about 2.05 hours. Compared with Comparative Example 4 in which the compound PN_A02 was formed in the N-type charge generation layer, Example 3 including the compounds PN_A01 and PN_A02 of the present invention had a driving voltage reduced by about 0.1 V and a luminous efficiency of about 2.3 cd / The external quantum efficiency increased about 1.4% and the lifetime decreased by about 2.07 hours.

Referring to FIG. 8, the driving voltage of the device according to the third embodiment of the present invention is lower than that of the device according to the third comparative example and the fourth comparative example. Referring to FIG. 9, the luminous efficiency of the device according to Example 3 of the present invention was increased as compared with the devices according to Comparative Examples 3 and 4. Referring to FIG. 10, the external quantum efficiency of the device according to Example 3 of the present invention was increased as compared with the devices according to Comparative Examples 3 and 4. Referring to FIG. 11, in the device according to Example 3 of the present invention, the time required from the initial luminance of 100% to reach 95% was increased compared to the device of Comparative Example 3, The time required from the initial luminance of 100% to reaching 95% of the device according to Example 3 of the present invention was found to be almost equal.

The results of the above Experiments 1 and 2 show that, in contrast to the organic electroluminescent devices of Comparative Examples 1 to 4 using a single material of phenanthroline compound or triazine compound as the N-type charge generation layer, It can be seen that the organic electroluminescent devices of the embodiments using the mixed N-type charge generation layer can lower the driving voltage while exhibiting luminous efficiency of at least equal level, external quantum efficiency and lifetime.

As described above, the compounds of the present invention include a compound containing two or more electron-rich nitrogen (N) atoms, thereby facilitating the electron injection with high electron mobility. Further, the compounds of the present invention can reduce the energy barrier in the N-type charge generation layer by mixing the structural isomers of triazine or the structural isomers of phenanthroline to form an N-type charge generation layer. In addition, the compounds of the present invention contain nitrogen (N) of sp ² hybrid orbitals having relatively high electrons, and this nitrogen bonds with an alkali metal or an alkaline earth metal, which is a dopant of the N-type charge generation layer, gap state. The formed gap state can smoothly transfer electrons from the N-type charge generation layer to the electron transport layer. Further, since the nonspairable electron pair of nitrogen bonds well with the alkali metal or alkaline earth metal contained in the N-type charge generation layer, the alkali metal or alkaline earth metal does not diffuse into the P-type charge generation layer, so that the lifetime can be improved.

Therefore, by forming the N-type charge generating layer with the compounds of the present invention, the energy barrier can be lowered and the electron mobility can be improved to lower the driving voltage of the device and improve the efficiency. In addition, the compounds of the present invention can prevent the dopant of the N-type charge generating layer from diffusing into the P-type charge generating layer, thereby improving the lifetime of the device.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: organic electroluminescent device 110: anode
120: Hole injection layer 130: Hole transport layer, First hole transport layer
140: first light emitting layer 150: electron transporting layer, first electron transporting layer
160N: N-type charge generation layer 160P: P-type charge generation layer
180: second hole transport layer 190: second light emitting layer
200: second electron transport layer 210: electron injection layer
220: cathode

Claims (12)

At least two light emitting parts including a light emitting layer; And
And a charge generation layer located between the light emitting portions,
Wherein the charge generation layer comprises compounds represented by the following Chemical Formulas 1 and 2 or compounds represented by Chemical Formulas 3 and 4 below.
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

R ₁ , R ₂ , L ₁ , A ₁ and A ₂ are each independently selected from the group consisting of hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, , A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted C1 to C60 alkoxy group, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms; R ₁ and L _{1 each} independently represent hydrogen, deuterium, a halogen atom, Hydlock Group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, there can be selected from a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a non-salt, wherein m and n are each 1 or 2;
In Formula 3 or 4, R ₁ , R ₂ , L ₁ , L ₂ , A ₁ , A ₂ , A ₃ and A ₄ each independently represent hydrogen, deuterium, a halogen atom, a hydroxyl group, A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted 6 to 6 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms, and R ₁ , R _2, L ₁ and L ₂ is selected from hydrogen, deuterium, Can not be selected from a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine, a hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, 1 or 2. The method according to claim 1,
Wherein each of R ₁ , R ₂ , L ₁ and L ₂ is independently one of the following compounds.

The method according to claim 1,
Wherein A ₁ , A ₂ , A ₃ and A ₄ are each independently one of the following compounds.

The method according to claim 1,
Wherein the charge generation layer comprises a P-type charge generation layer and an N-type charge generation layer, and the compounds are contained in the N-type charge generation layer. 5. The method of claim 4,
Wherein the N-type charge generation layer further comprises a dopant, wherein the dopant is one of an alkali metal, an alkaline earth metal, an alkali metal compound, an alkaline earth metal compound, an organic complex of an alkali metal or an organic complex of an alkaline earth metal Light emitting element. The method according to claim 1,
Wherein at least one of the at least two light emitting units is a light emitting unit emitting blue light and the other is a light emitting unit emitting yellow green. At least two light emitting parts including a light emitting layer; And
And a charge generation layer located between the light emitting portions,
Wherein the charge generation layer comprises compounds represented by the following formulas (5) and (6) or compounds represented by the following formulas (7) and (8).
[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

In Formula 5 or 6, R ₁ , R ₂ , L ₁ , A ₁ and A ₂ are each independently selected from the group consisting of hydrogen, deuterium, halogen atoms, hydroxyl groups, cyano groups, nitro groups, amino groups, , A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted C1 to C60 alkoxy group, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms; R ₁ and L _{1 each} independently represent hydrogen, deuterium, a halogen atom, Hydlock Group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, there can be selected from a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a non-salt, wherein m and n are each 1 or 2;
In Formula 7 or 8, R ₁ , R ₂ , L ₁ , L ₂ , A ₁ , A ₂ , A ₃ and A ₄ each independently represent hydrogen, deuterium, a halogen atom, a hydroxyl group, A substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, A substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, a substituted or unsubstituted 6 to 6 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 60 carbon atoms, A substituted or unsubstituted arylthio group having 6 to 60 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms, and R ₁ , R _2, L ₁ and L ₂ is selected from hydrogen, deuterium, Can not be selected from a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine, a hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, 1 or 2. 8. The method of claim 7,
Wherein each of R ₁ , R ₂ , L ₁ and L ₂ is independently one of the following compounds.

8. The method of claim 7,
Wherein A ₁ , A ₂ , A ₃ and A ₄ are each independently one of the following compounds.

8. The method of claim 7,
Wherein the charge generation layer comprises a P-type charge generation layer and an N-type charge generation layer, and the compounds are contained in the N-type charge generation layer. 11. The method of claim 10,
Wherein the N-type charge generation layer further comprises a dopant, wherein the dopant is one of an alkali metal, an alkaline earth metal, an alkali metal compound, an alkaline earth metal compound, an organic complex of an alkali metal or an organic complex of an alkaline earth metal Light emitting element. 8. The method of claim 7,
Wherein at least one of the at least two light emitting units is a light emitting unit emitting blue light and the other is a light emitting unit emitting yellow green.

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