KR100898073B1 - Quinoxaline ring containing compound and an organic light emitting device comprising the same - Google Patents

Abstract

The present invention relates to a quinoxaline ring-containing compound represented by Formula 1 and an organic light emitting device having the same:

<Formula 1>

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, a halogen atom, a hydroxy group, a cyano group, a substituted or unsubstituted C ₁ -C ₃₀ alkyl group, a substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ acyl group, substituted or unsubstituted C ₂ -C ₃₀ alkenyl group, substituted or unsubstituted C ₂ -C ₃₀ alkynyl group, substituted or unsubstituted A C ₇ -C ₃₀ aralkyl group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, or a substituted or unsubstituted C ₅ -C ₃₀ heteroaryl group;

n, a and b are 1 or 2;

L is a simple chemical bond, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₇ -C ₃₀ aralkylene group, or a substituted or unsubstituted C ₆ -C ₃₀ arylene group.

Quinoxaline, electron transport layer, organic light emitting device

Description

Quinoxaline ring containing compound and an organic light emitting device comprising the same

1A to 1C are cross-sectional views briefly illustrating a structure of an organic light emitting diode according to the present invention.

The present invention relates to a quinoxaline ring-containing compound and an organic light emitting device using the same. More particularly, the present invention relates to a quinoxaline ring-containing compound, which is a material having electrical stability and high electron transport ability, and an organic light emitting device including the same. It is about.

Electroluminescent devices are attracting attention because they are self-luminous devices that have a wide viewing angle, excellent contrast, and fast response time. The electroluminescent device includes an inorganic light emitting device using an inorganic compound as an emitting layer and an organic light emitting device using an organic compound, and the organic light emitting device has a higher luminance than an inorganic light emitting device. In particular, many studies have been conducted in that driving voltage and response speed are excellent and multicoloring is possible.

The organic light emitting device generally has a stacked structure of an anode / organic light emitting layer / cathode, and further an anode / organic light emitting layer / hole blocking layer / cathode, anode / organic layer by further stacking a hole blocking layer or an electron injection layer between the light emitting layer and the cathode. Light emitting layer / electron transport layer / cathode or anode / organic light emitting layer / hole blocking layer / electron injection layer / cathode.

Heteroaromatic compounds, such as oxadiazoles, thiadiazoles, or pyrimidines, etc. are known as said electron carrying layer formation material (refer US patent 6,559,256).

However, the organic light emitting device including the electron transport layer forming material or the hole blocking layer forming material known to date has a lot of room for improvement because the efficiency and power consumption characteristics are not satisfactory.

In order to solve the problems of the prior art, an object of the present invention is to provide a quinoxaline ring-containing compound and an organic light emitting device having the same that can improve the efficiency and power consumption characteristics of the organic light emitting device.

In order to achieve the above object of the present invention, the first aspect of the present invention,

It provides a quinoxaline ring-containing compound represented by the following formula (1):

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, a halogen atom, a hydroxy group, a cyano group, a substituted or unsubstituted C ₁ -C ₃₀ alkyl group, a substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ acyl group, substituted or unsubstituted C ₂ -C ₃₀ alkenyl group, substituted or unsubstituted C ₂ -C ₃₀ alkynyl group, substituted or unsubstituted A C ₇ -C ₃₀ aralkyl group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, or a substituted or unsubstituted C ₅ -C ₃₀ heteroaryl group;

n, a and b are 1 or 2;

L is a simple chemical bond, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₇ -C ₃₀ aralkylene group, or a substituted or unsubstituted C ₆ -C ₃₀ arylene group.

In order to achieve the another object of the present invention, the second aspect of the present invention,

A first electrode; Second electrode; And an organic light emitting device including at least an organic film between the first electrode and the second electrode, wherein the organic film includes a quinoxaline ring-containing compound represented by Chemical Formula 1.

The organic light emitting device having the quinoxaline ring-containing compound may improve efficiency and power consumption.

Since the quinoxaline ring-containing compound according to the present invention has excellent electron transport capability, it can be effectively used as an organic film-forming material to obtain an organic light emitting device having high efficiency, low voltage, and high brightness.

Hereinafter, the present invention will be described in more detail.

Since the quinoxaline ring-containing compound of the present invention has an anthracene ring that is easy to stack π-π and a quinoxaline ring having a high electron affinity at the same time, when synthesized and used as an electron transporting material, the electron transport ability is improved. Let's do it. In particular, when synthesized and used as an electron transport material, the lowest occupied molecular orbital (LUMO) characteristic suitable for the electron transport layer is exhibited.

The quinoxaline ring-containing compound is represented by the following formula (1).

<Formula 1>

In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen, a halogen atom, a hydroxy group, a cyano group, a substituted or unsubstituted C ₁ -C ₃₀ alkyl group, a substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, substituted or unsubstituted C ₁ -C ₃₀ acyl group, substituted or unsubstituted C ₂ -C ₃₀ alkenyl group, substituted or unsubstituted C ₂ -C ₃₀ alkynyl group, substituted or unsubstituted A C ₇ -C ₃₀ aralkyl group, a substituted or unsubstituted C ₆ -C ₃₀ aryl group, or a substituted or unsubstituted C ₅ -C ₃₀ heteroaryl group;

n, a and b are 1 or 2;

L is a simple chemical bond, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₇ -C ₃₀ aralkylene group, or a substituted or unsubstituted C ₆ -C ₃₀ arylene group.

Preferably, the quinoxaline ring-containing compound is a compound represented by the following formula (2).

R ₃ and R ₄ are each independently hydrogen, a halogen atom, a hydroxyl group, a cyano group, a substituted or unsubstituted C ₁ -C ₃₀ alkyl group, a substituted or unsubstituted C ₁ -C ₃₀ alkoxy group, a substituted or unsubstituted A substituted C ₁ -C ₃₀ acyl group, a substituted or unsubstituted C ₂ -C ₃₀ alkenyl group, a substituted or unsubstituted C ₂ -C ₃₀ alkynyl group, a substituted or unsubstituted C ₆ -C ₃₀ aralkyl group, a substituted or An unsubstituted C ₆ -C ₃₀ aryl group or a substituted or unsubstituted C ₅ -C ₃₀ heteroaryl group.

Specific examples of the unsubstituted C1-C30 alkyl group used in the chemical formula of the present invention include methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, hexyl and the like, and at least one of the alkyl groups The hydrogen atom is a halogen atom, hydroxy group, nitro group, cyano group, amino group, amidino group, hydrazinyl group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group of C1-C30, alkene of C1-C30 It may be substituted with a alkyl group, a C1-C30 alkynyl group, a C6-C30 aryl group, a C7-C30 arylalkyl group, a C2-C20 heteroaryl group, or a C3-C30 heteroarylalkyl group.

Specific examples of the unsubstituted C1-C20 alkoxy group used in the chemical formula of the present invention include methoxy, ethoxy, phenyloxy, cyclohexyloxy, naphthyloxy, isopropyloxy, diphenyloxy, and the like. At least one hydrogen atom of these alkoxy groups may be substituted with the same substituent as in the alkyl group described above.

Specific examples of the unsubstituted C1-C30 acyl group used in the chemical formula of the present invention include acetyl, ethylcarbonyl, isopropylcarbonyl, phenylcarbonyl, naphthylenecarbonyl, diphenylcarbonyl, cyclohexylcarbonyl and the like. At least one hydrogen atom of these acyl groups may be substituted with the same substituent as in the alkyl group described above.

The unsubstituted C ₂ -C ₃₀ alkenyl group used in the formula of the present invention means that it contains a carbon double bond in the middle or at the end of the alkyl group as defined above. Examples are ethylene, propylene, butylene, hexylene and the like. At least one hydrogen atom of these alkenyl groups may be substituted with the same substituent as in the alkyl group described above.

The unsubstituted C ₂ -C ₃₀ alkynyl group used in Formula 1 of the present invention means that it contains a carbon triple bond in the middle or the end of the alkyl group as defined above. Examples include acetylene, propylene, phenylacetylene, naph Acetylacetylene, isopropylacetylene, t-butylacetylene, diphenylacetylene and the like. At least one hydrogen atom of these alkynyl groups may be substituted with the same substituent as in the alkyl group described above.

Unsubstituted C6-C20 aryl groups used in the formulas of the present invention may be used alone or in combination to mean aromatic carbon rings comprising one or more rings, which rings may be attached or fused together in a pendant manner. At least one hydrogen atom in the aryl group may be substituted with the same substituent as in the alkyl group described above.

Examples of the aryl group include phenyl group, ethylphenyl group, ethyl biphenyl group, o-, m- and p-fluorophenyl group, dichlorophenyl group, dicyanophenyl group, trifluoromethoxyphenyl group, o-, m-, and p-tolyl group, o-, m- and p-cumenyl groups, mesityl groups, phenoxyphenyl groups, (α, α-dimethylbenzene) phenyl groups, (N, N'-dimethyl) aminophenyl groups, (N, N'-diphenyl) aminophenyl groups , Pentarenyl group, indenyl group, naphthyl group, methylnaphthyl group, anthracenyl group, azurenyl group, heptarenyl group, acenaphthylenyl group, phenenalenyl group, fluorenyl group, anthraquinolyl group, methyl anthryl group, phenanyl group Triyl group, triphenylene group, pyrenyl group, chrysenyl group, ethyl-crisenyl group, pisenyl group, perylenyl group, chloroperylenyl group, pentaphenyl group, pentacenyl group, tetraphenylenyl group, hexaphenyl group, hexasenyl Group, rubisenyl group, coroneyl group, trinaphthylenyl group, heptaphenyl group, heptasenyl group, pyrantrenyl group, obarenyl group, carbazole And the like groups.

The unsubstituted aralkyl group used in the formula of the present invention means that some of the hydrogen atoms in the aryl group as defined above are substituted with lower alkyl groups such as methyl, ethyl, propyl and the like. For example benzyl, phenylethyl and the like. At least one hydrogen atom of the arylalkyl group may be substituted with the same substituent as in the alkyl group described above.

The unsubstituted heteroaryl group used in the present invention includes 1, 2 or 3 heteroatoms selected from N, O, P or S, and the remaining ring atoms are C 1 to monovalent monocyclic monocyclic or 6 to 30 ring atoms or By bicyclic aromatic divalent organic compound is meant. At least one hydrogen atom of the heteroaryl group may be substituted with the same substituent as in the alkyl group described above.

Examples of the heteroaryl group include pyrazolyl group, imidazolyl group, oxazolyl group, thiazolyl group, triazolyl group, tetrazolyl group, oxadizolyl group, pyridinyl group, pyridazinyl group, pyrimidinyl group, Triazinyl group, carbazolyl group, indolyl group, etc. are mentioned.

Examples of the unsubstituted C6-C20 arylene group used in the present invention include phenylene, biphenylene, and the like, and at least one hydrogen atom of the phenylene group or biphenylene group may be substituted with the same substituent as in the alkyl group described above. Do.

Specific examples of the quinoxaline ring-containing compound represented by Chemical Formula 1 include a compound represented by the following Chemical Formula 3.

The quinoxaline ring-containing compound of Formula 1 may be prepared using various known methods, which can be easily recognized by those skilled in the art.

As described above, the quinoxaline ring-containing compound of the present invention not only has excellent electron transport ability, but also exhibits the lowest occupied electron LUMO property suitable for the electron transport layer, especially when synthesized and used as an electron transport material. The electron transport material must not only have high electron mobility but also have an appropriate LUMO energy level to facilitate electron injection from the electron injection layer to the light emitting layer. The following table shows the LUMO level and HOMO level according to the result of Density Functional Theory (DFT) calculation comparing the quinoxaline ring-containing compound of Formula 3 with a compound having a structure in which naphthacene or naphthalene is bonded to quinoxaline.

LUMO (eV) HOMO (eV) Emissive layer in Example 1 (DSA: TBPe (3%)) -1.63 -5.12 Formula 3 -1.91 -5.22 Comparative Compound 1 -2.01 -5.61 Comparative Compound 2 -2.15 -4.84

Comparative Compound 1 and Comparative Compound 2 are as follows.

The DFT calculation value of the LUMO energy level of the light emitting layer which is commonly used is about -1.6 eV (see the LUMO energy level value of the light emitting layer used in Example 1 below in the above table), and the difference between the energy levels of the electron transport layer and the light emitting layer is 0.3 eV. If it is above, the movement of an electron will become disadvantageous. Therefore, Comparative Compound 1 and Comparative Compound 2, in which naphthacene and naphthalene are bonded to quinoxaline, respectively, are expected to have difficulty in injecting electrons into the light emitting layer because of low LUMO energy. Therefore, when anthracene is bound to a quinoxaline ring having a high electron affinity, it has a suitable LUMO energy level as an electron transport material, and such a compound is advantageous for injection and movement of electrons. The table shows that the compound of formula 3, which is a quinoxaline ring containing compound according to the present invention, has a suitable LUMO energy level as the electron transport layer.

An organic light emitting device according to the present invention comprises a first electrode; Second electrode; And at least an organic film between the first electrode and the second electrode, wherein the organic film may include a quinoxaline ring-containing compound represented by Formula 1 as described above.

The structure of the organic light emitting device according to the present invention is very diverse. An electron transport layer is provided as an organic layer between the first electrode and the second electrode, and in addition to the electron transport layer, one selected from the group consisting of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, and an electron injection layer The above layer may further be included as an organic film. Such an organic film may include a quinoxaline ring-containing compound represented by Formula 1 as described above. For example, the organic layer including the quinoxaline ring-containing compound represented by Formula 1 of the organic light emitting device according to the present invention may be an electron transport layer, but is not limited thereto.

More specifically, various embodiments of the organic light emitting device according to the present invention refer to Figures 1a, 1b and 1c. The organic light emitting device of Figure 1a has a structure consisting of a first electrode / hole transport layer / light emitting layer / charge transport layer / a second electrode, the organic light emitting device of Figure 1b has a first electrode / hole injection layer / hole transport layer / light emitting layer / electron transport layer It has a structure consisting of an electron injection layer and a second electrode. In addition, the organic light emitting device of FIG. 1C has a structure of a first electrode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode. At this time, of course, the electron transport layer may include a quinoxaline ring-containing compound represented by the formula (1).

Hereinafter, a method of manufacturing an organic light emitting diode according to the present invention will be described with reference to the organic light emitting diode illustrated in FIG. 1C.

First, a first electrode material having a high work function on the substrate is formed by vapor deposition or sputtering to form a first electrode. The first electrode may be an anode. Herein, a substrate used in a conventional organic light emitting device is used, and an organic substrate or a transparent plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness is preferable. As the material for the first electrode, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2), zinc oxide (ZnO), and the like, which are transparent and have excellent conductivity, are used.

Next, a hole injection layer HIL may be formed on the first electrode by using various methods such as vacuum deposition, spin coating, casting, and LB.

When the hole injection layer is formed by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the structure and thermal properties of the hole injection layer as desired, and the deposition temperature is generally 50 to 500 ° C., It is preferable that a vacuum degree of 10 ⁻⁸ to 10 ⁻³ torr, a deposition rate of 0.01 to 100 μs / sec, and a film thickness are appropriately selected in a range of usually 10 μs to 5 μm.

The hole injection layer material is not particularly limited, and for example, a phthalocyanine compound such as copper phthalocyanine disclosed in U.S. Patent No. 4,356,429 or a starburst amine derivative described in Advanced Material, 6, p.677 (1994). Retained TCTA, m-MTDATA, m-MTDAPB, etc. can be used as the hole injection layer. For the chemical formula of m-MTDATA, refer to the following formula (4).

Next, a hole transport layer (HTL) may be formed on the hole injection layer by using various methods such as vacuum deposition, spin coating, cast, and LB. When the hole transport layer is formed by a vacuum deposition method, the deposition conditions vary depending on the compound used, but are generally selected from the ranges of conditions almost the same as that of the hole injection layer.

The hole transport layer material is not particularly limited and may be selected from any of known ones used in the hole transport layer. For example, carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1-biphenyl]- Conventional amine derivatives having aromatic condensed rings such as 4,4'-diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl benzidine (α-NPD), and the like Used. For the formula of α-NPD, see Formula 5.

Next, the light emitting layer EML may be formed on the hole transport layer by using a vacuum deposition method, a spin coating method, a cast method, an LB method, or the like. In the case of forming the light emitting layer by vacuum deposition, the deposition conditions vary depending on the compound used, but are generally selected from the ranges of conditions substantially the same as those of forming the hole injection layer.

The light emitting layer material is not particularly limited and a material arbitrarily selected from known materials, known host materials and dopant materials can be used as the light emitting layer material. In the case of the host material, for example, Alq ₃ or CBP (4,4'-N, N'-dicarbazole-biphenyl) or the like can be used. In the case of the dopant, for example, as the fluorescent dopant, IDE102, IDE105 and C545T available from Hayamibara can be used. Phosphorescent dopant Ir (PPy) ₃ (PPy = 2-phenylpyridine), F2Irpic which is a blue phosphorescent dopant, red phosphorescent dopant RD 61 by UDC, etc. can be used. In addition, a dopant represented by Formula 6 may be used:

Doping concentration is not particularly limited, but the content of the dopant is generally 0.01 to 15 parts by weight based on 100 parts by weight of the host and the dopant.

In the case of using the phosphorescent dopant in the light emitting layer, the hole blocking material (HBL) may be further laminated by vacuum deposition or spin coating in order to prevent the triplet excitons or holes from diffusing into the electron transport layer. Known hole blocking materials that can be used include, for example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, hole blocking materials described in JP 11-329734 (A1), BCP, and the like.

Next, the electron transport layer (ETL) is formed using various methods such as vacuum deposition, spin coating, and casting. The electron transport layer material may use a quinoxaline ring-containing compound represented by the formula (1) that can further improve the electron transport ability, and known such as quinoline derivatives, in particular tris (8-quinolinorate) aluminum (Alq ₃ ) The material of can also be used.

In addition, an electron injection layer (EIL), which is a material having a function of facilitating injection of electrons from the cathode, may be stacked on the electron transport layer, which does not particularly limit the material.

As the electron injection layer, materials such as LiF, NaCl, CsF, Li 2 O, BaO and the like can be used. The deposition conditions of the hole blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL) vary depending on the compound used, but are generally selected from the same range of conditions as the formation of the hole injection layer.

Finally, the second electrode may be formed on the electron injection layer by using a method such as vacuum deposition or sputtering. The second electrode may be used as a cathode. As the metal for forming the second electrode, a metal, an alloy, an electrically conductive compound having a low work function, and a mixture thereof may be used. Specific examples include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like. Can be mentioned. In addition, a transmissive cathode using ITO and IZO may be used to obtain the front light emitting device.

The organic light emitting device of the present invention includes a first electrode, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer shown in FIG. (EIL) and the organic light emitting element of the second electrode structure, as well as the structure of the organic light emitting element of various structures are possible, it is also possible to further form one or two intermediate layers as needed.

Hereinafter, the synthesis examples and examples of the compound 3 represented by the formula (3) (hereinafter referred to as "compound 3") according to the present invention will be specifically illustrated, but the present invention is not limited to the following examples.

Example

Synthesis Example  One

Compound 3 was synthesized according to the reaction route of Scheme 1 below:

Synthesis of Intermediate A

Benzyl (1.12 g, 5.35 mmol) and 4-bromobenzene-1,2-diamine (1 g, 5.35 mmol) were dissolved in 30 ml of ethanol, and heated to reflux for 12 hours. Cooling to room temperature yields the resulting solid compound, which is filtered and recrystallized from a dichloromethane / normal hexane solution to obtain pure intermediate A. (1.37g, 79% yield)

Synthesis of Intermediate B

The intermediate A (2 g, 5.54 mmol) was dissolved in THF (40 ml) dried under a nitrogen atmosphere, and butyllithium (2.7 ml, 6.65 mmol) was added dropwise at -78 ° C. After stirring for one hour at the same temperature, trimethylborate (1.85ml, 16.6mmol) was added. After raising the temperature to room temperature, after 1 hour, an aqueous 2N hydrochloric acid solution was added, stirred for 3 hours, and extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate, followed by removal of residual moisture. Separation by column chromatography (ethyl acetate: normal hexane = 2: 3) afforded intermediate B. (1.25g, 69% yield)

Synthesis of Compound 3

The intermediate B (1.22 g, 3.74 mmol) and 9,10-dibromoanthracene (0.59 g, 1.78 mmol) were added to a mixed solvent of potassium carbonate (1.23 g, 8.9 mmol) and THF, and stirred with Pd (PPh3). 4 (206 mg, 0.178 mmol) was added and stirred under reflux for 6 hours. After cooling to room temperature, the resulting solid compound was filtered with washing with water, ethanol and toluene to obtain Compound 3. (0.96 g, 73% yield) 1 H NMR (400 MHz, CDCl ₃ ) 8.42 (2H), 7.93 (1H), 7.80 (2H), 7.64-7.59 (4H), 7.42-7.34 (8H)

Example  One

Using Compound 3 synthesized in Synthesis Example 1 as an electron transporting layer, an organic light emitting device was manufactured having the following structure: m-MTDATA (750 kV) / α-NPD (150 kV) / DSA (300 kV): TBPe ( 3%) / Compound 3 (200 kPa) / LiF (80 kPa) / Al (3000 kPa).

The anode is used to cut Corning 15Ω / cm ² (1200Å) ITO glass substrate into 50mm × 50mm × 0.7mm size, ultrasonic cleaning in isopropyl alcohol and pure water for 5 minutes, and UV ozone cleaning for 30 minutes. It was. M-MTDATA was vacuum deposited on the substrate to form a hole injection layer having a thickness of 750 mm3. Subsequently, α-NPD was vacuum deposited on the hole injection layer to a thickness of 150 kV to form a hole transport layer. After the hole transport layer was formed, a light emitting layer having a thickness of 300 μs was formed by vacuum deposition using DSA as a phosphorescent host and 3% of TBPe as a dopant on the hole transport layer. Thereafter, Compound 3 was vacuum-deposited on the emission layer to form an electron transport layer having a thickness of 200 kHz. LiF 80 kV (electron injection layer) and Al 3000 kV (cathode) were sequentially vacuum deposited on the electron transport layer to form a LiF / Al electrode, thereby manufacturing an organic light emitting device as illustrated in FIG. 3.

Comparative example  One

An organic light-emitting device was manufactured in the same manner as in Example 1, except that the material of the electron transport layer was used as Alq 3: m-MTDATA (750 μs) / α-NPD (150 μs) / DSA (300 μs): TBPe (3% ) / Alq3 (200 Hz) / LiF (80 Hz) / Al (3000 Hz).

Evaluation example  One

For the above examples and comparative examples, (current-voltage characteristic, luminance characteristic, efficiency characteristic and power consumption characteristic) were evaluated and shown in Table 1 below. Keithley was used for the current-voltage characteristic evaluation, and an IVL measuring device (PhotoResearch PR650 Keithley 238) was used for the luminance characteristic evaluation, the efficiency characteristic evaluation, and the power consumption characteristic evaluation.

Drive voltage (V) Current density (mA / cm ² ) Luminance (cd / m ² ) Efficiency (Im / W) Color coordinates (x, y) Example 1 5.2 10 593 3.46 (0.146, 0.237) Comparative Example 1 5.7 10 518 2.84 (0.145, 0.241)

Since the quinoxaline ring-containing compound according to the present invention has excellent electron transport capability, it can be effectively used as an organic film-forming material to obtain an organic light emitting device having high efficiency, low voltage, and high brightness.

Claims (9)

delete delete delete delete A first electrode; Second electrode; And an organic light emitting device including at least an organic film between the first electrode and the second electrode, wherein the organic film comprises a quinoxaline ring-containing compound represented by Formula 1 below, wherein the organic film is an electron transport layer. Organic light emitting device: <Formula 1>

In said formula, R <1>, R <2>, R <3> and R <4> are respectively independently hydrogen; Halogen atom; Hydroxyl group; Cyano group; At least one hydrogen atom is a halogen atom, hydroxy group, nitro group, cyano group, amino group, amidino group, hydrazinyl group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group of C ₁ -C ₃₀ , C ₁ -C ₃₀ alkenyl group, C ₁ -C ₃₀ alkynyl group, C ₆ -C ₃₀ aryl group, C ₇ -C ₃₀ arylalkyl group, C ₂ -C ₂₀ heteroaryl group, or C ₃ -C ₃₀ A C ₁ -C ₃₀ alkyl group unsubstituted or substituted with a heteroarylalkyl group; Or at least one hydrogen atom is a halogen atom, hydroxy group, nitro group, cyano group, amino group, amidino group, hydrazinyl group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group of C ₁ -C ₃₀ , C ₁ -C ₃₀ alkenyl group, a heteroaryl group of C ₁ -C ₃₀ alkynyl, C ₆ -C ₃₀ aryl group, C ₇ -C ₃₀ arylalkyl group, C ₂ -C ₂₀ of, or C ₃ -C a heteroarylalkyl group in the _{30-substituted} or unsubstituted C ₆ -C ₃₀ aryl group; n, a and b are 1 or 2; L is a single bond, an unsubstituted C ₁ -C ₃₀ alkylene group, an unsubstituted C ₇ -C ₃₀ aralkylene group, or an unsubstituted C ₆ -C ₃₀ arylene group. The organic light emitting diode of claim 5, wherein the organic layer further comprises at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. device. 7. The device of claim 6, wherein the device comprises a first electrode / hole transport layer / light emitting layer / electron transport layer / second electrode, first electrode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / second electrode or An organic light emitting device having a structure of a first electrode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode. The organic light emitting device of claim 5, wherein the quinoxaline ring-containing compound represented by Chemical Formula 1 is represented by Chemical Formula 2: <Formula 2>

R3 and R4 are each independently hydrogen; Halogen atom; Hydroxyl group; Cyano group; At least one hydrogen atom is a halogen atom, hydroxy group, nitro group, cyano group, amino group, amidino group, hydrazinyl group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group of C ₁ -C ₃₀ , C ₁ -C ₃₀ alkenyl group, C ₁ -C ₃₀ alkynyl group, C ₆ -C ₃₀ aryl group, C ₇ -C ₃₀ arylalkyl group, C ₂ -C ₂₀ heteroaryl group, or C ₃ -C ₃₀ A C ₁ -C ₃₀ alkyl group unsubstituted or substituted with a heteroarylalkyl group; Or at least one hydrogen atom is a halogen atom, hydroxy group, nitro group, cyano group, amino group, amidino group, hydrazinyl group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, alkyl group of C ₁ -C ₃₀ , C ₁ -C ₃₀ alkenyl group, a heteroaryl group of C ₁ -C ₃₀ alkynyl, C ₆ -C ₃₀ aryl group, C ₇ -C ₃₀ arylalkyl group, C ₂ -C ₂₀ of, or C ₃ -C a heteroarylalkyl group in ₃₀ is a substituted or unsubstituted C ₆ -C ₃₀ aryl group. The organic light emitting device according to claim 5, wherein the quinoxaline ring-containing compound represented by Chemical Formula 1 is represented by the following Chemical Formula 3. <Formula 3>

Images