KR20210014859A - N-heterocyclic compound and organic light emitting device comprising the same - Google Patents

Abstract

The present invention relates to a novel N-heterocyclic compound and an organic light emitting device comprising the same. When the N-heterocyclic compound according to the present invention is employed as a material for an organic material layer, luminescent properties such as luminous efficiency, power efficiency, quantum efficiency, etc., of the compound induce the increase of light emitting properties, and thus the organic light emitting device having improved power consumption can be realized.

Description

N-heterocyclic compound and organic light emitting device including the same {N-HETEROCYCLIC COMPOUND AND ORGANIC LIGHT EMITTING DEVICE COMPRISING THE SAME}

The present invention relates to a novel N-heterocyclic compound and an organic light emitting device including the same.

An organic light-emitting device is a device that emits light while electrons and holes form a pair and then disappear when charge is injected into an organic film formed between an electron injection electrode (cathode) and a hole injection electrode (anode). This not only allows the device to be formed on a flexible transparent substrate such as plastic, but can be driven at a lower voltage than that of a plasma display panel or an inorganic EL (Electro Luminescence) display. In addition, it has the advantage of relatively low power consumption, wide viewing angle, excellent contrast, and fast response speed.

Typical organic light emitting devices include a substrate, an anode, a hole injection layer that accepts holes from the anode, a hole transport layer that transports holes, a light-emitting layer where holes and electrons combine to emit light, and an electron transport layer that receives electrons from the cathode and transfers them to the emission layer. And a cathode. In some cases, a light-emitting layer may be formed by doping a small amount of fluorescent or phosphorescent dye on the electron transport layer or hole transport layer without a separate light-emitting layer. In the case of using a polymer, a single polymer serves as the hole transport layer, the light-emitting layer, and the electron transport layer. Can also be performed at the same time.

As mentioned above, the organic light emitting device has a structure in which an organic material layer interposed between an anode and a cathode is disposed. As a voltage is applied to the organic light-emitting device, electrons and holes injected from the electrode are combined in the organic material layer to form a pair and then dissipate to emit light.At this time, the organic material layer may be configured as a single layer or multiple layers as necessary. For example, as the material of the organic material layer, a compound capable of constituting an emission layer by itself may be used, or a mixture of compounds capable of serving as a host or a dopant of the emission layer may be used. In addition, as a material of the organic material layer, a compound capable of performing a role of hole injection, hole transport, electron blocking, hole blocking, electron transport, and electron injection may be used.

Accordingly, development of a material for an organic material layer in order to improve the performance, life, or efficiency of the organic light emitting device is still required. In particular, there is an urgent need to develop a compound that can serve as a host for a light emitting layer and a compound that can be used for an electron transport layer.

KR 10-2016-0017055 A KR 10-2019-0075322 A KR 10-1994837 B1

An object of the present invention is to provide a novel N-heterocyclic compound, an organic light-emitting compound.

In addition, an object of the present invention is to provide an organic light-emitting device in which power consumption is improved by lowering a driving voltage and inducing an increase in power efficiency and quantum efficiency by using the N-heterocyclic compound as a material of an organic material layer.

For the purposes described above, the present invention provides an N-heterocyclic compound represented by the following formula (1).

[Formula 1]

[In Formula 1,

Ar is a substituted or unsubstituted 6 membered heteroaryl skeleton;

R ¹ is hydrogen, deuterium, halogen, cyano, C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;

R ² is halogen, cyano, C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;

n is an integer selected from 0 to 3, and when n is an integer of 2 or 3, R ² may be the same as or different from each other, and when n is 0, all three substituents are hydrogen;

m is an integer of 2 or 3;

The substitution of Ar is C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, mono or diC1-C30 alkylamino, mono or diC6 -C30 arylamino, nitro, hydroxy, and the like, occurring at any carbon atom by one or more substituents selected from the group consisting of, and combinations thereof; The heteroaryl is each independently at least one selected from B, N, O, S, P(=O), Si and P; The substituents repeated by n or m may be the same or different from each other.]

In addition, in the present invention, an organic light emitting device including the N-heterocyclic compound represented by Formula 1 is provided.

The N-heterocyclic compound according to the present invention is chemically stable and has high electron density by introducing two or more benzothiazole groups into a 6-membered heteroaryl skeleton derived from pyridine, 　pyrimidine, pyrazine, 　pyridazine, triazine, etc. Have. In addition, the glass transition temperature (Tg) is also excellent in thermal stability. The present invention has an advantage in that such high thermal stability becomes an important factor for providing driving stability to an organic light-emitting device.

The N-heterocyclic compound according to the present invention is an organic material layer material of an organic light-emitting device, and can exhibit effective effects. Specifically, the N-heterocyclic compound according to the present invention can be used as an organic material layer material capable of exhibiting effective effects such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like in an organic light emitting device. In particular, according to the present invention, it is used as a material for a light-emitting layer, exhibits excellent light-emitting properties and suppresses current leakage. In addition, it is used as a material for the electron transport layer, so that electrons are rapidly injected into the light emitting layer, and electrons and holes injected from the electrode can be injected in a balanced manner into the light emitting layer.

Therefore, the organic light-emitting device employing the N-heterocyclic compound according to the present invention can lower the driving voltage of the device and induce an increase in light-emitting characteristics such as power efficiency and quantum efficiency, thereby improving power consumption. It has an advantage that can provide. In addition, it has the advantage of being able to provide an organic light-emitting device having a long lifespan.

1 is a schematic view showing a stacked structure of an organic light emitting device (Device 1) according to an embodiment of the present invention,
2 is a graph showing current density (㎃/cm2) and luminance (cd/m2) at 0 to 15V of an organic light-emitting device (Device 1) according to an embodiment of the present invention.
3 is a graph showing current efficiency (cd/A) versus luminance (cd/m2) of an organic light-emitting device (Device 1) according to an embodiment of the present invention.
4 is a graph showing power efficiency (Im/W) versus luminance (cd/m2) of an organic light-emitting device (Device 1) according to an embodiment of the present invention.
5 is a diagram schematically showing a stacked structure of an organic light emitting device (Device 2) according to an embodiment of the present invention,
6 is a graph showing current density (㎃/cm2) and luminance (cd/m2) at 0 to 15V of an organic light-emitting device (Device 2) according to an embodiment of the present invention.
7 is a graph showing current efficiency (cd/A) versus luminance (cd/m2) of an organic light-emitting device (Device 2) according to an embodiment of the present invention.
8 is a graph showing power efficiency (Im/W) versus luminance (cd/m2) of an organic light-emitting device (Device 2) according to an embodiment of the present invention.
9 is a schematic view showing a stacked structure of an organic light emitting device (Device 3) according to an embodiment of the present invention,
10 is a graph showing the current density (㎃/cm2) and luminance (cd/m2) at 0 to 15V of the organic light emitting device (Device 3) according to an embodiment of the present invention.
11 is a graph showing current efficiency (cd/A) versus luminance (cd/m2) of an organic light-emitting device (Device 3) according to an embodiment of the present invention.
12 is a graph showing power efficiency (Im/W) versus luminance (cd/m2) of an organic light-emitting device (Device 3) according to an embodiment of the present invention.

The N-heterocyclic compound according to the present invention and the organic light emitting device including the same are described in detail below, but unless otherwise defined in the technical terms and scientific terms used at this time, those of ordinary skill in the technical field to which the present invention belongs Descriptions of known functions and configurations that have the meanings commonly understood and may unnecessarily obscure the subject matter of the present invention will be omitted in the following description.

As used herein, the term “alkyl” and other substituents including “alkyl” moieties are organic radicals derived from aliphatic hydrocarbons by one hydrogen removal, and include both straight chain or branched forms. In addition, as for the substituents including alkyl, alkoxy and other alkyl moieties according to the present invention, a short-chain substituent having 1 to 7 carbon atoms takes precedence, but it is a matter of course that a long-chain substituent of 8 or more is also an aspect of the present invention.

In addition, the term "aryl" in the present specification is an organic radical derived from an aromatic hydrocarbon by the removal of one hydrogen, and suitably contains 4 to 7, preferably 5 or 6 ring atoms in each ring. Or it includes a fused ring system, and includes a form in which a plurality of aryls are connected by a single bond. For example, phenyl, naphthyl, biphenyl, terphenyl, anthryl, indenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthyl, fluoranthenyl, etc. , Is not limited thereto.

In addition, the term "heteroaryl" in the present specification is an organic radical derived from an aromatic ring skeleton, and 1 to 4 members selected from B, N, O, S. Si and P as a ring member (ring atom) of the skeleton It includes a hetero atom, and the rest of the aromatic ring skeleton member refers to an aryl group that is carbon. In addition, in the present specification, the 6-membered heteroaryl skeleton refers to an aromatic ring skeleton including the above-described heteroatom, and refers to an aromatic ring skeleton including at least one or more Ns. For example, the 6-membered heteroaryl skeleton may be derived from pyridine, 　pyrimidine, pyrazine, 　pyridazine, triazine, and the like.

In addition, the term "cycloalkyl" as used herein is an organic radical derived from a fully saturated or partially unsaturated alicyclic hydrocarbon ring, and includes fused cyclic, bridged cyclic and spirocyclic groups. For example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, decalin, bike[3.1.1]heptane, bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, bike[3.2. 2] nonane, spiro [2.5] octane, spiro [3.5] nonane, including, but not limited to, adamantyl.

In addition, as used herein, “alkoxy” means alkyl-O-*, and “aryloxy” means aryl-O-*. In this case, the alkyl and aryl follow the above definition.

In addition, the term "amino" in the present specification means *-NH ₂ .

In addition, the term "halogen" used herein refers to a fluorine (F), chlorine (Cl), bromine (Br) or iodine (I) atom.

In addition, in the present specification, the number of carbon atoms according to the definition of the substituent described in Formula 1 does not include the number of carbon atoms of the substituent that can be further substituted.

The N-heterocyclic compound according to the present invention has a 6-membered heteroaryl skeleton containing at least one nitrogen atom as a parent nucleus, and 2 or 3 benzothiazole groups substituted or unsubstituted on any carbon atom of the parent nucleus It is a compound of a novel structure that is individually bonded.

In addition, the N-heterocyclic compound is an organic material having an organic light emitting device use, and is contained in an organic material layer such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer to exhibit effective effects.

Specifically, the N-heterocyclic compound is chemically stable and has a high electron density. In addition, it has thermal stability, that is, a high glass transition temperature (Tg), which can be an important factor providing driving stability to the organic light emitting device. In addition, the N-heterocyclic compound according to the present invention improves interfacial properties between organic substances and has improved solubility in various organic solvents. Accordingly, the N-heterocyclic compound according to the present invention has the advantage that it can be applied in various aspects as an organic material of an organic light emitting device.

Hereinafter, the present invention will be described in detail.

In the present invention, an N-heterocyclic compound represented by the following formula (1) is provided.

[Formula 1]

[In Formula 1,

Ar is a substituted or unsubstituted 6 membered heteroaryl skeleton;

R ¹ is hydrogen, deuterium, halogen, cyano, C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;

R ² is halogen, cyano, C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;

n is an integer selected from 0 to 3, and when n is an integer of 2 or 3, R ² may be the same as or different from each other, and when n is 0, all three substituents are hydrogen;

m is an integer of 2 or 3;

The substitution of Ar is C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, mono or diC1-C30 alkylamino, mono or diC6 -C30 arylamino, nitro, hydroxy, and the like, occurring at any carbon atom by one or more substituents selected from the group consisting of, and combinations thereof; The heteroaryl is each independently at least one selected from B, N, O, S, P(=O), Si and P; The substituents repeated by n or m may be the same or different from each other.]

With the structural features as described above, the N-heterocyclic compound can realize high luminous efficiency, and thus can be used as a material for a light emitting layer.

In addition, this can remove the energy barrier associated with electron injection, and provide an electron transport layer having an appropriate HOMO energy level and LUMO energy level, and thus can be used as a material for the electron transport layer. In addition, leakage of holes and leakage of current are effectively suppressed, and electrons are rapidly injected into the emission layer so that electrons can be injected in a balanced manner into the emission layer.

The N-heterocyclic compound according to an embodiment of the present invention is a six-membered element derived from pyridine, 　pyrimidine, pyrazine, 　pyridazine or triazine, in terms of implementing excellent luminous efficiency and improved driving life. It may have a heteroaryl skeleton.

In one aspect, when the N-heterocyclic compound has two benzothiazole groups, Ar may be selected from the following Structural Formula 1.

[Structural Formula 1]

[In the above structure,

R ¹¹ and R ¹² are independently of each other C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;

R ¹³ is hydrogen, C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;

a is an integer selected from 0 to 3, and when a is 0, all three substituents are hydrogen;

b is an integer selected from 0 to 2, and when b is 0, both substituents are hydrogen.]

As described above, when m in Formula 1 is 2, that is, when an N-heterocyclic compound having two benzothiazole groups is used as an electron transport layer material, the difference between the HOMO energy level of the electron transport layer and the HOMO energy level of the light emitting material layer Raises. Thus, hole leakage is effectively blocked.

Specifically, when m is 2 in Formula 1, Ar is selected from Structural Formula 1; R ¹ is hydrogen, halogen, cyano, C1-C30 alkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof; R ² is C1-C30 alkyl, C3-C30 cycloalkyl, or a combination thereof; The n may be an integer selected from 0 to 3.

Specifically, when m is 2 in Formula 1, Ar is selected from Structural Formula 1; R ¹ is hydrogen, halogen, cyano, C1-C7 alkyl, C6-C12 aryl, C3-C12 heteroaryl, or a combination thereof; R ² is C1-C7 alkyl, C3-C12 cycloalkyl, or a combination thereof; The n may be an integer selected from 0 to 3.

Specifically, when m is 2 in Formula 1, Ar is selected from Structural Formula 1; R ¹ is halogen, cyano, C1-C7 alkyl, fluorinated C1-C7 alkyl, aryl such as phenyl, naphthyl or biphenyl, or heteroaryl such as pyridine, pyrimidine, pyrazine, pyridazine, and triazine, and ; R ² is C1-C7 alkyl; The n may be an integer of 0 or 1.

Specifically, in Formula 1, n may be an integer of 0.

Specifically, Ar is selected from Structural Formula 1, and R ¹¹ , R ¹² and R ¹³ may each independently be hydrogen, halogen, cyano, C1-C7 alkyl, or fluorinated C1-C7 alkyl.

Specifically, Ar is selected from Structural Formula 1, and R ¹¹ , R ¹² and R ¹³ may be hydrogen or halogen independently of each other.

In another aspect, when the N-heterocyclic compound has three benzothiazole groups, Ar may be selected from the following Structural Formula 2.

[Structural Formula 2]

[In the above structure,

R ¹⁴ is C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;

R ¹⁵ is hydrogen, C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;

b is an integer selected from 0 to 2, and when b is 0, both substituents are hydrogen.]

As described above, when m in Formula 1 is 3, that is, when an N-heterocyclic compound having three benzothiazole groups is used as an electron transport layer material, the difference between the HOMO energy level of the electron transport layer and the HOMO energy level of the light emitting material layer Higher. In addition, when it is used as a material for a light emitting layer, it enables remarkably improved light emitting characteristics and at the same time a low driving voltage.

Specifically, when m is 3 in Formula 1, Ar is selected from Structural Formula 2; R ¹ is hydrogen, halogen, cyano, C1-C30 alkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof; R ² is C1-C30 alkyl, C3-C30 cycloalkyl, or a combination thereof; The n may be an integer selected from 0 to 3.

Specifically, when m is 3 in Formula 1, Ar is selected from Structural Formula 2; R ¹ is hydrogen, halogen, cyano, C1-C7 alkyl, C6-C12 aryl, C3-C12 heteroaryl, or a combination thereof; R ² is C1-C7 alkyl, C3-C12 cycloalkyl, or a combination thereof; The n may be an integer selected from 0 to 3.

Specifically, when m is 3 in Formula 1, Ar is selected from Structural Formula 2; R ¹ is halogen, cyano, C1-C7 alkyl, fluorinated C1-C7 alkyl, aryl such as phenyl, naphthyl or biphenyl, or heteroaryl such as pyridine, pyrimidine, pyrazine, pyridazine, and triazine, and ; R ² is C1-C7 alkyl; The n may be an integer of 0 or 1.

Specifically, in Formula 1, n may be an integer of 0.

Specifically, Ar is selected from Structural Formula 2, and R ¹⁴ and R ¹⁵ may each independently be hydrogen, halogen, cyano, C1-C7 alkyl, or fluorinated C1-C7 alkyl.

Specifically, Ar is selected from Structural Formula 2, and R ¹⁴ and R ¹⁵ may be independently hydrogen or halogen.

The N-heterocyclic compound according to an embodiment of the present invention has excellent chemical and thermal stability. In addition, in order to satisfy improved luminous efficiency, power efficiency, quantum efficiency, etc., the substitution position of the benzothiazole group substituted in the parent nucleus may be variously modified.

Specifically, the substitution position of the benzothiazole group substituted in the parent nucleus may be 4, 5, 6, or 7 times. The specific substitution position thereof can be understood from the following structural formula 3.

[Structural Formula 3]

For example, when the substitution position of the benzothiazole group substituted in the parent nucleus is 5, an organic light emitting device having a lower driving voltage and driving stability can be provided, thereby providing an organic light emitting device with improved power consumption. Good in terms.

For example, when the substitution position of the benzothiazole group substituted in the parent nucleus is 4, 6, or 7, a low driving voltage is also satisfied, and improved luminescence characteristics are implemented. These results suggest that the substitution position of the benzothiazole group can be appropriately modified according to the purpose without limitation.

Thus, more specifically, the N-heterocyclic compound according to an embodiment of the present invention may be at least one selected from compounds represented by the following Chemical Formulas 2 to 5.

[Formula 2]

[Chemical Formula 3]

[Formula 4]

[Chemical Formula 5]

[In Formulas 2 to 5,

A ₁ and A ₂ are each independently -N= or -CH=;

R ¹ is independently of each other halogen, cyano, C1-C30 alkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof, and each R ₁ may be the same or different from each other;

R ² are independently of each other C1-C30 alkyl, C3-C30 cycloalkyl, or a combination thereof;

n is an integer independently selected from 0 to 3.]

Specifically, in Formulas 2 to 5, R ¹ is independently from each other halogen, cyano, C1-C7 alkyl, C6-C12 aryl, C3-C12 heteroaryl, or a combination thereof; R ² is independently from each other C1-C7 alkyl, C3-C12 cycloalkyl, or a combination thereof; The n may be an integer selected from 0 to 3.

Specifically, in Formulas 2 to 5, R ¹ is independently of each other halogen, cyano, C1-C7 alkyl, halo C1-C7 alkyl, phenyl, naphthyl, or biphenyl, such as aryl, or pyridine, pyrimidine , Heteroaryl, such as pyrazine, pyridazine, and triazine; R ² are each independently C1-C7 alkyl; The n may be an integer of 0 or 1.

Specifically, in Formulas 2 to 5, n may be an integer of 0.

Most specifically, the N-heterocyclic compound according to an embodiment of the present invention may be at least one selected from compounds represented by the following Structural Formulas 3 and 4, but is not limited thereto.

[Structural Formula 3]

[Structural Formula 4]

The N-heterocyclic compound according to an embodiment of the present invention may be prepared as shown in Scheme 1 below, but is not limited thereto, and may be prepared through a known organic reaction.

[Scheme 1]

[In Reaction Formula 1,

The definition of each substituent is the same as the definition in Formula 3 above;

R is C1-C3alkyl;

Hal is a halogen.]

In addition, in the present invention, an organic light-emitting device including the N-heterocyclic compound is provided. Specifically, the organic light emitting device according to the present invention may include the N-heterocyclic compound in one or more organic material layers interposed between the first electrode and the second electrode.

In one aspect, the organic light-emitting device according to the present invention may include the N-heterocyclic compound in the emission layer.

In another aspect, the emission layer may include the N-heterocyclic compound as a host material. In addition, it goes without saying that the light emitting layer may further include a commercial host material and be used in the form of a mixture.

In another aspect, the organic light-emitting device according to the present invention may include the N-heterocyclic compound in the electron transport layer.

In another aspect, the electron transport layer may be used in a laminated form of two or more layers including organic materials different from each other. In this case, at least one or more electron transport layers may include the N-heterocyclic compound. That is, one surface of the first electron transport layer containing the N-heterocyclic compound and the first electron transport layer is located adjacent to the light emitting layer, and the other surface is located adjacent to the second electron transport layer, and the second electron transport layer is It may include a compound different from the N-heterocyclic compound included in the first electron transport layer or may include a commercial electron transport layer organic material.

In another aspect, the organic light emitting device according to the present invention may include the N-heterocyclic compound in an organic layer such as a hole injection layer, a hole transport layer, and an electron injection layer.

In another aspect, the organic light emitting device according to the present invention includes the N-heterocyclic compounds having different structures in at least two or more layers selected from organic material layers such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. It may be included.

Hereinafter, the organic light-emitting device of the present invention will be described in detail.

An organic light-emitting device according to an embodiment of the present invention includes a first electrode; A second electrode; And one or more organic material layers interposed between the first electrode and the second electrode. The organic material layer may have a single-layer structure consisting of one layer, or a multi-layer structure of two or more layers including a light emitting layer. When the organic material layer of the organic light emitting device has a multilayer structure, it may have a structure in which at least one layer selected from a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, etc. is stacked. However, the structure of the organic light emitting device is not limited thereto.

The first electrode may be an anode, and is an electrode for injecting holes into the hole injection layer. Therefore, the material for forming the anode is not limited as long as the properties are imparted to the anode. Examples of materials for forming the anode include metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; Or a conductive polymer; And the like. Specifically, metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), combinations of metals and oxides such as ZnO:Al or SnO2:Sb, poly(3-methylthiophene) , Poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT), conductive polymers such as polypyrrole and polyaniline, but are not limited thereto. In addition, the anode layer may be formed of only one type of the above-described materials or may be formed of a mixture of a plurality of materials, and a multi-layered structure composed of a plurality of layers having the same composition or different composition may be formed.

The organic material layer may include a hole injection layer (HIL), a hole blocking layer (HBL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), and the like. Can be omitted. The organic material layer may be formed by a vacuum deposition method or a solution coating method. Examples of the solution coating method include, but are not limited to, spin coating, dip coating, doctor blading, inkjet printing, or thermal transfer method.

The organic material layer includes the N-heterocyclic compound according to the present invention.

Specifically, the N-heterocyclic compound may be included in the emission layer. In this case, the emission layer may include a commercial emission layer material, and the N-heterocyclic compound of Formula 1 may be further mixed and used. Accordingly, the organic light emitting device according to the present invention realizes more improved light emitting characteristics. In this case, the light emitting layer material may include at least one selected from a silane-based compound and a phosphine oxide-based compound as a host material. In addition, the emission layer may further include a dopant. At this time, the dopant material may be a conventional red, green, blue dopant, Bt ₂ Ir (acac), Ir (piq) _3, etc. may be used as the red dopant used in the light emitting layer, and the green dopant may be Ir (ppy). ₃ , Ir(ppy) ₂ (acac), Ir(mpyp) _3, etc. may be used, and the blue dopant may be Firpic, DPAVBi, etc., but the present invention is not limited thereto.

The emission layer may be a phosphorescence emission layer. As mentioned, by including the N-heterocyclic compound of Formula 1 according to the present invention, it is possible to implement an organic light emitting device having high luminance and long life characteristics. In the light-emitting layer of the organic light-emitting device of the present invention, the film thickness of the light-emitting layer is not limited, but from the viewpoint of uniformity of the film, application of unnecessary high voltage during light emission, and improvement of the stability of light emission color against a driving current, 2 It can be adjusted in the range of nm to 5 μm, can be adjusted in the range of 5 to 50 nm, or can be adjusted in the range of 10 to 40 nm.

In addition, the light emitting layer can obtain a color of high luminance with higher efficiency by using a phosphorescent dopant together. In this case, the used dopant is not limited, and a known dopant may be selected and used as necessary. The phosphorescent dopant is a compound capable of emitting light from triplet excitons, and is not particularly limited as long as it emits light from triplet excitons. A specific example may be a metal complex including one or more metals selected from the group consisting of Ir, Ru, Pd, Pt, Os, and Re, and may be a porphyrin metal complex or an ortho metallized metal complex.

For example, the porphyrin metal complex may be specifically a porphyrin platinum complex.

For example, the ortho metallized metal complex is 2-phenylpyridine (2-phenylpyridine, ppy) derivative, 7,8-benzoquinoline derivative, 2- (2-thienyl) pyridine (2- (2-thienyl) pyridine, tp) derivatives, 2-(1-naphthyl)pyridine (2-(1-naphthyl)pyridine, npy) derivatives, 2-phenylquinoline (pq) derivatives, and the like may be included as ligands. E?, these derivatives may have a substituent as necessary. As an auxiliary ligand, a ligand other than the above ligand, such as acetylacetonato (acac) and picric acid, may be further included. For example, bisthienylpyridine acetylacetonate iridium (bisthienylpyridine acetylacetonate Iridium), bis (2-benzo [b] thiophen-2-yl-pyridine) (acetylacetonato) iridium (III) (bis (2-benzo [b]thiophen-2-yl-pyridine)(acetylacetonato)iridium(III), Ir(btp) ₂ (acac)), bis(2-phenylbenzothiazole)(acetylacetonato)iridium(III) (bis (2-phenylbenzothiazole)(acetylacetonato)iridium(III), Ir(bt) ₂ (acac)), bis(1-phenylisoquinoline)(acetylacetonato)iridium(III) (bis(1-phenylisoquinoline)(acetylacetonato) )Iridium(III), Ir(piq) ₂ (acac)), tris(1-phenylisoquinoline) iridium(III) (tris(1-phenylisoquinoline)iridium(III), Ir(piq) ₃ ), tris(2 -Phenylpyridine) iridium (III) (tris (2-phenylpyridine) iridium (III), Ir (ppy) ₃ ), tris (2-biphenylpyridine) iridium (tris (2-biphenylpyridine) iridium), tris (3- Biphenylpyridine) iridium (tris (3-biphenylpyridine) iridium), tris (4-biphenylpyridine) iridium (tris (4-biphenylpyridine) iridium), and the like, but are not limited thereto.

The amount of the dopant included in the light emitting layer is not limited, for example, it may be included in the range of 2 to 20 parts by weight based on 100 parts by weight of the host material (Chemical Formula 1), and the total content of the dopant relative to the total weight of the light emitting layer is 0.5 to 35 parts by weight. May be in the range of %.

Specifically, the N-heterocyclic compound may be included in the electron transport layer.

The electron transport layer (ETL) is mainly composed of a material containing a chemical component that attracts electrons. For this purpose, high electron mobility is required, and electrons are stably supplied to the light emitting layer through smooth electron transport. Accordingly, as the electron transport layer employs the N-heterocyclic compound, a low driving voltage and improved driving stability may be provided. In addition, leakage of current is effectively suppressed. As for the electron transport layer, the N-heterocyclic compound may be used as a single material, but may be used in combination with a conventional electron transport layer material to provide synergy to a desired effect. Typical electron transport layer materials include, for example, TSPO1 (diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide), TPBi (1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene); Alq ₃ (tris(8-hydroxyquinolinato)aluminum); BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline); PBD (2-(4-biphenyl)-5-(4-tert-butyl-phenyl)-1,3,4-oxadizole), TAZ (3-(4-biphenyl)-4-phenyl-5-(4- tert-butyl-phenyl)-1,2,4-triazole), OXD-7 (1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene) Azole compounds such as; tris(phenylquinoxaline) (TPQ); TmPyPB (3,3'-[5'-[3-(3-Pyridinyl)phenyl][1,1':3',1''-terphenyl]-3,3''-diyl]bispyridine) etc. However, it is not limited thereto. Preferably, TSPO1, TPBi or Alq3 may be used, and in an embodiment of the present invention, compound 1 (N2-246NS) or an N-heterocyclic compound according to the present invention is formed with TSPO1 or TPBi to form an electron transport layer, It was confirmed that more improved luminous efficiency can be implemented. In this case, the electron transport layer may be stacked on the light emitting layer to a thickness of 5 to 150 nm, the first electron transport layer comprising the N-heterocyclic compound according to the present invention and a second electron transport layer comprising TSPO1 or TPBi This may be a stacked one. At this time, the thickness ratio (a:b) of the first electron transport layer (a) and the second electron transport layer (b) is not limited, but may be 1:10 to 1:0.1, specifically 1:10 to 1: May be 1. In addition, the thickness refers to a vertical direction with respect to the long axis of the electron transport layer. In addition, the stacked electron transport layer may be stacked such that the first electron transport layer is adjacent to the emission layer, and the second electron transport layer may be stacked so that the second electron transport layer is adjacent to the emission layer.

The hole injection layer HIL may be formed on the first electrode by using various methods such as a vacuum deposition method, a spin coating method, a cast method, and a LB (Langmuir-Blodgett) method. The material is, for example, CuPc (copper phthalocyanine), NPD (N,N'-dinaphthyl-N,N'-phenyl-(1,1'-biphenyl)-4,4'-diamine), m-MTDATA (4, 4',4"-tris(3-Methylphenylphenylamino)triphenylamine), 1-TNATA (4,4',4''-tris[1-naphthyl(phenyl)amino]triphenylamine), 2-TNATA (4,4', Aromatic amines such as 4''-tris[2-naphthyl(phenyl)amino]triphenylamine), p-DPA-TDAB (1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino]benzene), etc., as a conductive polymer Polythiophene derivative poly(3,4-ethylenedioxythiophene)-poly(styrnesulfonate) (PEDOT:PSS), etc. In the embodiment of the present invention, PEDOT:PSS was used as a hole injection layer, and the hole injection layer It may be coated on the top of the first electrode to a thickness of 10 to 60 nm.

In addition, the hole transport layer (HTL) is formed on the top of the hole injection layer by using various methods such as vacuum deposition method, spin coating method, cast method, and LB method so that holes that have entered through the hole injection layer can be stably supplied to the light emitting layer. Can be. As a material for the hole transport layer that can be used, a material that is commonly used can be used, for example, NPB (N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine) , NPD (N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine), mCP (1,3-Bis(N-carbazolyl)benzene), TPD (N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine), TTB (N,N,N',N'-tetrakis(4-methylphenyl)-(1,1'-biphenyl)- 4,4-diamine), TTP (N1,N4-diphenyl-N1,N4-dim-tolylbenzene-1,4-diamine), ETPD (N,N'-bis(4-methylphenyl)-N,N'-bis (4-ethylphenyl)-[1,1'-(3,3'-dimethyl)biphenyl]-4,4'-diamine), VNPB (N4,N4''-bis(4-vinylphenyl)biphenyl-4,4 ''-diamine), ONPB (N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl)phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine ), OTPD (N4,N4'-bis(4-(6-((3-ethyloxetan-3-yl)methoxy)hexyl)phenyl)-N4,N4'-diphenylbiphenyl-4,4'-diamine) A hole transport material; Polymeric hole transport materials such as PVK (poly-N-vinylcarbazole), polyaniline, and (phenylmenyl) polysilane may be used. For example, NPD, mCP or PVK may be used. In addition, the hole transport layer may be stacked on the light emitting layer to a thickness of 10 to 60 nm.

In addition, a hole blocking layer (HBL) may be formed to prevent diffusion of triplet excitons or holes into the electron transport layer. In the case of forming the hole blocking layer by vacuum evaporation and spin coating, the conditions vary depending on the compound to be used, but may generally be within the same range of conditions as the hole injection layer. A known hole-blocking material can also be used, and examples thereof include an oxadiazole derivative, a triazole derivative, and a phenanthroline derivative. As a more specific example, BCP or the like may be used as a material for the hole blocking layer.

In addition, the electron injection layer EIL may be deposited to a thickness of 1 to 50 nm using LIF or lithium quinolate (Liq), but is not limited thereto.

In addition, the second electrode may be a negative electrode, and a specific example is a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or an alloy thereof, LiF A metal having a low work function, such as a multi-layered material such as /Al or LiO ₂ /Al, may be used, and more specifically, Al is preferred.

The organic light-emitting device according to the present invention shows an efficient host-dopant energy transfer mechanism, and thus can exhibit a reliable high-efficiency light emission characteristic based on an effect of improving electron density distribution. In addition, it is possible to secure high-performance light-emitting characteristics having high efficiency and long life in each color by overcoming the initial efficiency lowering characteristics and low life characteristics of existing materials.

The organic light-emitting device according to the present invention described above may be applied to a display device, and the display device may be a display device using a backlight unit, and the organic light-emitting device may be used as a light source and a single light source of a backlight unit. The display device may be an organic electroluminescent display (OLED), but is not limited thereto.

In the following, for a detailed understanding of the present invention, the N-heterocyclic compound according to the present invention, a method of manufacturing the same, and luminescence characteristics of the device are described with reference to the representative compound of the present invention, and the following examples illustrate the purpose of the present invention. It is not intended to limit the protection scope of the present invention.

[Production Example 1]

Preparation of compound a-1 (5-BOONS)

5-bromo-2-methylbenzo[d]thiazole (5-bromo-2-methylbenzo[d]thiazole, 20 g, 87.7 mmol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane)(4,4,4',4',5,5,5',5'-octamethyl-2 in, 2'-bi (1,3,2-dioxaborolane ), 44.40 g, 174.8 mmol), potassium acetate (KOAc, 26 g) and Pd (dppf) Cl ₂ (nitrogen atmosphere 2 g) N, N '- It was dissolved in dimethylformamide (DMF, 400 mL). The reaction was stirred at 80° C. for 24 hours. Thereafter, after cooling to room temperature (25° C.), extraction was performed with ethyl acetate and water to obtain an organic layer. The remaining moisture was removed using sodium sulfate (Na ₂ SO ₄ ), and the solvent was removed under reduced pressure and purified through column chromatography to obtain a white solid compound a-1 (22.9 g, yield: 95%). At this time, as a developing solvent, ethyl acetate/hexane was mixed at 1/9.

¹ H NMR (400 MHz, CDCl ₃ , δ): 8.36 (s, 1H), 7.78 (d, 1H), 7.72 (d, 1H), 2.80 (s, 3H), 1.34 (s, 12H).

Of comparative compound A (135NS) Produce

1,3,5-tribromobenzene (1,3,5-tribromobenzene, 5.49g, 17.44 mmol), 5-BOONS (12 g, 43.6 mmol), Pd(PPh ₃ ) ₄ (1 g), nitrogen It was dissolved in tetrahydrofuran (THF, 30mL) and 2M potassium carbonate (K ₂ CO ₃ , 10mL) in an atmosphere. The reaction was stirred at 65° C. for 24 hours. Then, after cooling to room temperature, extraction was performed with ethyl acetate and water to obtain an organic layer. The remaining moisture was removed using Na ₂ SO ₄ , and the solvent was removed under reduced pressure and purified through column chromatography to obtain a white solid compound A (4.58g, yield: 58%). At this time, the developing solvent was used by mixing ethyl acetate/hexane at 3/7.

¹ H NMR (400 MHz, CDCl ₃ , δ): 8.30 (s, 3H), 7.95-7.91 (m, 6H), 7.74-7.70 (m, 3H), 2.88 (s, 9H).

[Production Example 2]

Preparation of compound a-2 (6-BOONS)

6-bromo-2-methylbenzo[d]thiazole (6-bromo-2-methylbenzo[d]thiazole, 1 g, 4.4mmol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane)(4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane), 2.22 g, 8.7 mmol), potassium acetate (KOAc, 1.30 g) and Pd(dppf)Cl ₂ (0.10 g) were added to 1,4-diox in a nitrogen atmosphere. It was dissolved in sein (1,4-Dioxane, 20 mL). The reaction was stirred at 120° C. for 24 hours. Thereafter, after cooling to room temperature (25° C.), extraction was performed with ethyl acetate and water to obtain an organic layer. The remaining moisture was removed using sodium sulfate (Na ₂ SO ₄ ), and the solvent was removed under reduced pressure and purified through column chromatography to obtain a white solid compound a-2 (0.94 g, yield: 78%). At this time, as a developing solvent, ethyl acetate/hexane was mixed at 1/9.

¹ H NMR (400 MHz, CDCl ₃ , δ): 8.30 (s, 1H), 7.92 (d, 1H), 7.85 (d, 1H), 2.84 (s, 3H), 1.36 (s, 12H).

[Example 1]

Of compound 1 (N2-246NS) Produce

2,4,6-trichloropyrimidine (2,4,6-trichloropyrimidine, 0.50 g, 2.7 mmol), 5-BOONS (3.34 g, 12.1 mmol), triphenylphosphine (PPh ₃ , 0.48 g) and Pd (OAc) ₂ (0.21 g) is dissolved in 1,2-dimethoxyethane (25 mL) and 2M Na ₂ CO ₃ (13 mL) in a nitrogen atmosphere. The mixture was stirred at 90° C. for 24 hours. Then, after cooling to room temperature, extraction was performed with ethyl acetate and water to obtain an organic layer. The remaining moisture was removed using Na ₂ SO ₄ , and the solvent was removed under reduced pressure and purified through column chromatography to obtain a white solid compound 1 (0.83 g, yield: 58%). At this time, the developing solvent was used by mixing ethyl acetate/hexane at 3/7.

¹ H NMR (400 MHz, CDCl ₃ , δ): 9.39 (s, 1H), 8.91 (s, 2H), 8.83-8.81 (m, 1H), 8.41-8.38 (m, 2H), 8.21 (s, 1H) ), 8.02-7.97 (m, 3H), 2.91 (d, 9H).

[Example 2]

Compound 2 -1 (Cl-N2- 46NS6 ) Of manufacture

2,4,6-trichloropyrimidine (0.50 g, 2.7 mmol), 6-BOONS (3.34 g, 12.1 mmol), PPh ₃ (0.48 g) and Pd(OAc) ₂ (0.21 g) were 1 in nitrogen atmosphere. ,2-dimethoxyethane (25mL) and 2M Na ₂ CO ₃ (13mL) dissolved. The mixture was stirred at 90° C. for 24 hours. Then, after cooling to room temperature, extraction was performed with ethyl acetate and water to obtain an organic layer. Remaining moisture was removed using Na ₂ SO ₄ , and the solvent was removed under reduced pressure and purified through column chromatography to obtain white solid Compound 2-1 and Compound 2-2 (0.3g, yield: 27% ). At this time, a developing solvent is used by mixing ethyl acetate/hexane at 3:7.

Compound 2-1:

¹ H NMR (400 MHz, CDCl ₃ , δ): 8.05-7.99 (m, 4H), 7.70 (m, 2H), 2.86 (s, 6H).

[Examples 3 to 7]

Compounds 3 to 7 were prepared by a method similar to the preparation method of Example 1 or Example 2, and the data are shown in Table 1 below.

(Table 1)

[Example 8 and Example 9] Fabrication of an organic light emitting device (Device 1, ETL-1)

An organic light-emitting device employing the N-heterocyclic compound according to the present invention in an electron transport layer was manufactured (see FIG. 1). Specifically, a method of manufacturing the organic light emitting device is as follows.

As a substrate, ITO (indium tin oxide, 10 Ω per square) coated glass (25 mm × 25 mm × 0.7 mm size) was used, and after cleaning, it was treated with UV ozone for 10 minutes before device fabrication. Thereafter, the hole injection layer (HIL) was spin-coated with a PEDOT:PSS solution (Clevios AI 4083) at 3,200 rpm for 40 seconds to a thickness of 30 nm, and then dried at 150° C. for 30 minutes in vacuum. The light emitting layer (EML) on the hole injection layer is a solution obtained by dissolving polyvinylcarbazole (PVK):Ir(mppy) ₃ =93:7 (weight ratio) in 1,2-dichloroethane at 0.64% by weight, at 1,800 rpm at 40 After spin coating to a thickness of 30 nm for seconds, the remaining solvent was removed at 60° C. for 30 minutes. Thereafter, compound 1 (N2-246NS) synthesized according to Example 1 as a first electron transport layer (ETL-1) on the emission layer was vacuum thermally evaporated at 0.5 Å/s to form 10 nm. TPBi(2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H) as a second electron transport layer (ETL-2) on the first electron transport layer -benzimidazole)) was formed by vacuum thermal evaporation at 0.5 Å/s to form 40 nm LiF on the second electron transport layer at 0.1 Å/s at 1 nm thickness, and aluminum (Al) at 5.0 Å/s. It was formed by vacuum thermal evaporation to a thickness of 100 nm at s. Coating and drying of the light emitting layer was performed in an inert atmosphere in a glove box filled with nitrogen After fabrication of the final device, through an epoxy adhesive and a glass cover in the glove box. By sealing, Example 8 was produced.

In addition, an organic light-emitting device was fabricated in the same manner, but Example 9 was prepared by changing the thickness of the electron transport layer (ETL-1:ETL-2=10:40) to 15:35.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 2 to 4 and FIGS. 2 to 4 below.

[Comparative Example 1]

An organic light-emitting device was fabricated in the same manner as in Example 8, but had only the first electron transport layer without the second electron transport layer. That is, the electron transport layer of Comparative Example 1 was formed to have a thickness of 50 nm by vacuum thermal evaporation of TPBi at 0.5 Å/s.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 2 to 4 and FIGS. 2 to 4 below.

[Comparative Example 2 and Comparative Example 3]

An organic light-emitting device was fabricated in the same manner as in Example 8 or 9, but a compound (135NS) synthesized according to Preparation Example 1 for the material of the first electron transport layer was used. That is, the electron transport layer of Comparative Example 2 was formed by vacuum thermal evaporation of the compound (135NS) synthesized according to Preparation Example 1 as the first electron transport layer at 0.5 Å/s to form 10 nm, and the second electron transport layer (ETL-2). TPBi (ETL-1) was vacuum thermally evaporated at 0.5 Å/s to form 40 nm.

In addition, an organic light-emitting device was fabricated in the same manner, but the thickness of the electron transport layer (ETL-1:ETL-2=10:40) was changed to 15:35 to prepare Comparative Example 3.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 2 to 4 and FIGS. 2 to 4 below.

(Table 2)

(Table 3)

(Table 4)

As shown in Tables 2 to 4 and FIGS. 2 to 4, it was confirmed that the organic light emitting device including the N-heterocyclic compound according to the present invention as an electron transport layer material realized remarkably improved efficiency. Specifically, it was confirmed that according to the present invention, it was stably driven even at a lower driving voltage compared to the comparative example, as well as excellent luminous characteristics in quantum efficiency. In addition, such an effect was shown to be more remarkable with an increase in luminance, and it was confirmed that an advantage can be provided in the reduction of current efficiency and power efficiency according to an increase in luminance.

[Example 10 and Example 11] Fabrication of an organic light emitting device (Device 2, ETL-2)

An organic light-emitting device employing the N-heterocyclic compound according to the present invention in an electron transport layer was fabricated (see FIG. 5). Specifically, a method of manufacturing the organic light emitting device is as follows.

An organic light-emitting device was fabricated in the same manner as in Example 8, but 40 nm was formed by vacuum thermal evaporation of TPBi as a first electron transport layer at 0.5 Å/s, and in Example 1 as a second electron transport layer (ETL-2). Example 10 was prepared by forming 10 nm by vacuum thermal evaporation of the synthesized N2-246NS at 0.5 Å/s.

In addition, an organic light-emitting device was manufactured by the same method, but the thickness of the electron transport layer (ETL-1:ETL-2=10:40) was changed to 15:35, and Example 11 was prepared.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 5 to 7 and FIGS. 6 to 8 below.

[Comparative Example 4]

An organic light-emitting device was fabricated in the same manner as in Example 10, but had only the first electron transport layer without the second electron transport layer. That is, the electron transport layer of Comparative Example 4 was formed to have a thickness of 50 nm by vacuum thermal evaporation of TPBi at 0.5 Å/s.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 5 to 7 and FIGS. 6 to 8 below.

(Table 5)

(Table 6)

(Table 7)

As shown in Tables 5 to 7 and FIGS. 6 to 8, it was confirmed that the organic light-emitting device including the N-heterocyclic compound according to the present invention as an electron transport layer material realizes improved efficiency even if the stacking type is different. . Specifically, it was confirmed that according to the present invention, it was stably driven even at a lower driving voltage compared to the comparative example, as well as excellent luminous characteristics in quantum efficiency.

In addition, in the case of the electron transport layers (Device 2, ETL-2) stacked adjacent to the cathode, which is the second electrode, higher current efficiency and power even when the luminance increases as well as realizes improved quantum efficiency with a lower driving voltage. It was confirmed that efficiency can be implemented. As a result of this, it was confirmed that more stable current efficiency and power efficiency can be implemented even in thousands of nits or tens of thousands of nits.

[Example 12 and Example 13] Fabrication of an organic light emitting device (Device 3, EML)

An organic light-emitting device employing the N-heterocyclic compound according to the present invention in the light-emitting layer was fabricated (see FIG. 9). Specifically, a method of manufacturing the organic light emitting device is as follows.

As a substrate, ITO (indium tin oxide, 10 Ω per square) coated glass (25 mm × 25 mm × 0.7 mm size) was used, and after cleaning, it was treated with UV ozone for 10 minutes before device fabrication. Thereafter, the hole injection layer (HIL) was spin-coated with a PEDOT:PSS solution (Clevios AI 4083) at 3,200 rpm for 40 seconds to a thickness of 30 nm, and then dried at 150° C. for 30 minutes in vacuum. The light emitting layer (EML) on the hole injection layer is a solution obtained by dissolving a host: dopant (Ir (mppy) ₃ ) = 93:7 in tetrahydrofuran at 0.64% by weight and spin-coating at 1,800 rpm for 40 seconds to a thickness of 40 nm. The remaining solvent was removed at 60° C. for 30 minutes. The host was used by mixing TCTA (Tris (4-carbazoyl-9-ylphenyl) amine 97% | Sigma-Aldrich) and Compound 1 (N2-246NS) synthesized according to Example 1 in a 1:1 molar ratio. Thereafter, TPBi(2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole), ETL) was vacuumed at 0.5 Å/s as an electron transport layer on the emission layer. Vacuum thermal evaporation was performed to form 50 nm LiF on the electron transport layer at 0.1 Å/s to a thickness of 1 nm, and aluminum (Al) at 5.0 Å/s to a thickness of 100 nm to form a vacuum thermal evaporation (vacuum thermal evaporation). The coating and drying of the light-emitting layer were carried out in an inert atmosphere in a glove box filled with nitrogen After fabrication of the final device, Example 12 was prepared by sealing through an epoxy adhesive and a glass cover in the glove box.

In addition, an organic light-emitting device was fabricated in the same manner, but the light-emitting layer material (TCTA: N2-246NS) of Example 12 was used as TAPC (4,4'-cyclohexylidenebis [N,N-bis(4-methylphenyl)benzenamine]). Example 13 was prepared by changing the compound 1 (N2-246NS) synthesized according to Example 1 to a light-emitting layer material (TAPC: N2-246NS) in which a 1:1 molar ratio was mixed.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 8 to 10 and FIGS. 10 to 12 below.

[Comparative Examples 5 to 7]

An organic light-emitting device was fabricated in the same manner as in Example 12, but only polyvinyl carbazole was used as a host material in the emission layer of Example 12 (Comparative Example 5), or as a host material in the emission layer of Example 12. Changed to TPBi(2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) instead of Compound 1 (N2-246NS) synthesized according to Example 1 Thus, Comparative Example 6 was prepared.

In addition, an organic light-emitting device was fabricated in the same manner as in Example 13, but instead of compound 1 (N2-246NS) synthesized according to Example 1, which is a host material, of the emission layer of Example 13, it was changed to TPBi. 7 was made.

A light emission test was performed by applying a voltage of 0 to 15 V to the organic light emitting device fabricated as described above, and measurement results of light emission characteristics and basic physical properties are shown in Tables 8 to 10 and FIGS. 10 to 12 below.

(Table 8)

(Table 9)

(Table 10)

As shown in Tables 8 to 10 and FIGS. 10 to 12, the organic light emitting device including the N-heterocyclic compound according to the present invention as a light emitting layer material maximizes the formation of excitons by balancing the density of holes and electrons. It was confirmed that the driving voltage is further lowered and the excitons in the light emitting layer can be effectively confined, thereby significantly increasing the efficiency, power efficiency, and quantum efficiency. In addition, it is possible to implement more excellent durability by suppressing the roll-off phenomenon at a high current density, and thus can have long life characteristics.

In addition, it has been confirmed that remarkable power efficiency and current efficiency can be realized at thousands or tens of thousands of nit, which is the luminance of an organic light emitting device that is actually used. Specifically, in the case of Example 12, which is an organic light-emitting device comprising the N-heterocyclic compound according to the present invention as a light emitting layer material, the current efficiency improved by 290% or more compared to Comparative Example 5 using only polyvinylcarbazole as a host material. (At 10000 nit), it was confirmed that the current efficiency improved by more than 190% compared to Comparative Example 6, which was changed to TPBi instead of Compound 1 (N2-246NS) synthesized according to Example 1 as a host material (At 10000 nit). Such an effect is a synergistic effect that was not recognized in the prior art, and there was no specific application example thereof.

Although the embodiments of the present invention have been described in detail as described above, those of ordinary skill in the art to which the present invention pertains, without departing from the spirit and scope of the present invention as defined in the appended claims. The invention may be implemented by various modifications. Therefore, changes in the embodiments of the present invention will not be able to depart from the technology of the present invention.

Claims (12)

An N-heterocyclic compound represented by the following formula (1):
[Formula 1]

In Formula 1,
Ar is a substituted or unsubstituted 6 membered heteroaryl skeleton;
R ¹ is hydrogen, deuterium, halogen, cyano, C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;
R ² is halogen, cyano, C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;
n is an integer selected from 0 to 3, and when n is an integer of 2 or 3, R ² may be the same as or different from each other, and when n is 0, all three substituents are hydrogen;
m is an integer of 2 or 3;
The substitution of Ar is C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, mono or diC1-C30 alkylamino, mono or diC6 -C30 arylamino, occurring on any carbon atom by one or more substituents selected from the group consisting of nitro, hydroxy and combinations thereof; The heteroaryl is each independently at least one selected from B, N, O, S, P(=O), Si and P; The substituents repeated by n or m may be the same or different from each other. The method of claim 1,
In Formula 1,
Ar is,
An N-heterocyclic compound which is a substituted or unsubstituted 6-membered heteroaryl skeleton containing 1 to 3 nitrogen sources (=N-) among 6 ring members. The method of claim 1,
When m in Formula 1 is 2,
Ar is selected from the following structures, N-heterocyclic compounds:

In the above structure,
R ¹¹ and R ¹² are independently of each other C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;
R ¹³ is hydrogen, C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;
a is an integer selected from 0 to 3, and when a is 0, all three substituents are hydrogen;
b is an integer selected from 0 to 2, and when b is 0, both substituents are hydrogen. The method of claim 1,
When m in Formula 1 is 3,
Ar is selected from the following structures, N-heterocyclic compounds:

In the above structure,
R ¹⁴ is C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;
R ¹⁵ is hydrogen, C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C1-C30 alkoxy, C6-C30 aryloxy, C6-C30 aryl, or a combination thereof;
b is an integer selected from 0 to 2, and when b is 0, both substituents are hydrogen. The method of claim 1,
In Formula 1,
R ¹ is hydrogen, halogen, cyano, C1-C30 alkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof;
R ² is C1-C30 alkyl, C3-C30 cycloalkyl, or a combination thereof;
Wherein n is an integer selected from 0 to 3, N-heterocyclic compound. The method of claim 1,
The N-heterocyclic compound,
At least one, an N-heterocyclic compound selected from compounds represented by the following formulas 2 to 5:
[Formula 2]

[Chemical Formula 3]

[Formula 4]

[Chemical Formula 5]

In Chemical Formulas 2 to 5,
A ₁ and A ₂ are each independently -N= or -CH=;
R ¹ is independently of each other halogen, cyano, C1-C30 alkyl, C6-C30 aryl, C3-C30 heteroaryl, or a combination thereof, and each R ₁ may be the same or different from each other;
R ² are independently of each other C1-C30 alkyl, C3-C30 cycloalkyl, or a combination thereof;
n is an integer selected from 0 to 3 independently of each other. The method of claim 6,
In Chemical Formulas 2 to 5,
R ¹ is independently from each other halogen, cyano, C1-C7 alkyl, C6-C12 aryl, C3-C12 heteroaryl, or a combination thereof, and each R ¹ may be the same as or different from each other;
R ² is C1-C7 alkyl;
Wherein n is an integer selected from 0 to 3, N-heterocyclic compound. The method of claim 6,
In Chemical Formulas 2 to 5,
Wherein n is an integer of 0, an N-heterocyclic compound. A first electrode; A second electrode; And at least one organic material layer interposed between the first electrode and the second electrode, wherein at least one of the organic material layers comprises the N-heterocyclic compound according to any one selected from claims 1 to 8. That is, an organic light-emitting device. The method of claim 9,
The organic material layer,
An organic light-emitting device comprising a light emitting layer, wherein the light emitting layer contains the N-heterocyclic compound. The method of claim 10,
The organic material layer,
An organic light-emitting device comprising an electron transport layer, wherein the electron transport layer contains the N-heterocyclic compound. The method of claim 11,
The electron transport layer,
It includes a first electron transport layer and a second electron transport layer made of an organic material,
The first electron transport layer or the second electron transport layer includes the N-heterocyclic compound.

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