KR102399446B1 - Organic compound, organic light emitting diode and organic light emiting device having the compound - Google Patents

Abstract

In the present invention, the molecular orbital function is localized to the electron donor moiety at both the energy level of the molecular orbital having the highest energy among the highest-occupied molecular orbitals calculated by molecular orbital calculation and the energy level of the molecular orbital having lower energy than this. To an organic light emitting diode and an organic light emitting device in which an organic compound distributed as Since the organic compound of the present invention has excellent charge transport properties, it is possible to prevent an increase in the driving voltage caused by a delay in charge injection in the light emitting diode, and to induce light emission in the entire region of the organic material layer, not in the interfacial region with the adjacent layer. Therefore, it is possible to improve the luminous efficiency and lifespan of the device.

Description

Organic compound, organic light emitting diode and organic light emitting device including the same

The present invention relates to an organic compound used in an organic light emitting diode, and more particularly, to an organic compound that can be used as a material for an organic material layer of an organic light emitting diode, an organic light emitting diode including the same, and an organic light emitting device.

Recently, with the enlargement of the display device, the demand for a flat display device that occupies less space is increasing. As one of the flat panel display devices, an organic light emitting diode (OLED) display device including a light emitting diode, also called an organic electroluminescent device (OELD), is attracting attention.

An organic light emitting diode (OLED) display device does not require a backlight unit required in a liquid crystal display device (LCD), and is a self-luminous display device that emits light by a light emitting pixel unit of a light emitting diode. Since the organic light emitting diode display can simplify the process, it can implement a lightweight, thin, and very thin display, can be driven at a low voltage (10V or less), consume relatively little power, and has excellent color purity. . In addition, the organic light emitting diode display has excellent viewing angle and contrast ratio compared to LCD, and it is attracting attention as a next-generation display after LCD because the device can be formed on a flexible transparent substrate such as plastic. .

The light emitting diode used in the organic light emitting diode display device injects electric charge into the light emitting layer formed of an organic material formed between the electron injection electrode (cathode) and the hole injection electrode (anode), after which electrons and holes are paired. It is an element that emits light as it decays. In the light emitting layer, electrons and holes meet to form excitons, and by this energy, the organic compound included in the light emitting layer becomes an excited state. It generates and emits the generated energy as light to emit light.

The light emitting layer constituting the light emitting diode may have a single layer structure of a light emitting material layer, or may have a multilayer structure to improve light emitting efficiency and lifespan of the device. For example, the light emitting layer of the light emitting diode may include a hole injection layer (HIL), a hole transporting layer (HTL), an emitting material layer (EML), and an electron transporting layer (ETL). and an electron injection layer (EIL).

A brief overview of the manufacturing process of an organic light emitting diode is as follows:

(1) First, a material such as indium tin oxide (ITO) is deposited on a transparent substrate to form an anode.

(2) A hole injection layer is formed on the anode. The hole injection layer is formed of an organic material such as Dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN) with a thickness of 10 nm to 60 nm. formed by vapor deposition.

(3) Next, a hole transport layer is formed on the hole injection layer. The hole transport layer is formed by depositing an organic material such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]-biphenyl(NPB) to about 20 nm to 60 nm. In the case of a phosphorescent device, an exciton blocking layer such as an electron blocking layer (EBL) may be formed between the hole transport layer and the light emitting material layer in order to effectively confine triplet excitons in the light emitting material layer.

(4) Next, a light emitting material layer, also called an organic light emitting layer, is formed on the hole transport layer. The light emitting material layer may include an appropriate host and dopant. For example, in the case of blue fluorescence, 9,10-Bis(1-naphtyl)anthracene(α-ADN) is often used as a host and 4,4′-bis[2-(4-(N, N-diphenylamino)phenyl)vinyl]biphenyl(DPAVBi) or diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)-phenyl]-amine (BD-1) 1 to 50% by weight, for example 1 to 10% by weight, and deposited to a thickness of 20 nm to 60 nm.

(5) Next, an electron transport layer and an electron injection layer are formed on the light emitting material layer. For example, tris-(8-hydroxyquinoline aluminum; Alq ₃ ) is used as the electron transport layer, and LiF is used as the electron injection layer. In the case of a phosphorescent device, in order to effectively confine triplet excitons in the light emitting material layer, a hole blocking layer (HBL) may be formed before the electron transport layer is formed.

(6) Next, a cathode is formed on the electron injection layer.

As described above, in the light emitting diode, holes and electrons respectively injected from the anode and the cathode form excitons in the light emitting layer to emit light. When only one material is used as a light emitting material, color purity, luminous efficiency, and lifetime of the device may be deteriorated. In order to improve the efficiency and lifetime of the device, the light emitting layer is typically composed of a host and a dopant. In the host-dopant binary system, the host transmits energy to the dopant rather than generating excitons and emitting light by itself, thereby generating high-efficiency light through the dopant. That is, the energy obtained when excitons are formed in the light emitting layer and transition to the ground state is finally transferred to the dopant through the host. As the probability of exciton formation in the dopant increases, luminous efficiency increases.

The light emitting material used in the organic light emitting device is the most important factor determining the light emitting efficiency of the device. In particular, in a host-dopant binary system, the host has a great influence on the efficiency and lifespan of the light emitting device, so an appropriate host must be selected. In this regard, Korean Patent Registration No. 10-1404346 suggests that a vinyl-type polynorbornene polymer can be used as a green phosphorescent host.

However, the light emitting material used in the organic light emitting device must have high quantum efficiency and good mobility of electrons and holes. Among the currently used light emitting materials, since the host has a wide band gap, in particular, hole injection is delayed, which increases the driving voltage of the device. In addition, holes and electrons cannot be injected into the light emitting layer in a balanced manner, so that light is emitted at the interface with the layer adjacent to the light emitting layer, thereby reducing the efficiency or lifespan of the device.

In particular, in recent years, the development of high-efficiency and long-life organic light emitting diodes has emerged as an urgent task. Considering the level of device characteristics required by mid- to large-sized OLED panels, it has thermal stability compared to conventional light emitting materials, and at the same time has excellent charge injection properties to prevent interfacial light emission, thereby improving device luminous efficiency and device lifespan There is a need to develop materials that can do this.

An object of the present invention is to provide an organic compound having excellent charge transport properties, an organic light emitting diode using the same, and an organic light emitting device.

Another object of the present invention is an organic compound capable of inducing a low driving voltage of a device by improving the thin film durability of the device, and inducing excellent luminous efficiency and color purity, and improved device lifespan, an organic light emitting diode and organic light emitting diode using the same It is intended to provide a device.

According to one aspect of the present invention having the above object, the present invention provides an organic compound in which a plurality of HOMO molecular orbitals are localized in an electron donor moiety composed of a bicarbazole core.

In the organic compound, a phenyl group, a biphenyl group and/or a terphenyl group may be substituted for a nitrogen atom constituting one carbazole group among the bicarbazole group core, and 4 to 6 aromatic rings may be substituted for a nitrogen atom constituting another carbazole group. The condensed homoaryl group and/or the heteroaryl group formed may be substituted.

According to another aspect of the present invention, the present invention relates to an organic light emitting diode in which the organic compound is included in an organic material layer.

According to another aspect of the present invention, the present invention relates to an organic light emitting device including an organic light emitting diode in which the organic compound is included in an organic material layer.

The organic compound of the present invention is localized to the bicarbazole core, in which the highest-level molecular-occupied orbital (HOMO), followed by HOMO, and sequentially high highest-level molecular-occupied orbital (HOMO-N) functions are electron donor moieties. distributed locally. That is, the organic compound of the present invention has the highest energy level of the highest molecular occupied orbital (HOMO) having the highest energy level among the HOMO molecular orbitals distributed corresponding to the electron donor moiety of the molecule, and the highest level having the lowest energy level. The ΔE _H value, which is defined as the difference in the energy levels of the molecular-level occupied orbital (HOMO-N), is 1.0 eV or more. When an electric field is applied to the light emitting device to which the organic compound of the present invention is applied, stability with respect to cation radicals formed by electron loss is greatly improved.

The organic compound of the present invention can improve the transport rate or transfer rate of electric charges. Therefore, when the organic compound of the present invention is applied to the organic material layer of the organic light emitting diode, since charge injection is not delayed, the device can be sufficiently driven even at a low voltage.

In particular, when the organic compound of the present invention is used, charges are injected into the organic material layer in a balanced manner, so that the charge balance in the organic material layer can be optimized. Accordingly, by preventing light emission at the interface between adjacent layers, light can be emitted in the entire region of the organic material layer, thereby improving durability, luminous efficiency, and/or device lifespan of the device.

Therefore, the organic compound of the present invention can be used as an organic material layer of an organic light emitting diode, for example, a light emitting material layer, as well as a common layer material such as a hole injection layer, a hole transport layer, and/or an exciton blocking layer.

1 shows the highest occupied molecular orbital (HOMO) function in the organic compound synthesized according to the present invention, and the highest occupied molecular orbital (HOMO-N, N is 1, 2, 3, etc.) function that is sequentially lower than that of HOMO. It is a schematic diagram schematically illustrating the state of being locally distributed in the bicarbazole core, which is an electron donor moiety. Among the occupied molecular orbitals, the highest molecular orbital is represented by HOMO, and sequentially lower molecular orbitals compared to HOMO are represented by HOMO-1, HOMO-2, HOMO-3, etc., respectively. Among the substituents that can be connected to the bicarbazole core, the remaining substituents except for the substituent connected to the nitrogen atom are omitted.
2 is a diagram schematically illustrating a mechanism of a resonance structure in which a radical cation formed when a compound synthesized according to the present invention loses electrons is locally distributed in the bikibazole core, which is an electron donor moiety.
3 is a cross-sectional view schematically showing the structure of an organic light emitting diode according to an exemplary embodiment of the present invention.
4 is a cross-sectional view schematically showing the structure of an organic light emitting diode according to another exemplary embodiment of the present invention.
5 is a cross-sectional view schematically illustrating an organic light emitting diode display as an example of an organic light emitting device to which an organic light emitting diode according to the present invention is applied.
6 to 10 are graphs showing NMR analysis results of compounds synthesized according to exemplary embodiments of the present invention, respectively.

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

[Organic compound]

The light emitting material used in the organic light emitting diode must have high luminous efficiency such as quantum efficiency and high electron and hole mobility. The light emitting material must also be uniformly formed in the light emitting material layer and stably induce light emission. Recently, the development of high-efficiency and long-life organic light-emitting devices has emerged as an urgent task. In the light-emitting layer of a binary system composed of two independent organic compounds, the host, which acts as an energy transmitter, has good color purity and can be vacuum deposited It should have an appropriate molecular weight. In addition, the glass transition temperature and thermal decomposition temperature are high, so thermal stability must be secured, high electrochemical stability is required for long life, and it must be easy to form an amorphous thin film. There should be no movement. The organic compound according to an aspect of the present invention is configured to satisfy these characteristics, and may be represented by the following Chemical Formula 1.

Formula 1

(In Formula 1, R ₁ To R ₁₆ are each independently connected to an adjacent carbazole group, or a hydrogen atom, a deuterium atom, a tritium atom, an unsubstituted or substituted C1~ C10 alkyl group, an unsubstituted or substituted C5~ C30 homo Aryl group, unsubstituted or substituted C5~ C30 hetero aryl group, unsubstituted or substituted C6~ C30 homo arylalkyl group, unsubstituted or substituted C6~ C30 hetero arylalkyl group, unsubstituted or substituted C6~ C30 homo aryloxy selected from the group consisting of an actual group and an unsubstituted or substituted C6~ C30 heteroaryloxyl group; Ar ₁ is selected from the group consisting of an unsubstituted or substituted C5~ C30 homoaryl group, a phenyl group, a biphenyl group, and a terphenyl group; ₂ is unsubstituted or substituted with a functional group selected from the group consisting of a C1 to C10 alkyl group, a C5 to C30 homo aryl group, a C6 to C30 homo arylalkyl group and a C6 to C30 homo aryloxyl group, and 4 to 6 aromatic rings substituted with a functional group selected from the group consisting of a condensed homoaryl group consisting It is a condensed heteroaryl group consisting of 6 aromatic rings)

As used herein, 'unsubstituted' or 'unsubstituted' means that a hydrogen atom is substituted, and in this case, the hydrogen atom includes light hydrogen, deuterium and tritium.

In the present specification, the substituent in 'substituted' is, for example, an unsubstituted or halogen-substituted alkyl group, an unsubstituted or halogen-substituted alkoxy group, halogen, cyano group, carboxyl group, carbonyl group, amine group, alkylamine group, nitro group, hydrazyl group, sulfonic acid group, alkyl silyl group, alkoxy silyl group, cycloalkyl silyl group, aryl silyl group, unsubstituted or substituted aryl group, heteroaryl group, etc. However, the present invention is not limited thereto.

In the present specification, 'heteroaromatic ring', 'heterocycloalkylene group', 'heteroarylene group', 'heteroarylalkylene group', 'heteroaryloxyylene group', 'heterocycloalkyl group', 'heteroaryl group', ' The term 'hetero' used in 'heteroarylalkyl group', 'heteroaryloxyl group', 'heteroarylamine group', etc. is at least one of the carbon atoms constituting these aromatic or alicyclic rings, for example, 1 to It means that 5 carbon atoms are substituted with one or more heteroatoms selected from the group consisting of N, O, S and combinations thereof.

According to one exemplary embodiment, when R ₁ to R ₁₆ in Formula 1 are a substituent of an aromatic ring, or Ar ₁ and/or Ar ₂ are substituted with an aromatic ring, these aromatic rings are each independently unsubstituted or substituted phenyl group, biphenyl group, terphenyl group, tetraphenyl group, naphthyl group, anthracenyl group, indenyl group, phenalenyl group, phenanthrenyl group, azulenyl group, pyrenyl group, fluorenyl group, tetracenyl group, indacenyl group, or an unfused or fused homoaromatic ring, such as a spiro fluorenyl group, and/or a pyrrolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a tetrazinyl group, Imidazolyl group, pyrazolyl group, indolyl group, carbazolyl group, benzocarbazolyl group, dibenzocarbazolyl group, indolocarbazolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazole group Diary, quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, benzoquinolinyl group, Benzoisoquinolinyl group, benzoquinazolinyl group, benzoquinoxalinyl group, acridinyl group, phenanthrolinyl group, furanyl group, pyranyl group, oxazinyl group, oxazolyl group, oxadiazolyl group, triazolyl group, deoxy It may be an uncondensed or condensed heteroaromatic ring such as a nyl group, a benzofuranyl group, a dibenzofuranyl group, a thiopyranyl group, a thiazinyl group, a thiophenyl group or an N-substituted spirofluorenyl group.

For example, in Formula 1, when Ar ₁ and/or Ar ₂ are substituted with an aromatic functional group, these functional groups are unsubstituted or substituted with a phenyl group at meta or para positions, such as a phenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, or a spiro group. A homoaryl group such as a fluorenyl group and/or a benzothiophenyl group unsubstituted or substituted with a phenyl group at the meta or para position, a dibenzothiophenyl group, a benzofuranyl group, a dibenzofuranyl group, a pyrrolyl group, a pyridinyl group, Pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazolyl group, pyrazolyl group, indolyl group, carbazolyl group, benzocarbazolyl group, dibenzocarbazolyl group, indolocarba Zolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, pr It may be a heteroaryl group such as a talazinyl group, a quinoxalinyl group, a cinolinyl group, a quinazolinyl group, a benzoquinolinyl group, a benzoisoquinolinyl group, a benzoquinazolinyl group or a benzoquinoxalinyl group. For example, in Formula 1, Ar ₁ and/or Ar ₂ may be substituted with a phenyl group, but the present invention is not limited thereto.

In one exemplary embodiment, Ar ₁ in Formula 1 is a homoaryl group such as a phenyl group, a biphenyl group, or a terphenyl group that is unsubstituted or substituted with a phenyl group at meta or para positions. Meanwhile, in Formula 1, Ar ₂ may be an unsubstituted or substituted fused homoaryl group or a fused heteroaryl group, and these fused homoaryl groups and fused heteroaryl groups form a fused ring comprising 4 to 6 aromatic rings. can do. When Ar ₂ forms a condensed ring composed of 4 to 6 aromatic rings, an organic compound having a desired band gap can be obtained while the length of the conjugated (conjugated) of the entire organic compound is increased.

Specifically, in Formula 1, the condensed aromatic ring constituting Ar ₂ is unsubstituted or substituted triphenylene, tetraphene, chrysene, fluoranthene, acephenanthrylene (acephenanthrylene), aceanthrylene, pyrene, tetracene, pleiadene, pycene, pentaphene, benzo-tetraphene, It may be a homocondensed aryl group such as perylene, dibenzo-pehenanthrene, pentacene, tetraphenylene, hexacene, or indenofluorene, but , the present invention is not limited thereto.

In addition, the condensed aromatic ring constituting Ar ₂ in Formula 1 is heterocondensed such as unsubstituted or substituted azatriphenylene, indeno-carbazole, indolo-carbazole, etc. It may be an aryl group, but the present invention is not limited thereto. Preferably, the condensed aromatic ring constituting Ar ₂ in Formula 1 is unsubstituted or substituted triphenylene or azatriphenylene.

Since the organic compound represented by Formula 1 has improved charge, particularly hole injection, transport and/or movement characteristics, by applying the organic compound represented by Formula 1 to a light emitting device, durability, light emitting characteristics, device characteristics, etc. of the light emitting device can be improved, which will be described. 1 shows the highest occupied molecular orbital (HOMO) function in the compound synthesized according to the present invention, and the highest occupied molecular orbital (HOMO-N, N is 1, 2, 3, etc.) function that is sequentially lower than that of HOMO. It is a schematic diagram schematically showing the state of being locally distributed in the bicarbazole core, which is a donor moiety, and FIG. 2 is a radical cation formed when the compound synthesized according to the present invention loses electrons is an electron donor moiety It is a diagram schematically showing the mechanism of the locally distributed resonance structure in the bikibazole core.

In the p-type organic compound applied to the conventional organic light emitting diode, the function of the Highest Occupied Molecular Orbital (HOMO), which is the highest energy level occupied by the molecule, is locally distributed in the electron donor moiety. However, the function of the highest level occupied molecular orbital (HOMO-N) at a lower level than that of HOMO is non-locally distributed throughout the molecule. In other words, in the conventional p-type organic compound, the distribution of the molecular orbital function at the HOMO energy level and the distribution of the molecular orbital function at the lower energy level (HOMO-N) do not match. It means that it is located non-locally in For example, in the conventional p-type host, the molecular orbital function of the HOMO level is locally distributed to the electron donor moiety (the distribution of the HOMO level molecular orbital function and the electron donor moiety are identical), but the HOMO- 1 level molecular orbital distribution is non-locally distributed throughout the molecule (HOMO-1 level molecular orbital distribution and electron donor moiety are inconsistent).

As such, when the distributions of electron donor moieties and HOMO molecular orbitals do not match, the positive charge present in the cation radical is It is also non-locally distributed in the entire molecule or in the Lowest Unoccupied Molecular Orbital (LUMO). Accordingly, when the compound is applied to the organic material layer of the light emitting device, the transport path of holes, which are positive charge carriers, is not sufficiently formed in the organic material layer. is brought about

On the other hand, as shown in FIG. 1, the organic compound synthesized according to the present invention has not only the molecular orbital function at the HOMO energy level, but also the molecular orbital function at the HOMO-N energy level sequentially lower than that of the HOMO electron donor. Locally distributed to the moiety, the bicarbazole core. That is, in the organic compound synthesized according to the present invention, the distribution of the electron donor moiety and the HOMO molecular orbital function of various energy level states is identical.

For example, in the organic compound of the present invention, not only the molecular orbital function of the HOMO level, but also the molecular orbital function of the sequentially lower HOMO-N (N is 1, 2, 3) level is localized to the electron donor moiety. distribution (the molecular orbital function distribution of the HOMO/HOMO-N level coincides with the electron donor moiety). If the HOMO molecular orbital function is distributed in a moiety other than the electron donor moiety, it may be undesirable in terms of molecular stability. According to the present invention, by appropriately adjusting the functional group substituted for the carbazole group (especially Ar ₁ and/or Ar ₂ in Formula 1), the HOMO molecular orbital function of various energy levels is distributed in the bicarbazole moiety, which is an electron donor moiety. can be adjusted

That is, in the organic compound synthesized according to the present invention, HOMO molecular orbitals of different energy level states among various molecular bonding orbitals to which electrons can bind are still locally distributed only in electron donor moieties. In other words, the organic compound synthesized according to the present invention has the energy level of the highest energy level highest occupied molecular orbital (HOMO) of the highest energy level among the highest occupied molecular orbitals coincident with the electron donor moiety and the electron donor moiety. The value of ΔE _H , which can be defined as the difference in the energy level of the highest occupied molecular orbital (HOMO-N) of the lowest energy level among the highest occupied molecular orbitals (for example, [HOMO - HOMO-3]), is quite large. . For example, ΔE _H of the organic compound synthesized according to the present invention may be 1.0 eV or more, for example, 1.0 to 4.0 eV, preferably 2.0 to 3.0 eV. When the ΔE _H value is greater than 1.0 eV, the resistance change rate in the thin film constituting the device decreases, and thus device characteristics may be improved. For example, ΔE _H of an organic compound may be measured using Gaussian 09 (functional function B3LYP/base function 6-31G ^* ), but the present invention is not limited thereto.

That is, as shown in FIG. 2, when the organic compound synthesized in the present invention is converted into a cationic radical by passing electrons to an adjacent molecule, the positive charge present in the cationic radical is still an electron donor moiety, bicarbazole Distributed locally in the core. That is, the organic compound of the present invention has a width ( ΔE _H ) is quite wide.

As such, when the organic compound synthesized according to the present invention is applied to the organic material layer of the light emitting device, molecular orbitals having different energy levels among molecular orbitals capable of binding with electrons are localized to the bicarbazole moiety functioning as an electron donor. distributed Accordingly, in the organic material layer, a hole transporting or hole transporting path as a positive charge carrier can be formed widely. As a result, charge injection and charge transport properties are improved in the organic material layer, so that excitons do not disappear, and interfacial emission can be prevented. In particular, by introducing a homo or hetero condensed aryl group having a polycyclic structure to Ar ₂ in Formula 1, high triplet energy (T ₁ ) can be maintained, and electrochemical stability due to an additional resonance effect can be improved.

That is, since the organic compound according to the present invention is distributed such that the function of the highest occupied molecular orbital according to the various energy level states to which electrons can bind corresponds to the electron donor moiety (that is, the ΔE _H value is large), It is possible to improve the charge injection and transport properties. By expanding the charge transfer or transport path, the drive voltage of the device is prevented from increasing due to the delay in charge injection, so that the device can be sufficiently driven even at a low voltage. In addition, when the organic compound of the present invention is used, charges are injected in a balanced manner in the organic material layer, so that the charge balance in the organic material layer can be optimized. Accordingly, light emission can be prevented from emitting light at the interface between adjacent layers and light can be emitted in the entire area of the organic material layer, thereby improving luminous efficiency and/or device lifespan.

Further, in one exemplary embodiment, the organic compound synthesized according to the present invention has a bandgap energy defined as the difference between the HOMO energy level and the LUMO energy level of -5.0 eV or more. In this case, the organic compound synthesized according to the present invention may have a conjugated surface of 18π electrons or more. Accordingly, the organic compound according to the present invention may be utilized as a host of an organic material layer constituting a light emitting device, for example. For example, since the organic compound synthesized according to the present invention has excellent hole transport properties, it can be applied as a p-type host in a light emitting diode. For example, the organic compound represented by Formula 1 may be applied to a hole injection layer, a hole transport layer, a light emitting material layer, and/or an electron blocking layer constituting the light emitting diode.

In one exemplary embodiment, it may be preferable that each of the bicarbazole moieties constituting the organic compound according to the present invention is bonded at the 3-3' position. Such an organic compound may be represented by the following formula (2).

Formula 2

(In Formula 2, R ₂₁ to R ₃₄ are each independently a hydrogen atom, a deuterium atom, a tritium atom, an unsubstituted or substituted C1 to C10 alkyl group, an unsubstituted or substituted C5 to C30 homoaryl group, an unsubstituted or substituted C5~ C30 heteroaryl group, unsubstituted or substituted C6~ C30 homo arylalkyl group, unsubstituted or substituted C6~ C30 hetero arylalkyl group, unsubstituted or substituted C6~ C30 homo aryloxyl group, and unsubstituted or substituted Selected from the group consisting of C6~ C30 hetero aryloxyl group; Ar ₁ and Ar ₂ are each the same as defined in Formula 1)

In the organic compound represented by Formula 2, the bicarbazole moiety is 3-3' linked. Since the electric charge can pass in a straight line along the HOMO orbital distribution of the organic compound represented by the formula (2), the electric charge can move smoothly. Accordingly, it is possible to prevent the increase in the driving voltage of the device due to the charge injection delay, thereby lowering the driving voltage, and inducing the balanced injection of charges from the organic material layer to prevent interfacial light emission with the adjacent layer. In addition, it is possible to improve the luminous efficiency of the light emitting device and improve the device lifespan.

More specifically, the organic compound that can be applied as a host in the organic material layer of the organic light emitting diode may include any one of the compounds PPH1 to PPH6 represented by Chemical Formula 3.

Formula 3

The organic compounds represented by the aforementioned Chemical Formulas 1 to 3 have a large ΔE _H value and thus have excellent charge transport properties. In particular, the energy bandgap of the organic compounds represented by Chemical Formulas 1 to 3 is as wide as -5.0 eV or more, and has a triplet energy greater than that of the dopant. Therefore, when the organic compound represented by the above-described Chemical Formulas 1 to 3 is used as a host having improved hole transport properties of the organic material layer constituting the light emitting diode, the energy transferred to the dopant is prevented from being reversely transferred to the host, resulting in high luminous efficiency. can have In addition, since the organic compound represented by Chemical Formulas 1 to 3 has excellent hole transport properties, it may be used as a material for a hole injection layer, a hole transport layer, a light emitting material layer, and/or an electron blocking layer constituting a light emitting diode.

[Light emitting diode and organic light emitting device]

As described above, for example, in the organic compounds represented by Chemical Formulas 1 to 3, the distribution of the electron donor moiety and the highest occupancy molecular orbital function of various energy levels is identical (that is, since the ΔE _H value is large) ), charge injection and transport properties, as well as light emitting properties and durability. Accordingly, the organic compound represented by Chemical Formulas 1 to 3 will be described with respect to the structure of the organic light emitting diode. 3 is a schematic cross-sectional view of a light emitting diode according to a first exemplary embodiment of the present invention.

As shown in FIG. 3 , the light emitting diode 100 according to the first exemplary embodiment of the present invention has a first electrode 110 and a second electrode 120 facing each other, and the first and second electrodes ( An organic material layer 130 positioned between 110 and 120 is included. The organic layer 130 is a hole injection layer (HIL; 140), a hole transport layer (HTL; 150), a light emitting material layer (EML; 160), and an electron transport layer (ETL; 170) sequentially stacked from the first electrode 110 . and an electron injection layer (EIL) 180 .

The first electrode 110 is made of a conductive material having a relatively large work function and is an anode. For example, the first electrode 110 may be formed of indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

The second electrode 120 is made of a conductive material having a relatively small work function value and is a cathode. For example, the second electrode 120 may be made of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy thereof.

The hole injection layer 140 is positioned between the first electrode 110 and the hole transport layer 150 , and improves the interface characteristics between the inorganic first electrode 110 and the organic hole transport layer 150 . In one exemplary embodiment, the hole injection layer 140 is 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine ; MTDATA), copper phthalocyanine (CuPc), tris (4-carbazoyl-9-yl-phenyl) amine (Tris (4-carbazoyl-9-yl-phenyl) amine; TCTA), N,N'- Diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (N,N'-diphenyl-N,N'-bis(1-naphthyl)- 1,1'-biphenyl-4,4"-diamine; α-NPB; NPD), 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (1,4,5,8, 9,11-hexaazatriphenylenehexacarbonitrile; HATCN), 1,3,5-tris [4- (diphenylamino) phenyl] benzene (1,3,5-tris [4- (diphenylamino) phenyl] benzene, TDAPB), poly ( 3,4-ethylenedioxythiophene)polystyrene sulfonate (poly(3,4-ethylenedioxythiphene)polystyrene sulfonate; PEDOT/PSS), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4 -(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine (N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9) -phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine) and/or may be composed of any one and a compound represented by the following formula (4). In another exemplary embodiment, the hole injection layer 140 may be formed of at least one compound of organic compounds represented by Chemical Formulas 1 to 3. The hole injection layer 140 may be omitted depending on the characteristics of the organic light emitting diode 100 .

Formula 4

The hole transport layer 150 is positioned between the first electrode 110 and the light emitting material layer 160 and adjacent to the light emitting material layer 160 . In one exemplary embodiment, the hole transport layer 150 is N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (N ,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine; TPD), NPD, 4,4'-bis(N-carbazolyl)- 1,1'-biphenyl (4,4'-bis(N-carbazolyl)-1,1'-biphenyl; CBP), N-(biphenyl-4-yl)-9,9-dimethyl-N-( 4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine(N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-( 9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine) and/or N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carba zol-3-yl)phenyl)biphenyl)-4-amine (N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4- amine), such as an aromatic amine compound. In another exemplary embodiment, the hole transport layer 150 may be formed of at least one compound of organic compounds represented by Chemical Formulas 1 to 3

The light emitting material layer 160 may be formed by doping a host with a dopant in order to increase the light emitting efficiency of the device. At least one organic compound represented by Chemical Formulas 1 to 3 may be used as a host of the light emitting material layer 160 . For example, since the organic compound represented by Chemical Formulas 1 to 3 has an electron donating moiety, it may be used as a p-type host of the light emitting material layer 160 .

In an exemplary embodiment, only at least one organic compound represented by Chemical Formulas 1 to 3, which is a compound having excellent hole transport properties, is used as a host of the light emitting material layer 160 , and hole transport properties in the light emitting material layer 160 are used. Alternatively, the electron transfer characteristics may be improved.

In another exemplary embodiment, at least one organic compound represented by Chemical Formulas 1 to 3, which is a p-type host, is used as a host of the light emitting material layer 160 , and an n-type host having an electron accepting moiety separately (For example, Host2 of Comparative Synthesis Example) can be used together. In this case, the HOMO energy level of the p-type host, which is the organic compound represented by Formulas 1 to 3, is higher than the HOMO energy level of the n-type host, and the LUMO energy level of the n-type host is the organic compound represented by Formulas 1 to 3 It may be lower than the LUMO energy level of the compound p-type host. In addition, the triplet energy level (E _T1 ^H ) of the p-type host and the n-type host is higher than that of the dopant (E _T1 ^D ), and the singlet energy of the p-type host and the n-type host is higher than that of the p-type host and the n-type host. The level E _S1 ^H may be higher than the singlet energy level E _S1 ^D of the dopant.

When the p-type host and the n-type host are used together, the p-type host and the n-type host, which are organic compounds represented by Chemical Formulas 1 to 3, form an excited state charge transfer complex in the light emitting material layer 160 . It can form an exciplex that is a transfer complex. The triplet energy level and the singlet energy level of the exciplex are higher than the triplet energy level and the singlet energy level of the dopant, respectively, so that energy transfer from the triplet state or the singlet state of the exciplex to the dopant may occur.

As such, when a p-type host, which is an organic compound represented by Chemical Formulas 1 to 3, and an n-type host, which are organic compounds represented by Chemical Formulas 1 to 3, are used as the host of the light emitting material layer 160 , the light emitting diode 100 can be driven even at a low voltage. In this case, the light emitting diode 100 having high luminous efficiency and long life can be realized by inducing light emission in the entire region of the light emitting material layer 160 . At this time, by adopting a dopant having a triplet energy lower than the triplet energy of the host, the energy transferred to the dopant is prevented from being reverse-transferred to the host, so that high luminous efficiency can be obtained, and the charge from the host to the dopant is easily transferred can be transferred

When the host-dopant system is adopted, the p-type host and the n-type host represented by Formulas 1 to 3 and the n-type host each contain 20 to 80% by weight, preferably 30 to 70% by weight, more preferably 40 to It may be mixed in a proportion of 60% by weight. By appropriately controlling the mixing ratio of the p-type host and the n-type host, holes and electrons can be injected into the light emitting material layer 160 in a balanced manner, thereby improving the light emitting efficiency and device lifespan of the light emitting diode 100 . can be improved

The light emitting material layer 160 includes a dopant in addition to the host, which is an organic compound represented by Chemical Formulas 1 to 3. For example, the dopant included in the light emitting material layer 160 may be a phosphorescent dopant. The phosphorescent dopant that can be used in the light emitting material layer 160 is not particularly limited, and is, for example, a complex of metal atoms composed of iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt). Preferably, it is a metal complex such as iridium (Ir) or platinum (Pt), and particularly preferably is an iridium (Ir) complex.

Considering that the organic compound represented by Formulas 1 to 3 is used as a host, charges can be efficiently transferred from these hosts, and it is necessary to prevent reverse-transfer of energy to the host. For this purpose, it may be preferable to use a dopant having an energy band gap between the energy band gaps of the organic compounds represented by Chemical Formulas 1 to 3, that is, a dopant having a triplet energy equal to or less than the triplet energy of the host. In one exemplary embodiment, the dopant that may be used in the light emitting material layer 160 may be at least one material represented by the following Chemical Formula 5 or Chemical Formula 6, but the present invention is not limited thereto.

Formula 5

Formula 6

(In Formula 5, R ₄₁ to R ₄₉ are each independently hydrogen, deuterium, tritium, halogen, unsubstituted or halogen-substituted C1-C30 alkyl group, cyano group, unsubstituted or substituted C3-C30 cycloalkyl group, unsubstituted unsubstituted or substituted C3~C30 heterocycloalkyl group, unsubstituted or substituted C5~C30 aryl group, unsubstituted or substituted C5~C30 heteroaryl group, unsubstituted or substituted C6~C30 arylalkyl group, unsubstituted or substituted C6 -C30 heteroarylalkyl group, unsubstituted or substituted C6~C30 aryloxyl group and unsubstituted or substituted C6~C30 heteroaryloxyl group selected from the group consisting of; R ₅₀ is hydrogen, deuterium, tritium or unsubstituted A substituted C1~ C30 alkyl group; r is an integer of 1 to 4; In Formula 6, R ₅₁ to R ₅₈ are each independently hydrogen, deuterium, tritium, halogen, an unsubstituted or halogen-substituted C1~ C30 alkyl group, cya No group, unsubstituted or substituted C3 to C30 cycloalkyl group, unsubstituted or substituted C3 to C30 heterocycloalkyl group, unsubstituted or substituted C5 to C30 aryl group, unsubstituted or substituted C5 to C30 heteroaryl group, unsubstituted From the group consisting of an unsubstituted or substituted C6~C30 arylalkyl group, an unsubstituted or substituted C6~C30 heteroarylalkyl group, an unsubstituted or substituted C6~C30 aryloxyl group, and an unsubstituted or substituted C6~C30 heteroaryloxyl group selected or linked together with an adjacent substituent to form an unsubstituted or substituted C5-C30 aromatic ring; In Formulas 5 and 6, L is represented by the following Formula 7; In Formulas 5 and 6, n is 1 to 3 integer)

Formula 7

(In Formula 7, R ₆₁ to R ₆₈ are each independently hydrogen, deuterium, tritium, halogen, unsubstituted or halogen-substituted C1-C30 alkyl group, cyano group, unsubstituted or substituted C3-C30 cycloalkyl group, unsubstituted unsubstituted or substituted C3~C30 heterocycloalkyl group, unsubstituted or substituted C5~C30 aryl group, unsubstituted or substituted C5~C30 heteroaryl group, unsubstituted or substituted C6~C30 arylalkyl group, unsubstituted or substituted C6 ~ C30 hetero arylalkyl group, unsubstituted or substituted C6~ C30 aryloxyl group, and unsubstituted or substituted C6~ C30 hetero aryloxyl group selected from the group consisting of, or linked together with an adjacent substituent, unsubstituted or substituted C5 to form an aromatic ring of ~C30)

In one exemplary embodiment, the dopant of the light emitting material layer 160 may be at least one of D1 to D13 represented by Chemical Formula 8 below.

Formula 8

When the organic compound represented by Chemical Formulas 1 to 3 is used as a host in the light emitting material layer 160 and a dopant receiving energy from the host is used, the dopant is approximately based on the host applied to the light emitting material layer 160 . It may be doped in a proportion of 0.1 to 50% by weight, preferably 1 to 20% by weight.

An electron transport layer 170 and an electron injection layer 180 may be sequentially stacked between the light emitting material layer 160 and the second electrode 120 . The material constituting the electron transport layer 170 requires high electron mobility, and electrons are stably supplied to the light emitting material layer 160 through smooth electron transport.

In one exemplary embodiment, the electron transport layer 170 is oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, benzimidazole. , may be a derivative such as triazine. For example, the electron transport layer 170 may include tris-(8-hydroxyquinoline aluminum; Alq ₃ ), 2-biphenyl-4-yl-5-(4-tert-butyl). Phenyl)-1,3,4-oxadiazole (2-biphenyl-4-yl-5-(4-t-butylphenyl)-1,3,4-oxadiazole; PBD), spiro-PBD, lithium quinolate (lithium quinolate; Liq), 2-[4-(9,10-di-2-naphthalenyl-2-anthracenyl)phenyl]-1-phenyl-1H-benzimidazole (2-[4-(9) ,10-di-2-naphthalenyl-2-anthracenyl)phenyl]-1-phenyl-1H-benzimidazole), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-bi Phenyl-4-olato)aluminum (Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum, BAlq), 3-(biphenyl-4-yl )-5-(4-terbutylphenyl)-4-phenyl-4H-1,2,4-triazole (3-(biphenyl-4-yl)-5-(4-terbutylphenyl)-4-phenyl-4H -1,2,4-triazole, TAZ), 4,7-diphenyl-1,10-phenanthroline (4,7-diphenyl-1,10-phentanthroline, Bphen), tris (phenylquinoxaline) (tris (phenylquinoxaline, TPQ) and/or 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene, TPBi) and / or may be made of any one material represented by the following Chemical Formula 9, but the present invention is not limited thereto.

Formula 9

The electron injection layer 180 is positioned between the second electrode 120 and the electron transport layer 170 , and the lifespan of the device may be improved by improving the characteristics of the second electrode 120 . In one exemplary embodiment, the material of the electron injection layer 180 is an alkali halide-based material such as LiF, CsF, NaF, BaF ₂ and/or Liq, lithium benzoate, sodium stearate (sodium). stearate) may be used, but the present invention is not limited thereto.

That is, the light emitting diode 100 according to the first embodiment of the present invention has first and second electrodes 110 and 120 facing each other, and a hole injection layer between the first and second electrodes 110 and 120 . 140 , the organic material layer 130 including the hole transport layer 150 , the light emitting material layer 160 , the electron transport layer 170 , and the electron injection layer 180 . Since the organic compounds of Chemical Formulas 1 to 3 have excellent hole transport properties, in particular, among these organic material layers 130 , at least one constituting the hole injection layer 140 , the hole transport layer 150 , and/or the light emitting material layer 160 . It can be used alone or in combination with a dopant.

As described above, since the organic compound of the present invention has very excellent charge transport properties, when the organic compound is applied to the hole injection layer 140 , the hole transport layer 150 , and/or the light emitting material layer 160 , the charge The light emitting diode 100 can be driven even at a low voltage due to the improvement of the transport capability. In particular, when the organic compound represented by Chemical Formulas 1 to 3 is used in the light emitting material layer 160 , charges are injected in a balanced manner to induce light emission in the entire region of the light emitting material layer 160 , and the light emitting diode 100 . ) to improve the luminous efficiency and/or lead to a longer lifespan.

Even in the light emitting diode 100 of the first embodiment, the organic compound of Chemical Formulas 1 to 3 may be used in at least one of the organic material layers 130 to induce low driving voltage, excellent luminous efficiency, and/or improved device lifespan. . The light emitting diode according to another embodiment of the present invention may include an additional organic material layer so that charges can be injected and moved in a more balanced manner. FIG. 4 schematically shows a light emitting diode 200 according to a second embodiment of the present invention. It is one cross section.

4, the light emitting diode 200 according to the second embodiment of the present invention has a first electrode 210 and a second electrode 220 facing each other, and the first and second electrodes 210, 220) and an organic material layer 230 positioned between them. The organic material layer 230 is a hole injection layer 240, a hole transport layer 250, an electron blocking layer (EBL; 310) that are sequentially stacked from the first electrode 210, a light emitting material layer 260, a hole blocking layer ( HBL; 320), an electron transport layer (ETL; 170), and an electron injection layer (EIL; 180).

The first electrode 210 is made of a conductive material having a relatively large work function value and is an anode. For example, the first electrode 110 may be formed of indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

The second electrode 220 is made of a conductive material having a relatively small work function value and is a cathode. For example, the second electrode 220 may be made of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy thereof.

The hole injection layer 240 is positioned between the first electrode 210 and the hole transport layer 250 , and improves the interface characteristics between the inorganic first electrode 210 and the organic hole transport layer 250 . In one exemplary embodiment, the hole injection layer 240 may be formed of MTDATA, CuPc, TCTA, NPB, HATCN, TDAPB, PEDOT/PSS, and/or any one represented by Formula 4 and a compound. In another exemplary embodiment, the hole injection layer 240 may be formed of at least any one of organic compounds represented by Chemical Formulas 1 to 3. The hole injection layer 240 may be omitted depending on the characteristics of the organic light emitting diode 200 .

The hole transport layer 250 is positioned between the first electrode 210 and the light emitting material layer 260 and adjacent to the light emitting material layer 260 . In one exemplary embodiment, the hole transport layer 250 is TPD, NPB, CBP, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carba) zol-3-yl)phenyl)-9H-fluoren-2-amine and/or N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl) It may be composed of an aromatic amine compound such as phenyl)biphenyl)-4-amine. In another exemplary embodiment, the hole transport layer 250 may be formed of at least any one of organic compounds represented by Chemical Formulas 1 to 3.

On the other hand, when holes move to the second electrode 220 through the light emitting material layer 260 or electrons pass through the light emitting material layer 260 to the first electrode 210, the lifetime and efficiency of the device are reduced. can bring To prevent this, the light emitting diode 200 according to the second embodiment of the present invention may include an exciton blocking layer on at least one of an upper portion and a lower portion of the light emitting material layer 260 .

For example, the light emitting diode 200 according to the second embodiment of the present invention includes an electron blocking layer 255 that can control and prevent the movement of electrons between the hole transport layer 250 and the light emitting material layer 260 . can be located In one exemplary embodiment, the electron blocking layer 255 is TCTA tris [4- (diethylamino) phenyl] amine (tris [4- (diethylamino) phenyl] amine), N- (biphenyl-4-yl) )-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, tri-p-tolylamine (tri-p- tolylamine), 1,1-bis (4- (N, N-di (p-tolyl) amino) phenyl) cyclohexane (1,1-bis (4- (N, N'-di (ptolyl) amino) phenyl) )cyclohexane;TAPC), MTDATA, mCP, mCBP, CuPC, N,N'-bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-bi Phenyl]-4,4'-diamine (N,N'-bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4 '-diamine; DNTPD), TDAPB and/or (N-(biphenyl)-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi [fluoren]-2-amine ((N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[fluoren]-2- amine) In another exemplary embodiment, the electron blocking layer 255 may be formed of at least one organic compound represented by Chemical Formulas 1 to 3.

The light emitting material layer 260 may be formed by doping a host with a dopant in order to increase the light emitting efficiency of the device. An organic compound represented by Chemical Formulas 1 to 3 may be used as a host of the light emitting material layer 260 . For example, at least one organic compound represented by Chemical Formulas 1 to 3 may be used as the p-type host of the light emitting material layer 260 . In this case, an n-type host (eg, Host2 of Comparative Synthesis Example) may be included in the light emitting material layer 260 .

In this case, the light emitting material layer 260 may include, for example, a dopant such as a phosphorescent dopant having a lower triplet energy than the organic compound represented by Chemical Formulas 1 to 3. For example, the dopant may be a phosphorescent complex represented by Chemical Formulas 5 to 8. When the light emitting material layer 260 is composed of a host-dopant, the dopant may be doped in an amount of about 0.1 to 50% by weight, preferably 1 to 20% by weight based on the host.

In addition, in the second embodiment of the present invention, the hole blocking layer 265 is positioned as another exciton blocking layer between the light emitting material layer 260 and the electron transport layer 270, so that the light emitting material layer 260 and the electron transport layer 270 are located. Prevents the movement of holes between them. In one exemplary embodiment, oxadiazole, triazole, phenanthroline, benzoxazole that may be used in the electron transport layer 270 as a material of the hole blocking layer 265 . ), benzothiazole, benzimidazole, and derivatives such as triazine may be used. For example, the hole blocking layer 265 is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2, 9-dimethyl-4,7-diphenyl-1,10-phenanthroline; BCP), Alq ₃ , Liq, bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl -4-olato)aluminum (Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-Biphenyl-4-olato)aluminum; BAlq), bis-4,6-(3,5 -di-3-pyridylphenyl)-2-methylpyrimidine (bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine; B3PYMPM), 2-biphenyl-4-yl- 5-(4-tert-butylphenyl)-1,3,4-oxadiazole (2-biphenyl-4-yl-5-(4-t-butylphenyl)-1,3,4-oxadiazole; PBD) , spiro-PBD and/or may be made of any one material represented by Formula 9, but the present invention is not limited thereto.

Meanwhile, an electron transport layer 270 and an electron injection layer 280 may be sequentially stacked between the light emitting material layer 260 and the second electrode 220 . The material constituting the electron transport layer 270 requires high electron mobility, and electrons are stably supplied to the light emitting material layer 260 through smooth electron transport.

In one exemplary embodiment, the electron transport layer 270 is oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, benzimidazole. , may be a derivative such as triazine. For example, the electron transport layer 270 may include Alq3, PBD, spiro-PBD, Liq, 2-[4-(9,10-di-2-naphthalenyl-2-anthracenyl)phenyl]-1-phenyl -1H-benzimidazole, BAlq, TAZ, Bphen, TPQ, TPBi, and/or any one of the materials represented by Formula 9 above, but the present invention is not limited thereto.

The electron injection layer 280 is positioned between the second electrode 220 and the electron transport layer 270 , and by improving the characteristics of the second electrode 220 , the lifespan of the device may be improved. In one exemplary embodiment, as the material of the electron injection layer 280, an alkali halide-based material such as LiF, CsF, NaF, BaF ₂ and/or an organometallic material such as Liq, lithium benzoate, sodium stearate, etc. may be used. However, the present invention is not limited thereto.

That is, in the light emitting diode 200 according to the second embodiment of the present invention, as compared to the light emitting diode 100 according to the first embodiment, the movement of holes or electrons to at least one of the upper and lower surfaces of the light emitting material layer 260 . It further includes at least one of the electron blocking layer 255 and the hole blocking layer 265 as an exciton blocking layer that can prevent the. Since the organic compounds of Chemical Formulas 1 to 3 have excellent hole transport properties, among these organic material layers 230 , in particular, the hole injection layer 240 , the hole transport layer 250 , the electron blocking layer 255 and/or the light emitting material layer 260 . ) may be used alone or together with a dopant in at least one layer constituting the .

As described above, since the organic compound of the present invention has very excellent charge transport properties, the organic compound is applied to the hole injection layer 240 , the hole transport layer 250 , the electron blocking layer 255 and/or the light emitting material layer 260 . ), it is possible to drive the light emitting diode 200 even at a low voltage by improving the charge transport ability. In particular, when the organic compound represented by Chemical Formulas 1 to 3 is used in the light emitting material layer 260 , charges are injected in a balanced manner to induce light emission in the entire region of the light emitting material layer 260 , and the light emitting diode 200 . ) to improve the luminous efficiency and/or lead to a longer lifespan.

The organic light emitting diode according to the present invention may be applied to an organic light emitting diode display device or an organic light emitting device such as a lighting device to which the above-described organic light emitting diode is applied. As an example, a display device to which the organic light emitting diode of the present invention is applied will be described. 5 is a schematic cross-sectional view of an organic light emitting diode display device according to an exemplary embodiment of the present invention.

As shown in FIG. 5 , the organic light emitting diode display 300 includes a driving thin film transistor Td as a driving element, a planarization layer 360 covering the driving thin film transistor Td, and a planarization layer 360 on the and an organic light emitting diode 400 connected to the driving thin film transistor Td as a driving element. The driving thin film transistor Td includes a semiconductor layer 310 , a gate electrode 330 , a source electrode 352 , and a drain electrode 354 , and in FIG. 5 , a driving thin film having a coplanar structure A transistor Td is shown.

The substrate 302 may be a glass substrate, a thin flexible substrate, or a polymer plastic substrate. For example, the flexible substrate may include polyimide (PI), polyethersulfone (PES), polyethylenenaphthalate (PEN), polyethylene terephthalate (PET), and polycarbonate (PC). It may be formed by any one of them. The driving thin film transistor Td, which is a driving element, and the substrate 302 on which the organic light emitting diode 400 is positioned form an array substrate.

A semiconductor layer 310 is formed on the substrate 302 . For example, the semiconductor layer 310 may be formed of an oxide semiconductor material. In this case, a light blocking pattern (not shown) and a buffer layer (not shown) may be formed under the semiconductor layer 310 , and the light blocking pattern prevents light from being incident on the semiconductor layer 310 so that the semiconductor layer 310 prevents the light from entering the semiconductor layer 310 . to prevent deterioration by Alternatively, the semiconductor layer 310 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 310 may be doped with impurities.

A gate insulating layer 320 made of an insulating material is formed on the entire surface of the substrate 302 on the semiconductor layer 310 . The gate insulating layer 320 may be made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx).

The gate electrode 330 made of a conductive material such as metal is formed on the gate insulating layer 320 to correspond to the center of the semiconductor layer 310 . Also, a gate line (not shown) and a first capacitor electrode (not shown) may be formed on the gate insulating layer 320 . The gate wiring may extend along the first direction, and the first capacitor electrode may be connected to the gate electrode 330 . Meanwhile, although the gate insulating layer 320 is formed on the entire surface of the substrate 302 , the gate insulating layer 320 may be patterned in the same shape as the gate electrode 330 .

An interlayer insulating layer 340 made of an insulating material is formed on the entire surface of the substrate 302 on the gate electrode 330 . The interlayer insulating layer 340 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx), or an organic insulating material such as benzocyclobutene or photo-acryl. there is.

The interlayer insulating layer 340 has first and second semiconductor layer contact holes 342 and 344 exposing top surfaces of both sides of the semiconductor layer 310 . The first and second semiconductor layer contact holes 342 and 344 are positioned at both sides of the gate electrode 330 to be spaced apart from the gate electrode 330 . Here, the first and second semiconductor layer contact holes 342 and 344 are also formed in the gate insulating layer 320 . In contrast, when the gate insulating layer 320 is patterned to have the same shape as the gate electrode 330 , the first and second semiconductor layer contact holes 342 and 344 are formed only in the interlayer insulating layer 340 .

A source electrode 352 and a drain electrode 354 made of a conductive material such as metal are formed on the interlayer insulating layer 340 . In addition, a data line (not shown), a power line (not shown), and a second capacitor electrode (not shown) extending along the second direction may be formed on the interlayer insulating layer 340 .

The source electrode 352 and the drain electrode 354 are spaced apart from the center of the gate electrode 330 , respectively, on both sides of the semiconductor layer 310 through the first and second semiconductor layer contact holes 342 and 344 , respectively. contact Although not shown, the data line extends along the second direction and intersects the gate line to define a pixel area, and the power line for supplying a high potential voltage is spaced apart from the data line. The second capacitor electrode is connected to the drain electrode 354 and overlaps the first capacitor electrode to form a storage capacitor using the interlayer insulating film 340 between the first and second capacitor electrodes as a dielectric layer.

Meanwhile, the semiconductor layer 310 , the gate electrode 330 , the source electrode 352 , and the drain electrode 354 form the driving thin film transistor Td. The driving thin film transistor Td illustrated in FIG. 5 has a coplanar structure in which a gate electrode 330 , a source electrode 352 , and a drain electrode 354 are positioned on the semiconductor layer 310 . Alternatively, the driving thin film transistor Td may have an inverted staggered structure in which a gate electrode is positioned under a semiconductor layer and a source electrode and a drain electrode are positioned over the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

In addition, a switching thin film transistor (not shown), which is a switching element having a structure substantially the same as that of the driving thin film transistor Td, is further formed on the substrate 302 . The gate electrode 330 of the driving thin film transistor Td is connected to a drain electrode (not shown) of the switching thin film transistor (not shown), and the source electrode 352 of the driving thin film transistor Td is connected to a power wiring (not shown). connected In addition, the gate electrode (not shown) and the source electrode (not shown) of the switching thin film transistor (not shown) are respectively connected to the gate line and the data line.

Meanwhile, the organic light emitting diode display 300 may include a color filter (not shown) that absorbs light generated by the organic light emitting diode 400 . For example, a color filter (not shown) may absorb red (R), green (G), blue (B), and white (W) light. In this case, red, green, and blue color filter patterns for absorbing light may be formed separately for each pixel region, and each of these color filter patterns is an organic light emitting diode (OLED) emitting light of a wavelength band to be absorbed. 400) may be disposed to overlap the organic material layer 430, respectively. By adopting a color filter (not shown), the organic light emitting diode display 300 may realize full-color.

For example, when the organic light emitting diode display 300 is a bottom light emitting type, a color filter (not shown) that absorbs light may be positioned on the interlayer insulating film 340 corresponding to the organic light emitting diode 400 . . In an alternative embodiment, when the organic light emitting diode display 300 is a top emission type, the color filter may be positioned above the organic light emitting diode 400 , that is, above the second electrode 420 .

A planarization layer 360 is formed over the entire surface of the substrate 302 on the source electrode 352 and the drain electrode 354 . The planarization layer 360 has a flat top surface and has a drain contact hole 362 exposing the drain electrode 354 of the driving thin film transistor Td. Here, the drain contact hole 362 is illustrated as being formed directly above the second semiconductor layer contact hole 344 , but may be formed to be spaced apart from the second semiconductor layer contact hole 344 .

The light emitting diode 400 is positioned on the planarization layer 360 and includes a first electrode 410 connected to the drain electrode 354 of the driving thin film transistor Td, and an organic material layer sequentially stacked on the first electrode 410 . 430 and a second electrode 420 .

One electrode 410 is formed separately for each pixel area. The first electrode 410 may be an anode, and may be made of a conductive material having a relatively large work function value. For example, the first electrode 410 may be made of a transparent conductive material such as ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO.

Meanwhile, when the organic light emitting diode display 300 of the present invention is a top-emission type, a reflective electrode or a reflective layer may be further formed under the first electrode 310 . For example, the reflective electrode or the reflective layer may be formed of an aluminum-palladium-copper (APC) alloy.

Also, a bank layer 370 covering an edge of the first electrode 410 is formed on the planarization layer 360 . The bank layer 370 exposes the center of the first electrode 410 corresponding to the pixel area.

An organic material layer 430 is formed on the first electrode 410 . In one exemplary embodiment, the organic material layer 430 may have a single-layer structure of a light emitting material layer. On the other hand, as shown in FIGS. 3 to 4 , the organic light emitting layer 430 includes a plurality of holes such as a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting material layer, a hole blocking layer, an electron transport layer and/or an electron injection layer. It may consist of an organic material layer of

A second electrode 420 is formed on the substrate 302 on which the organic material layer 430 is formed. The second electrode 420 is located on the entire surface of the display area and is made of a conductive material having a relatively small work function value and may be used as a cathode. For example, the second electrode 420 may be formed of any one of an alloy or combination thereof such as aluminum (Al), magnesium (Mg), calcium (ca), silver (Ag), or an aluminum-magnesium alloy (AlMg). can

On the second electrode 420 , an encapsulation film 380 is formed to prevent external moisture from penetrating into the organic light emitting diode 400 . The encapsulation film 380 may have a stacked structure of a first inorganic insulating layer 382 , an organic insulating layer 384 , and a second inorganic insulating layer 386 , but is not limited thereto.

As described above, the organic light emitting diode 400 includes an organic material layer 430 in which the organic compound represented by Chemical Formulas 1 to 3 is used as a host, for example. The organic compounds represented by Chemical Formulas 1 to 3 have a large ΔE _H value and thus excellent charge transport properties, have a wide energy bandgap of -5.0 eV or more, and have triplet energy greater than that of a dopant.

Therefore, when the organic compound represented by Chemical Formulas 1 to 3 is used as a host in which the hole transport properties of the organic material layer 430 constituting the organic light emitting diode 400 are improved, the energy transferred to the dopant is reverse-transferred to the host. can be prevented As such, since the organic compounds represented by Chemical Formulas 1 to 3 have very excellent charge transport properties, when applied to the organic material layer 430 , the organic light emitting diode 400 can be driven even at a low voltage. In addition, since charges are injected in a balanced manner from the organic material layer 430 to prevent interfacial light emission, the light emitting efficiency of the organic light emitting diode 400 may be improved and/or a long lifespan may be induced.

Hereinafter, the present invention will be described through exemplary embodiments, but the present invention is not limited to the technical ideas described in the following examples.

Synthesis Example 1: Synthesis of PPH1 compound

1) 9-(biphenyl-3-yl)-9H-carbazole synthesis

[Scheme 1a]

50 g (299 mmol) of carbazole, 60 g (350 mmol) of 3-metabromobiphenyl, 86 g (897 mmol) of sodium tert-butoxide, Tris (dibenzylideneacetone) dipalladium (0) (Pd ₂ (dba) ₃ ) 14 g (359) mmol) and tritertiary butylphosphine 15 ml (30 mmol) were suspended in 1000 ml xylene and stirred under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. After removing the organic solution, silica gel column was performed to obtain compound 9-(biphenyl-3-yl)-9H-carbazole, 60 g.

2) 9-(biphenyl-3-yl)-3-bromo-9H-carbazole synthesis

[Scheme 1b]

Compound 9-(biphenyl-3-yl)-9H-carbazole 37 g (114 mmol) and N-Bromosuccinimide (NBS) 22 g (126 mmol) were suspended in 600 ml of dimethylformamide and stirred at room temperature for 12 hours. After adding distilled water to the reaction solution, the mixture is stirred at room temperature for 6 hours. After the stirring solution is filtered under reduced pressure, the solid is added to methyl alcohol and stirred at room temperature. After filtration under reduced pressure, compound 9-(biphenyl-3-yl)-3-bromo-9H-carbazole, 40g, was obtained.

3) 9-(biphenyl-3-yl)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole synthesis

[Scheme 1c]

Compound 9- (biphenyl-3-yl) -3-bromo-9H-carbazole 40 g (100 mmol), bis (pinacolato) diboron 38 g (151 mmol), [1,1'-Bis (diphenylphosphino) ferrocene] Dichloropalladium(II)(Pd(dppf)Cl ₂ ) 4 g (5 mmol) and potassium acetate 20 g (201 mmol) were suspended in 600 ml of 1,4-dioxane and stirred under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The organic solution was removed and recrystallized to obtain compound 9-(biphenyl-3-yl)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole, 23g. got it

4) PPH1 synthesis

[Scheme 1d]

3-boronic ester-9-indolocarbazole 10g (19 mmol), 3-bromo-9-phenyl carbazole 6g (19 mmol), Tetrakis(triphenylphosphine)palladium(0) (Pd(PPh ₃ ) ₄ ) 0.2 g (0.2 mmol) and 5 g (38 mmol) of potassium carbonate were suspended in 150 ml of toluene, 50 ml of ethyl alcohol, and 50 ml of distilled water, followed by stirring under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The reaction solution was distilled under reduced pressure and recrystallized to obtain compound PPH1, 4g. The results of NMR analysis of the synthesized PPH1 compound are shown in FIG. 6 .

Synthesis Example 2: Synthesis of PPH2 compound

[Scheme 2]

3-boronic ester-9-azatriphenylenecarbazole 10 g (19 mmol), 3-bromo-9-biphenylcarbazole 6.5 g (19 mmol), Pd (PPh ₃ ) ₄ 0.3 g (0.3 mmol) , 7 g (57 mmol) of potassium carbonate was suspended in 150 ml of toluene, 50 ml of ethyl alcohol, and 50 ml of distilled water, followed by stirring under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The reaction solution was distilled under reduced pressure and recrystallized to obtain compound PPH2, 5 g. The results of NMR analysis of the synthesized PPH2 compound are shown in FIG. 7 .

Synthesis Example 3: Synthesis of PPH3 compound

1) 9-phenyl-9H-carbazole synthesis

[Scheme 3a]

50 g (299 mmol) of carbazole, 60 g (359 mmol) of bromophenyl, 86 g (897 mmol) of sodium tert-butoxide, 14 g (359 mmol) of Pd ₂ (dba) ₃ , 15 ml of tritertiary butyl phosphine (30 mmol) was suspended in 1000 ml of xylene and stirred under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. After removing the organic solution, silica gel column was performed to obtain a compound 9-phenyl-9H-carbazole, 60 g.

2) Synthesis of 3-bromo-9-phenyl-9H-carbazole

[Scheme 3b]

Compound 9-phenyl-9H-carbazole 37 g (114 mmol) and NBS 22 g (126 mmol) were suspended in 600 ml of dimethylformamide, followed by stirring at room temperature for 12 hours. After adding distilled water to the reaction solution, the mixture is stirred at room temperature for 6 hours. After the stirring solution is filtered under reduced pressure, the solid is added to methyl alcohol and stirred at room temperature. After filtration under reduced pressure, the compound 3-bromo-9-phenyl-9H-carbazole, 40 g, was obtained.

3) Synthesis of 9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole

[Scheme 3c]

Compound 3-bromo-9-phenyl-9H-carbazole 40 g (100 mmol), bis (pinacolato) diboron 38 g (151 mmol), Pd (dppf) Cl ₂ 4 g (5 mmol), potassium acetate 20 g (201 mmol) ) was suspended in 600 ml of 1,4-dioxane and stirred under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The organic solution was removed and recrystallized to obtain the compound 9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole, 23 g.

4) PPH3 synthesis

[Scheme 3d]

3-boronic ester-9-azatriphenylenecarbazole 11 g (19 mmol), 3-bromo-9-phenylcarbazole 6 g (19 mmol), Pd (PPh ₃ ) ₄ 0.2 g (0.2 mmol), potassium 5 g (38 mmol) of carbonate was suspended in 150 ml of toluene, 50 ml of ethyl alcohol, and 50 ml of distilled water, followed by stirring under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The reaction solution was distilled under reduced pressure and recrystallized to obtain compound PPH3, 7g. The results of NMR analysis of the synthesized PPH3 compound are shown in FIG. 8 .

Synthesis Example 4: Synthesis of PPH4 compound

[Scheme 4]

3-boronic ester-9-triphenylenecarbazole 10g (19 mmol), 3-bromo-9-phenylcarbazole 6g (mmol), Pd (PPh ₃ ) ₄ 0.2g (0.2 mmol), potassium carbonate 5g (38 mmol) was suspended in 150 ml of toluene, 50 ml of ethyl alcohol, and 50 ml of distilled water, followed by stirring under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The reaction solution was distilled under reduced pressure and recrystallized to obtain compound PPH4, 6g. The results of NMR analysis of the synthesized PPH4 compound are shown in FIG. 9 .

Synthesis Example 5: Synthesis of PPH5 compound

[Scheme 5]

3-boronic ester-9-triphenylenecarbazole 10g (19 mmol), 3-bromo-9-metabiphenylcarbazole 8g (19 mmol), Pd (PPh ₃ ) ₄ 0.2g (0.2 mmol), 5 g (38 mmol) of potassium carbonate was suspended in 150 ml of toluene, 50 ml of ethyl alcohol, and 50 ml of distilled water, followed by stirring under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The reaction solution was distilled under reduced pressure and recrystallized to obtain compound PPH5, 6g. The results of NMR analysis of the synthesized PPH5 compound are shown in FIG. 10 .

Synthesis Example 6: Synthesis of PPH6 compound

[Scheme 6]

3-boronic ester-9-azatriphenylenecarbazole 10 g (19 mmol), 3-bromo-9-biphenylcarbazole 6 g (19 mmol), Pd (PPh ₃ ) ₄ 0.4 g (0.3 mmol), 5 g (38 mmol) of potassium carbonate was suspended in 150 ml of toluene, 50 ml of ethyl alcohol, and 50 ml of distilled water, followed by stirring under reflux for 12 hours. Extract with dichloromethane and distilled water, and filter the organic layer with silica gel. The reaction solution was distilled under reduced pressure and recrystallized to obtain compound PPH6, 6.5 g.

Comparative Synthesis Examples 1 to 2: Host Synthesis

4-(3-triphenylen-2-yl)phenyl)dibenzo[b,d]thiophene(4-(3-(triphenylen-2-yl)phenyl)dibenzo[b, which is a conventional light emitting host material shown below ,d]thiophene; Host1; Comparative Synthesis Example 1) and 3-(4,6-diphenyl-1,3,5-triazin-2-yl)-1-phenyl-1,3-dihydroindolo[ 2,3-b]carbazole (3-(4,6-diphenyl-1,3,5-triazin-2-yl)-1-phenyl-1,3-dihydroindolo[2,3-b]carbazole; Host2 ; Comparative Synthesis Example 2) was synthesized, respectively.

Experimental Example 1: Measurement of physical properties of compounds

For the organic compounds synthesized in Synthesis Examples 1 to 6 and Comparative Synthesis Examples 1 to 2, respectively, the energy level of the lowest unoccupied molecular orbital (LUMO), the energy level of the highest occupied molecular orbital (HOMO), and the band gap energy measured. The measurement results are shown in Table 1 below. The HOMO of the organic compound synthesized according to the present invention is -5.0 eV or more, and the bandgap energy is smaller than that of Host1 and Host2. Therefore, it was confirmed that the organic compound synthesized according to the present invention has sufficient bandgap energy to be used as a host of a light emitting diode.

Physical properties of organic compounds compound Bandgap ^b (eV) LUMO ^c (eV) HOMO ^a (eV) Host1 3.80 -2.20 -6.00 Host2 3.26 -2.23 -5.49 PPH1 3.20 -2.24 -5.44 PPH2 3.16 -2.27 -5.47 PPH3 3.19 -2.27 -5.46 PPH4 3.25 -2.37 -5.62 PPH5 3.20 -2.22 -5.42 PPH6 3.21 -2.31 -5.52 a: Absorption onset of 0.02 mM solution in CH ₂ Cl ₂
b: measured at absorption onset
c: LUMO = [bandgap energy - HOMO level]

On the other hand, ΔE _H was measured using Gaussian 09 (functional function B3LYP/base function 6-31G ^* ) of the organic compounds synthesized in Synthesis Examples 1 to 6 and Comparative Synthesis Example 1, respectively, and thin film resistance measurement by impedance spectrometry measurement The values were calculated. The measurement results are shown in Table 2 below.

HOMO energy level gap and resistance change rate of organic compounds compound ΔE _H (eV) Resistance change rate (relative value) Host1 0.8 100 PPH1 2.1 27 PPH2 2.2 34 PPH3 2.6 32 PPH4 2.7 28 PPH5 2.5 23 PPH6 2.4 22

Example One: organic light emitting diode produce

ITO (reflector) / hole injection layer / first hole transport layer / second hole transport layer / electron blocking layer / light emitting material layer / electron transport layer / electron injection layer / cathode (Cathode) / organic light emitting diode stacked in the order of CPL production did The ITO substrate was washed with UV ozone before use and then loaded into the evaporation system. After cleaning the substrate, the substrate was transferred into a vacuum deposition chamber, and the layers were deposited in the following order by evaporation from a heating boat under about 10 ^-7 Torr vacuum.

(a) hole injection layer: 100 Å, HIL(3%) / HTL1 (N-biphneyyl-4-yl)-9,9-dimethyl-N-(4-9-phenyl-9H-carbazol-3-yl) phenyl)-9H-floren-2-amine, 97%)

(b) first hole transport layer: 1200 Å, HTL1

(c) second hole transport layer: 250 Å, HTL2 (N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine)

(d) electron blocking layer: 150 Å, EBL (N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[fluoren]- 2-amine)

(e) light emitting material layer: 400 Å, first host (PPH1), second host (Host2) (1:1) / G-dopant (D7 of Formula 8, 5%)

(f) electron transport layer: 300 Å, ETL / Liq (2:1)

(g) electron injection layer 30Å, Mg / LiF (3:1)

(h) cathode 140 Å, Ag/Mg (4:1)

(i) CPL (capping layer)

After CPL was formed, it was encapsulated with glass. After deposition of these layers, they were transferred from the deposition chamber into a drying box for film formation and subsequently encapsulated using UV curing epoxy and moisture getter. This organic light-emitting diode has an emission area of 9 mm 2 . The structures of HIL, HTL1, HTL2, EBL, ETL, and Liq used when laminating each organic material layer in this embodiment are shown below.

Examples 2 to 6: Fabrication of organic light emitting diodes

As a host of the light emitting material layer, PPH2:Host2 (Example 2), PPH3:Host2 (Example 3), PPH4:Host2 (Example 4), PPH5:Host2 (Example 5), PPH6:Host2 (Example 6) The procedure of Example 1 was repeated except for using an organic light emitting diode, respectively.

Comparative Example 1: Fabrication of an organic light emitting device

An organic light emitting diode was manufactured by repeating the procedure of Example 1 except that Host1:Host2 was used as a host of the light emitting material layer.

Experimental Example 2: Evaluation of physical properties of organic light emitting diodes

Driving voltage, luminous efficiency, color coordinates, and device lifetime were evaluated for the organic light emitting diodes manufactured in Examples 1 to 6 and Comparative Example 1, respectively. To evaluate the physical properties of the device, the manufactured organic light emitting diode was connected to an external power supply (KEITHLEY), and evaluated at room temperature using a photometer (PR 650). For the organic light emitting diode, the driving voltage, luminous efficiency, external quantum efficiency, CIE color coordinates, and lifetime time from 100% to 95% at 20,000 nit luminance standard constant current at 8,000 nit luminance standard are shown in Table 3 below.

Measurement of physical properties of organic light emitting diodes Sample host Voltage (V) Efficiency (Cd/A) Color coordinates (x,y) Lifetime (T ₉₅ , h) Example 1 PPH1:Host2 4.18 158.0 0.238,0.723 280 Example 2 PPH2:Host2 4.25 162.8 0.240,0.716 295 Example 3 PPH3:Host2 4.04 165.9 0.236,0.716 310 Example 4 PPH4:Host2 4.27 161.3 0.255,0.709 330 Example 5 PPH5:Host2 4.03 165.5 0.209,0.703 300 Example 6 PPH6:Host2 4.11 157.6 0.243,0.715 290 comparative example Host1:Host2 4.75 131.4 0.220,0.725 140

As shown in Table 3, light emission when the organic compound synthesized according to the present invention is used as the p-type host of the light emitting material layer, compared to the case of using the conventional p-type host as the host of the light emitting material layer The driving voltage of the diode was reduced by up to 15.0%, the luminous efficiency increased by up to 26.2%, and the device lifetime was improved by up to 135.7%. These results are interpreted to be due to the fact that the organic compound synthesized according to the present invention improved the charge transport ability in the light emitting material layer and induced light emission in the entire region of the light emitting material layer.

In the above, the present invention has been described based on exemplary embodiments and examples of the present invention, but the present invention is not limited to the technical ideas described in the above embodiments and examples. Rather, those of ordinary skill in the art to which the present invention pertains can easily propose various modifications and changes based on the above-described embodiments and examples. However, it is clear from the appended claims that all such modifications and changes fall within the scope of the present invention.

100, 200, 400: organic light emitting diode 110, 210, 410: first electrode
120, 220, 420: second electrode 130, 230, 430: organic material layer
140, 240: hole injection layer 150, 250: hole transport layer
160, 260: light emitting material layer 170, 270: electron transport layer
180, 280: electron injection layer 255: electron blocking layer
265: hole blocking layer
300: organic light emitting diode display device Td: driving thin film transistor

Claims (15)

An organic compound represented by the following formula (1).
Formula 1

(In Formula 1, R ₁ to R ₁₆ are each independently connected to an adjacent carbazole group, or selected from the group consisting of a hydrogen atom, a deuterium atom, a tritium atom, and a C1~ C10 alkyl group; Ar _One is unsubstituted or C5~ C30 selected from the group consisting of a phenyl group substituted with a homoaryl group, a biphenyl group and a terphenyl group; Ar ₂ is a dibenzoisoquinolinyl group)
The method of claim 1,
The compound represented by Formula 1 is an organic compound including a compound represented by Formula 2 below.
Formula 2

(In Formula 2, R ₂₁ to R ₃₄ are each independently selected from the group consisting of a hydrogen atom, a deuterium atom, a tritium atom, and a C1-C10 alkyl group; Ar ₁ and Ar ₂ are each the same as defined in Formula 1 )
The method of claim 1,
The compound represented by Formula 1 is an organic compound including any one of PPH2, PPH3, and PPH6 represented by Formula 3 below.
Formula 3

a first electrode;
a second electrode facing the first electrode; and
At least one organic material layer positioned between the first electrode and the second electrode,
The organic material layer is an organic light emitting diode comprising the organic compound according to any one of claims 1 to 3.
5. The method of claim 4,
The organic material layer is an organic light emitting diode comprising at least one of a hole injection layer, a hole transport layer, a light emitting material layer, and an electron blocking layer.
5. The method of claim 4,
The organic compound is an organic light emitting diode used as a host of the light emitting material layer.
7. The method of claim 6,
The light emitting material layer is an organic light emitting diode comprising a dopant represented by the following Chemical Formula 5 or Chemical Formula 6.
Formula 5

Formula 6

(In Formula 5, R ₄₁ to R ₄₉ are each independently hydrogen, deuterium, tritium, halogen, unsubstituted or halogen-substituted C1-C30 alkyl group, cyano group, unsubstituted or substituted C3-C30 cycloalkyl group, unsubstituted unsubstituted or substituted C3~C30 heterocycloalkyl group, unsubstituted or substituted C5~C30 aryl group, unsubstituted or substituted C5~C30 heteroaryl group, unsubstituted or substituted C6~C30 arylalkyl group, unsubstituted or substituted C6 -C30 heteroarylalkyl group, unsubstituted or substituted C6~C30 aryloxyl group and unsubstituted or substituted C6~C30 heteroaryloxyl group selected from the group consisting of; R ₅₀ is hydrogen, deuterium, tritium or unsubstituted A substituted C1~ C30 alkyl group; r is an integer of 1 to 4; In Formula 6, R ₅₁ to R ₅₈ are each independently hydrogen, deuterium, tritium, halogen, an unsubstituted or halogen-substituted C1~ C30 alkyl group, cya No group, unsubstituted or substituted C3 to C30 cycloalkyl group, unsubstituted or substituted C3 to C30 heterocycloalkyl group, unsubstituted or substituted C5 to C30 aryl group, unsubstituted or substituted C5 to C30 heteroaryl group, unsubstituted From the group consisting of an unsubstituted or substituted C6~C30 arylalkyl group, an unsubstituted or substituted C6~C30 heteroarylalkyl group, an unsubstituted or substituted C6~C30 aryloxyl group, and an unsubstituted or substituted C6~C30 heteroaryloxyl group selected or linked together with an adjacent substituent to form an unsubstituted or substituted C5-C30 aromatic ring; In Formulas 5 and 6, L is represented by the following Formula 7; In Formulas 5 and 6, n is 1 to 3 integer)
Formula 7

(In Formula 7, R ₆₁ to R ₆₈ are each independently hydrogen, deuterium, tritium, halogen, unsubstituted or halogen-substituted C1-C30 alkyl group, cyano group, unsubstituted or substituted C3-C30 cycloalkyl group, unsubstituted unsubstituted or substituted C3~C30 heterocycloalkyl group, unsubstituted or substituted C5~C30 aryl group, unsubstituted or substituted C5~C30 heteroaryl group, unsubstituted or substituted C6~C30 arylalkyl group, unsubstituted or substituted C6 ~ C30 hetero arylalkyl group, unsubstituted or substituted C6~ C30 aryloxyl group and unsubstituted or substituted C6~ C30 hetero aryloxyl group selected from the group consisting of, or linked together with an adjacent substituent to unsubstituted or substituted C5 to form an aromatic ring of ~C30)
Board,
a driving thin film transistor positioned on the substrate; and
An organic light emitting device including the organic light emitting diode according to claim 4 positioned on the substrate and connected to the driving thin film transistor.
The organic light emitting device of claim 8 , wherein the organic light emitting device comprises an organic light emitting diode display. The method of claim 1,
In Formula 1, R ₁ to R ₁₆ are each independently connected to an adjacent carbazole group, or are a hydrogen atom, a deuterium atom or a tritium atom, and Ar ₁ is selected from the group consisting of a phenyl group, a biphenyl group and a terphenyl group, An organic compound wherein the phenyl group, the biphenyl group and the terphenyl group are each independently unsubstituted or substituted with a phenyl group.
3. The method of claim 2,
In Formula 2, R ₂₁ to R ₃₄ are each independently a hydrogen atom, a deuterium atom, or a tritium atom, Ar ₁ is selected from the group consisting of a phenyl group, a biphenyl group, and a terphenyl group, the phenyl group, the biphenyl group, and the An organic compound wherein each terphenyl group is independently unsubstituted or substituted with a phenyl group.
a first electrode;
a second electrode facing the first electrode, and
At least one organic material layer positioned between the first electrode and the second electrode,
The organic material layer is an organic light emitting diode comprising the organic compound according to claim 10 or 11.
13. The method of claim 12,
The organic compound is an organic light emitting diode included in the light emitting material layer.
13. The method of claim 12,
The organic compound is an organic light emitting diode used as a host of the light emitting material layer.
Board,
a driving thin film transistor positioned on the substrate, and
An organic light emitting device comprising the organic light emitting diode of claim 12 positioned on the substrate and connected to the driving thin film transistor.

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