KR101400387B1 - Phosphorescent material for Organic electroluminescent device - Google Patents

Abstract

Wherein each of X1, X2, X3, Y1, Y2, Y3, Z1, Z2 and Z3 is selected from carbon (C) or nitrogen (N), at least one of which is nitrogen, R2 and R3 are each independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl compounds, arylsilyl compounds, an aryloxy group, an alkyloxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group.
The

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphorescent material for an organic electroluminescent device,

The present invention relates to a phosphorescent material for an organic electroluminescent device, and more particularly to a phosphorescent material for an organic electroluminescent device having a high triplet energy.

An organic electroluminescent device is a device that injects electric charge into a light emitting material layer formed between an electron injecting electrode (cathode) and a hole injecting electrode (anode) to form an electron and a hole. Not only can the device be formed on a flexible transparent substrate such as a plastic but also has advantages in driving voltage and power consumption.

The organic electroluminescent device includes an anode, a hole injecting layer (HIL), a hole transporting layer (HTL), an emitting material layer (EML) An electron transporting layer (ETL), an electron injecting layer (EIL), and a cathode.

Here, a dopant is added to the light emitting material layer if necessary. For example, a red light emitting layer may be formed by depositing 4,4'-N, N'-dicarbazolbiphenyl (CBP) to a thickness of 30 nm to 60 nm, and bis (2-phenylquinoline) acetylacetonate iridium III) (Ir (phq) 2acac) is doped to about 5 to 10%.

In recent years, a phosphorescent material is used more frequently than a fluorescent material in a luminescent material layer. In the case of a fluorescent material, only about 25% of the single excitons formed in the emitter layer are used to make light, and 75% of the triplet is mostly lost to heat, while the phosphors convert both singlet and triplet to light It has a luminescent mechanism. Phosphorescent dopants generally contain heavy atoms such as Ir, Pt, and Eu in the center of organic matter, and have a high probability of electron transition from triplet to singlet.

However, since such a dopant is abruptly reduced in efficiency due to the concentration quenching phenomenon, the light emitting material layer can not be constituted by itself. Thus, a luminescent layer is formed together with the host material having higher thermal stability and higher triplet energy than the dopant.

In the light emitting process of an organic electroluminescent device including a phosphor, a hole injected from an anode and electrons injected from a cathode are encountered in a host material of the light emitting layer, and a single-excited exciton formed in the host is a single- Energy transition occurs, and the triplet exciton becomes energy transfer to the triplet of the dopant. Since the excitons transferred to a single term of the dopant are again transferred to the triplet of the dopant, all the excitons are terminated at the triplet level of the dopant. The excitons thus formed transition to the ground state and emit light.

At this time, for efficient energy transfer to the dopant, the triplet energy of the host material must be greater than the triplet energy of the dopant. However, referring to FIG. 1, CBP, which is widely used as a conventional host material, has a triplet energy of 2.6 eV, so that the triplet of phosphorescent dopant known as FIrpic (iridum-bis (4,6-difluorophenylpyridinato- Energy is less than the energy, the energy reversal phenomenon occurs from the host material to the dopant and the efficiency is lowered. In particular, the reduction in efficiency occurs at a low temperature. Therefore, it is required to develop a novel phosphor having a triple energy of 2.6 eV or more and excellent thermal stability.

When the triplet energies of the hole transporting layer or the electron transporting layer adjacent to the front and rear of the light emitting material layer are smaller than the triplet energy of the dopant, the energy inversion occurs from the dopant or host to these layers, thereby significantly reducing the efficiency. Therefore, the triplet energy of the hole / electron transport layer material as well as the host material of the light emitting layer is a very important factor in the phosphorescent device.

The present invention provides a phosphorescent material having a triplet energy of 2.6 eV or more to prevent a problem of lowering the luminous efficiency of an organic electroluminescent device. In particular, the triplet energy of the host material is made higher than the triplet energy of the dopant to prevent the degradation of the luminous efficiency.

It is also possible to use a phosphorescent material having high triplet energy which can be used for a hole transporting layer or an electron transporting layer, thereby improving the efficiency of an organic electroluminescent device.

In order to solve the above problems, the present invention is represented by the following formula: wherein each of X1, X2, X3, Y1, Y2, Y3, Z1, Z2 and Z3 is selected from carbon (C) At least one of them is nitrogen and each of R1, R2 and R3 is selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compound, aromatic compound, alkylsilyl compound, an aryl silyl compound, an alkoxy compound, an aryloxy compound, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group. do.

The

Each of R1, R2, R3 and R4 is independently selected from the group consisting of a hydrogen atom, a halogen atom, a halogen atom, a halogen atom, (H), fluorine (F), chlorine (Cl), an aliphatic compound, an aromatic compound, an alkyl silyl compound, an aryl silyl compound, an alkoxy compound, An alkyloxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group.

The

R2, R3, R4, and R5 are each hydrogen (H), and each of X, Y and Z is selected from carbon (C) or nitrogen (N) Fluorine (F), chlorine (Cl), an aliphatic compound, an aromatic compound, an alkyl silyl compound, an aryl silyl compound, an alkoxy compound, An alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group.

The

The aliphatic compound is characterized by containing C1 to C20 aryl and C1 to C20 alkyl.

The aromatic group material is characterized by including phenyl, naphthyl, biphenyl, terphenyl, and phenanthrenyl.

In another aspect, the present invention provides a liquid crystal display comprising: a first electrode; A second electrode facing the first electrode; A light emitting material layer disposed between the first and second electrodes, wherein the light emitting material layer is represented by the following formula: X1, X2, X3, Y1, Y2, Y3, Z1, Z2, (C) or nitrogen (N), at least one of which is nitrogen and each of R1, R2 and R3 is selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, An alkyl silyl compound, an aryl silyl compound, an alkoxy compound, an aryloxy compound, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, an aryl amino group And a dopant having triplet energy smaller than that of the host material. The present invention also provides an organic electroluminescent device comprising the same.

The

A first electrode; A second electrode facing the first electrode; And X2, Y1, Y2, Z1, and Z2 each represent a carbon (C) or nitrogen (N) atom, and the light emitting material layer is disposed between the first and second electrodes. And at least one of R 1, R 2, R 3 and R 4 is selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl an alkyl silyl compound, an aryl silyl compound, an alkoxy compound, an aryloxy compound, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, And a dopant having a triplet energy smaller than that of the host material.

The

A first electrode; A second electrode facing the first electrode; And a light emitting material layer disposed between the first and second electrodes, wherein the light emitting material layer is represented by the following formula: wherein each of X, Y and Z is selected from carbon (C) or nitrogen (N) At least one is nitrogen and each of R 1, R 2, R 3, R 4 and R 5 is independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl A host material selected from the group consisting of an aryl silyl compound, an alkoxy compound, an aryloxy compound, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, And a dopant having triplet energy smaller than that of the host material.

The

A hole injection layer disposed between the first electrode and the light emitting material layer; A hole transport layer disposed between the hole injection layer and the light emitting material layer; An electron injection layer disposed between the light emitting material layer and the second electrode; And an electron transport layer disposed between the electron injection layer and the light emitting material layer, wherein at least one of the hole transport layer and the electron transport layer is made of the host material.

Since the phosphorescent material of the present invention has a triplet energy of 2.8 eV or more, the efficiency of the organic electroluminescent device can be increased.

Since the phosphorescent material of the present invention is used in the light emitting material layer and has a larger triplet energy of the dopant, the problem of lowering the luminous efficiency can be prevented.

In addition, by using the phosphorescent material of the present invention having triplet energy of 2.8 eV or more for the hole transporting layer or the electron transporting layer, the luminous efficiency of the organic electroluminescent device can be improved.

1 is a PL spectrum of CBP which is a host material for a conventional organic electroluminescent device.
2 is a UV spectrum and a PL spectrum of a phosphorescent material for an organic electroluminescence device according to an embodiment of the present invention.
3 is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present invention.

Hereinafter, a structure of a phosphor for an organic electroluminescence device according to the present invention, a synthesis example thereof, and an organic electroluminescence device using the same will be described.

- First Embodiment -

The phosphorescent material according to the first embodiment of the present invention has a structure in which three carboline groups are substituted at the para position of a tri-phenyl amine, and is represented by the following formula (1).

Formula 1

In Formula 1, each of X1, X2, X3, Y1, Y2, Y3, Z1, Z2 and Z3 is selected from carbon (C) or nitrogen (N), and at least one of them is nitrogen. For example, α-carbolin when X1 = N and Y1 = Z1 = C, β-carbolin when Y1 = N, X1 = Z1 = C, and γ-carbolin to be.

Each of R 1, R 2 and R 3 in the above formula (1) may be independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compound, aromatic compound, alkylsilyl compound, an alkoxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group.

For example, the aliphatic compound may be a C1 to C20 aryl or a C1 to C20 alkyl group, and the aromatic group material may include phenyl, naphthyl, biphenyl, , Terphenyl, and phenanthrenyl.

For example, the phosphorescent material represented by Formula 1 may be one of a plurality of materials represented by Formula 2 below.

(2)

로 표시되는 본 발명의 제 1 실시예에 따른 유기전계발광소자용 인광 물질은 아래 제 1 합성예에 의해 얻어진다.In the formula (2)

The phosphorescent material for an organic electroluminescence device according to the first embodiment of the present invention is obtained by the following first synthesis example.

1st Synthetic example

1. Synthesis of N- (4-nitrophenyl) -α-carboline

N- (4-nitrophenyl) -α-carboline is synthesized by the following reaction scheme 1.

Scheme 1

Specifically, 10 g (60 mmol) of α-carboline, 8.6 g (61 moles) of 4-fluoronitrobenzene and 1.58 g (66 mmole) of NaH and 100 ml of DMF were added to a 250 ml two neck flask and refluxed for 12 hours. After completion of the reaction, 100 ml of water was added to precipitate and filtered to obtain 17.4 g (57%) of a solid.

2. Synthesis of 4- (N-α-carbazolyl) benzenamine

4- (N -? - carbazolyl) benzenamine is synthesized by the following reaction formula (2).

Scheme 2

Specifically, 7 g (23.8 mmole) of N- (4-nitrophenyl) -α-carboline, 16.31 g (72.1 mmole) of SnCl2 and 100 ml of ethanol were placed in a 250 ml two-necked flask and refluxed for 4 hours. After the reaction was completed, NaOH was added to neutralize and extracted with ether. Distilled under reduced pressure, 5.2 g (84%) of 4- (N-α-carbazolyl) benzenamine was obtained.

3. Synthesis of N- (4-bromophenyl) -α-carboline

N- (4-bromophenyl) -? - carboline is synthesized by the following reaction formula (3).

Scheme 3

Specifically, 8 g (47.6 mmol) of α-carboline, 20 g (70.6 moles) of CuI, 0.68 g of 1,2-cyclohexyldiamine, 25.4 g of K3PO4 and 150 ml of Dioxane were added to a 250 ml two-necked flask and refluxed for 12 hours . After 150 ml of water was mixed and precipitated, 9.3 g of solid was obtained by silicagel chromatography using MC (methylene chloride) solvent. The yield was 60%.

4. Synthesis of 4,4 ', 4 "- (N-α-carbolinyl) -triphenylamine

4,4 ', 4 "- (N -? - carbolinyl) -triphenylamine is synthesized by the following reaction formula (4).

Scheme 4

Specifically, 2 g (7.7 mmole) of 4- (N-α-carbazolyl) benzenamine and 5.5 g (18 mmole) of N- (4-bromophenyl) -α-carboline, 50 ml of toluene, and 2.2 g 0.3 g (0.3 mmole) of Pd2 (dba) 3 and 0.4 g (2 mmole) of tris-t-butylphosphine were added to the flask and refluxed under a nitrogen atmosphere for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and then precipitated in 100 ml of methanol. methylencholride, adsorbed on silicagel, and 3.4 g (yield 60%) of white powder was obtained through silicagel column chromatography using THF as a developing solvent

- Second Embodiment -

The phosphorescent material according to the second embodiment of the present invention has a structure in which two carboline groups and one carbazole group are substituted at the para position of tri-phenyl amine, and is represented by the following Chemical Formula 3.

(3)

In Formula 3, each of X1, X2, Y1, Y2, Z1 and Z2 is selected from carbon (C) or nitrogen (N), and at least one of them is nitrogen. For example, α-carbolin when X1 = N and Y1 = Z1 = C, β-carbolin when Y1 = N, X1 = Z1 = C, and γ-carbolin to be.

In Formula 3, R 1, R 2, R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compound, aromatic compound, alkylsilyl compound, An alkoxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group.

For example, the aliphatic compound may be a C1 to C20 aryl or a C1 to C20 alkyl group, and the aromatic group material may include phenyl, naphthyl, biphenyl, , Terphenyl, and phenanthrenyl.

For example, the phosphorescent material represented by Formula 3 may be one of a plurality of materials represented by Formula 4 below.

Formula 4

로 표시되는 본 발명의 제 2 실시예에 따른 유기전계발광소자용 인광 물질은 아래 제 2 합성예에 의해 얻어진다.In the formula (4)

The phosphorescent material for an organic electroluminescence device according to the second embodiment of the present invention is obtained by the following second synthesis example.

Second Synthetic example

1. Synthesis of 4- (N-α-carbolinyl) -4, '4 "-di (N-carbazolyl) -triphenylamine

4- (N-α-carbolinyl) -4,4'-di (N-carbazolyl) -triphenylamine is synthesized by the following reaction formula (5).

Scheme 5

Specifically, 2 g (7.7 mmole) of 4- (N-carbazolyl) benzenamine and 5.5 g (18 mmole) of N- (4-bromophenyl) -α-carboline, 50 ml of toluene, and 2.2 g ), 0.3 g (0.3 mmole) of Pd2 (dba) 3 and 0.4 g (2 mmole) of tris-t-butylphosphine were placed and refluxed in a nitrogen atmosphere for 12 hours. After the completion of the reaction, the reaction mixture was cooled to room temperature and placed in 100 ml of methanol to obtain a precipitate. After dissolving in methylenecholide and adsorbing on silicagel, 3.7 g (65%) of white powder was obtained through silicagel column chromatography using THF as a developing solvent

- Third Embodiment -

The phosphorescent material according to the third embodiment of the present invention has a structure in which one carboline group and two carbazole groups are substituted at the para position of a tri-phenyl amine, and is represented by the following Chemical Formula 5.

Formula 5

In Formula 5, each of X, Y and Z is selected from carbon (C) or nitrogen (N), and at least one of them is nitrogen. For example,? -Carbolin when X = N and Y1 = Z = C,? -Carbolin when Y = N, X = Z = C, to be.

In Formula 5, R 1, R 2, R 3, R 4 and R 5 are each hydrogen, fluorine, chlorine, an aliphatic compound, an aromatic compound, an alkyl silyl, An aryl silyl compound, an alkoxy compound, an aryloxy compound, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, and an aryl amino group.

For example, the aliphatic compound may be a C1 to C20 aryl or a C1 to C20 alkyl group, and the aromatic group material may include phenyl, naphthyl, biphenyl, , Terphenyl, and phenanthrenyl.

For example, the phosphor represented by Formula 5 may be one of a plurality of materials represented by Formula 6 below.

6

로 표시되는 본 발명의 제 3 실시예에 따른 유기전계발광소자용 인광 물질은 아래 제 3 합성예에 의해 얻어진다.In the above formula (6)

The phosphorescent material for an organic electroluminescence device according to the third embodiment of the present invention is obtained by the following third synthesis example.

Third Synthetic example

1. Synthesis of 4- (N-α-carbolinyl) -4, '4 "-di (N-carbazolyl) -triphenylamine

4- (N-α-carbolinyl) -4,4'-di (N-carbazolyl) -triphenylamine is synthesized by the following reaction scheme 6.

Scheme 6

Specifically, 2 g (7.7 mmole) of 4- (N-α-carbazolyl) benzenamine and 5.5 g (18 mmole) of N- (4-bromophenyl) -carbazole, 50 ml of toluene, and 2.2 g , 0.3 g (0.3 mmole) of Pd2 (dba) 3 and 0.4 g (2 mmole) of tris-t-butylphosphine were placed and refluxed in a nitrogen atmosphere for 12 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and poured into 100 ml of methanol to obtain a precipitate. After dissolving in methylenecholide and adsorbing on silicagel, 3.6 g (63%) of white powder was obtained through silicagel column chromatography using THF as a developing solvent

(TATA로 약칭), 화학식4의

(DACTA로 약칭) 및 화학식6의

(ADCTA로 약칭)으로 각각 표시된 본 발명의 인광물질에 대하여 UV 흡수 스펙트럼과 저온(77K)에서의 PL(photoluminescence) 스펙트럼을 측정하여 도 2에 나타내었다.(2)

(Abbreviated as TATA), the formula

(Abbreviated as DACTA) and the formula

(Abbreviated as ADCTA), and the PL (photoluminescence) spectrum at a low temperature (77 K) was measured for the phosphor of the present invention and shown in FIG.

As shown in FIG. 2, the phosphorescent material of the present invention has a triplet energy of 2.8 eV or more. Therefore, it has higher triplet energy than CBP used as a host material of the conventional light emitting material layer, and is larger than 2.7 eV, which is the triplet energy of the commonly used dopant, so that the energy transfer from the host material to the dopant is prevented can do. Therefore, the light emitting efficiency is improved.

In addition, since the phosphorescent material of the present invention has triplet energy higher than that of the dopant, the phosphorescent material of the present invention can be used as a hole transporting layer or an electron transporting layer, and it is possible to prevent the occurrence of energy reversal from a dopant to a hole transporting layer or an electron transporting layer.

An embodiment of an organic electroluminescent device including the phosphorescent material is shown in FIG.

As shown, the organic electroluminescent device includes first and second substrates (not shown) facing each other, and an organic light emitting diode (E) formed between the first and second substrates (not shown) .

The organic light emitting diode E includes a first electrode 110 serving as an anode, a second electrode 130 serving as a cathode, and an organic emission layer 120 formed between the first and second electrodes 110 and 130. [ ).

The first electrode 110 is made of a relatively high work function material such as indium-tin-oxide (ITO), and the second electrode 130 is made of a material having a relatively low work function value, For example, aluminum (Al) or an aluminum alloy (AlNd). In addition, the organic light emitting layer 120 has red, green, and blue organic light emission patterns.

The organic light emitting layer 120 may include a hole injection layer (HTL) 121, a hole transporting layer (HIL) 121, and a hole transporting layer (HIL) 121 sequentially from the first electrode 110 in order to maximize luminous efficiency. An emission layer 122, an emitting material layer (EML) 123, an electron transporting layer 124, and an electron injection layer 125.

At least one of the light emitting material layer 123, the hole transporting layer 122 and the electron transporting layer 124 may include the phosphorescent material of the present invention represented by any one of Chemical Formulas 1, 3 and 5 .

For example, when the light emitting material layer 123 includes the phosphorescent material of the present invention as a host material, about 1 to 10 wt% dopant is added. At this time, since the phosphorescent material has a triplet energy of 2.8 eV or more, which is larger than that of the dopant, the occurrence of the energy reversal phenomenon from the host material to the dopant is prevented. Therefore, the luminous efficiency can be increased. For example, the dopant may be FIrpic (iridum-bis (4,6-difluorophenylpyridinato-N, C2) -picolinate).

When the hole transport layer 122 or the electron transport layer 124 is made of the phosphorescent material of the present invention, the phosphorescent material has a triplet energy of 2.8 eV or more, which is larger than the dopant of the light emitting material layer 123, Is prevented. Therefore, the organic electroluminescent device has an advantage that the energy efficiency of the organic electroluminescent device can be prevented from lowering.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that

110: first electrode
120: organic light emitting layer
121: Hole injection layer
122: hole transport layer
123: luminescent material layer
124: electron transport layer
125: electron injection layer
130: second electrode

Claims (9)

Wherein each of X1, X2, X3, Y1, Y2, Y3, Z1, Z2 and Z3 is selected from nitrogen (N) or unsubstituted hydrocarbon (CH), at least one of which is nitrogen, R2 and R3 are each independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl compounds, arylsilyl compounds, alkyloxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkylamino group, an aryl (aryl) group, amino group. < / RTI >
The

Wherein at least one of X1, X2, Y1, Y2, Z1 and Z2 is selected from nitrogen (N) or unsubstituted hydrocarbon (CH) May be a compound selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl compounds, aryl silyl compounds, alkoxy compounds, An alkoxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, an aryl amino group, A phosphorescent material for an organic electroluminescence device to be selected.
The

R2, R3, R4, and R5 are each selected from the group consisting of hydrogen (H), hydrogen (H), hydrogen, ), Fluorine (F), chlorine (Cl), an aliphatic compound, an aromatic compound, an alkyl silyl compound, an aryl silyl compound, an alkoxy compound, an aryloxy ) Alkyl group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, an aryl amino group, A phosphorescent material for a light emitting device.
The

4. The method according to any one of claims 1 to 3,
Wherein the aliphatic compound comprises a C1 to C20 alkyl.
4. The method according to any one of claims 1 to 3,
Wherein the aromatic group material includes phenyl, naphthyl, biphenyl, terphenyl, and phenanthrenyl. 2. The phosphorescent material according to claim 1, wherein the aromatic group material is selected from the group consisting of phenyl, naphthyl, biphenyl, terphenyl and phenanthrenyl.
A first electrode;
A second electrode facing the first electrode;
And a light emitting material layer disposed between the first and second electrodes,
The light emitting material layer is represented by the following chemical formula and each of X1, X2, X3, Y1, Y2, Y3, Z1, Z2 and Z3 is selected from nitrogen (N) or unsubstituted hydrocarbon (CH) Each of R1, R2 and R3 is independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl compounds, aryl silyl An alkoxy compound, an aryloxy compound, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group , An aryl amino group, and a dopant having triplet energy smaller than that of the host material.
The

A first electrode;
A second electrode facing the first electrode;
And a light emitting material layer disposed between the first and second electrodes,
Wherein at least one of the X1, X2, Y1, Y2, Z1 and Z2 is selected from nitrogen (N) or unsubstituted hydrocarbon (CH) , R3 and R4 are each independently selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl compounds, arylsilyl compounds, an alkyloxy group, an aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkylamino group, an arylamino group, an aryl amino group, and a dopant having triplet energy lower than that of the host material.
The

A first electrode;
A second electrode facing the first electrode;
And a light emitting material layer disposed between the first and second electrodes,
R2, R3, R4, and R5 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, Each of which is selected from the group consisting of hydrogen (H), fluorine (F), chlorine (Cl), aliphatic compounds, aromatic compounds, alkylsilyl compounds, aryl silyl compounds, alkoxy compounds An aryloxy group, an alkyl phosphoryl group, an alkyl sulfuryl group, an aryl sulfuryl group, an alkyl amino group, an aryl amino group And a dopant having triplet energy smaller than that of the host material.
The

9. The method according to any one of claims 6 to 8,
A hole injection layer disposed between the first electrode and the light emitting material layer;
A hole transport layer disposed between the hole injection layer and the light emitting material layer;
An electron injection layer disposed between the light emitting material layer and the second electrode;
And an electron transport layer disposed between the electron injection layer and the light emitting material layer,
Wherein at least one of the hole transporting layer and the electron transporting layer is made of the host material.

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