KR102577042B1 - Organic compounds, organic light emitting diode and organic light emittid device having the compounds - Google Patents

Abstract

The present invention is an arylene group moiety in which condensed heteroaromatic moieties that function as electron donors are located on both sides, and are substituted with two cyano groups that function as electron acceptors between the condensed heteroaromatic moieties. It relates to organic compounds linked through aromatic rings. Since it contains both an electron donor and an electron acceptor moiety in one molecule, charges can easily move within the molecule, thereby improving luminous efficiency. The organic compound of the present invention can be used as a delayed fluorescent dopant, and the organic compound of the present invention can be applied to organic light-emitting devices such as organic light-emitting diodes, displays, and lighting devices with low driving voltage and excellent luminous efficiency and color purity. It can be utilized.

Description

Organic compounds, organic light-emitting diodes and organic light-emitting devices containing the same {ORGANIC COMPOUNDS, ORGANIC LIGHT EMITTING DIODE AND ORGANIC LIGHT EMITTID DEVICE HAVING THE COMPOUNDS}

The present invention relates to organic compounds, and more specifically, to organic compounds that have excellent luminous efficiency and can be applied to the light-emitting layer of an organic light-emitting diode, and to organic light-emitting diodes and organic light-emitting devices containing the same.

As one of the currently widely used flat display devices, the technology of organic light emitting diode devices, also called organic electroluminescent devices (OELD), is developing at a rapid pace. Organic light emitting diodes (OLED) are formed of a thin organic thin film of less than 2000 Å, and can produce images in one direction or two directions depending on the configuration of the electrode used.

In addition, an organic light-emitting diode display device, which is one of the organic light-emitting devices including organic light-emitting diodes, can form elements on a flexible transparent substrate such as plastic, making it possible to implement a flexible or foldable display device. In addition, organic light emitting diode displays can be driven at low voltages and have excellent color purity, which has great advantages over liquid crystal display devices (LCDs).

The organic light emitting diode includes a hole injection electrode (anode), an electron injection electrode (cathode), and an organic light emitting layer formed between the anode and the cathode. To increase luminous efficiency, the organic light emitting layer is sequentially stacked on the hole injection electrode: hole injection layer (HIL), hole transport layer (HTL), light emitting material layer (EML), electron transport layer (ETL), and electron injection layer (EIL). ) may include. At this time, holes injected from the anode and electrons injected from the cathode combine in the light-emitting material layer to form excitons, which become an unstable energy state (excited state), and then return to a stable ground state ( It returns to the ground state and emits light. The external quantum efficiency (EQE; η _ext ) of the light emitting material applied to the light emitting material layer can be calculated using the following equation (1).

(In equation (1), η _S/T is the exciton generation efficiency (singlet/triplet ratio), г is the charge balance factor; Φ is the radiative quantum efficiency; η _out-coupling is the optical -Extraction efficiency (out-coupling efficiency)

Exciton generation efficiency (η _S/T ) is the rate at which generated excitons are converted into light, and has a limited value of up to 0.25 for fluorescent materials. In theory, when a hole and an electron meet to form an exciton, depending on the arrangement of the spin, a singlet exciton in the form of a paired spin and a triplet exciton in the form of an unpaired spin are formed. Generated in a ratio of 1:3. This is because in fluorescent materials, only singlet excitons participate in light emission, and the remaining 75% of triplet excitons do not participate in light emission.

The charge balance factor (г) refers to the balance of holes and electrons forming excitons, and generally has a value of '1' assuming 100% 1:1 matching. Radiation quantum efficiency (Φ) is a value related to the actual luminous efficiency of a light-emitting material, and in a host-dopant system, it depends on the photoluminescence (PL) of the dopant.

Light-extraction efficiency (η _out-coupling ) is the ratio of light extracted to the outside among the light emitted from the light-emitting material. In general, when a thin film is formed by thermally depositing an isotropic light-emitting material, individual light-emitting molecules do not have a certain orientation and exist in a disordered state. The light-extraction efficiency in this random orientation state is generally assumed to be a value of 0.2. Therefore, when combining the four factors shown in equation (1), the maximum luminous efficiency of an organic light-emitting diode using a fluorescent material is only about 5%.

On the other hand, phosphorescent materials have a light-emitting mechanism that converts both singlet and triplet excitons into light. Phosphorescent materials convert singlet excitons into triplet excitons through inter system crossing (ISC). Therefore, when a phosphorescent material that uses both singlet and triplet excitons is used, the low luminous efficiency of the fluorescent material can be improved. When a metal complex containing a heavy metal such as Ir or Pt is used as a phosphorescent material, a transition from a triplet state to a singlet state is possible due to strong spin-orbit coupling caused by the heavy metal element. However, the color purity of blue phosphorescent materials in particular is difficult to apply to display devices, and their lifespan is also very short, falling far short of the commercialization level.

Phosphorescent hosts, including blue phosphorescent hosts, must have a triplet energy higher than that of the phosphorescent dopant material to prevent back energy transfer of the triplet energy of the phosphorescent dopant to the triplet energy of the host. However, when an organic aromatic compound has an extended conjugated structure or has a fused ring, the triplet energy is drastically lowered, so the number of organic molecules that can be used as a phosphorescent host is extremely limited. In addition, in order to have high triplet energy, the phosphorescent host is designed to have a fairly wide energy band gap. Due to the phosphorescent host material with a wide energy band gap, charge injection and transport are delayed, and as a result, the driving voltage of the organic light-emitting diode increases, which has a negative effect on power consumption and electrical stress is applied to the material that makes up the light-emitting layer. As a result, a problem occurred in which the lifespan characteristics of the device deteriorated.

The purpose of the present invention is to provide an organic compound that can improve luminous efficiency, an organic light-emitting diode and an organic light-emitting device that use the organic compound to reduce power consumption by lowering the driving voltage and have improved device lifespan.

According to one aspect of the present invention, the present invention provides two condensed heteroaromatic moieties having one or two nitrogen atoms functioning as electron donors on both sides, and at least two condensed heteroaromatic moieties functioning as electron acceptors. Provided is an organic compound consisting of a central aromatic moiety (core) substituted with two cyano groups (-CN).

For example, the condensed heteroaromatic rings on both sides, which function as electron donors, each have an unsubstituted or substituted carbazoyl group (carbazoyl group, acridly group, and/or phenoxazinyl group). ), etc., and the electron donor and electron acceptor may be connected through a linker consisting of 1 to 2 aromatic rings.

According to another aspect of the present invention, the present invention provides an organic light emitting diode and an organic light emitting device in which the above-described organic compound is applied to the organic light emitting layer.

For example, the organic compound may be applied to the light emitting material layer.

In one exemplary embodiment, the organic compounds of the present invention can be used as dopants in a light emitting material layer.

The organic compound according to the present invention has condensed heterocyclic moieties containing 1 to 2 nitrogen atoms located on both sides to act as electron donors, and an electron acceptor between the condensed heterocyclic moieties. ) proposes an organic compound in which at least two arylene group moieties substituted with cyano groups are linked through an aromatic ring.

Condensed heterocyclic moieties on both sides consisting of three or more aromatic rings function as electron donors, and the central heteroarylene group moiety substituted with at least two cyano groups is used as an electron acceptor. As the steric hindrance between the condensed heterocyclic moieties on both sides constituting the electron donor and the central heteroarylene group moiety substituted with at least two cyano groups that function as electron acceptors increases, the dihedral angle between the electron donor and electron acceptor increases. This increases. As the formation of a conjugate structure between the two-sided condensed heterocyclic moiety, which functions as an electron donor, and the central arylene group moiety, which functions as an electron acceptor, is limited, the highest occupied molecular orbital (HOMO) energy of organic compounds is reduced. Light emission efficiency can be improved by easily separating the state and the lowest level unoccupied molecular orbital (LUMO) energy state.

In addition, a dipole is formed from the condensed heterocyclic moiety, which functions as an electron donor, to an arylene group moiety substituted with at least two cyano groups, which functions as an electron acceptor, thereby increasing the dipole moment inside the molecule. While doing so, the luminous efficiency can be further improved.

In addition, the condensed heterocyclic moieties on both sides, which function as electron donors, are connected to the arylene group moiety substituted with at least two cyano groups located in the center through a linking group consisting of 1 to 2 aromatic rings. As the distance between the electron donor and the electron acceptor increases, the overlap between HOMO and LUMO decreases, thereby reducing the difference between the triplet energy level and the singlet energy level ( _ΔEST ). The red shift problem of light emitted from the organic light-emitting layer containing the organic compound according to the present invention can be minimized by steric hindrance through the linking group.

Moreover, because the condensed heterocyclic moiety, which functions as an electron donor, can form a rigid structure, the three-dimensional conformation of the molecule is greatly limited. When the organic compound according to the present invention emits light, there is no energy loss due to changes in the three-dimensional structure of the molecule, and since the emission spectrum can be limited to a specific range, high color purity can be achieved.

Therefore, the organic compound of the present invention can be used as a dopant for an organic light-emitting layer constituting an organic light-emitting diode, for example, a light-emitting material layer, to lower the driving voltage of the light-emitting device and improve luminous efficiency. Because it can be driven at low voltages, the materials that make up the light-emitting device do not deteriorate due to the heat generated at the high voltage required when driving the light-emitting device, thus reducing the load when driving the light-emitting device and increasing the lifespan of the device. do.

Ultimately, by applying the organic compound according to the present invention, luminous efficiency and device lifespan characteristics are improved, and organic light-emitting devices such as organic light-emitting diodes that can emit green light and organic light-emitting diode displays and lighting devices can be implemented. .

1 is a schematic diagram illustrating a light emission mechanism when an organic compound according to an exemplary embodiment of the present invention is used as a delayed fluorescent material.
Figure 2 is a cross-sectional view schematically showing an organic light-emitting diode in which an organic compound is applied to the organic light-emitting layer according to an exemplary embodiment of the present invention.
Figure 3 is a schematic diagram for explaining the energy level of an organic compound with a material used as a host when used as a delayed fluorescent material according to an exemplary embodiment of the present invention.
Figure 4 is a cross-sectional view schematically showing an organic light-emitting diode in which an organic compound is applied to the organic light-emitting layer according to another exemplary embodiment of the present invention.
FIG. 5 is a cross-sectional view schematically showing an organic light emitting diode display device as an example of an organic light emitting device having an organic light emitting diode in which an organic compound is applied to an organic light emitting layer according to an exemplary embodiment of the present invention.

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

[Organic Compound]

The organic compound according to the present invention has a condensed ring with a strong chemical structure and is connected to the condensed heteroaromatic moiety on both sides, which functions as an electron donor, through an appropriate aromatic linker (or linker) to the condensed heteroaromatic moiety. , and contains a central arylene moiety substituted with at least two cyano groups that function as electron acceptors. The organic compound according to the present invention may be represented by the following formula (1).

Formula 1

(In Formula 1, R ₁ to R ₄ each independently contain 1 or 2 nitrogen atoms and are an unsubstituted or substituted C ₁₀ to C ₃₀ condensed heteroaromatic substituent consisting of 3 to 5 rings; R ₅ to R ₈ are each independently hydrogen, deuterium, tritium, cyano group, an unsubstituted or substituted C ₁₀ to C ₃₀ condensed homo-aromatic substituent consisting of 3 to 5 condensed rings, or 1 or 2 nitrogen atoms. and is an unsubstituted or substituted C ₁₀ to C ₃₀ condensed heteroaromatic substituent consisting of 3 to 5 rings; Ar ₁ and Ar ₂ are each independently a C ₅ to C ₃₀ homoaryl group, C ₄ to C ₃₀ Hetero aryl group, C ₅ ~ C ₃₀ homo arylalkyl group, C ₄ ~ C ₃₀ hetero arylalkyl group, C ₅ ~ C ₃₀ homo aryloxyl group, C ₄ ~ C ₃₀ hetero aryloxyl group, C ₅ ~ C ₃₀ homo arylamine group and C ₄ ~ C ₃₀ heteroarylamine group; Ar ₃ , L ₁ and L ₂ are each independently selected from the group consisting of C ₅ ~ C ₃₀ homo arylene group, C ₄ ~ C ₃₀ hetero arylene group, C ₅ ~ C ₃₀ homo arylalkylene group, C ₄ ~ C ₃₀ hetero aryl alkylene group, C ₅ ~ C ₃₀ homo aryloxylene group, and C ₄ ~ C ₃₀ hetero aryloxylene group; a and b are each independent is 0 or 1)

In this specification, 'unsubstituted' or 'unsubstituted' means that the 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, a C ₁ to C ₂₀ alkyl group that is unsubstituted or substituted with a halogen atom, cyano group and/or nitro group, unsubstituted or substituted with a halogen atom, cyano group and/or nitro group. C ₁ ~ C ₂₀ alkoxy group, halogen atom, cyano group, alkyl halide group such as -CF ₃ , hydroxy group, carboxyl group, carbonyl group, amine group unsubstituted or substituted with halogen atom, cyano group and/or nitro group, respectively. , C ₁ ~ C ₁₀ alkyl substituted amine group, C ₅ ~ C ₃₀ aryl substituted amine group, C ₄ ~ C ₃₀ heteroaryl substituted amine group, nitro group, hydrazyl group, sulfonic acid group, C ₁ ~ C ₂₀ alkyl silyl group, C ₁ ~ C ₂₀ alkoxy silyl group, C ₃ ~ C ₃₀ cycloalkyl silyl group, C ₅ ~ C ₃₀ aryl silyl group, C ₄ ~ C ₃₀ heteroaryl silyl group, C ₅ ~ C ₃₀ aryl group , C ₄ to C ₃₀ heteroaryl group, C ₅ to C ₃₀ homo aralkyl group, C ₄ to C ₃₀ hetero aralkyl group, C ₅ to C ₃₀ homo aralkoxy group or C ₄ to C ₃₀ hetero aralkoxy group, etc. However, the present invention is not limited thereto.

In the present specification, 'hetero aromatic ring', 'hetero cycloalkylene group', 'hetero aryl group', 'hetero arylalkyl group', 'hetero aryloxyl group', 'hetero aryl amine group', 'hetero arylene group', 'hetero aryl group' The term 'hetero' used in 'alkylene group', 'hetero aryloxylene group', etc. means that at least one carbon atom, for example, 1 to 5 carbon atoms constituting these aromatic or alicyclic rings, is N, O , S, and combinations thereof.

In one exemplary embodiment, R ₁ to R ₄ located on both sides of the organic compound molecule represented by Formula 1 each independently contain 1 to 2 nitrogen atoms, preferably 1 nitrogen atom, and 3 It constitutes a condensed heteroaromatic ring consisting of from 5 aromatic rings, preferably 3 aromatic rings. For example, R ₁ to R ₄ are each independently a C ₁₀ to C ₃₀ fused heteroaryl group, a C ₁₀ to C ₃₀ fused heteroarylalkyl group, or a C ₁₀ to C ₃₀ fused heteroaryl group containing 1 to 2 nitrogen atoms. It may be an oxyl group or a C ₁₀ to C ₃₀ condensed heteroarylamine group, and is preferably a C ₁₀ to C ₃₀ condensed heteroaryl group.

For example, R ₁ to R ₄ are each independently an unsubstituted or substituted carbazoyl moiety, an acridinyl moiety, an acridonyl moiety, and/or a phenoxazinyl moiety. ) can form a moiety. Specifically, R ₁ to R ₄ are each independently unsubstituted or substituted carbazoyl group, benzocarbazoyl group, dibenzocarbazoyl group, indenocarbazoyl group, acridinyl group, benzoacridinyl group, dibenzoacridi. Nyl group, indenoacridonyl group, acridonyl group, benzoacridonyl group, dibenzoacridonyl group, indenoacridonyl group, phenoxazinyl group, benzophenoxazinyl group, dibenzophenoxazinyl group and/or indenope Noksajinil group can be formed. Preferably, R ₁ to R ₄ may each independently have a carbazoyl moiety.

According to one exemplary embodiment, in Formula 1, Ar ₁ and Ar ₂ may each independently be a C ₅ to C ₃₀ homo aryl group or a C ₄ to C ₃₀ hetero aryl group. For example, Ar ₁ and Ar ₂ are R ₁ to R ₄ , which are located on both sides of the molecule and function as electron donors, and at least two are located at the center of the molecule and function as electron acceptors. It can function as a linking group that mediates between arylene rings (Ar ₃ ) substituted with cyano groups.

For example, in Formula 1, Ar1 and _Ar2 are each independently unsubstituted or substituted phenyl group, biphenyl group, terphenyl group, tetraphenyl group, naphthyl group, anthracenyl group, indenyl group, phenalenyl group, phenanthrenyl group, and azure group. Uncondensed or fused homo-aromatic rings, such as a nyl group, pyrenyl group, fluorenyl group, tetracenyl group, indacenyl group or spiro fluorenyl group, and/or pyrrolyl group, pyridinyl group, pyrimidinyl group , pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazolyl group, pyrazolyl group, indolyl group, carbazolyl group, benzocarbazolyl group, dibenzocarbazolyl group, indolocarbazolyl group, Indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cynolinyl group, quinazolinyl group, phthalazinyl group , quinoxalinyl group, cynolinyl group, quinazolinyl group, benzoquinolinyl group, benzoisoquinolinyl group, benzoquinazolinyl group, benzoquinoxalinyl group, acridinyl group, phenanthrolinyl group, furanyl group, pyranyl group, oxa Zinyl group, oxazolyl group, oxadiazolyl group, triazolyl group, dioxynyl group, benzofuranyl group, dibenzofuranyl group, thiopyranyl group, thiazinyl group, thiophenyl group or N-substituted spiro fluorenyl It may be an uncondensed or fused heteroaromatic ring such as a group.

For example, in Formula 1 Ar ₁ and/or Ar ₂ is each independently a homoaryl group such as a phenyl group, biphenyl group, terphenyl group, naphthyl group, anthracenyl group, fluorenyl group, or spirofluorenyl group, and/or a benzothiophenyl group, a dibenzothiophenyl group, or a benzothiophenyl group. Furanyl group, dibenzofuranyl group, pyrrolyl group, pyridinyl group, pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazolyl group, pyrazolyl group, indolyl group, carbazolyl group , benzocarbazolyl group, dibenzocarbazolyl group, indolocarbazolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, 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 or benzoquinoxali It may be a heteroaryl group such as a nyl group.

At this time, if the number of aromatic rings constituting Ar ₁ and/or Ar ₂ in Formula 1 increases, the conjugated structure in the entire organic compound may become too long, and the band gap of the organic compound may be excessively reduced. Therefore, the number of aromatic rings constituting each of Ar ₁ and/or Ar ₂ in Formula 1 is preferably 1 to 2, more preferably 1. In addition, with regard to the injection and transfer characteristics of charges, Ar ₁ and/or Ar ₂ in Formula 1 may each be a 5-membered ring to a 7-membered ring, especially It may be preferred that it is a 6-membered ring. For example, in Formula 1, Ar ₁ and/or Ar ₂ are each independently substituted or unsubstituted phenyl group, biphenyl group, naphthyl group, biphenyl group, pyrrole group, imidazole group, pyrazole group, pyridinyl group, pyrazinyl group. group, pyrimidinyl group, pyridazinyl group, furanyl group, or thiophenyl group.

Meanwhile, in one non-limiting embodiment, Ar ₃ , which may be another linking group (linker) in Formula 1, may be an aromatic arylene group substituted with at least two cyano groups that substantially function as electron acceptors. At this time, Ar ₁ to Ar ₃ may each be a linking group that mediates a condensed heteroaromatic ring (R ₁ to R ₄ ) as an electron acceptor and at least two cyano groups as an electron donor. At this time, Ar ₃ constituting the aromatic arylene group is connected to R ₅ to R _{8 ,} which may be hydrogen, deuterium, tritium, another cyano group, or another condensed aromatic ring, through another aromatic linking group (L ₁ , L ₂ ). can be connected

Meanwhile, R ₅ to R ₈ are each independently hydrogen, deuterium, tritium, cyano group, an unsubstituted or substituted C ₁₀ to C ₃₀ condensed homoaryl group consisting of 3 to 5 condensed rings, or 1 or 2 It may be a C ₁₀ to C ₃₀ condensed heteroaromatic ring containing two nitrogen atoms and consisting of 3 to 5 rings. For example, when a and b are 0, R ₅ to R ₈ may each independently be hydrogen, deuterium, tritium, or cyano group, and when a and b are 1, R ₅ to R ₈ may each independently be hydrogen, deuterium, tritium, or cyano group. An unsubstituted or substituted C ₁₀ to C ₃₀ fused homo aryl group consisting of 3 to 5 condensed rings, or a C 10 to C 30 fused hetero aryl group containing 1 or 2 nitrogen atoms and consisting of ₃ to ₅ rings. It may be an aromatic ring.

At this time, in Formula 1, when R ₅ to R ₈ are made of a condensed aromatic ring, R ₅ to R ₈ are a condensed homoaryl group made of 3 to 5 aromatic rings (e.g., anthracenyl group, phenalenyl group, phenanthre group) Nyl group, pyrenyl group, fluorenyl group, indacenyl group, etc.) or a fused heteroaryl group consisting of 3 to 5 aromatic rings containing 1 or 2 nitrogen atoms (e.g., carbazoyl moiety, acridyl group) moiety, an acridol moiety, or a phenoxazyl moiety).

Ar ₃ , L ₁ and/or L ₂ that mediate between the electron donor moiety and the electron acceptor moiety may each independently be an unsubstituted or substituted aromatic linking group. For example, when Ar ₃ , L ₁ and/or L ₂ are unsubstituted or substituted C ₅ to C ₃₀ homo arylene groups, Ar ₃ , L ₁ and/or L ₂ are each independently unsubstituted or substituted Phenylene, biphenylene, terphenylene, tetraphenylene, indenylene, naphthylene, azulenylene, inda Indacenylene, acenaphthylene, fluorenylene, spiro-fluorenylene, phenalenylene, phenanthrenylene, anthracenylene ), fluoranthrenylene, triphenylenylene, pyrenylene, chrysenylene, naphthacenylene, picenylene, perylenyl It may be selected from the group consisting of perylenylene, pentaphenylene, and hexacenylene.

In another alternative embodiment, when Ar ₃ , L ₁ and/or L ₂ are unsubstituted or substituted C ₄ ˜C ₃₀ hetero arylene groups, Ar ₃ , L ₁ and/or L ₂ are each independently unsubstituted. Or substituted pyrrolylene, imidazolylene, pyrazolylene, pyridinylene, pyrazinylene, pyrimidinylene, pyridazinyl Pyridazinylene, isoindolylene, indolylene, indazolylene, purinylene, quinolinylene, isoquinolinylene , benzoquinolinylene, phthalazinylene, naphthyridinylene, quinoxalinylene, quinazolinylene, benzoquinolinylene, benzoiso Quinolinylene group, benzoquinazolinylene group, benzoquinoxalinylene group, cinnolinylene group, phenanthridinylene group, acridinylene group, phenanthrolinylene group, phena phenazinylene, benzoxazolylene, benzimidazolylene, furanylene, benzofuranylene, thiophenylene, benzothiophenylene ( benzothiophenylene, thiazolylene, isothiazolylene, benzothiazolylene, isoxazolylene, oxazolylene, triazonylene, tetrazolylene, oxa Oxadiazolylene group, triazinylene group, benzofuranylene group, dibenzofuranylene group, benzofurodibenzofuranylene group, benzothienobenzofuranylene group, benzothienodibenzofuranyl Len group, benzothiophenylene group, dibenzothiophenylene group, benzothiethobenzothiophenylene group, benzothienodibenzothiophenylene group, carbazyolylene group, benzocarbazolylene group, dibenzocarbazolylene group, indolocarba Can be selected from the group consisting of zolylene group, indenocarbazolylene group, benzofurocarbazolylene group, benzothienocarbazolylene group, imidazopyrimidinylene group, and imidazopyridinylene group. there is.

In one exemplary embodiment, when the number of aromatic rings constituting each of Ar ₃ , L ₁ and/or L ₂ increases, the conjugated structure in the entire organic compound becomes excessively long, thereby reducing the band gap of the organic compound. This may be reduced too much. Therefore, the number of aromatic rings constituting each of Ar ₃ , L ₁ and/or L ₂ is preferably 1 to 2, more preferably 1. Also, with regard to the injection and transfer characteristics of charges, Ar ₃ , L ₁ and/or L ₂ may each be a 5-membered ring to a 7-membered ring, especially 6-membered ring. -It may be preferable that it is a 6-membered ring. For example, Ar ₃ , L ₁ and/or L ₂ are each independently unsubstituted or substituted phenylene group, biphenylene group, pyrrolylene group, imidazolylene group, pyrazonylene group, pyridinylene group, pyrazinylene group. , it may be a pyrimidinylene group, a pyridazinylene group, a furanylene group, or a thiophenylene group.

The organic compound represented by Formula 1 can function as an electron donor, has condensed heteroaromatic moieties (R ₁ to R ₄ ) on both sides with a rigid structure, and has an appropriate linking group (Ar ₁ to Ar ₃ ). At least two cyano groups that can function as electron acceptors are connected through. Since the steric hindrance of the condensed heteroaromatic moiety consisting of at least three aromatic rings is large, the three-dimensional organic compound of the present invention is synthesized by forming a chemical bond with the condensed heteroaromatic moiety located on both sides of the molecule. Conformation is limited. Accordingly, the organic compound according to the present invention has a rigid structure, thereby improving thermal stability. When the organic compound represented by Formula 1 emits light, there is no energy loss due to changes in the three-dimensional structure of the molecule, and good color purity can be achieved because the emission spectrum can be limited to a specific range.

In particular, by using the organic compound according to the present invention, low-voltage driving is possible, power consumption can be reduced, and a light emitting diode with improved luminous efficiency can be implemented. For example, the organic compound according to the present invention can be used as a dopant for the organic light-emitting layer constituting the organic light-emitting diode, and in particular has so-called delayed fluorescence characteristics, which will be described.

Figure 1 is a schematic diagram for explaining the light emission mechanism when the organic compound according to the present invention is used as a delayed fluorescent compound. Delayed fluorescence can be divided into thermally activated delayed fluorescence (TADF) and field activated delayed fluorescence (FADF). Triplet excitons are activated by heat or an electric field, resulting in conventional fluorescence. So-called super-fluorescence, which exceeds the maximum luminous efficiency of the material, can be achieved.

That is, in delayed fluorescent compounds, triplet excitons are activated by heat or electric fields generated when driving the device, and the triplet excitons also participate in light emission. In general, delayed fluorescent compounds have both an electron donor moiety and an electron acceptor moiety, so they can be converted to an intramolecular charge transfer (ICT) state. When a delayed fluorescent compound capable of ICT is used as a dopant, an exciton having a singlet energy level (S ₁ ) and an exciton having a triplet energy level (T ₁ ) in the delayed fluorescent compound move to the ICT state, which is an intermediate state, and the bottom It transitions to the ground state (S ₀ ) (S ₁ → ICT ← T ₁ ). Since both excitons with a singlet energy level (S ₁ ) and excitons with a triplet energy level (T ₁ ) participate in light emission, internal quantum efficiency is improved, and thus luminous efficiency is improved.

Conventional fluorescent materials have the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) spread throughout the molecule, so they exist between the singlet state and the triplet state. Mutual conversion is not possible (selection rule). However, in compounds having an ICT state, the orbitals of HOMO and LUMO overlap less, so the interaction between the orbitals of the HOMO state and the orbitals of the LUMO state is small. Therefore, changes in the spin state of an electron do not affect other electrons, and a new charge transfer band (CT band) that does not follow the selection rule is formed.

That is, because the electron acceptor moiety and the electron donor moiety in the delayed fluorescent compound are spaced apart within the molecule, the dipole moment within the molecule exists in a polarized state with a large polarization state. When the dipole moment is polarized, the interaction between the orbitals of the HOMO and LUMO states becomes small, and transition from the triplet state and singlet state to the intermediate state (ICT) becomes possible. Accordingly, excitons having a singlet energy level (S ₁ ) as well as excitons having a triplet energy level (T ₁ ) participate in light emission. That is, when the light-emitting device is driven, the exciton with 25% of the singlet energy level (S ₁ ) and the exciton with 75% of the triplet energy level (T ₁ ) transition to the intermediate state (ICT) by heat or electric field. Since light emission occurs as it falls back to the ground state (S ₀ ), the internal quantum efficiency theoretically becomes 100%.

A dopant to implement delayed fluorescence needs to have the following characteristics. The dopant must have both an electron donor moiety and an electron acceptor moiety in one molecule, so it must be able to implement the ICT state. Dopant usually takes the form of a complex in the ICT state (ICT complex), and has both an electron donor moiety and an electron acceptor moiety in one bonsai, so electron transfer easily occurs within the molecule. In other words, in the ICT complex, under certain conditions, one electron moves from the electron donor moiety to the electron acceptor portion, causing separation of charges within the molecule.

In addition, in order for energy transfer to occur in both the triplet state and the singlet state, the dopant for implementing delayed fluorescence must have a difference (ΔE _ST ) of 0.3 between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ). It should be below eV, for example between 0.05 and 0.3 eV. In this case, materials with a small energy difference between the singlet state and the triplet state not only exhibit fluorescence when an intersystem crossing (ISC) occurs, in which energy is transferred from the singlet state to the triplet state, but also exhibit heat at room temperature. Reverse Inter System Crossing (RISC) occurs from the triplet state to a higher energy singlet state due to energy or an electric field, and as this singlet state transitions to the ground state, delayed fluorescence appears. In the case of delayed fluorescence, an efficiency of up to 100% can be theoretically achieved, making it possible to achieve internal quantum efficiency equivalent to that of conventional phosphorescent materials containing heavy metals.

ICT complexes capable of delayed fluorescence are formed by the external environment, and this can be easily confirmed by comparing the absorption and emission wavelengths of solutions in various solvents, which can be expressed in the following equation (2).

In the above equation, △ν is the stock shift value, and ν _abs and ν _fl are the wave numbers of the maximum absorption wavelength and maximum emission wavelength, respectively. In addition, h is Plank's constant, c is the velocity of light, a is the onsager cavity radius, and △μ is the dipole moment of the excited state and the ground state. ) represents the difference in dipole moment (△μ = μ _e - μ _g ). △f is a value representing the orientational polarizability of the solvent and is expressed by the dielectric constant (ε) and refractive index (n) of the solvent as shown in equation (3) below.

At this time, the formation of the ICT complex can be confirmed by comparing the absorption wavelength and emission wavelength in the solution state using various solvents. This is because the degree of polarization (i.e., the size of the dipole moment) when excited is determined by the polarity of the surroundings. Specifically, Δf, which is the directional polarizability of the mixed solvent, can be used by calculating the directional polarizability values of each pure solvent as a ratio of the mole fraction, and the presence or absence of ICT complex formation can be calculated as Δf using the above equation (Lippert-Mataga equation). This can be determined by checking whether a linear relationship appears when plotting and Δν. In other words, stabilization of the ICT complex occurs depending on the directional polarization of the solvent, and the emission wavelength shifts to a longer wavelength depending on the degree of stabilization. Therefore, when the ICT complex is formed, Δf and Δν form a linear graph, and conversely, when Δf and Δν form a linear graph, it can be seen that the light-emitting material is an ICT complex.

The organic compound represented by Formula 1 has delayed fluorescence characteristics because a condensed heteroaromatic moiety that functions as an electron donor and a central arylene group moiety with at least two cyano groups that function as electron acceptors coexist in one molecule. can be shown. In particular, because the steric hindrance between the condensed heteroaromatic moiety and the arylene group moiety substituted with at least two cyano groups is large, the formation of a conjugated structure is limited and is easily separated into HOMO and LUMO states. As dipoles are formed in the condensed heteroaromatic moieties located on both sides of the molecule and the central arylene moiety substituted with at least two cyano groups, the dipole moment inside the molecule increases, thereby improving luminous efficiency. As the electron donor and electron acceptor coexist within the molecule, the overlap between the HOMO and LUMO of the molecule is reduced.

In addition, since the electron donor and electron acceptor are connected through an appropriate linking group (Ar ₁ to Ar ₃ ), the overlap between HOMO and LUMO in the molecule is further reduced, so the difference in energy levels between the triplet energy level and the singlet energy level ( _ΔEST ) can be reduced. In particular, since each side has a condensed heteroaromatic moiety with a strong structure, the three-dimensional structure between the arylene group moiety constituting the central electron acceptor and the condensed heteroaromatic moiety constituting the electron donors on both sides is limited. There is no energy loss when emitting light, and good green light emission can be achieved.

In particular, when using the organic compound represented by Formula 1 as a dopant of the light-emitting material layer, the triplet energy level of the organic compound represented by Formula 1 is lower than the triplet energy of the conventional phosphorescent material, and the energy band gap is lower than that of the conventional phosphorescent material. Narrower than the material. Therefore, the organic host used with the organic compound represented by Formula 1 does not need to have a triplet energy level as high as when using a conventional phosphorescent material, and the band gap does not need to be wide. Therefore, there is no need to use an organic compound with high triplet energy, which was a limitation when applying conventional phosphorescent materials, as a host, and it is not necessary to use a phosphorescent host with a wide energy band gap. Using a host with a wide energy band gap can prevent charge injection and transport from being delayed, thereby increasing the driving voltage of the light emitting diode, increasing power consumption, and deteriorating the lifespan characteristics of the device.

In one exemplary embodiment, the organic compound according to the present invention includes an organic compound represented by Formula 2 below:

Formula 2

(In Formula 2, R ₁₁ to R ₁₄ are each independently selected from the group consisting of a carbazoyl group, benzocarbazoyl group, dibenzocarbazoyl group, and indenocarbazoyl group; R ₁₅ and R ₁₆ are each independently selected from the group consisting of hydrogen , deuterium, tritium, cyano group, carbazoyl group, benzocarbazoyl group, dibenzocarbazoyl group and indenocarbazoyl group; L ₃ is a phenylene group; a and b are defined in Formula 1 same as what was done)

More specifically, the organic compound according to the present invention may be any one compound represented by the following formula (3).

Formula 3

The organic compounds represented by Formulas 2 to 3 have a condensed heteroaromatic moiety consisting of two carbazoyl moieties with a rigid structure that function as electron donors on both sides, and at least two central moieties that function as electron acceptors. The arylene group moiety substituted with a cyano group is connected through an aromatic linkage group having an appropriate conjugate structure. A condensed heteroaromatic moiety, which is an electron donor, and an arylene group substituted with at least two cyano groups, which are electron acceptors, exist in one molecule, increasing the dipole moment, and HOMO and LUMO can be easily separated, increasing the dipole moment. It has a structure. Therefore, organic compounds represented by Formulas 2 to 3 can be applied as delayed fluorescent materials, and the luminous efficiency of organic light-emitting diodes can be improved and color purity can be improved by using organic compounds represented by Formulas 2 to 3. . In addition, by applying organic compounds represented by Formulas 2 to 3 to organic light-emitting diodes, power consumption can be reduced by lowering the driving voltage of the organic light-emitting diode, and electrical stress on the organic materials constituting the light-emitting layer is reduced, thereby improving the device's Lifespan characteristics can be improved.

[Organic light emitting diode and organic light emitting device]

As described above, by applying the organic compounds represented by Formulas 1 to 3 to the organic light-emitting layer constituting the organic light-emitting diode, particularly high-purity light-emitting colors can be obtained, and power consumption can be reduced by lowering the driving voltage, A light emitting device with improved device lifespan characteristics can be implemented. This will be explained. Figure 2 is a cross-sectional view schematically showing an organic light-emitting diode in which an organic compound is applied to the organic light-emitting layer according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the organic light emitting diode 100 according to the first embodiment of the present invention includes a first electrode 110 and a second electrode 120 facing each other, and the first and second electrodes 110. , 120) and an organic light-emitting layer 130 located between them. In an exemplary embodiment, the organic light-emitting layer 130 includes a hole injection layer (HIL, 140), a hole transfer layer (HTL, 150), and a light-emitting material sequentially stacked from the first electrode 110. It includes an emissive material layer (EML, 160), an electron transfer layer (ETL, 170), and an electron injection layer (EIL, 180).

The first electrode 110 may be an anode that supplies holes to the light emitting material layer 160. The first electrode 110 is preferably made of a conductive material with a relatively high work function, for example, transparent conductive oxide (TCO). In an exemplary embodiment, the first electrode 110 is made of indium-tin-oxide (ITO), indium-zinc-oxide (IZO), or indium-tin-zinc-oxide. (indium-tin-zinc oxide; ITZO), tin oxide (SnO), zinc oxide (ZnO), indium-copper-oxide (indium-copper-oxide; ICO), and aluminum:zinc oxide (Al:ZnO; AZO). It can be done.

The second electrode 120 may be a cathode that supplies electrons to the light emitting material layer 160. The second electrode 120 is made of a conductive material with a relatively small work function value, for example, aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy or combination thereof with reflective properties. It can be made of good materials.

The hole injection layer 140 is located 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 made of 4,4',4"-Tris(3-methylphenylamino)triphenylamine; MTDATA), 4,4',4"-Tris(N,N-diphenyl-amino)triphenylamine (4,4',4"-Tris(N,N-diphenyl-amino)triphenylamine; NATA), 4 ,4',4"-Tris(N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine (4,4',4"-Tris(N-(naphthalene-1-yl)-N -phenyl-amino)triphenylamine; 1T-NATA), 4,4',4"-tris(N-(naphthalen-2-yl)-N-phenyl-amino)triphenylamine(4,4',4"- Tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine; 2T-NATA), Copper phthalocyanine (CuPc), Tris(4-carbazoyl-9yl-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; NPB; NPD), 1,4,5,8,9,11 -Hexaazatriphenylenehexacarbonitrile, Dipyrazino[2,3-f:2'3'-h]quinoxaline-2,3,6,7,10 ,11-hexacarbonitrile; HAT-CN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (1,3,5-tris[4-(diphenylamino)phenyl]benzene; TDAPB), poly (3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT/PSS) and/or 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 the like. Depending on the characteristics of the organic light emitting diode 100, the hole injection layer 140 may be omitted.

The hole transport layer 150 is located 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, 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), NPB, 4,4'-bis(N-carbazolyl)- 1,1'-biphenyl (4,4'-bis(N-carbazolyl)-1,1'-biphenyl; CBP), poly[N,N'-bis(4-butylphenyl)-N,N'- Bis(phenyl)-benzidine](Poly[N,N'-bis(4-butylpnehyl)-N,N'-bis(phenyl)-benzidine]; Poly-TPD), Poly[(9,9-dionylflu orenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))](Poly[(9,9-dioctylfluorenyl-2,7-diyl )-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], TFB), di-[4-(N,N-di-p-tolyl-amino)phenyl]cyclohexane (Di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane; TAPC), 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-carbazole-3 -yl)phenyl)biphenyl)-4-amine (N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine), etc. It may be made of a compound selected from the group consisting of, but the present invention is not limited thereto.

The light emitting material layer 160 may be formed by doping a host with a dopant. For example, the light emitting material layer 160 may have about 1 to 50% by weight of dopant added to the host and may emit green light.

In one exemplary embodiment, organic compounds represented by Chemical Formulas 1 to 3 may be used as a dopant of the light emitting material layer 160. Meanwhile, the dopant, which is an organic compound represented by Formula 1 to Formula 3, used in the light-emitting material layer 160 may be a dopant with delayed fluorescence characteristics.

As described above, compounds with delayed fluorescence properties are activated by heat or an electric field and have an intermediate energy state such as the ICT complex form. Since both excitons having a singlet energy level and excitons having a triplet energy level are involved in light emission, the light emission efficiency of the organic light emitting diode 100 can be improved.

The difference (ΔE _ST ) between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of the organic compounds represented by Formulas 1 to 3 may be 0.3 eV or less, for example, 0.05 to 0.3 eV. If the difference (ΔE _ST ) between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of the organic compound represented by Formula 1 to Formula 3 that can be used as a delayed fluorescent dopant is 0.3 eV or less, these energy levels The quantum efficiency of the dopant can be improved by transitioning to an intermediate energy state and finally falling to the ground state. In other words, the smaller ΔE _ST is, the higher the luminous efficiency can be. If the difference between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of the dopant is 0.3 eV or less, the singlet state is reduced by heat or electric field. The exciton and triplet state exciton can transition to the intermediate state, the ICT complex state (ΔE _ST ≤0.3).

Meanwhile, in order to implement delayed fluorescence, the host included in the light-emitting material layer 160 must be able to induce excitons in the triplet state in the dopant to participate in light emission without being quenched. Figure 3 is a schematic diagram for explaining the energy level of the delayed fluorescent compound when an organic compound according to an exemplary embodiment of the present invention is used as a host.

As shown in FIG. 3, the energy level of the host to implement delayed fluorescence must be appropriately adjusted with the dopant. First, the triplet energy level (T ₁ ^H ) and singlet energy level (S ₁ ^H ) of the host must be higher than the triplet energy level (T ₁ ^D ) and singlet energy level (S ₁ ^D ) of the dopant, respectively. In particular, if the triplet energy level of the host (T _1H ) is not sufficiently higher than the triplet energy level of the dopant (T ₁ ^D ), the triplet state exciton of the dopant is transferred to the triplet energy level of the host (T ₁ ^H ). Because it passes over and annihilates as non-luminescence, the triplet state exciton of the dopant does not contribute to the emission.

Additionally, it is necessary to appropriately adjust the HOMO energy level and LUMO energy level of the host and dopant. For example, the difference between the highest occupied molecular orbital energy level of the host (HOMO ^H ) and the highest occupied molecular orbital energy level of the dopant (HOMO ^D ) (|HOMO ^H -HOMO ^D |) or the lowest unoccupied molecular orbital of the host. The difference between the energy level (LUMO _H ) and the lowest unoccupied molecular orbital energy level (LUMO ^D ) of the dopant (|LUMO ^H -LUMO ^D |) may preferably be 0.5 eV or less, for example, 0.1 to 0.5 eV or less. there is. Accordingly, the efficiency of charge transfer from the host to the dopant is improved, ultimately improving luminous efficiency.

In one exemplary embodiment, the host of emissive material layer 160 is 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile (9-(3- (9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile; mCP-CN), CBP, 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (3, 3'-bis(N-carbazolyl)-1,1'-biphenyl; mCBP), 1,3-bis(carbazol-9-yl)benzene; MCP ), (Oxybis(2,1-phenylene))bis(diphenylphosphine oxide; DPEPO), 2T-NATA, TCTA, 1,3, 5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-Tri[(3-pyridyl)-phen-3-yl]benzene; TmPyPB), 2,6-di( 9H-carbazol-9-yl)pyridine (2,6-Di(9H-carbazol-9-yl)pyridine; PYD-2Cz), 3', 5'-di(carbazol-9-yl)-[1 ,1'-bipheyl]-3,5-dicarbonitrile (3',5'-Di(carbazol-9-yl)-[1,1'-bipheyl]-3,5-dicarbonitrile; DCzTPA), 4 '-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile(4'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile; pCzB-2CN), 3'-(9H- Carbazol-9-yl) biphenyl-3,5-dicarbonitrile (3'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile; mCzB-2CN), 9-(4-(9H -Carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole (9-(4-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole), 9 -(3-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole (9-(3-(9H-carbazol-9-yl)phenyl)-9H-3,9 '-bicarbazole) and/or 4-(3-triphenylene-2-yl)phenyl)dibenzo[b,d]thiophene (4-(3-(triphenylene-2-yl)-phenyl)dibenzo[b ,d]thiophene), etc., but the present invention is not limited thereto.

Returning to FIG. 2 , 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 forming 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 composed of oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, and benzimidazole. , it may be a derivative of triazine, etc. For example, the electron transport layer 170 is made of tris-(8-hydroxyquinoline aluminum; Alq ₃ ), 2-biphenyl-4-yl-5-(4-tertiary-butylphenyl) )-1,3,4-oxadiazole (2-biphenyl-4-yl-5-(4-t-butylphenyl)-1,3,4-oxadiazole; PBD), spiro-PBD, lithium quinolate ( lithium quinolate; Liq), 1,3,5-Tris(N-phenylbenzimidazol-2-yl)benzene; TPBi), 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), 4,7-diphenyl-1,10-phenanthroline (4,7-diphenyl-1,10-phenanthroline; Bphen), 2,9-bis( Naphthalene-2-yl)4,7-diphenyl-1,10-phenanthroline (2,9-Bis(naphthalene-2-yl)4,7-diphenyl-1,10-phenanthroline; NBphen), 2, 9-Dimethyl-4,7-diphenyl-1,10-phenathroline (2,9-Dimethyl-4,7-diphenyl-1,10-phenathroline; BCP), 3-(4-biphenyl)-4 -Phenyl-5-tert-butylphenyl-1,2,4-triazole (3-(4-Biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole; TAZ), 4- (Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (4-(Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4- triazole; NTAZ), 1,3,5-tri(p-pyrid-3-yl-phenyl)benzene (1,3,5-Tri(p-pyrid-3-yl-phenyl)benzene; TpPyPB), 2 ,4,6-Tris(3'-(pyridin-3-yl)biphenyl-3-yl)1,3,5-triazine (2,4,6-Tris(3'-(pyridin-3-yl) )biphenyl-3-yl)1,3,5-triazine; TmPPPyTz), poly[(9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9, 9-dioctylfluorene)](Poly[9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene]-alt-2,7- (9,9-dioctylfluorene)]; PFNBr) and/or tris(phenylquinoxaline; TPQ), etc., but the present invention is not limited thereto.

The electron injection layer 180 is located between the second electrode 120 and the electron transport layer 170, and the lifespan of the device can 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, and BaF ₂ and/or Liq (lithium quinolate), lithium benzoate, and sodium. Organometallic materials such as sodium stearate may be used, but the present invention is not limited thereto.

The organic light-emitting diode 100 according to an exemplary embodiment of the present invention has a dopant, which is an organic compound represented by Formula 1 to Formula 3 and has delayed fluorescence properties, in the light-emitting material layer 160 constituting the organic light-emitting layer 130. there is. Since excitons in both singlet energy state and triplet energy state are involved in light emission, light emission efficiency is improved.

Organic compounds represented by Formulas 1 to 3 coexist with an electron donor moiety and an electron acceptor moiety, so the dipole moment increases, HOHO and LUMO are easily separated, and the dipole moment has a structure that can increase. , has delayed fluorescence characteristics. In addition, the three-dimensional structure between the condensed heteroaromatic moiety, which has a rigid structure on both sides, and the arylene group moiety substituted with at least two cyano groups in the center is greatly restricted, making it possible to achieve good green light emission while reducing energy loss during light emission. You can.

In addition, compared to the case of using a conventional phosphorescent material containing a heavy metal, the organic host included in the light-emitting material layer (EML, 160) together with the organic compounds represented by Formulas 1 to 3 have a high triplet energy level. There is no need to have it, and the band gap does not need to be wide. Therefore, the problems caused by using an organic host with a wide energy band gap, that is, the injection and transport of charges are delayed, and as a result, the driving voltage of the light emitting diode 100 increases, power consumption increases, and the lifespan of the device is shortened. Deterioration of characteristics can be prevented.

Meanwhile, the organic light emitting diode according to the present invention may further include one or more exciton blocking layers. Figure 4 is a cross-sectional view schematically showing an organic light-emitting diode to which a phosphorescent compound is applied according to a second exemplary embodiment of the present invention. As shown in FIG. 4, the organic light emitting diode 200 according to the second embodiment of the present invention includes a first electrode 210 and a second electrode 220 facing each other, and a first and second electrode 210. , 220) and an organic light-emitting layer 230 located between them.

In an exemplary embodiment, the organic light emitting layer 230 includes a hole injection layer 240, a hole transport layer 250, a light emitting material layer 260, an electron transport layer 270, and an electron layer sequentially stacked from the first electrode 210. Includes an injection layer 280. In addition, the organic light-emitting layer 230 includes an electron blocking layer (EBL) 255 and/or a first exciton blocking layer located between the hole transport layer 250 and the light-emitting material layer 260. ) and a hole blocking layer (HBL, 265), which is a second exciton blocking layer, located between the electron transport layer 270.

As described above, the first electrode 210 may be an anode and may be made of conductive materials with relatively high work function values, such as ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO. The second electrode 220 may be a cathode and may be made of Al, Mg, Ca, Ag, or an alloy or combination thereof, which are conductive materials with a relatively low work function value.

The hole injection layer 240 is located between the first electrode 210 and the hole transport layer 22. The hole injection layer 240 is MTDATA, NATA, 1T-NATA, 2T-NATA, CuPc, TCTA, NPB (NPD), HAT-CN, TDAPB, PEDOT/PSS and/or N-(biphenyl-4-yl) -9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine.

The hole transport layer 250 is located between the first electrode 210 and the light emitting material layer 260 and adjacent to the light emitting material layer 260. The hole transport layer 250 includes TPD, NPD (NPB), CBP, Poly-TPD, TFB, TAPC, 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-carbazole-3 It may be composed of a compound selected from the group including aromatic amine compounds such as -yl)phenyl)biphenyl)-4-amine.

The light emitting material layer 260 may be formed by doping a host with a dopant. For example, the light emitting material layer 260 may have about 1 to 50% by weight of dopant added to the host and may emit green light. For example, organic compounds represented by Formulas 1 to 3 are used as dopants of the light emitting material layer 260, and include mCP-CN, CBP, mCBP, MCP, DPEPO, 2T-NATA, TCTA, TmPyPB, PYD-2Cz, DCzTPA, pCzB-2CN, mCzB-2CN, 9-(4-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole, 9-(3-(9H-carbazole- Compounds such as 9-yl)phenyl)-9H-3,9'-bicarbazole and/or 4-(3-triphenylen-2-yl)phenyl)dibenzo[b,d]thiophene are luminescent substances. May be used as a host for layer 260.

The electron transport layer 270 is located between the light emitting material layer 260 and the electron injection layer 280. For example, the electron transport layer 270 is made of oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, benzimidazole, triazine, etc. It may be a derivative. For example, the electron transport layer 270 may be made of Alq ₃ , PBD, Spiro-PBD, Liq, BAlq, Bphen, NBphen, BCP, TAZ, NTAZ, TpPyPB, TmPPPyTz, PFNBr and/or TPQ, etc. The invention is not limited to this.

The electron injection layer 280 is located between the second electrode 220 and the electron transport layer 270. The material of the electron injection layer 280 may be an alkali halide-based material such as LiF, CsF, NaF, or BaF ₂ and/or an organic metal-based material such as Liq, lithium benzoate, or sodium stearate, but the present invention does not apply to this. It is not limited.

Meanwhile, when holes move from the light emitting material layer 260 to the second electrode 220 or electrons pass through the light emitting material layer 260 to the first electrode 210, the lifespan and efficiency of the device may be reduced. You can. To prevent this, the organic light emitting diode 200 according to the second exemplary embodiment of the present invention has at least one exciton blocking layer located adjacent to the light emitting material layer 260.

For example, the organic light emitting diode 200 according to the second embodiment of the present invention has an electron blocking layer that can control and prevent the movement of electrons between the hole transport layer 250 and the light emitting material layer 260. layer, EBL, 255) is located.

For example, the electron blocking layer 255 includes TCTA, 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, TAPC, MTDATA, mCP, mCBP, CuPC, N,N'- bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine(N,N'-bis[4- [bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine; DNTPD) and/or TDAPB.

In addition, a hole blocking layer 265 is located between the light emitting material layer 260 and the electron transport layer 270 as a second exciton blocking layer to prevent the movement of holes between the light emitting material layer 260 and the electron transport layer 270. do. In one exemplary embodiment, oxadiazole, triazole, phenanthroline, benzoxazole, and benzoate, which can be used in the electron transport layer 270, are used as materials for the hole blocking layer. Derivatives such as thiazole (benzothiazole), benzimidazole, and triazine may be used.

For example, the hole blocking layer 265 is made of BCP, BAlq, Alq ₃ , PBD, and Spiro, which have a low HOMO (highest occupied molecular orbital) energy level compared to the material used in the light-emitting material layer 260. -PBD, Liq and/or bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (bis-4,6-(3,5-di-3-pyridylphenyl) -2-methylpyrimidine; B3PYMPM) and combinations thereof.

The organic light-emitting diode 200 according to the second embodiment of the present invention has a dopant in the light-emitting material layer 160, which is an organic compound represented by Formula 1 to Formula 3 and has delayed fluorescence characteristics. Organic compounds represented by Formulas 1 to 3 have a structure in which an electron donor moiety and an electron acceptor moiety coexist within one molecule, increasing the dipole moment, HOHO and LUMO are easily separated, and the dipole moment can be increased. Because of this, it has delayed fluorescence properties. In addition, the three-dimensional structure between the condensed heteroaromatic moiety constituting the electron donor and the arylene group moiety substituted with at least two cyano groups constituting the electron acceptor is limited. Therefore, when organic compounds represented by Formulas 1 to 3 are used as dopants of a light emitting device, luminous efficiency is improved and an organic light emitting diode 200 with good color purity can be manufactured. Since there is no need to use an organic host with high triplet energy and a wide bandgap, power consumption can be reduced by lowering the driving voltage of the light emitting diode 200, and the lifespan of the device can be improved. In addition, since the organic light emitting diode 200 according to the second embodiment of the present invention includes at least one exciton blocking layer 255, 265, the charge transport layer 250, 270 adjacent to the light emitting material layer 260 By preventing light emission at the interface, the light emission efficiency and lifespan of the organic light emitting diode 200 can be further improved.

The organic light-emitting diode according to the present invention can be applied to organic light-emitting devices such as organic light-emitting diode displays or lighting devices using the above-mentioned organic light-emitting diodes. As an example, a display device using the organic light emitting diode of the present invention will be described. Figure 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 device 300 includes a driving thin film transistor (Td), which is a driving element, a planarization layer 360 covering the driving thin film transistor (Td), and a planarization layer 360 on the planarization layer 360. It is located and includes an organic light emitting diode 400 connected to a driving thin film transistor (Td), which is 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. In Figure 5, the driving thin film has a coplanar structure. Represents a transistor (Td).

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

A semiconductor layer 310 is formed on the substrate 302. For example, the semiconductor layer 310 may be made 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 entering the semiconductor layer 310, thereby preventing light from entering the semiconductor layer 310. prevents 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 film 320 made of an insulating material is formed on the entire surface of the substrate 302 on the semiconductor layer 310. The gate insulating film 320 may be made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx).

A gate electrode 330 made of a conductive material such as metal is formed on the gate insulating film 320 corresponding to the center of the semiconductor layer 310. Additionally, a gate wiring (not shown) and a first capacitor electrode (not shown) may be formed on the gate insulating film 320. The gate wiring extends along the first direction, and the first capacitor electrode may be connected to the gate electrode 330. Meanwhile, the gate insulating film 320 is formed on the entire surface of the substrate 302, but the gate insulating film 320 may be patterned into the same shape as the gate electrode 330.

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

The interlayer insulating film 340 has first and second semiconductor layer contact holes 342 and 344 exposing upper surfaces on both sides of the semiconductor layer 310 . The first and second semiconductor layer contact holes 342 and 344 are located on both sides of the gate electrode 330 and spaced apart from the gate electrode 330 . Here, the first and second semiconductor layer contact holes 342 and 344 are also formed within the gate insulating film 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 within 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 film 340. Additionally, a data wire (not shown), a power wire (not shown), and a second capacitor electrode (not shown) extending along the second direction may be formed on the interlayer insulating film 340.

The source electrode 352 and the drain electrode 354 are positioned spaced apart from each other around the gate electrode 330, and are connected to 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 wire extends along the second direction and intersects the gate wire to define the pixel area, and the power wire supplying a high potential voltage is located spaced apart from the data wire. The second capacitor electrode is connected to the drain electrode 354 and overlaps the first capacitor electrode, thereby forming 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, gate electrode 330, source electrode 352, and drain electrode 354 form a driving thin film transistor (Td). The driving thin film transistor Td illustrated in FIG. 5 has a coplanar structure in which the gate electrode 330, the source electrode 352, and the drain electrode 354 are located on the top of the semiconductor layer 310. In contrast, the driving thin film transistor Td may have an inverted staggered structure in which the gate electrode is located at the bottom of the semiconductor layer, and the source electrode and drain electrode are located at the top of 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 with substantially the same structure as 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 the 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 the power wiring (not shown). connected. Additionally, the gate electrode (not shown) and the source electrode (not shown) of the switching thin film transistor (not shown) are connected to the gate wire and data wire, respectively.

Meanwhile, the organic light emitting diode display device 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 that absorb light can be formed separately for each pixel area, and each of these color filter patterns is an organic light-emitting diode (OLED) that emits light in the wavelength band to be absorbed. They may be arranged to overlap each other with the organic light-emitting layer 430 in 400). By adopting a color filter (not shown), the organic light emitting diode display device 300 can implement full color.

For example, when the organic light emitting diode display device 300 is a bottom emitting type, a color filter (not shown) that absorbs light may be located on the upper part of 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 emitting type, the color filter may be located on top of the organic light emitting diode 400, that is, on top of the second electrode 420.

A planarization layer 360 is formed on 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 shown as being formed directly above the second semiconductor layer contact hole 344, but may be formed spaced apart from the second semiconductor layer contact hole 344.

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

1 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 with a relatively high 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 device 300 of the present invention is a top-emission type, a reflective electrode or a reflective layer may be further formed below the first electrode 310. For example, the reflective electrode or the reflective layer may be made of aluminum-palladium-copper (APC) alloy.

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

An organic light-emitting layer 430 is formed on the first electrode 410. In one exemplary embodiment, the organic light-emitting layer 430 may have a single-layer structure of a light-emitting material layer. In contrast, the organic light emitting layer 430, as shown in Figures 2 and/or 4, includes 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 be composed of multiple layers of the same organic material.

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

An encapsulation film 380 is formed on the second electrode 420 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 to this.

As described above, the organic light emitting diode 400 is represented by Formula 1 to Formula 3 in the organic light emitting layer 430, and an organic compound having delayed fluorescence characteristics is used as a dopant to improve luminous efficiency. Organic compounds of Formulas 1 to 3 have delayed fluorescence properties because an electron donor moiety and an electron acceptor moiety coexist within one molecule. In addition, the three-dimensional structure between the condensed heteroaromatic moiety constituting the electron donor and the arylene group moiety substituted with at least two cyano groups constituting the electron acceptor is limited. Therefore, when organic compounds represented by Formulas 1 to 3 are used as dopant of a light emitting device, luminous efficiency is improved and an organic light emitting diode 400 with good color purity can be manufactured. Since there is no need to use an organic host with high triplet energy and a wide bandgap, power consumption can be reduced by lowering the driving voltage of the light emitting diode 400 and the organic light emitting diode display device 300 including the same, and the device can improve the lifespan of

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 Compound 1

(1) Synthesis of compound a

Carbazole 13.5 g (0.0808 mol) was dissolved in DMF under a nitrogen atmosphere and stirred. 3.52 g (0.0808 mol) of NaH was added and stirred until no gas was generated. Afterwards, 5 g (0.0261 mol) of 3,5-difluorobromobenzene was added and stirred at 130°C for 15 hours. After the reaction was completed, distilled water, acetone, and ethyl acetate were used as washing solutions and filtered. After sufficient washing, 9.4 g of yellow solid Compound a was obtained (yield: 74%).

(2) Synthesis of compound b

Under a nitrogen atmosphere, 9.40 g (0.0193 mol) of a was dissolved in diethyl ether solvent and stirred. At -78°C, 11.57 mL (0.0289 mol) of n-BuLi was slowly added and stirred at room temperature for 30 minutes. Again, 4.91 mL (0.0289 mol) of triethyl borate was slowly added at -78°C and stirred at room temperature for 15 hours. After the reaction was completed, one or two drops of HCl were added to create an acidic atmosphere, and then distilled water was added. Diethyl ether solvent was removed, extracted with methylene chloride and distilled water, and moisture and solvent were removed. After recrystallization using methylene chloride and hexane solvent, 7 g of white solid b was obtained (yield: 80%).

(3) Synthesis of compound 1

Under a nitrogen atmosphere, 2.9 g (0.0209 mol) of potassium carbonate was dissolved in 30 mL of methanol and stirred. 1.5 g (0.00525 mol) of 2,5-Dibromoterephthalonitrile and 5.22 g (0.0115 mol) of b were dissolved in 60 mL of tetrahydrofuran solvent and added. Palladium acetate 0.24 g (0.00107 mol) and Triphenylphosphine 0.55 g (0.00230 mol) were additionally added and stirred. After stirring for 12 hours under reflux conditions, the reaction was terminated and extraction was performed using ethyl acetate and distilled water. It was purified by column chromatography using chloroform and hexane, and wet purification was completed by recrystallization with methylene chloride and hexane. 0.61 g of pink solid Compound 1 was obtained (yield: 12%).

Synthesis Example 2: Synthesis of Compound 2

Under a nitrogen atmosphere, 2.9 g (0.0209 mol) of potassium carbonate was dissolved in 30 mL of methanol and stirred. 1.5 g (0.00525 mol) of 4,6-Dibromoterephthalonitrile and 5.22 g (0.0115 mol) of b were dissolved in 60 mL of tetrahydrofuran solvent and added. Palladium acetate 0.24 g (0.00107 mol) and Triphenylphosphine 0.55 g (0.00230 mol) were additionally added and stirred. After stirring for 12 hours under reflux conditions, the reaction was terminated and extraction was performed using ethyl acetate and distilled water. It was purified by column chromatography using chloroform and hexane, and wet purification was completed by recrystallization with methylene chloride and hexane. 0.8 g of yellow solid Compound 2 was obtained (yield: 16%).

Synthesis Example 3: Synthesis of Compound 3

Under a nitrogen atmosphere, 2.9 g (0.0209 mol) of potassium carbonate was dissolved in 30 mL of methanol and stirred. 1.5 g (0.00525 mol) of 4,5-dibromophthalonitrile and 5.22 g (0.0115 mol) of b were dissolved in 60 mL of tetrahydrofuran solvent and added. Palladium acetate 0.24 g (0.00107 mol) and Triphenylphosphine 0.55 g (0.00230 mol) were additionally added and stirred. After stirring for 12 hours under reflux conditions, the reaction was terminated and extraction was performed using ethyl acetate and distilled water. It was purified by column chromatography using chloroform and hexane, and wet purification was completed by recrystallization with methylene chloride and hexane. 0.5 g of yellow solid Compound 2 was obtained (yield: 10%).

Example 1: Light-emitting diode production

An organic light-emitting diode was manufactured by applying Compound 1 synthesized in Synthesis Example 1 as a dopant in the light-emitting material layer. First, a glass substrate with an ITO (including a reflector) electrode measuring 40 mm After cleaning the substrate, it was treated with O ₂ plasma in a vacuum for 2 minutes and transferred to a deposition chamber to deposit other layers on the top. The organic layer was deposited in the following order by evaporation from a heating boat under a vacuum of about 10 ^-7 Torr.

Hole injection layer (HAT-CN, 7 nm), hole transport layer (NPB, 55 nm), electron blocking layer (mCBP, 10 nm), emitting material layer (4-(3-triphenylen-2-yl)phenyl) Dibenzo[b,d]thiophene was used as a host, and Compound 1 was doped with 35% by weight, 35 nm), a hole blocking layer (B3PYMPM, 10 nm), an electron transport layer (TPBi, 20 nm), and an electron injection layer ( LiF), cathode (Al).

After forming a CPL (capping layer), it was encapsulated with glass. After deposition of these layers, they were transferred from the deposition chamber into a dry box for film formation and subsequently encapsulated using UV cured epoxy and a moisture getter.

Example 2: Light-emitting diode production

A light-emitting diode was manufactured by repeating the procedure of Example 1, except that Compound 2 synthesized in Synthesis Example 2 was used instead of Compound 1 as the dopant of the light-emitting material layer.

Example 3: Light-emitting diode production

A light-emitting diode was manufactured by repeating the procedure of Example 1, except that Compound 3 synthesized in Synthesis Example 3 was used instead of Compound 1 as the dopant of the light-emitting material layer.

Comparative Examples 1 to 2: Light-emitting diode production

A light-emitting diode was manufactured by repeating the procedure of Example 1, except that the compounds shown below were used instead of Compound 1 as the dopant of the light-emitting material layer.

Experimental example: Measurement of emission characteristics of organic light-emitting diode

The physical properties were measured for the organic light emitting diodes manufactured in Examples 1 to 3 and Comparative Examples 1 to 2, respectively. Each organic light-emitting diode with an emission area of 9 mm2 was connected to an external power source, and device characteristics were evaluated at room temperature using a current source (KEITHLEY) and a photometer (PR 650). Driving voltage (V), current efficiency (cd/A), power efficiency (lm/W), external quantum efficiency (EQE, %) of each light emitting diode measured at a current density of 10 mA/cm2, The CIE color coordinate measurement results are shown in Table 1 below.

Evaluation of light emitting characteristics of light emitting diodes Sample V cd/A lm/W EQE (%) CIEx Comparative Example 1 4.96 11.67 7.39 6.94 (0.170, 0.263) Comparative Example 2 5.55 8.94 5.06 5.74 (0.170, 0.234) Example 1 4.51 37.31 25.97 12.91 (0.381, 0.581) Example 2 4.72 40.85 27.22 13.99 (0.373, 0.586) Example 3 4.83 46.22 30.08 15.65 (0.330, 0.598)

As shown in Table 1, compared to the case where the organic compound of Comparative Example 1 was used as the dopant of the light-emitting material layer, when the organic compound synthesized according to the present invention was used as the dopant of the light-emitting material layer, the driving voltage was up to 9.0%. decreased, and current efficiency, power efficiency, and external quantum efficiency improved by up to 296.1%, 307.0%, and 125.5%, respectively. In addition, compared to the case where the organic compound of Comparative Example 2 was used as the dopant of the light-emitting material layer, when the organic compound synthesized according to the present invention was used as the dopant of the light-emitting material layer, the driving voltage decreased by up to 18.7%, and the current efficiency , power efficiency and external quantum efficiency were improved by up to 417.0%, 494.4%, and 172.6%, respectively. In particular, the compounds used in Comparative Examples 1 and 2 emit blue light, but the organic compound synthesized according to the present invention emits green light, so the light emission characteristics are different. In the end, it was confirmed that by applying the organic compound of the present invention to the light-emitting layer, the driving voltage can be significantly lowered and an organic light-emitting diode with good luminous efficiency can be manufactured. Therefore, by using the organic light emitting diode to which the organic compound of the present invention is applied, light emitting devices such as organic light emitting diode displays and/or lighting devices with improved luminous efficiency and low driving voltage can be implemented.

Although the present invention has been described above based on exemplary embodiments and examples of the present invention, the present invention is not limited to the technical ideas described in the above embodiments and examples. Rather, anyone skilled in the art to which the present invention pertains can easily make 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 rights 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 light emitting 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, 265: exciton blocking layer 300: organic light emitting diode display device

Claims (15)

Any organic compound represented by the following formula (3).
Formula 3



According to clause 1,
The organic compound is Compound 3, Compound 7, Compound 8, Compound 9, or Compound 10.
According to clause 1,
The organic compound is Compound 3 or Compound 7.
a first electrode and a second electrode facing each other;
Comprising an organic light-emitting layer located between the first electrode and the second electrode,
The organic light-emitting layer is an organic light-emitting diode comprising any one organic compound represented by the following formula (3).
Formula 3



According to clause 4,
An organic light emitting diode where the organic compound is Compound 3, Compound 7, Compound 8, Compound 9, or Compound 10.
According to clause 4,
The organic compound is Compound 3 or Compound 7 in an organic light emitting diode.
According to clause 4,
An organic light-emitting diode wherein the organic light-emitting layer includes a light-emitting material layer containing a light-emitting material, and the organic compound is used as a dopant of the light-emitting material layer.
According to clause 7,
An organic light emitting diode wherein the light emitting material layer further includes a host.
According to clause 8,
The difference between the highest occupied molecular orbital energy level of the host (HOMO ^H ) and the highest occupied molecular orbital energy level (HOMO ^D ) of the dopant (|HOMO ^H -HOMO ^D |) or the lowest unoccupied molecular orbital of the host An organic light-emitting diode in which the difference between the energy level (LUMO ^H ) and the lowest unoccupied molecular orbital energy level (LUMO ^D ) of the dopant (|LUMO ^H -LUMO ^D |) is 0.5 eV or less.
According to clause 4,
An organic light-emitting diode in which the difference (ΔE _ST ) between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of the organic compound is 0.3 eV or less.
Board;
An organic light emitting diode located on the substrate and described in any one of claims 4 to 10; and
A driving element located on the substrate and connected to the first electrode of the organic light-emitting diode
An organic light emitting device comprising:
According to clause 11,
The organic light emitting device includes an organic light emitting diode display device. The method of claim 8, wherein the host is 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile, 4,4'-bis(N-carbazolyl)- 1,1'-biphenyl, 3,3'-bis(N-carbazolyl)-1,1'-biphenyl, 1,3-bis(carbazol-9-yl)benzene, (oxybis(2, 1-phenylene))bis(diphenylphosphine oxide), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,6-di(9H-carbazole-9 -yl) pyridine, 3',5'-di(carbazol-9-yl)-[1,1'-biphenyl]-3,5-dicarbonitrile 4'-(9H-carbazol-9-yl) ) Biphenyl-3,5-dicarbonitrile, 3'-(9H-carbazol-9-yl) Biphenyl-3,5-dicarbonitrile, 9-(4-(9H-carbazol-9-yl )phenyl)-9H-3,9'-bicarbazole, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole, 4-(3-tri An organic light emitting diode selected from the group consisting of phenylen-2-yl) phenyl) dibenzo [b, d] thiophene and combinations thereof.
According to clause 8,
The light emitting material layer is an organic light emitting diode in which 1 to 50% by weight of the dopant is added to the host.
According to clause 8,
An organic light emitting diode wherein the triplet energy level and singlet energy level of the host are higher than the triplet energy level and singlet energy level of the dopant, respectively.