KR102517937B1 - Organic light emitting device - Google Patents

Abstract

An organic light emitting device according to an embodiment of the present invention is located between an anode and a cathode, and includes light emitting units each including a light emitting layer, a P-type charge generation layer located between the light emitting units, and the light emitting layer and the P-type charge generation unit. It includes at least one mixed layer positioned between the layers, and the mixed layer is characterized in that it consists of a mixed layer of triazine compounds represented by Formula 1, a mixed layer of phenanthroline compounds represented by Formula 2, or a mixed layer thereof.

Description

Organic light emitting device {ORGANIC LIGHT EMITTING DEVICE}

The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device capable of reducing a driving voltage and improving efficiency.

BACKGROUND OF THE INVENTION [0002] Video display devices, which implement various information on a screen, are a core technology of the information and communication era, and are developing toward thinner, lighter, portable and high performance. Recently, with the development of the information society, as the demand for various types of display devices increases, liquid crystal displays (LCDs), plasma display panels (PDPs), electroluminescent displays (Electro Luminescent Displays) , ELD), Field Emission Display (FED), Organic Light Emitting Diode (OLED), and other flat panel display devices are being actively researched.

Among them, the organic light emitting device is a device that emits light while disappearing after electrons and holes form pairs when charge is injected into an organic light emitting layer formed between an anode and a cathode. Organic light emitting diodes can be formed on flexible transparent substrates such as plastic, and can be driven at a lower voltage than plasma displays or inorganic light emitting displays, consume relatively less power, and have excellent colors. there is. In particular, an organic light emitting device that implements white is a device that 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, as well as lighting.

In the development of white organic light emitting devices, research and development are underway according to each method because high efficiency, long lifespan, color purity, color stability according to changes in current and voltage, and ease of device manufacturing are important. The white organic light emitting device structure can be largely divided into a single layer light emitting structure and a multilayer light emitting structure. Among them, a multilayer light emitting structure in which a fluorescent blue light emitting layer and a phosphorescent yellow light emitting layer are stacked in tandem is mainly adopted for a white organic light emitting device having a long lifespan.

Specifically, a phosphorescent light emitting structure in which a first light emitting unit using a blue fluorescent element as a light emitting layer and a second light emitting unit structure using a yellow phosphorescent element as a light emitting layer are stacked. In the white organic light emitting diode, white light is implemented by a mixing effect of blue light emitted from the blue fluorescent element and yellow light emitted from the yellow phosphorescent element. A charge generation layer is provided between the first light emitting unit and the second light emitting unit to double the efficiency of the current generated in the light emitting layer and facilitate charge distribution. The charge generation layer is composed of an N-type charge generation layer and a P-type charge generation layer.

However, in the above-described multilayer light emitting structure device, the driving voltage of the entire multilayer light emitting structure device may be greater than the sum of the driving voltages of each light emitting unit, or the efficiency of the device may be lowered compared to a single layer light emitting device. In particular, when the N-type charge generation layer is doped with an alkali metal or an alkaline earth metal, the alkali metal doped in the N-type charge generation layer moves toward the electron transport layer together with electrons as the device is driven. As a result, the alkali metal present at the interface between the N-type charge generation layer and the electron transport layer increases, and the alkali metal doped at the interface between the P-type charge generation layer and the N-type charge generation layer decreases. Therefore, the amount of electrons injected into the electron transport layer is reduced due to the increased amount of alkali metal at the interface between the N-type charge generation layer and the electron transport layer, thereby increasing the driving voltage and reducing the lifetime. In addition, due to a difference in LUMO (Lowest Unoccupied Molecular Orbital) energy level between the N-type charge generation layer and the P-type charge generation layer, the electron injected from the cathode is injected into the N-type charge generation layer. In addition, due to the difference in LUMO energy levels between the electron transport layer and the N-type charge generation layer, the movement of electrons from the N-type charge generation layer to the electron transport layer is not smooth, resulting in deterioration in device performance and lifespan. Accordingly, it is difficult to construct a high-efficiency organic light emitting diode having a multi-layer light emitting structure due to the complexity of the structure.

The present invention provides an organic light emitting device capable of reducing driving voltage and improving efficiency.

In order to achieve the above object, an organic light emitting device according to an embodiment of the present invention is positioned between an anode and a cathode and includes light emitting parts each including a light emitting layer, a P-type charge generation layer positioned between the light emitting parts, and and at least one mixed layer positioned between the light emitting layer and the P-type charge generation layer, wherein the mixed layer is a mixed layer of triazine compounds represented by the following formula (1), a mixed layer of phenanthroline compounds represented by the following formula (2), or these It is characterized by consisting of a mixed layer of.

[Formula 1]

In Formula 1, X ₁ to X ₁₀ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.

[Formula 2]

In Formula 2, X ₁ to X ₆ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.

The triazine compound represented by Formula 1 is characterized in that any one selected from the compounds represented below.

Wherein R ₁ and R ₂ are each independently hydrogen, deuterium, 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, a phosphoric acid group or A salt thereof, 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 alkynyl group having 2 to 60 carbon atoms, or a substituted or unsubstituted carbon atom having 1 to 60 carbon atoms. Alkoxy group, substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, substituted or unsubstituted aryl group having 6 to 60 carbon atoms, substituted or unsubstituted aryloxy group, substituted or unsubstituted aryl having 6 to 60 carbon atoms It is any one selected from a thio group and a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms.

The R ₁ and R ₂ are each independently any one selected from the compounds shown below.

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The phenanthroline compound represented by Chemical Formula 2 is characterized in that any one selected from the compounds represented below.

It is characterized in that it further comprises an electron transport layer between the light emitting layer and the P-type charge generation layer.

The mixed layer is located between the electron transport layer and the P-type charge generation layer, and is characterized in that it consists of a mixture of the triazine compounds or a mixture of the triazine compound and the phenanthroline compound.

The mixed layer is an electron transport layer, and is characterized in that it consists of a mixture of the triazine compounds or a mixture of the triazine compound and the phenanthroline compound.

It is characterized in that it further comprises an N-type charge generation layer located between the P-type charge generation layer and the electron transport layer.

The mixed layer is the N-type charge generation layer, and is characterized in that it is composed of a mixture of the phenanthroline compounds or a mixture of the triazine compound and the phenanthroline compound.

The mixed layer is located between the electron transport layer and the N-type charge generation layer, and is characterized in that it is composed of a mixture of the phenanthroline compounds or a mixture of the triazine compound and the phenanthroline compound.

The mixed layer includes a first mixed layer and a second mixed layer disposed on the first mixed layer, the first mixed layer is an electron transport layer, the second mixed layer is an N-type charge generation layer, and the first mixed layer is the triazine. A mixture of compounds or a mixture of the triazine compound and the phenanthroline compound, and the second mixed layer is a mixture of the phenanthroline compounds or a mixture of the triazine compound and the phenanthroline compound. .

The mixed layer is located between the electron transport layer and the N-type charge generation layer, the mixed layer includes a first mixed layer and a second mixed layer disposed on the first mixed layer, and the first mixed layer is composed of the triazine compounds. It is characterized by mixing or mixing the triazine compound and the phenanthroline compound, and the second mixed layer is made of a mixture of the phenanthroline compounds or a mixture of the triazine compound and the phenanthroline compound.

The triazine compound of the present invention contains three electron-rich nitrogen (N), thereby facilitating the transport of electrons by having fast electron mobility, and including a substituent having relatively fast electron mobility, so that it can move from the mixed layer to the light emitting layer. Facilitates the transport of electrons. In addition, since the phenanthroline compound of the present invention contains two electron-rich nitrogen (N), it has high electron mobility and facilitates electron transport. In particular, the phenanthroline compound contains nitrogen (N) of an sp2 hybrid orbital that is relatively rich in electrons, and this nitrogen is bound to an alkali metal or alkaline earth metal, which is a dopant of the N-type charge generation layer, to form a gap state (gap). state) is formed. Accordingly, electrons can be smoothly transported from the N-type charge generation layer to the electron transport layer by the formed gap state.

Therefore, the organic light emitting device of the present invention includes a mixed layer between the light emitting layer and the P-type charge generation layer, and uses a compound containing two or more nitrogen atoms in the mixed layer and a substituent having relatively fast electron mobility, so that N Efficiency and performance of the device may be improved by efficiently transferring electrons transferred from the type charge generation layer to the light emitting layer. In addition, since the transfer of electrons from the N-type charge generation layer to the electron transport layer is smooth, it is possible to improve the problem of reduced lifespan caused by poor electron injection. In addition, it is possible to improve a problem in which a driving voltage increases when electrons injected into the N-type charge generation layer move to the electron transport layer due to a difference in LUMO energy level between the electron transport layer and the N-type charge generation layer.

1 to 6 are views illustrating an organic light emitting device according to a first embodiment of the present invention.
7 and 8 are views illustrating an organic light emitting device according to a second embodiment of the present invention.
9 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Examples 1 and 2 of the present invention.
10 is a graph showing the luminous efficiency according to the luminance of the devices manufactured according to Comparative Examples 1 and 2 of the present invention.
11 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Examples 1 and 2 of the present invention.
12 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 1 of the present invention.
13 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Example 1 and Example 1 of the present invention.
14 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 2 of the present invention.
15 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Example 1 and Example 2 of the present invention.
16 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 3 of the present invention.
17 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Example 1 and Example 3 of the present invention.
18 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 4 of the present invention.
19 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Example 1 and Example 4 of the present invention.
20 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Example 1, Example 5 and Example 6 of the present invention.
21 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Example 1, Example 5, and Example 6 of the present invention.
22 is a graph showing the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 7 of the present invention.
23 is a graph showing quantum efficiency according to luminance of devices manufactured according to Comparative Example 1 and Example 7 of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal precedence relationship is described in terms of 'after', 'following', 'next to', 'before', etc. It can also include non-continuous cases unless is used.

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

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. may be

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

<First Embodiment>

1 to 6 are views showing an organic light emitting device according to a first embodiment of the present invention.

Referring to FIG. 1, the organic light emitting device 100 of the present invention generates light emitting parts ST1 and ST2 positioned between an anode 110 and a cathode 220 and charge generation positioned between the light emitting parts ST1 and ST2. Layer 160 is included. The first light emitting part ST1 constitutes one light emitting device unit, and includes a first hole injection layer 120, a first hole transport layer 130, a first light emitting layer 140, a first electron transport layer 150, A mixed layer 300 is included.

The anode 110 is an electrode for injecting holes and may be any one of indium tin oxide (ITO), indium zinc oxide (IZO), and zinc oxide (ZnO) having a high work function. In addition, when the anode 110 is a reflective electrode, the anode 110 includes a reflective layer made of any one of aluminum (Al), silver (Ag), and nickel (Ni) under a layer made of any one of ITO, IZO, or ZnO. can include more.

The first hole injection layer 120 may serve to facilitate the injection of holes from the anode 110 to the first light emitting layer 140, and may include copper phthalocyanine (CuPc), poly(3,4)-ethylenedioxythiophene (PEDOT) ), PANI (polyaniline) and NPD (N, N'-bis (naphthalen-1-yl) -N, N'-bis (phenyl) -2,2'-dimethylbenzidine) consisting of at least one selected from the group consisting of may, but is not limited thereto. The thickness of the first hole injection layer 120 may be 1 to 150 nm. Here, when the thickness of the first hole injection layer 120 is 1 nm or more, hole injection characteristics can be improved, and when the thickness is 150 nm or less, an increase in the thickness of the first hole injection layer 120 is minimized to minimize an increase in driving voltage. can do. The first hole injection layer 120 may not be included in the configuration of the organic light emitting device depending on the structure or characteristics of the device.

The first hole transport layer 130 serves to facilitate hole transport, and NPD (N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-2,2' -dimethylbenzidine), TPD (N,N'-bis(3-methylphenyl)-N,N'-bis-(phenyl)-benzidine), spiro-TAD(2,2',7,7'-tetrakis(N, It may consist of one or more selected from the group consisting of N-diphenylamino) -9,9'-spirofluorene) and MTDATA (4,4',4"-Tris (N-3-methylphenyl-N-phenylamino)-triphenylamine) The first hole transport layer 130 may have a thickness of 1 to 150 nm, but is not limited thereto. An increase in the driving voltage may be minimized by minimizing an increase in the thickness of the first hole transport layer 130 .

The first light-emitting layer 140 may emit light of one color among red, green, and blue, and may be a blue light-emitting layer in the present embodiment. In the case of a blue light emitting layer, the first light emitting layer 140 includes a host material such as CBP (4,4'-bis(carbazol-9-yl)biphenyl) and phosphorescent light including an iridium-based dopant material. It may be made of a material, but is not limited thereto. Alternatively, it may be made of a fluorescent material including any one selected from the group consisting of spiro-DPVBi, spiro-CBP, distylbenzene (DSB), distryl arylene (DSA), PFO-based polymer and PPV-based polymer, but is limited thereto It doesn't work. Here, 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.

The first electron transport layer 150 serves to facilitate electron transport, and Alq ₃ (tris (8-hydroxy-quinolinato) aluminum), PBD (2- (4-biphenyl) -5- (4-tert -butylphenyl)-1,3,4-oxadiazole), TAZ(3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), DPT(2-biphenyl-4- yl-4,6-bis-(4′-pyridin-2-yl-biphenyl-4-yl)-[1,3,5]triazine) and BAlq (Bis(2-methyl-8-quinolinolate)-4- (phenylphenolato)aluminum), but is not limited thereto. The thickness of the first electron transport layer 150 may be 1 to 150 nm. Here, when the thickness of the first electron transport layer 150 is 1 nm or more, there is an advantage of minimizing the decrease in electron transport characteristics, and when the thickness is 150 nm or less, an increase in the thickness of the first electron transport layer 150 is minimized to increase the driving voltage. rise can be minimized.

A charge generation layer (CGL) 160 is positioned on the first light emitting part ST1. The first light emitting part ST1 and the second light emitting part ST2 have a structure connected 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 to inject charges into the light emitting layers. That is, the N-type charge generation layer 160N supplies electrons to the first light-emitting layer 140 adjacent to the anode, and the P-type charge generation layer 160P supplies holes to the light-emitting layer of the second light-emitting part ST2. , It is possible to further increase the light emitting efficiency of the organic light emitting device having a plurality of light emitting layers, and also lower the driving voltage. Therefore, the charge generation layer 160 has a significant effect on the luminous efficiency and driving voltage, which are characteristics of the organic light emitting device.

The N-type charge generation layer 160N may be formed of a metal or an organic material doped with N-type. Here, the metal may be one material selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Sm, Eu, Tb, Dy, and Yb. In addition, as the material of the N-type dopant and the host used in the N-type doped organic material, commonly used materials may be used. For example, the N-type dopant may be an alkali metal, an alkali metal compound, an alkaline earth metal or an alkaline earth metal compound. Specifically, the N-type dopant may be one selected from the group consisting of Li, Cs, K, Rb, Mg, Na, Ca, Sr, Eu, and Yb. The ratio of the dopant is mixed at 1 to 10% relative to 100% of the entire host. Here, the work function of the dopant is preferably 2.5 eV or more. The host material may be an organic material having 20 or more and 60 or less carbon atoms having a heterocycle containing a nitrogen atom, for example, Alq ₃ (tris (8-hydroxy-quinolinato) aluminum), phenanthroline It may be one substance selected from the group consisting of derivatives, hydroxy quinoline derivatives, benzazole derivatives, and silole derivatives.

The P-type charge generation layer 160P may be formed of a metal or an organic material doped with P-type. Here, the metal may be made of one or two or more alloys selected from the group consisting of Al, Cu, Fe, Pb, Zn, Au, Pt, W, In, Mo, Ni, and Ti. In addition, as the material of the P-type dopant and the host used in the organic material doped with the P-type, materials commonly used may be used. For example, the P-type dopant is a tetracyanoquinodimethane derivative such as F ₄ -TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane), iodine, FeCl ₃ , FeF ₃ and SbCl ₅ It may be one material selected from the group consisting of. In addition, the host is NPB (N, N'-bis (naphthaen-1-yl) -N, N'-bis (phenyl) -benzidine), TPD (N, N'-bis (3-methylphenyl) N, N It may be one material selected from the group consisting of '-bis(phenyl)-benzidine) and TNB (N,N,N',N'-tetra-naphthalenyl-benzidine).

A second hole injection layer 170, a second hole transport layer 180, a second light emitting layer 190, a second electron transport layer 200 and an electron injection layer 210 on the charge generation layer 160 A second light emitting part ST2 is located. The second hole injection layer 170, the second hole transport layer 180, and the second electron transport layer 200 are the first hole injection layer 120 and the first hole transport layer 130 of the first light emitting part ST1 described above. ) and the configuration of the first electron transport layer 150 may be the same as or different from each other. A detailed description of the same configuration will be omitted.

The second light-emitting layer 190 is a light-emitting layer that emits one color such as red, green, and blue, and may be a yellow light-emitting layer in the present embodiment. When the second light emitting layer 190 is a yellow light emitting layer, a single layer structure of a yellow-green light emitting layer or a green light emitting layer or a multilayer structure of a yellow-green light emitting layer and a green light emitting layer can be made with Here, the second light emitting layer 190 includes a yellow-green light emitting layer, a green light emitting layer, or a multilayer structure of a yellow-green light emitting layer and a green light emitting layer. In this embodiment, a single layer structure of a yellow light emitting layer emitting yellow green will be described as an example. The second light-emitting layer 190 includes at least one selected from CBP (4,4'-bis(carbazol-9-yl)biphenyl) and BAlq (Bis(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium). It may be made of a phosphorescent yellow-green dopant that emits yellow-green light to the host. However, it is not limited thereto.

The electron injection layer 210 serves to facilitate the transport of electrons, and Alq ₃ (tris (8-hydroxy-quinolinato) aluminum), PBD (2- (4-biphenyl) -5- (4-tert- butylphenyl)-1,3,4-oxadiazole), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), and BAlq (Bis(2-methyl- 8-quinolinolate) -4- (phenylphenolato) aluminum) may be used, but is not limited thereto. On the other hand, the electron injection layer 210 may be made of a metal compound, and the metal compound is, for example, LiQ, LiF, NaF, KF, RbF, CsF, FrF, BeF ₂ , MgF ₂ , CaF ₂ , SrF ₂ , BaF ₂ And RaF ₂ It may be any one or more selected from the group consisting of, but is not limited thereto. The electron injection layer 210 may have a thickness of 1 to 50 nm. Here, when the thickness of the electron injection layer 210 is 1 nm or more, there is an advantage in minimizing the deterioration of electron injection characteristics, and when the thickness is 50 nm or less, an increase in the thickness of the electron injection layer 210 is minimized to increase the driving voltage. rise can be minimized. Therefore, the second hole injection layer 170, the second hole transport layer 180, the second light emitting layer 190, the second electron transport layer 200 and the electron injection layer 210 are included on the charge generation layer 160. and constitutes a second light emitting part ST2.

A cathode 220 is positioned on the second light emitting part ST2. The cathode 220 is an electron injection electrode and may be made of magnesium (Mg), calcium (Ca), aluminum (Al), silver (Ag), or an alloy thereof having a low work function. Here, the cathode 220 may be formed to a thickness thin enough to transmit light when the organic light emitting device has a front or double side light emitting structure, and may reflect light when the organic light emitting device has a bottom light emitting structure. It can be made thick enough.

Meanwhile, in the present invention, the mixed layer 300 is included in the first light emitting part ST1. The mixed layer 300 is located between the first electron transport layer 150 and the N-type charge generation layer 160N, so that electrons can be smoothly transported from the N-type charge generation layer 160N to the first electron transport layer 150. play a role

In the present invention, various experiments have been conducted to improve electron injection characteristics from the N-type charge generation layer 160N to the first electron transport layer 150. Through this experiment, it was recognized that the driving voltage increased when electrons injected into the N-type charge generation layer moved to the electron transport layer due to the difference in LUMO energy levels between the electron transport layer and the N-type charge generation layer. Therefore, the mixed layer 300 is formed between the first electron transport layer 150 and the N-type charge generation layer 160N to reduce driving voltage and improve efficiency. In particular, the present invention introduces a mixed layer 300 in which triazine compounds are mixed or a triazine compound and a phenanthroline compound are mixed through various experiments to minimize the increase in the driving voltage of the device and improve the efficiency.

The triazine compound of the present invention contains three electron-rich nitrogen (N), thereby facilitating the transport of electrons due to high electron mobility. In addition, the triazine compound includes a substituent having a relatively high electron mobility, thereby facilitating electron transport from the mixed layer to the light emitting layer.

In an embodiment of the present invention, the triazine compound used in the mixed layer 300 is represented by Formula 1 below.

[Formula 1]

In Formula 1, X ₁ to X ₁₀ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.

In addition, the triazine compound represented by Formula 1 consists of any one selected from the compounds represented below.

Among the above compounds, R ₁ and R ₂ are each independently hydrogen, deuterium, halogen atom, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazine, hydrazone, carboxyl group or its salt, sulfonic acid group or its salt , A phosphoric acid group or a salt thereof, 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 alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted carbon number 1 to 60 alkoxy group, substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, substituted or unsubstituted aryl group having 6 to 60 carbon atoms, substituted or unsubstituted aryloxy group, substituted or unsubstituted 6 to 60 carbon atoms It is any one selected from a 60 arylthio group and a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms.

Specifically, R ₁ and R ₂ each independently consist of any one selected from compounds shown below.

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or

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In addition, since the phenanthroline compound of the present invention contains two electron-rich nitrogen (N), it has high electron mobility and facilitates electron transport. In addition, the phenanthroline compound includes a substituent having relatively high electron mobility, thereby facilitating electron transport from the mixed layer to the light emitting layer.

In an embodiment of the present invention, the phenanthroline compound used in the mixed layer 300 is represented by Chemical Formula 2 below.

[Formula 2]

In Formula 2, X ₁ to X ₆ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.

The phenanthroline compound represented by Formula 2 consists of any one selected from the compounds shown below.

Here, since R ₁ and R ₂ are the same as R ₁ and R ₂ of the triazine compound described above, their descriptions are omitted.

The mixed layer 300 of the present invention is located between the first electron transport layer 150 and the N-type charge generation layer 160N, and functions as a mixed electron transport layer or a mixed N-type charge generation layer. The mixed electron transport layer is a mixed layer in which compounds are mixed but has excellent electron transport properties, and the mixed N-type charge generation layer is a mixed layer in which compounds are mixed but has excellent charge generation characteristics.

The mixed layer 300 of the present invention is made of a mixture of triazine compounds or a mixture of a triazine compound and a phenanthroline compound, and may function as a mixed electron transport layer. In addition, the mixed layer 300 of the present invention may be made of a mixture of phenanthroline compounds or a mixture of a triazine compound and a phenanthroline compound, and may serve as a mixed N-type charge generation layer. Here, when the mixed layer 300 functions as a mixed N-type charge generation layer, the mixed layer 300 may be made of a metal or an organic material doped with N-type. Here, the metal may be one material selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Sm, Eu, Tb, Dy, and Yb. In addition, the N-type dopant used in the N-type doped organic material may be an alkali metal, an alkali metal compound, an alkaline earth metal, or an alkaline earth metal compound. Specifically, the N-type dopant may be one selected from the group consisting of Li, Cs, K, Rb, Mg, Na, Ca, Sr, Eu, and Yb. The ratio of the dopant is mixed at 1 to 10% relative to 100% of the entire host. Here, the work function of the dopant is preferably 2.5 eV or more.

The triazine compound of the present invention has better electron transport properties than charge generation properties, and the phenanthroline compound has better charge generation properties than electron transport properties. Therefore, in the case of the mixed layer 300 serving as the mixed electron transport layer of the present invention, at least the triazine compound is included and formed, and in the case of the mixed layer 300 serving as the mixed N-type charge generation layer, at least the phenanthroline compound is included. formed by including

Meanwhile, the mixed layer 300 has a thickness of 10 to 600 Å. When the thickness of the mixed layer 300 is 10 Å or more, electron transport characteristics can be improved, and when the thickness of the mixed layer 300 is 600 Å or less, an increase in the driving voltage can be minimized by minimizing an increase in the thickness of the mixed layer 300 . In addition, the mixed layer 300 is formed so that the mixed compounds have a certain mixing ratio. For example, the mixed layer 300 may include mixed compounds having the same mixing ratio or different mixing ratios. Therefore, the mixing ratio of the mixed layer 300 is 0.1:99.9 vol% to 99.9:0.1 vol%. Here, when the mixing ratio of the mixed layer 300 is 0.1: 99.9 vol% or more, the electron transport properties of the mixed materials can be maximized, and when the mixing ratio is 99.9: 0.1 vol% or less, the weakening of the properties of any one material can be minimized.

As described above, the present invention forms a mixed layer acting as a mixed electron transport layer or a mixed N-type charge generation layer between the electron transport layer and the N-type charge generation layer, but a mixture of triazine compounds, a mixture of a triazine compound and a phenanthroline compound Or by forming a mixture of phenanthroline compounds, the transport of electrons transferred from the N-type charge generation layer to the electron transport layer is facilitated.

Meanwhile, unlike the structure of FIG. 1 described above, the organic light emitting device according to the first embodiment of the present invention may include a mixed layer 300 between the light emitting layer and the N-type charge generation layer instead of the electron transport layer.

Referring to FIG. 2 , the mixed layer 300 of the present invention is located between the first light emitting layer 140 and the N-type charge generation layer 160N. Here, the mixed layer 300 serves as an electron transport layer, and easily transports electrons from the N-type charge generation layer 160N to the first light emitting layer 140 . When the mixed layer 300 of the present invention serves as an electron transport layer, the mixed layer 300 is made of a mixture of triazine compounds or a mixture of a triazine compound and a phenanthroline compound. As described above, since the triazine compound has excellent electron transport properties, even if a mixed layer is used instead of the electron transport layer, the role of the electron transport layer can be sufficiently performed.

Meanwhile, unlike the structure of FIGS. 1 and 2 described above, the organic light emitting device according to the first embodiment of the present invention includes a mixed layer 300 between the electron transport layer and the P-type charge generation layer instead of the N-type charge generation layer. It could be.

Referring to FIG. 3 , the mixed layer 300 of the present invention is located between the electron transport layer 150 and the P-type charge generation layer 160P. Here, the mixed layer 300 serves as an N-type charge generation layer, and transports electrons to the first electron transport layer 150 by generating electrons. When the mixed layer 300 of the present invention serves as an N-type charge generation layer, the mixed layer 300 is made of a mixture of phenanthroline compounds or a mixture of a triazine compound and a phenanthroline compound. As described above, since the phenanthroline compound has excellent electron generation characteristics, even if a mixed layer is used instead of the N-type charge generation layer, the role of the N-type charge generation layer can be sufficiently performed.

On the other hand, the organic light emitting device according to the first embodiment of the present invention, unlike the structure of FIGS. 1 to 3 described above, the first instead of the electron transport layer and the N-type charge generation layer between the blue light emitting layer and the P-type charge generation layer. A mixed layer 310E and a second mixed layer 310N may be provided.

Referring to FIG. 4 , the mixed layer of the present invention includes a first mixed layer 310E and a second mixed layer 310N positioned between the first light emitting layer 140 and the P-type charge generation layer 160P. Here, the first mixed layer 310E serves as an electron transport layer, and easily transports electrons from the second mixed layer 310N to the first light emitting layer 140 . When the first mixed layer 310E of the present invention serves as an electron transport layer, the first mixed layer 310E is made of a mixture of triazine compounds or a mixture of a triazine compound and a phenanthroline compound. As described above, since the triazine compound has excellent electron transport properties, even if the first mixed layer is used instead of the electron transport layer, the role of the electron transport layer can be sufficiently performed. In addition, the second mixed layer 310N serves as an N-type charge generation layer, and generates electrons and transports them to the first mixed layer 310E. When the second mixed layer 310N of the present invention serves as an N-type charge generation layer, the second mixed layer 310N is made of a mixture of phenanthroline compounds or a mixture of a triazine compound and a phenanthroline compound. As described above, since the phenanthroline compound has excellent electron generation characteristics, even if the second mixed layer is used instead of the N-type charge generation layer, it can sufficiently perform the role of the N-type charge generation layer.

Here, the first mixed layer 310E and the second mixed layer 310N may be formed by mixing a triazine compound and a phenanthroline compound and have the same configuration. At this time, the first mixed layer 310E and the second mixed layer 310N may structurally appear as one layer, and the thickness of the first mixed layer 310E and the second mixed layer 310N may be 10 to 600 Å, respectively, or The sum of the thicknesses of the first mixed layer 310E and the second mixed layer 310N may be 10 to 600 Å.

Meanwhile, unlike the structure of FIGS. 1 to 4 , the organic light emitting device according to the first embodiment of the present invention includes a first mixed layer 310E and a second mixed layer 310N between the electron transport layer and the N-type charge generation layer. may be provided.

Referring to FIG. 5 , the mixed layer of the present invention includes a first mixed layer 310E and a second mixed layer 310N positioned between the electron transport layer 150 and the N-type charge generation layer 160N. Here, the first mixed layer 310E serves as a mixed electron transport layer, and easily transports electrons from the N-type charge generation layer 160N and the second mixed layer 310N to the electron transport layer 150 . When the first mixed layer 310E of the present invention serves as a mixed electron transport layer, the first mixed layer 310E is made of a mixture of triazine compounds or a mixture of a triazine compound and a phenanthroline compound. In addition, the second mixed layer 310N serves as a mixed N-type charge generation layer, and generates electrons and transports them to the first mixed layer 310E. When the second mixed layer 310N of the present invention serves as a mixed N-type charge generation layer, the second mixed layer 310N is made of a mixture of phenanthroline compounds or a mixture of a triazine compound and a phenanthroline compound.

As described above, the triazine compound of the present invention contains three electron-rich nitrogen (N), thereby facilitating the transport of electrons by having fast electron mobility, and including a substituent having relatively fast electron mobility , facilitates the transport of electrons from the mixed layer to the light emitting layer. In addition, since the phenanthroline compound of the present invention contains two electron-rich nitrogen (N), it has high electron mobility and facilitates electron transport. In particular, the phenanthroline compound contains nitrogen (N) of an sp2 hybrid orbital that is relatively rich in electrons, and this nitrogen is bound to an alkali metal or alkaline earth metal, which is a dopant of the N-type charge generation layer, to form a gap state (gap). state) is formed. Accordingly, electrons can be smoothly transported from the N-type charge generation layer to the electron transport layer by the formed gap state.

Therefore, the organic light emitting device of the present invention includes a mixed layer between the light emitting layer and the P-type charge generation layer, and uses a compound containing two or more nitrogen atoms in the mixed layer and a substituent having relatively fast electron mobility, so that N Efficiency and performance of the device may be improved by efficiently transferring electrons transferred from the type charge generation layer to the light emitting layer. In addition, since the transfer of electrons from the N-type charge generation layer to the electron transport layer is smooth, it is possible to improve the problem of reduced lifespan caused by poor electron injection. In addition, it is possible to improve a problem in which a driving voltage increases when electrons injected into the N-type charge generation layer move to the electron transport layer due to a difference in LUMO energy levels between the electron transport layer and the N-type charge generation layer.

6 is an energy band diagram of an organic light emitting diode according to a first embodiment of the present invention.

Referring to FIG. 6 , the organic light emitting device of the present invention includes a hole transport layer 180, a P-type charge generation layer 160P, a second mixed layer 310N, a first mixed layer 310E, and an electron transport layer 150. . The second mixed layer 310N supplies electrons to the adjacent electron transport layer 150 and the P-type charge generation layer 160P supplies holes to the adjacent hole transport layer 180 . In general, when electrons are transferred from the N-type charge generation layer to the electron transport layer, the driving voltage increases because the electron injection barrier is large. In the present invention, a first mixed layer 310E and a second mixed layer 310N acting as an N-type charge generating layer are formed between the P-type charge generation layer 160P and the electron transport layer 150, thereby forming the second mixed layer 310N. It lowers the injection barrier of electrons moving from the electron transport layer 150. In particular, the phenanthroline compound contains nitrogen (N) of an sp2 hybrid orbital that is relatively rich in electrons, and this nitrogen is combined with an alkali metal or alkaline earth metal as a dopant of the second mixed layer 310N serving as an N-type charge generation layer. combine to form a gap state. Therefore, electrons can be smoothly transported to the electron transport layer by the formed gap state.

<Second Embodiment>

7 and 8 are views showing an organic light emitting device according to a second embodiment of the present invention. In the following, the same reference numerals are attached to the same components as those of the first embodiment described above, and description thereof will be omitted.

Referring to FIG. 7 , the organic light emitting device 100 of the present invention includes a plurality of light emitting parts ST1 , ST2 , and ST3 positioned between an anode 110 and a cathode 220 and a plurality of light emitting parts ST1 , ST2 , It includes the first charge generation layer 160 and the second charge generation layer 230 positioned between ST3). In this embodiment, it has been shown and described that three light emitting units are positioned between the anode 110 and the cathode 220, but it is not limited thereto, and four or more light emitting units are provided between the anode 110 and the cathode 220. may also include

More specifically, the first light emitting part ST1 constitutes one light emitting element unit and includes the first light emitting layer 140 . The first light emitting layer 140 may emit light of any one of red, green, and blue, and may be a blue light emitting layer emitting blue in the present embodiment. 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, 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 part 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 the first light emitting layer 140 has a first hole injection layer 120 thereon. An electron transport layer 150 and a mixed layer 300 are included. Therefore, the first light emitting unit including the hole injection layer 120, the first hole transport layer 130, the first light emitting layer 140, the first electron transport layer 150, and the mixed layer 300 on the anode 110 ( ST1) is composed. The hole injection layer 120 and the first hole transport layer 130 may not be included in the configuration of the first light emitting part ST1 depending on the structure or characteristics of the device.

A first charge generation layer 160 is positioned on the first light emitting part ST1. The first charge generation layer 160 is a PN junction charge generation layer in which the N-type charge generation layer 160N and the P-type charge generation layer 160P are bonded, and generates charges or separates them into holes and electrons to each light emitting layer. Inject holes and electrons.

Meanwhile, a second light emitting part ST2 including a second light emitting layer 190 is positioned on the first charge generation layer 160 . The second light emitting layer 190 may emit light of one color among red, green, and blue, and may be, for example, a yellow light emitting layer emitting yellow in the present embodiment. The yellow light-emitting layer may be 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 or a green light-emitting layer and a red light-emitting layer or yellow-green. It may be made of a multilayer structure of a light emitting layer and a red light emitting layer. The second light emitting part ST2 further includes a second hole transport layer 180 between the first charge generation layer 160 and the second light emitting layer 190, and second electrons are disposed on the second light emitting layer 190. A transport layer 200 is included. Accordingly, the second light emitting part 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 charge generation layer 160 .

In the same manner as in the first embodiment described above, the present invention introduced a mixed layer 300 that functions as a mixed electron transport layer by mixing triazine compounds or a mixture of a triazine compound and a phenanthroline compound. However, in the second embodiment of the present invention, various mixed layer structures of FIGS. 2 to 5 disclosed in the first embodiment may be applied. A detailed description of this will be omitted since it has been described in the first embodiment.

A second charge generation layer 230 is positioned on the second light emitting part ST2. The second charge generation layer 230 is a PN junction charge generation layer in which the N-type charge generation layer 230N and the P-type charge generation layer 230P are bonded, and generates charges or separates them into holes and electrons to each light emitting layer. Inject holes and electrons. A third light emitting part ST3 including a third light emitting layer 250 is positioned on the second charge generation layer 230 . The third light emitting layer 250 may emit light of one color among red, green, and blue, and may be, for example, a blue light emitting layer emitting blue in the present embodiment. 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, 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 part ST3 includes a third hole transport layer 240 between the second charge generation layer 230 and the third light emitting layer 250, and a third electron transport layer on the third light emitting layer 250. (260) and an electron injection layer (210). Since the third electron transport layer 260 is formed in the same manner as the above-described first electron transport layer 150, a description thereof is omitted. Therefore, the third light emitting portion ST3 including the third hole transport layer 240, the third light emitting layer 250, the third electron transport layer 260, and the electron injection layer 210 on the second charge generation layer 230. ) constitutes A cathode 220 is provided on the third light emitting part ST3 to constitute an organic light emitting device according to the second embodiment of the present invention.

On the other hand, referring to FIG. 8, in FIG. 7 of the present invention described above, the N-type charge generation layer 160N of the first electron transport layer 150 and the first charge generation layer 160 includes a mixed layer 300. However, it is not limited thereto, and a mixed layer 320 may be further included between the second light emitting layer 200 of the second light emitting part ST2 and the N-type charge generation layer 230N of the second charge generation layer 230. there is. In addition, the mixed layer 320 formed between the second light emitting layer 200 of the second light emitting part ST2 and the N-type charge generation layer 230N of the second charge generation layer 230 is disclosed in the first embodiment. A structure of various mixed layers of FIGS. 2 to 5 may be applied.

As described above, the triazine compound of the present invention contains three electron-rich nitrogen (N), thereby facilitating the transport of electrons by having fast electron mobility, and including a substituent having relatively fast electron mobility , facilitates the transport of electrons from the mixed layer to the light emitting layer. In addition, since the phenanthroline compound of the present invention contains two electron-rich nitrogen (N), it has high electron mobility and facilitates electron transport. In particular, the phenanthroline compound contains nitrogen (N) of an sp2 hybrid orbital that is relatively rich in electrons, and this nitrogen is bound to an alkali metal or alkaline earth metal, which is a dopant of the N-type charge generation layer, to form a gap state (gap). state) is formed. Accordingly, electrons can be smoothly transported from the N-type charge generation layer to the electron transport layer by the formed gap state.

Therefore, the organic light emitting device of the present invention includes a mixed layer between the light emitting layer and the P-type charge generation layer, and uses a compound containing two or more nitrogen atoms in the mixed layer and a substituent having relatively fast electron mobility, so that N Efficiency and performance of the device may be improved by efficiently transferring electrons transferred from the type charge generation layer to the light emitting layer. In addition, since the transfer of electrons from the N-type charge generation layer to the electron transport layer is smooth, it is possible to improve the problem of reduced lifespan caused by poor electron injection. In addition, it is possible to improve a problem in which a driving voltage increases when electrons injected into the N-type charge generation layer move to the electron transport layer due to a difference in LUMO energy levels between the electron transport layer and the N-type charge generation layer.

Hereinafter, synthetic examples of the compounds of the present invention will be described in detail in the following examples. However, the following examples are intended to illustrate the present invention, and the present invention is not limited to the following examples.

synthesis example One : phenanthroline synthesis of compounds

1) Synthesis of Intermediate A

In a round bottom flask, 1-(4-bromophenyl)ethanone (11.5 g, 0.058 mol), 8-aminoquinoline-7-carbaldehyde ) (10 g, 0.058 mol), 800 mL of ABS ethanol (Absolute EtOH), and 13 g of potassium hydroxide (KOH) were added, the temperature was raised to reflux, and the mixture was stirred for 15 hours. After cooling the reaction solution to room temperature, the organic layer was recovered by extracting with dichloromethane (CH ₂ Cl ₂ , MC)/water. After concentrating the organic layer under reduced pressure, dichloromethane was developed using aluminum oxide (Al ₂ O ₃ ) to obtain 9.5 g of Intermediate A through column separation.

2) Synthesis of compound PN03_A02 (2-(4-(10-phenylanthracen-9-yl)phenyl)-1,10-phenanthroline)

In a round bottom flask, intermediate A 2.68g (8mmol), 9-phenylanthracene-10-boronic acid (2.8g, 9mmol), tetrakis(triphenylphosphine)palladium(0) (0.4g, 0.3mmol), toluene 60mL, ethanol 15mL, and 2M potassium carbonate 8ml were added and refluxed and stirred for 12 hours. After completion of the reaction, the reaction solution is filtered to obtain a crude product. The filtered crude product was dissolved by heating in chloroform (CHCl ₃ ), filtered under reduced pressure in aluminum oxide (Al ₂ O ₃ ), concentrated and recrystallized to obtain 1.8 g of a PN03_A02 compound.

3) Synthesis of Compound Compound PN03_A03

In a round bottom flask, 2.68 g (8 mmol) of intermediate A, 9-phenylanthracene-10-boronic acid (2.8 g, 9 mmol), tetrakis (triphenylphosphine) palladium (0) (0.4g, 0.3mmol), toluene 60mL, ethanol 15mL, and 2M potassium carbonate 8ml were added and refluxed and stirred for 12 hours. After completion of the reaction, the reaction solution is filtered to obtain a crude product. The filtered crude product was dissolved by heating in chloroform (CHCl ₃ ), filtered under reduced pressure in aluminum oxide (Al ₂ O ₃ ), concentrated and recrystallized to obtain 1.8 g of a PN03_A03 compound.

synthesis example 2 : of triazine compounds synthesis

1) Synthesis of Compound TA03_A05

2-(4,4,5,5-tetramethyl-1,3,2-dioxyborolen-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 (5.63 g 11.6mmol), tetrakistriphenylphosphine palladium (0) (Pd(PPh ₃ ) ₄ ) (0.53g 0.46mmol), 4M potassium carbonate aqueous solution (10ml), toluene ( Tolulene) 30ml, ethanol (ethanol) 10ml was added and stirred under reflux for 12 hours. After the reaction was completed, 50 ml of H ₂ O was added, stirred for 3 hours, filtered under reduced pressure, separated by column chromatography using methylene chloride and hexane as eluents, and then MC recrystallized. 5.6 g of compound TA03_A05 was obtained.

2) Synthesis of Compound TA03_A04

2-(4,4,5,5-tetramethyl-1,3,2-dioxyborolen-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 (5.70 g 11.6mmol), tetrakistriphenylphosphine palladium (0) (Pd(PPh ₃ ) ₄ ) (0.53g 0.46mmol), 4M potassium carbonate aqueous solution (10ml), toluene ( Tolulene) 30ml, ethanol (ethanol) 10ml was added and stirred under reflux for 12 hours. After the reaction was completed, 50 ml of H ₂ O was added, stirred for 3 hours, filtered under reduced pressure, separated by column chromatography using methylene chloride and hexane as eluents, and then MC recrystallized. 5.2 g of compound TA03_A04 was obtained.

3) Synthesis of Compound TA03_A07

2-(4,4,5,5-tetramethyl-1,3,2-dioxyborolen-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 D (5.63 g 11.6mmol), tetrakistriphenylphosphine palladium (0) (Pd(PPh ₃ ) ₄ ) (0.53g 0.46mmol), 4M potassium carbonate aqueous solution (10ml), toluene ( Tolulene) 30ml, ethanol (ethanol) 10ml was added and stirred under reflux for 12 hours. After the reaction was completed, 50 ml of H ₂ O was added, stirred for 3 hours, filtered under reduced pressure, separated by column chromatography using methylene chloride and hexane as eluents, and then MC recrystallized. 4.8g compound TA03_A07 was obtained.

Hereinafter, an embodiment of fabricating an organic light emitting device using the aforementioned compounds as an electron transport layer or an N-type charge generation layer will be described. The thickness or formation conditions of the organic layers below do not limit the scope of the present invention.

Experiment 1: Measurement of device characteristics according to the presence or absence of a mixed layer

comparative example One

A hole injection layer, a hole transport layer, a blue light emitting layer, an electron transport layer, an N-type charge generation layer, a P-type charge generation layer, a hole transport layer, a yellow light emitting layer, an electron transport layer, an electron injection layer, and a cathode are formed on an ITO substrate to form a two-stack structure. An organic light emitting device was manufactured. Here, the electron transport layer was formed of an imidazole compound and the N-type charge generation layer was formed of an anthracene compound.

comparative example 2

A device was manufactured with the same configuration as in Comparative Example 1, except that the electron transport layer and the N-type charge generation layer were formed by mixing an imidazole compound and an anthracene compound, respectively.

The current density according to the driving voltage of the device manufactured according to Comparative Examples 1 and 2 is measured and shown in FIG. 9, and the luminous efficiency according to the luminance is measured and shown in FIG. 11, and the driving voltage, luminous efficiency and quantum efficiency are shown in Table 1 below. (For the driving voltage, luminous efficiency and quantum efficiency, the value of Comparative Example 1 was regarded as 100%, and the value of Comparative Example 2 was expressed as a percentage, and the driving current of the device was 10 mA/cm 2 .)

drive voltage luminous efficiency quantum efficiency Comparative Example 1 100 100 100 Comparative Example 2 99 101 101

9 to 11 and Table 1, compared to Comparative Example 1 in which the electron transport layer and the N-type charge generation layer were not composed of a mixture of materials, the electron transport layer and the N-type charge generation layer were composed of a mixture of materials. In Example 2, the driving voltage was reduced by 1% and the luminous efficiency and quantum efficiency were increased by 1%.

Through this result, it was confirmed that even if the electron transport layer and the N-type charge generation layer were mixed with an imidazole compound and an anthracene compound, the change in the characteristics of the device was insignificant.

Experiment 2: Measurement of characteristics of a device having an electron transport layer composed of a mixed layer

Example One

In the same configuration as in Comparative Example 1, the electron transport layer was formed by mixing the triazine compound TA03_A04 and the phenanthroline compound PN03_A02, and the N-type charge generation layer was formed with the phenanthroline compound PN03_A02. A device was manufactured. .

Example 2

In the same configuration as in Comparative Example 1 described above, the electron transport layer was formed by mixing the triazine compound TA03_A04 and the phenanthroline compound PN03_A03, and the N-type charge generation layer was formed with the phenanthroline compound PN03_A03. A device was manufactured. .

The current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 1 was measured and shown in FIG. 12, and the quantum efficiency according to luminance was measured and shown in FIG. In addition, the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 2 was measured and shown in FIG. 14, and the quantum efficiency according to luminance was measured and shown in FIG. 15. Their driving voltages and quantum efficiencies are shown in Table 2 below. (For driving voltage and quantum efficiency, the value of Comparative Example 1 was regarded as 100%, and the values of Examples 1 and 2 were expressed as percentages, and the driving current of the device was 10 mA/cm 2 .)

drive voltage quantum efficiency Comparative Example 1 100 100 Example 1 93.93 101.42 Example 2 93.75 101.42

Referring to FIGS. 12 to 15 and Table 2, compared to Comparative Example 1 in which the electron transport layer and the N-type charge generation layer were not composed of a mixture of materials, the electron transport layer was composed of a mixture of a triazine compound and a phenanthroline compound. In Example 1, in which the N-type charge generation layer was composed of a phenanthroline compound, the driving voltage was reduced by 6.07% and the quantum efficiency was increased by 1.42%, and in Example 2, the driving voltage was reduced by 6.25% and the quantum efficiency was increased by 1.42%.

Through this result, it was confirmed that the driving voltage of the device was reduced and the quantum efficiency was increased by providing an electron transport layer composed of a mixture of a triazine compound and a phenanthroline compound.

Experiment 3: Measurement of characteristics of a device having an N-type charge generation layer composed of a mixed layer

Example 3

With the same configuration as in Comparative Example 1 described above, the electron transport layer was formed with the triazine compound TA03_A07, and the N-type charge generation layer was formed by mixing the triazine compound TA03_A07 and the phenanthroline compound PN03_A22. A device was manufactured. .

Example 4

In the same configuration as in Comparative Example 1 described above, the electron transport layer was formed with the triazine compound TA02_A24, and the N-type charge generation layer was formed by mixing the triazine compound TA02_A24 and the phenanthroline compound PN03_A16. A device was manufactured. .

The current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 3 was measured and shown in FIG. 16, and the quantum efficiency according to luminance was measured and shown in FIG. In addition, the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 4 was measured and shown in FIG. 18, and the quantum efficiency according to luminance was measured and shown in FIG. Their driving voltages and quantum efficiencies are shown in Table 3 below. (For driving voltage and quantum efficiency, the value of Comparative Example 1 was regarded as 100%, and the values of Examples 3 and 4 were expressed as percentages, and the driving current of the device was 10 mA/cm 2 .)

drive voltage quantum efficiency Comparative Example 1 100 100 Example 3 97.05 102.34 Example 4 97.14 102.35

16 to 19 and Table 3, compared to Comparative Example 1 in which the electron transport layer and the N-type charge generation layer were not composed of a mixture of materials, the electron transport layer was composed of a triazine compound and the N-type charge generation layer In Example 3 composed of a triazine compound and a phenanthroline compound, the driving voltage was reduced by 2.95% and the quantum efficiency was increased by 2.34%, and in Example 4, the driving voltage was reduced by 2.86% and the quantum efficiency was increased by 2.35%.

Through this result, it was confirmed that the driving voltage of the device was reduced and the quantum efficiency was increased by providing an electron transport layer composed of a mixture of a triazine compound and a phenanthroline compound.

Experiment 4: Measurement of characteristics of a device having an electron transport layer composed of a mixed layer and an N-type charge generation layer

Example 5

In the same configuration as in Comparative Example 1, the electron transport layer was formed by mixing the triazine compound TA03_A05 and TA02-A24 in a 1: 1 ratio, and the N-type charge generation layer was formed by mixing the triazine compound TA03_A05 and the phenanthroline compound PN03_A16. A device was manufactured by changing only the formation.

Example 6

With the same configuration as in Example 5 described above, a device was manufactured except that the electron transport layer was formed by mixing the triazine compounds TA03_A05 and TA02-A24 in a ratio of 2:1.

Example 7

In the same configuration as in Example 5, the electron transport layer was formed by mixing the triazine compounds TA03_A05 and TA19-A23, and the N-type charge generation layer was formed by mixing the phenanthroline compounds PN03_A02 and PN03_A16. Device was manufactured.

The current density according to the driving voltage of the devices manufactured according to Comparative Example 1, Example 5, and Example 6 was measured and shown in FIG. 20, and the quantum efficiency according to luminance was measured and shown in FIG. In addition, the current density according to the driving voltage of the devices manufactured according to Comparative Example 1 and Example 7 was measured and shown in FIG. 22, and the quantum efficiency according to luminance was measured and shown in FIG. Their driving voltages and quantum efficiencies are shown in Table 4 below. (For driving voltage and quantum efficiency, the value of Comparative Example 1 was regarded as 100%, and the values of Examples 5, 6, and 7 were expressed in percent, and the driving current of the device was 10 mA/cm 2 .)

drive voltage quantum efficiency Comparative Example 1 100 100 Example 5 96.97 104.83 Example 6 94.85 105.31 Example 7 100 123.20

20, 21 and Table 4, compared to Comparative Example 1 in which the electron transport layer and the N-type charge generation layer were not composed of a mixture of materials, the electron transport layer was composed of triazine compounds and the N-type charge generation layer In Example 5 composed of a phenanthroline compound and a triazine compound, the driving voltage was reduced by 3.03% and the quantum efficiency was increased by 3.83%, and in Example 6, the driving voltage was reduced by 5.15% and the quantum efficiency was increased by 5.31%. In particular, compared to Example 5 in which the electron transport layer was formed by mixing TA03_A05 and TA02-A24 in a ratio of 1:1, the device driving voltage in Example 6 in which the electron transport layer was formed by mixing TA03_A05 and TA02-A24 in a ratio of 2:1 was further reduced. It was confirmed that the quantum efficiency was further increased.

Through this result, it was confirmed that the driving voltage and quantum efficiency characteristics of the device can be improved by adjusting the mixing ratio of a specific material in the electron transport layer in which the triazine compounds are mixed.

In addition, referring to FIGS. 22, 23 and Table 4, compared to Comparative Example 1 in which the electron transport layer and the N-type charge generation layer were not composed of a mixture of materials, the electron transport layer was composed of triazine compounds and N-type charge generation layer was formed. In Example 7, in which the generated layer was composed of phenanthroline compounds, the driving voltage was the same, but the quantum efficiency was increased by 23.20%.

Through this result, by providing an electron transport layer composed of a mixture of triazine compounds and an N-type charge generation layer composed of a mixture of phenanthroline compounds, the quantum efficiency can be significantly increased while maintaining the driving voltage of the device at the same level. confirmed.

100: organic light emitting element 110: anode
120: first hole injection layer 130: first hole transport layer
140: first light emitting layer 150: first electron transport layer
160N: N-type charge generation layer 160P: P-type charge generation layer
170: second hole injection layer 180: second hole transport layer
190: second light emitting layer 200: second electron transport layer
210: electron injection layer 220: cathode

Claims (13)

Light emitting units located between the anode and the cathode, each including a light emitting layer;
a P-type charge generation layer positioned between the light emitting units; and
At least one mixed layer positioned between the light emitting layer and the P-type charge generation layer,
The mixed layer is composed of a mixed layer of triazine compounds represented by Formula 1 below, a mixed layer of phenanthroline compounds represented by Formula 2 below, or a mixed layer thereof,
The mixed layer includes a first mixed layer and a second mixed layer disposed on the first mixed layer, the first mixed layer is an electron transport layer, the second mixed layer is an N-type charge generation layer, and the first mixed layer is the triazine. A mixture of compounds or a mixture of the triazine compound and the phenanthroline compound, and the second mixed layer is a mixture of the phenanthroline compounds or a mixture of the triazine compound and the phenanthroline compound. Characterized in that organic light-emitting device.
[Formula 1]

In Formula 1, X ₁ to X ₁₀ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.
[Formula 2]

In Formula 2, X ₁ to X ₆ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively. According to claim 1,
An organic light emitting device, characterized in that the triazine compound represented by Formula 1 is any one selected from compounds represented by the following.

delete According to claim 1,
The R ₁ and R ₂ are each independently an organic light emitting device, characterized in that any one selected from the compounds shown below.

In the above compounds,

which is indicated by

,

or

any one selected from

which is indicated by

,

or

one selected from According to claim 1,
An organic light emitting device, characterized in that the phenanthroline compound represented by Chemical Formula 2 is any one selected from the compounds represented below.

delete delete delete delete delete delete delete Light emitting units located between the anode and the cathode, each including a light emitting layer;
a P-type charge generation layer positioned between the light emitting units;
an electron transport layer positioned between the light emitting layer and the P-type charge generation layer;
an N-type charge generation layer positioned between the P-type charge generation layer and the electron transport layer; and
A mixed layer positioned between the electron transport layer and the N-type charge generation layer,
The mixed layer is composed of a mixed layer of triazine compounds represented by Formula 1 below, a mixed layer of phenanthroline compounds represented by Formula 2 below, or a mixed layer thereof,
The mixed layer includes a first mixed layer and a second mixed layer disposed on the first mixed layer, and the first mixed layer is made of a mixture of the triazine compounds or a mixture of the triazine compound and the phenanthroline compound. The organic light emitting device, characterized in that the second mixed layer is made of a mixture of the phenanthroline compounds or a mixture of the triazine compound and the phenanthroline compound.
[Formula 1]

In Formula 1, X ₁ to X ₁₀ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.
[Formula 2]

In Formula 2, X ₁ to X ₆ are each independently CH or C(R ₁ ) or C(R ₂ ), and R ₁ and R ₂ are each independently selected from aromatic ring compounds having 6 to 50 carbon atoms or N , It is selected from heterocyclic compounds containing one or more S, O or Si atoms and having 5 to 50 carbon atoms, and the C(R ₁ ) or C(R ₂ ) is present or absent in the same ring, respectively.

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