KR20110102680A - Red color phosphorescent host material and organic electroluminescent display device using the same - Google Patents

Abstract

The present invention relates to a red phosphorescent host material and an organic light emitting device using the same.
In the present invention, at least one heterocyclic group material is substituted for each of nitrogen positioned at both sides of a biphenyl derivative, so that the red phosphorescent host is soluble and soluble and has excellent brightness and luminous efficiency. It is a feature to provide a material and an organic light emitting display device using the same.

Description

Red phosphorescent host material and Organic electroluminescent display device using the same

The present invention relates to a red phosphorescent host material and an organic light emitting device using the same. More specifically, the present invention relates to a red phosphorescent host material that can be dissolved and has excellent brightness and luminous efficiency, and an organic light emitting device comprising the same.

Recently, as the size of the display device increases, the demand for a flat display device having less space is increasing. As one of the flat display devices, an organic light emitting diode (OLED) technology, also called an organic light emitting diode (OLED), has a high speed. It has been developed and several prototypes have already been announced.

The organic electroluminescent device is a device that emits light when electrons and holes are paired and then disappear when electrons are injected into the light emitting material layer formed between the electron injection electrode (cathode) and the hole injection electrode (anode). Not only can the device be formed on a flexible transparent substrate such as plastic, but it can also be driven at a lower voltage (less than 10V) compared to a plasma display panel or an inorganic electroluminescent (EL) display. In addition, the power consumption is relatively low, there is an advantage that the color is excellent. In addition, the organic electroluminescent (EL) device can display three colors of green, blue, and red, and thus, has become a subject of much interest as a next-generation rich color display device. Here is a brief look at the process of manufacturing an organic light emitting device,

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

(2) forming a hole injecting layer (HIL) on the anode; The hole injection layer is formed by mainly depositing copper phthalocyanine (CuPc) represented by Chemical Formula 1-1 to a thickness of 10 nm to 30 nm.

(3) Next, a hole transport layer (HTL) is formed on the hole injection layer. This hole transport layer is formed by depositing about 30nm to 60nm 4,4'-bis [N- (1-naphtyl) -N-phenylamino] -biphenyl (NPB) represented by the following formula (1-2).

(4) Next, an emitting material layer (EML) is formed on the hole transport layer. At this time, a dopant is added as necessary.

For example, in the light emitting material layer, a red light emitting layer, a green light emitting layer, and a blue light emitting layer constitute one pixel to express various grayscales. For example, the green light emitting layer may be formed by depositing tris (8-hydroxyquinolalate aluminum) (tris (8-hydroxyquinolatealuminum), Alq3) represented by the following formula (1-3) to a thickness of 30 nm to 60 nm. As a dopant, MQD (N-methylquinacridone) (N-Methylquinacridone) is mainly used.

(5) Next, an electron transport layer (ETL) and an electron injecting layer (EIL) are successively formed on the light emitting material layer. In this case, the electron transport layer is made of tris (8-hydroxy-quinolate) aluminum (Alq3).

(6) Next, a cathode is formed on the electron injection layer, and finally a protective film is formed on the cathode.

Formula 1-1

Formula 1-2

Formula 1-3

In the structure as described above, the light emitting material layer implements blue, green, and red to realize full color images.

In the case of the light emitting material, excitons are formed by recombination of electrons and holes injected from both electrodes, and singlet excitons are involved in phosphorescence and triplet excitons. The triplet excitons with 75% generation probability involved in phosphorescent material show superior luminous efficiency than fluorescent materials using singlet excitons with 25% generation probability. Among these phosphorescent materials, red phosphorescent materials may have a very high luminous efficiency compared to fluorescent materials, and thus, many researches have been conducted as important methods for increasing the efficiency of organic light emitting diodes.

Since the exciton of the red phosphorescent dopant has a spectrum in the range of about 580 nm to 670 nm (2.12 eV to 1.84 eV), the triplet energy of the host must be at least 1.8 eV for efficient energy transfer. As the host materials used to date, organometallic complexes such as aluminum (Al) and CBP are used, but these materials have a poor solubility and thus have limitations in application to solution devices. On the other hand, polymers or dendrimer-type materials containing carbazole units used for solutions have difficulty in securing purity because they have a large molecular weight and are limited in sublimation / vaporization purification.

Therefore, it is necessary to develop new materials capable of sublimation / vaporization purification with a relatively small molecular weight, film formation in solution state, and triplet energy of 1.8 eV or more. The material in solution is particularly suitable for manufacturing large area devices since it is possible to make the device not only by the deposition process but also by the coating process.

An object of the present invention is to provide a red phosphorescent host material having excellent solubility, capable of solution processing, and excellent brightness and luminous efficiency.

The present invention also provides an organic light emitting display device which can realize a high brightness image using the red phosphorescent host material and can reduce power consumption by lowering a driving voltage.

In order to solve the above problems, the present invention is represented by the following formula, each of A1 and A3 is selected from a substituted or unsubstituted heterocyclic group material, each of A2 and A3 is a substituted or unsubstituted heterocyclic group material, Or it provides a red phosphorescent host material for an organic light emitting device characterized in that selected from substituted or unsubstituted aromatic group material.

The heterocyclic group material may be pyridinyl, bipyridinyl, quinolinyl, isoquinolinyl, quinoxalinyl, terpyridinyl, phenoxrollinyl ( phenanthrolinyl).

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

Substituents of the heterocyclic group material and the aromatic group material are C1 ~ C20 aryl, C1 ~ C20 alkyl, C1 ~ C20 alkenyl, C1 ~ C20 alkylyl , C1 ~ C20 alkoxy (alkoxy) or C1 ~ C20 alkylsilyl (alkylsilyl), phenylsilyl (Phenylsilyl), halogen (halogen), cyano (cyano) is characterized in that it is selected.

In another aspect, the present invention comprises a first electrode; A second electrode facing the first electrode; And a light emitting material layer positioned between the first and second electrodes, wherein the light emitting material layer is represented by the following formula, and each of A1 and A3 is selected from a substituted or unsubstituted heterocyclic group material, and A2 and Each A3 provides an organic electroluminescent device characterized in that it comprises a substituted or unsubstituted heterocyclic group material, or a red phosphorescent host compound selected from substituted or unsubstituted aromatic group materials.

The heterocyclic group material may be pyridinyl, bipyridinyl, quinolinyl, isoquinolinyl, quinoxalinyl, terpyridinyl, phenoxrollinyl ( phenanthrolinyl).

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

Substituents of the heterocyclic group material and the aromatic group material are C1 ~ C20 aryl, C1 ~ C20 alkyl, C1 ~ C20 alkenyl, C1 ~ C20 alkylyl , C1 ~ C20 alkoxy (alkoxy) or C1 ~ C20 alkylsilyl (alkylsilyl), phenylsilyl (Phenylsilyl), halogen (halogen), cyano (cyano) is characterized in that it is selected.

The light emitting material layer may include a light emitting material layer solution containing 1-10 wt% of the red phosphorescent host compound and a dopant of 1-10 wt% of the light emitting material layer solution.

A hole injection layer between the first electrodes; A hole transport layer disposed between the hole injection layer and the light emitting material layer; An electron transport layer on the light emitting material layer; It characterized in that it comprises an electron injection layer located between the electron transport layer and the second electrode.

Since the red phosphorescent host material of the present invention has excellent solubility, the red phosphorescent host material has an advantage in that a film can be formed by a solution process. As a result, the large area organic light emitting display device can be easily manufactured.

In addition, the organic light emitting display device using the red phosphorescent host material may realize a high brightness image and reduce power consumption.

1A and 1B are graphs showing PL spectra of a red phosphorescent host material according to an embodiment of the present invention.
2 is a schematic cross-sectional view of an organic light emitting display device according to an embodiment of the present invention.

Hereinafter, a structure of a red phosphorescent host material according to the present invention, a synthesis example thereof, and an organic light emitting display device using the same will be described.

The red phosphorescent host material of the present invention is characterized by having a soluble property by replacing at least one heterocyclic group material with each nitrogen positioned at both sides of the biphenyl derivative, and is represented by the following Chemical Formula 2.

Formula 2

Here, each of A1 and A3 is selected from a substituted or unsubstituted heterocyclic group material, and each of A2 and A3 is selected from a substituted or unsubstituted heterocyclic group material, or a substituted or unsubstituted aromatic group material.

The aromatic group material includes phenyl, naphthyl, biphenyl, terphenyl and phenanthrenyl.

In addition, the heterocyclic group material is pyridinyl, bipyridinyl, quinolinyl, isoquinolinyl, quinoxalinyl, terpyridinyl, terpyridinyl, phenanthrol Phenanthrolinyl.

For example, the heterocyclic group material and the substituent of the aromatic group material may be C1 ~ C20 aryl, C1 ~ C20 alkyl, C1 ~ C20 akenyl, C1 ~ C20 alkyl Alkynyl, C1 ~ C20 alkoxy (alkoxy) or C1 ~ C20 Alkylsilyl (alkylsilyl), phenylsilyl (Phenylsilyl), halogen (halogen), cyano (cyano).

Such a red phosphorescent host material is soluble by replacing at least one heterocyclic group material with each nitrogen positioned at both sides of the biphenyl derivative, and further displacing the heterocyclic group material or aromatic group material with nitrogen. Has characteristics.

For example, A1 to A4 may be selected from a plurality of substance groups represented by Formula 3 below. As mentioned above, each of A1 and A3 should be selected from heterocyclic group materials.

(3)

In Formula 3, any one of R 1 to R 7 is a methyl group, and the others are hydrogen.

According to the selection of Al to A4, the red phosphorescent host material of Formula 2 may be any one of a plurality of materials represented by the following Formula 4. Here, for the convenience of explanation, symbols of RH1 to RH109 are attached to the bottom of each material.

Formula 4

Hereinafter, a synthesis example of the red phosphorescent host material of the present invention will be described by taking the red phosphorescent host material represented by RH-39 in Chemical Formula 4 as an example of the red phosphorescent host material for an organic light emitting device according to the present invention.

Synthesis Example 1

1. Preparation of Phenyl-quinolin-3-yl-amine

The phenyl-quinolin-3-yl-amine is synthesized by the following Scheme 1.

Scheme 1

Specifically, phenylamine (2.0 g, 21.5 mmol), 3-bromo-quinoline (4.5 g, 21.5 mmol), Pmol (OAc) 2 3mol%, BINAP 6mol%, Na in a 250 mL 2-neck flask Add + tBuO- (4.1 g, 43.0 mmol) and dissolve in 200 mL of toluene. Thereafter, reflux and stir for 24 hours. After completion of the reaction, the toluene was distilled under reduced pressure, dissolved with methylene chloride, and filtered through a short column using silica-gel. The filtered solution was distilled under reduced pressure and recrystallized in methylenechloride / methanol solvent to obtain phenyl-quinolin-3-yl-amine.

2. Preparation of Quinolinyl phenyl amine Derivatives

The quinolinyl phenyl amine derivative represented by RH-39 in Chemical Formula 4 is prepared by the following Scheme 2.

Scheme 2

Specifically, phenyl-quinolin-3-yl-amine (4.0 g, 18.1 mmol), 4,4'-dibromo-biphenyl (2.8 g, 36.4 mmol), Pd (OAc) 2 3 mol% in a 250 mL 2-neck flask Add BINAP 6mol%, Na + tBuO- (3.5 g, 43.0 mmol) and dissolve in 200 mL of toluene. Then, refluxed and stirred for 24 hours. After completion of the reaction, the toluene was distilled under reduced pressure, dissolved with methylenechloride, and filtered through a short column using silicagel. The filtered solution was distilled under reduced pressure and recrystallized from a methylenechloride / methanol solvent. After several times column purification using hexane and ethyl acetate to obtain a quinolinyl phenyl amine derivative represented by RH-39 of formula 4.

Synthesis Example 2

1. Preparation of Naphthalen-1-yl-pyridin-2-yl-amine

The naphthalen-1-yl-pyridin-2-yl-amine is synthesized by the following Scheme 3.

Scheme 3

Specifically, naphthalen-1-ylamine (2.0 g, 13.4 mmol), 2-bromo-pyridine (2.1 g, 13.4 mmol), Pd (OAc) 2 3mol%, BINAP 6mol%, Na + in a 250 mL 2-neck flask Add tBuO- (2.6 g, 26.8 mmol) and dissolve in 200 mL of toluene. Then, refluxed and stirred for 24 hours. After completion of the reaction, the toluene was distilled under reduced pressure, dissolved with methylene chloride, and filtered through a short column using silicagel. The filtered solution was distilled under reduced pressure and recrystallized from a methylenechloride / methanol solvent to obtain naphthalen-1-yl-pyridin-2-yl-amine.

2. Preparation of Naphthyl-pyridyl amine Derivatives

The naphthyl-pyridyl amine derivative represented by RH-81 in Chemical Formula 4 is prepared by the following Scheme 4.

Scheme 4

Specifically, Naphthalen-1-yl-pyridin-2-yl-amine (4.0 g, 13.3 mmol), 4,4'-Dibromo-biphenyl (2.1 g, 6.6 mmol), Pd (OAc) in a 250 mL 2-neck flask 2) 3 mol%, BINAP 6mol%, Na + tBuO- (2.5 g, 26.4 mmol) is dissolved in 200 mL of toluene. Then, refluxed and stirred for 24 hours. After completion of the reaction, the toluene was distilled under reduced pressure, dissolved with methylene chloride, and filtered through a short column using silicagel. The filtered solution was distilled under reduced pressure and recrystallized from a methylenechloride / methanol solvent. After several column purification using hexane and ethyl acetate to obtain a naphthyl-pyridyl amine derivative represented by RH-81 of formula 4.

Hereinafter, the performance of the red phosphorescent host material according to the present invention and the organic electroluminescent device using the same through Experimental Example 1 to Example 7 for producing an organic light emitting device using the red phosphorescent host material of the present invention. Explain.

Experimental Example 1

The light emitting area of the indium tin oxide (ITO) layer on the substrate was patterned to have a size of 3 mm x 3 mm and then washed. After coating the PEDOT with a thickness of about 500 kPa on the ITO layer at 5000 rpm, it is dried for about 30 minutes on a hot plate. Thereafter, the red phosphorescent host material represented by RH-81 in Chemical Formula 4 was dissolved to 2wt% of 1,2-dichlorobenzen solvent, and then 1wt% of RH-81 solution containing Ir (phq) 2 (acac) as a red dopant was added. To prepare a light emitting material layer solution. The light emitting material layer solution was spin-coated at 3000 rpm to produce a red light emitting material layer having a thickness of about 400 μs. After the transfer to a vacuum chamber maintaining 1X10-6 torr, the device was completed by laminating in the order of TPBI (300 kPa), LiF (10 kPa), Al (1000 kPa). The characteristics of the device are shown in Table 1 below.

Experimental Example 2

The light emitting area of the indium tin oxide (ITO) layer on the substrate was patterned to have a size of 3 mm x 3 mm and then washed. After coating the PEDOT with a thickness of about 500 kPa on the ITO layer at 5000 rpm, it is dried for about 30 minutes on a hot plate. After dissolving the red phosphorescent host material represented by RH-81 in Formula 4 to 2wt% of 1,2-dichlorobenzen solvent, 2wt% of RH-81 solution containing Ir (phq) 2 (acac) as red dopant To prepare a light emitting material layer solution. The light emitting material layer solution was spin-coated at 3000 rpm to produce a red light emitting material layer having a thickness of about 400 μs. After the transfer to a vacuum chamber maintaining 1X10-6 torr, the device was completed by laminating in the order of TPBI (300 kPa), LiF (10 kPa), Al (1000 kPa). The characteristics of the device are shown in Table 1 below.

Experimental Example 3

The light emitting area of the indium tin oxide (ITO) layer on the substrate was patterned to have a size of 3 mm x 3 mm and then washed. After coating the PEDOT with a thickness of about 500 kPa on the ITO layer at 5000 rpm, it is dried for about 30 minutes on a hot plate. After dissolving the red phosphorescent host material represented by RH-81 in Formula 4 to 2wt% of 1,2-dichlorobenzen solvent, 3wt% of the RH-81 solution in which Ir (phq) 2 (acac) was dissolved as a red dopant was added. To prepare a light emitting material layer solution. The light emitting material layer solution was spin-coated at 3000 rpm to produce a red light emitting material layer having a thickness of about 400 μs. After the transfer to a vacuum chamber maintaining 1X10-6 torr, the device was completed by laminating in the order of TPBI (300 kPa), LiF (10 kPa), Al (1000 kPa). The characteristics of the device are shown in Table 1 below.

Experimental Example 4

The light emitting area of the indium tin oxide (ITO) layer on the substrate was patterned to have a size of 3 mm x 3 mm and then washed. After coating the PEDOT with a thickness of about 500 kPa on the ITO layer at 5000 rpm, it is dried for about 30 minutes on a hot plate. After dissolving the red phosphorescent host material represented by RH-39 in Formula 4 to 2wt% of 1,2-dichlorobenzen solvent, 3wt% of RH-81 solution containing Ir (phq) 2 (acac) as red dopant was added. To prepare a light emitting material layer solution. The light emitting material layer solution was spin-coated at 3000 rpm to produce a red light emitting material layer having a thickness of about 400 μs. After the transfer to a vacuum chamber maintaining 1X10-6 torr, the device was completed by laminating in the order of TPBI (300 kPa), LiF (10 kPa), Al (1000 kPa). The characteristics of the device are shown in Table 1 below.

Experimental Example 5

The light emitting area of the indium tin oxide (ITO) layer on the substrate was patterned to have a size of 3 mm x 3 mm and then washed. After coating the PEDOT with a thickness of about 500 kPa on the ITO layer at 5000 rpm, it is dried for about 30 minutes on a hot plate. After dissolving the red phosphorescent host material represented by RH-39 in Formula 4 to 2wt% of 1,2-dichlorobenzen solvent, 5wt% of Ir (phq) 2 (acac) dissolved in red dopant was added. To prepare a light emitting material layer solution. The light emitting material layer solution was spin-coated at 3000 rpm to produce a red light emitting material layer having a thickness of about 400 μs. After the transfer to a vacuum chamber maintaining 1X10-6 torr, the device was completed by laminating in the order of TPBI (300 kPa), LiF (10 kPa), Al (1000 kPa). The characteristics of the device are shown in Table 1 below.

Experimental Example 6

The light emitting area of the indium tin oxide (ITO) layer on the substrate was patterned to have a size of 3 mm x 3 mm and then washed. After coating the PEDOT with a thickness of about 500 kPa on the ITO layer at 5000 rpm, it is dried for about 30 minutes on a hot plate. After dissolving the red phosphorescent host material represented by RH-39 in Formula 4 to 2wt% of 1,2-dichlorobenzen solvent, 7wt% of RH-81 solution containing Ir (phq) 2 (acac) as red dopant was added. To prepare a light emitting material layer solution. The light emitting material layer solution was spin-coated at 3000 rpm to produce a red light emitting material layer having a thickness of about 400 μs. After the transfer to a vacuum chamber maintaining 1X10-6 torr, the device was completed by laminating in the order of TPBI (300 kPa), LiF (10 kPa), Al (1000 kPa). The characteristics of the device are shown in Table 1 below.

Here, PEDOT is represented by Formula 5-1, Ir (phq) 2 (acac) is represented by Formula 5-2, and TPBI is represented by Formula 5-3, respectively.

Formula 5-1

Formula 5-2

Formula 5-3

Experimental Example 1 Experimental Example 2 Experimental Example 3 Experimental Example 4 Experimental Example 5 Experimental Example 6 turn-on voltage
(1cd / m2)
5.1
5.3
4.3
5.1
4.9
4.5 operating voltage
(1000cd / m2)
5.9
5.9
6.1
6.3
5.5
5.3 maximum
efficiency 17.95 cd / A
9.21 lm / W 21.45 cd / A
11.6 lm / W 12.2 cd / A
5.8 lm / W 6.9 cd / A
3.3 lm / W 7.8 cd / A
4.5 lm / W 7.2 cd / A
4.2 lm / W efficiency
(1000cd / m2) 17.6 cd / A
9.1 lm / W 20.6 cd / A
10.8 lm / W 11.6 cd / A
5.9 lm / W 6.76 cd / A
3.3 lm / W 7.69 cd / A
4.3 lm / W 7.2 cd / A
4.2 lm / W CIE (x, y)
(1000cd / m2) 0.55, 0.41 0.58, 0.40 0.57, 0.41 0.58, 0.40 0.58, 0.40 0.59, 0.40

1A and 1B are graphs showing PL spectra of a red phosphorescent host material according to an embodiment of the present invention. 1A is a PL (photoluminescence) spectrum measured under liquid nitrogen after dissolving RH-81 of Chemical Formula 4 in 2-methyl-tetrahydro-furan, and FIG. 2A shows 2-H-39 of RH-39 of Chemical Formula 4; After dissolving in tetrahydro-furan, it is a PL (photoluminescence) spectrum measured under liquid nitrogen conditions.

As shown in FIGS. 1A and 1B, the red phosphorescent host material according to an embodiment of the present invention has triplet energy of about 2.37 eV and about 2.33 eV, respectively. That is, since it has triplet energy larger than 1.8 eV, it has the advantage of excellent luminous efficiency.

An embodiment of an organic light emitting display device including the red phosphorescent host material is illustrated in FIG. 2.

As illustrated, the organic light emitting diode 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 is an organic light emitting layer 120 formed between the first electrode 110 serving as an anode, the second electrode 130 serving as a cathode, and the first and second electrodes 110 and 130. )

The first electrode 110 is formed of a material having a relatively high work function, for example, indium tin oxide (ITO), and the second electrode 130 is formed of a material having a relatively low work function, for example. For example, it is made of aluminum (Al) or aluminum alloy (AlNd). In addition, the organic light emitting layer 130 includes red, green, and blue organic light emitting patterns.

The organic light emitting layer 130 has a multilayer structure, that is, a hole injection layer (HTL) 121 and a hole transporting layer (hole transporting layer; HIL) sequentially from the first electrode 110 in order to maximize luminous efficiency. ) 122, an emitting material layer (EML) 123, an electron transporting layer 124, and an electron injection layer 125.

Here, the light emitting material layer 123 includes a red phosphorescent host material represented by Chemical Formula 2. The red phosphorescent host material is dissolved in a solvent such as 1,2-dichlorobenzen at about 1-10 wt%, and a dopant is added at about 1-10 wt% to prepare a light emitting material layer solution. The light emitting material layer solution is coated to form the light emitting material layer 123. The light emitting material layer 123 may further include green and blue light emitting material layers.

The organic light emitting diode having such a structure has an advantage in manufacturing a large area organic light emitting diode because the light emitting material layer 123 is formed by coating a light emitting material layer solution. In addition, it is possible to realize a high-brightness image, and also to improve the luminous efficiency to enable a low power drive has the advantage that the power consumption is reduced.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

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

Claims (10)

Represented by the following formula, each of A1 and A3 is selected from a substituted or unsubstituted heterocyclic group material, and each of A2 and A3 is selected from a substituted or unsubstituted heterocyclic group material, or a substituted or unsubstituted aromatic group material. Red phosphorescent host material for an organic light emitting device characterized in that the.

The method of claim 1,
The heterocyclic group material may be pyridinyl, bipyridinyl, quinolinyl, isoquinolinyl, quinoxalinyl, terpyridinyl, phenoxrollinyl ( red phosphorescent host material characterized by containing phenanthrolinyl).
The method of claim 1,
The aromatic group material is a red phosphorescent host material, characterized in that it comprises phenyl, naphthyl, biphenyl, terphenyl, phenanthrenyl.
The method of claim 1,
Substituents of the heterocyclic group material and the aromatic group material are C1 ~ C20 aryl, C1 ~ C20 alkyl, C1 ~ C20 alkenyl, C1 ~ C20 alkylyl , C1-C20 alkoxy or C1-C20 alkylsilyl, phenylsilyl, Phenylsilyl, halogen (cyano), characterized in that the red phosphorescent host material.
A first electrode;
A second electrode facing the first electrode;
A light emitting material layer positioned between the first and second electrodes,
The light emitting material layer is represented by the following formula, each of A1 and A3 is selected from a substituted or unsubstituted heterocyclic group material, each of A2 and A3 is a substituted or unsubstituted heterocyclic group material, or a substituted or unsubstituted An organic electroluminescent device characterized in that it comprises a red phosphorescent host compound selected from the group of aromatic groups.

The method of claim 5, wherein
The heterocyclic group material may be pyridinyl, bipyridinyl, quinolinyl, isoquinolinyl, quinoxalinyl, terpyridinyl, phenoxrollinyl ( organic electroluminescent device comprising phenanthrolinyl).
The method of claim 5, wherein
The aromatic group material is an organic electroluminescent device, characterized in that it comprises phenyl (naphthyl), biphenyl (biphenyl), terphenyl (terphenyl), phenanthrenyl (phenanthrenyl).
The method of claim 5, wherein
Substituents of the heterocyclic group material and the aromatic group material are C1 ~ C20 aryl, C1 ~ C20 alkyl, C1 ~ C20 akenyl, C1 ~ C20 alkylyl , C1 ~ C20 alkoxy (alkoxy) or C1 ~ C20 Alkylsilyl (alkylsilyl), Phenylsilyl (Phenylsilyl), Halogen (halogen), Cyano (cyano) is characterized in that the organic light emitting device.
6. The method of claim 5,
And the light emitting material layer comprises a light emitting material layer solution containing 1-10 wt% of the red phosphorescent host compound and a dopant of 1-10 wt% of the light emitting material layer solution.
The method of claim 5, wherein
A hole injection layer between the first electrodes;
A hole transport layer disposed between the hole injection layer and the light emitting material layer;
An electron transport layer on the light emitting material layer;
And an electron injection layer disposed between the electron transport layer and the second electrode.

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