KR20060036670A - Phosphorescent iridium complex and organic electroluminescent device comprising same - Google Patents

Abstract

The present invention relates to an iridium organic complex of Formula 1 and an organic electroluminescent device comprising the same as a light emitting material, the iridium organic complex according to the present invention is excellent in electrical stability and luminous efficiency, it is possible to implement high luminance and high color purity Since the red light is emitted, it can be usefully used as a light emitting material of the organic electroluminescent device.

Where

R ₁ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen, halogen, carboxyl, amino, cyano, nitro, C _1-6 linear or branched alkyl, C _6-18 substituted or unsubstituted aryl, C _1-6 straight or branched alkoxy, or C _4-6 hetero ring;

R ₂ and R ₃ are each independently hydrogen, halogen, carboxyl, amino, cyano, nitro, C _1-6 straight or branched alkyl, C _6-18 substituted or unsubstituted aryl, C _{1- 6} straight-chain or branched alkoxy, or is a C _4-6 heterocyclic, fused to each other may form an aromatic ring;

R ₄ and R ₅ are each independently hydrogen, C _1-6 straight or branched alkyl, C _1-6 alkyl including halogen atoms such as F and Cl, substituted or unsubstituted C _6-18 Aryl, C _4-12 hetero ring, primary or tertiary alkyl or aryl amine, C _1-6 alkoxy, cyano or nitro;

X is CH or N.

Description

Iridium complex and organic electroluminescent device including the same {PHOSPHORESCENT IRIDIUM COMPLEX AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING SAME}             

1 to 3 are schematic cross-sectional views of organic electroluminescent devices according to the present invention, respectively.

4 is a schematic structural cross-sectional view of an organic electroluminescent device manufactured in an embodiment of the present invention.

The present invention relates to an iridium organic complex having a red phosphorescent light emitting property and an organic electroluminescent device comprising the same as a light emitting material.

The flat panel display plays a very important role in supporting a highly visual information society, centered on the internet, which is rapidly growing in recent years. In particular, organic electroluminescent devices (organic EL devices) capable of low voltage driving with self-luminous type have superior viewing angles and contrast ratios compared to liquid crystal displays (LCDs), which are mainstream flat panel displays, and require no backlight. Light weight and thinness are possible, and it has an advantage in terms of power consumption. In addition, the fast response speed and wide color reproduction range have attracted attention as a next generation display device.

In general, an organic EL device is formed on a glass substrate in order of an anode made of a transparent electrode, an organic thin film including a light emitting region, and a metal electrode. The organic thin film may include a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), or an electron injection layer in addition to the light emitting layer (EML). injection layer (EIL), and may further include an electron blocking layer (EBL) or a hole blocking layer (HBL) due to light emission characteristics of the emission layer.

When an electric field is applied to the organic EL device having such a structure, holes are injected from the anode and electrons are injected from the cathode, and the injected holes and electrons are recombined in the emission layer through the hole transport layer and the electron transport layer, respectively, and emit excitons. To form. The light emitting excitons formed emit light while transitioning to ground states. In this case, the light emitting layer (dopant) may be doped into the light emitting layer (host) to increase the efficiency and stability of the light emitting state.

Recently, phosphorescent phosphors as well as fluorescent phosphors can be used as light emitting materials for organic EL devices (DF O'Brien et al., Applied Physics Letters , 74 ( 3 ), 442-444, 1999; MA Baldo et al. , Applied Physics letters , 75 ( 1 ), 4-6, 1999), and these phosphorescences are characterized by the transition of electrons from the ground state to the excited state, and then through intersystem crossing, After the light emission transition, the triplet excitons are composed of a mechanism that emits light while transitioning to the ground state. At this time, the transition to the triplet excitons does not directly transition to the ground state (spin forbidden), since the process of transition to the ground state after the flipping of the electron spin proceeds (lifetime) than fluorescence (lifetime) It has a longer characteristic. That is, the emission duration of fluorescence emission is only several nanoseconds, but the phosphorescence emission corresponds to several micro seconds, which is a relatively long time.

In addition, in quantum mechanics, when the holes injected from the anode and the electrons injected from the cathode recombine to form a light-emitting excitons, the formation ratio of the singlet and triplet is 1: 3. Antiluminescence excitons are generated about three times more than singlet excitation excitons. Therefore, in the case of using a phosphorescent light emitting material, there is an advantage that can achieve a three times higher luminous efficiency than the fluorescent light emitting material.

As a molecular structure that is easy to phosphorescence, a metal complex including a metal having a large atomic number as a molecular structure that is easy to carry out transit is applicable. Among these, iridium organic complex is attracting attention as a material having excellent phosphorescence efficiency. However, there are many problems such as luminous efficiency, color purity and electrical stability, and especially in the case of blue and red light emission, it is very urgent to develop a phosphorescent light emitting material having excellent luminous efficiency, color purity and electrical stability.

Accordingly, an object of the present invention is to provide a red phosphorescent light emitting material having excellent electrical stability and luminous efficiency, high luminance and high color purity and an organic electroluminescent device including the same.

In accordance with the above object, the present invention provides an iridium organic complex of formula (I):

Formula 1

Where

R ₁ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen, halogen, carboxyl, amino, cyano, nitro, C _1-6 linear or branched alkyl, C _6-18 substituted or unsubstituted aryl, C _1-6 straight or branched alkoxy, or C _4-6 hetero ring;

R ₂ and R ₃ are each independently hydrogen, halogen, carboxyl, amino, cyano, nitro, C _1-6 straight or branched alkyl, C _6-18 substituted or unsubstituted aryl, C _{1- 6} straight-chain or branched alkoxy, or is a C _4-6 heterocyclic, fused to each other may form an aromatic ring;

R ₄ and R ₅ are each independently hydrogen, C _1-6 straight or branched alkyl, C _1-6 alkyl including halogen atoms such as F and Cl, substituted or unsubstituted C _6-18 Aryl, C _4-12 hetero ring, primary or tertiary alkyl or aryl amine, C _1-6 alkoxy, cyano or nitro;

X is CH or N.

Hereinafter, the present invention will be described in detail.

As shown in Formula 1, the iridium organic complex according to the present invention has two main ligands, a benzoquinoline or a benzoquinoxaline structure and the other auxiliary ligand. It consists of a pyrazole (phenylpyrazole) structure.

In general, it is known that the luminescence properties of iridium complexes are determined by the main ligands, and the role of the auxiliary ligands causes a slight change in the emission wavelength (5 nm to 20 nm) or a slight influence on the emission efficiency (Thompson et al., J.). Am. Chem. Soc. , 123, 4304). As the auxiliary ligand, a ligand of the acetylacetone type is generally used, but in the present invention, a novel auxiliary ligand, phenylpyrazole, is introduced. The organic electroluminescent device including the same has a high content of 10 cd / A or more. It can exhibit luminous efficiency.

In addition, the luminescence properties of the iridium organic complex vary greatly depending on the type of the substituents R ₄ and R _{5. In} the present invention, as the R ₄ and R ₅ substituents, electron donor groups such as alkyl groups, alkoxy groups or amine groups, And electron-withdrawing groups such as halogen atoms (F, Cl, etc.), cyano groups, nitro groups, or trifluoromethyl.

Preferred examples of the iridium organic complex of the present invention are shown below.

The iridium organic complex according to the present invention is the main ligand of each compound according to a known method using bridged iridium (Mark E. Thomson, J. Am. Chem. Soc. , 2001, 123, 4304). And iridium chloride hydrate (IrCl ₃ xH ₂ O) in the presence of a solvent, followed by reaction with an excess of 1-phenylpyrazole.

In addition, the present invention provides an organic electroluminescent device comprising the compound as a light emitting material in the light emitting layer.

The organic electroluminescent device according to the present invention is a monolayer comprising a light emitting layer including the iridium organic complex of Formula 1 as a light emitting material as a light emitting material between a positive electrode, a negative electrode and two electrodes, or a positive electrode, together with a charge transport layer. The light emitting layer and the cathode including the iridium organic complex of Formula 1 as a light emitting material have a multilayer structure in which the cathodes are sequentially stacked.

In general, a multilayer device having a combination of a light emitting layer and a charge transporting layer exhibits superior characteristics, rather than a single layered device consisting of only one light emitting layer, which is an energy barrier when charge is injected from an electrode by properly combining the light emitting material and the charge transporting material. This is because the charge transport layer binds the holes or electrons injected from the electrode to the light emitting layer region so that the number density of the injected holes and electrons is balanced. In particular, in the case of a phosphorescent light emitting device, since the emission duration of the phosphorescent material is long, in order to increase efficiency, it is necessary to trap holes in the light emitting layer so that the holes remain in the light emitting layer for a long time to show excellent phosphorescence properties. More preferred.

A schematic cross-sectional view of the organic electroluminescent device of the present invention is shown in FIGS. As shown in FIG. 1, the basic organic electroluminescent device of the present invention has a structure in which a transparent electrode (anode), a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a metal electrode (cathode) are sequentially stacked. 2, a hole blocking layer is provided between the light emitting layer and the electron transporting layer as shown in FIG. 2, or as shown in FIG. 3, or the hole blocking layer is disposed between the light emitting layer and the electron transporting layer and between the light emitting layer and the hole transporting layer, respectively. Layers and electron blocking layers may be further included.

In the organic electroluminescent device according to the present invention, the transparent electrode (anode) and the metal electrode (cathode) are conventional electrode materials, for example, the transparent electrode is indium tin oxide (ITO) or SnO ₂ , and the metal electrode Silver may be formed of a metal such as Li, Mg, Ca, Ag, Al, and In, or an alloy thereof, and the metal electrode may have a single layer or a multilayer structure of two or more layers.

In addition, the light emitting layer may include at least one selected from the compounds of the general formula (1) of the present invention as a light emitting material, at this time, other compounds known in the art, for example, 4,4-dicarbazole bis of the formula (2) Phenyl (CBP) may be included as a host by doping the compound of Formula 1 thereto.

The hole transport layer may be a conventional hole transport material, for example, 4,4-bis [N- (1-naphthyl) -N-phenyl-amine] biphenyl (α-NPD) of Formula 3, and N of Formula 4 , N-diphenyl-N, N-bis (3-methylphenyl) -1,1-biphenyl-4,4-diamine (TPD) and poly- (N-vinylcarbazole) (PVCz) and the like alone or in combination It may contain a mixture of two or more kinds, and may be laminated as two or more layers as a separate layer.

The hole blocking layer has a low unoccupied molecular orbital (LUMO) value between 5.5 and 7.0, and is composed of a material having excellent electron transporting ability with a significant drop in hole transporting capacity. Such materials include bastocuproine of Formula 5 , BCP), 3- (4-biphenylyl) -4-phenyl-5- (4-t-butylphenyl) -1,2,4-triazole (TAZ) of Formula 6 and bis of Formula 7 (8-hydroxy-2-methylquinolinato) -aluminum biphenoxide (BAlq) and the like are suitable. In addition, as the electron blocking layer, a material having a large LUMO value is generally used, and iridium (III) tris (1-phenylpyrazole-N, C ^{2 ′} ) (Ir (ppz) ₃ ) Etc. are suitable.

The electron transporting layer (electron transporting emissive layer) may be composed of a conventional electron transporting material such as tris (8-quinolinolato) aluminum (Alq ₃ ), rubrene, or the like alone or in combination of two or more thereof. Two or more separate layers may be stacked.

In addition, for example, copper is provided between the anode and the hole transport layer in order to improve device characteristics such as luminous efficiency and lifetime. A conventional hole injection layer containing copper phthalocyanine (CuPc) can be inserted, and a conventional electron injection layer containing, for example, LiF, can be inserted between the cathode and the electron transport layer.

The anode, cathode, light emitting layer, transport layer, injection layer and blocking layer may be formed by a conventional deposition method.

The iridium organic complex of the present invention is a compound having a red phosphorescence emission property and exhibits excellent chemical and electrical stability, luminous efficiency, high luminance emission and excellent color purity, and thus can be usefully used as a red phosphorescence emission material of an organic electroluminescent device.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited to the following examples.

Example 1 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1a

<Step 1>

The main ligand of Formula 1a was stirred under reflux for 24 hours at 140 ° C. with iridium chloride hydrate (IrCl ₃ xH ₂ O, Aldrich) in a solvent mixed with ethoxyethanol and water in a 3: 1 ratio, and then the resulting solid was produced. Was filtered, washed with water, diethyl ether and hexane in that order and dried to obtain the iridium complex of formula (1a).

<Step 2>

Water-based detergent, ultrapure water, isopropyl alcohol and methanol were used sequentially to A glass substrate (Asahi Glass Co., Sheet Resistance 8 Ω / cm ² ) coated with indium tin oxide (ITO) was ultrasonically cleaned to prepare a transparent electrode (anode).

Copper phthalocyanine (CuPc) was deposited on the transparent electrode to form a 20 nm hole injection layer, and 4,4-bis [N- (1-naphthyl) -N-phenyl-amine] biphenyl (α) thereon. -NPD) was deposited to form a hole transporting layer of 20 nm, and then the compound of Formula 1a obtained in step 1 using 4,4-dicarbazole bisphenyl (CBP) as the host (10 wt. % Was deposited on the hole transport layer at a rate of 1 nm / sec to form a light emitting layer of 30 nm.

After co-deposition, Vasocuproin (BCP) was deposited on the light emitting layer at a rate of 0.1 nm / sec to form a 10 nm hole blocking layer, and then tris (8-quinolinolato) aluminum (Alq ₃ ) was deposited thereon. ) Was deposited on the light emitting layer to form an electron transport layer of 40 nm, and LiF was deposited to form an electron injection layer of 1 nm. By depositing Al on the electron injection layer to form a cathode of 150 nm, an organic electroluminescent device according to the invention was prepared.

As shown in FIG. 4, the manufactured organic electroluminescent device is made of [ITO transparent electrode (150 nm) / CuPc hole injection layer (20 nm) / α-NPD hole transport layer (40 nm) / CBP + compound 1a, a light emitting layer ( 30 nm) / BCP hole blocking layer (10 nm) / Alq ₃ electron transport layer (40 nm) / LiF electron injection layer (1 nm) / Al electrode (150 nm)] are laminated in order from the bottom.

The electroluminescent (EL) characteristics of the organic electroluminescent device manufactured as described above were measured by applying a forward bias DC voltage to the PR-650 of photo research, and as a result, an initial turn-on voltage of 3 V was obtained. In the luminance and luminous efficiency was confirmed to be 1.1 cd / m ² and 14.5 cd / A, respectively, at a driving voltage of 8.5 V confirmed the luminance of 1,053 cd / m ² and the luminous efficiency of 12.1 cd / A. In this case, it can be seen that the color coordinates of the organic electroluminescent device manufactured by x, y = [0.62, 0.38] represent light corresponding to red color. The maximum luminance of the device was 32,910 cd / m ² at a driving voltage of 15.5 V.

Example 2 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1b

After the compound of Formula 1b was synthesized in the same manner as in Step 1 of Example 1, an organic electroluminescent device was manufactured by the same method as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 3.5 V were 1.05 cd / m ² and 14.5 cd / A, respectively. The driving voltage of 9 V was 1,201 cd / m ² . Luminance and luminous efficiency of 11 cd / A were shown. In this case, the color coordinates can be seen that the organic electroluminescent device manufactured with x, y = [0.65, 0.35] emits light corresponding to red color, and the maximum luminance of the device was 29,302 cd / m ² at a driving voltage of 16 V. .

Example 3 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1c

After the compound of Formula 1c was synthesized in the same manner as in Step 1 of Example 1, an organic electroluminescent device was manufactured in the same manner as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and the luminous efficiency at the initial driving voltage of 3.0 V were 1.2 cd / m ² and 13.8 cd / A, respectively, and the driving voltage of 8 V was 1,032 cd / m ² . Luminance and luminous efficiency of 10.4 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.65, 0.35], and the maximum luminance of the device was 30,192 cd / m ² at a driving voltage of 15V.

Example 4 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1d

Synthesis of the compound of Formula 1d in the same manner as in Step 1 of Example 1, and then doped in a weight ratio of 8% by weight based on the host material CBP when forming the light emitting layer in the same manner as in Step 2 of Example 1 An organic electroluminescent device was manufactured.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 3.5 V were 1.0 cd / m ² and 13.2 cd / A, respectively, and the driving voltage of 8.5 V was 1,138 cd / m ² . Luminance and luminous efficiency of 10.2 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.66, 0.34], and the maximum luminance of the device was 31,930 cd / m ² at a driving voltage of 15V.

Example 5 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1e

Synthesis of the compound of Formula 1e in the same manner as in Step 1 of Example 1, and then doped in a weight ratio of 8% by weight based on the CBP as a host material when forming the light emitting layer in the same manner as in Step 2 of Example 1 An organic electroluminescent device was manufactured.

By this measure the electroluminescent properties in the target result, the brightness and luminous efficiency at an initial driving voltage of 3.0 V was confirmed that each 1.1 cd / m ² and 13.2 cd / A, the drive voltage 9.5 V of 1,291 cd / m ² Luminance and luminous efficiency of 9.9 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.66, 0.34], and the maximum luminance of the device was 28,102 cd / m ² at a driving voltage of 15.5 V.

Example 6 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1f

After the compound of Formula 1f was synthesized in the same manner as in Step 1 of Example 1, the organic electroluminescent device was manufactured by the same method as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 3.0 V were 1.15 cd / m ² and 14.2 cd / A, respectively, and the driving voltage of 9.5 V was 1,043 cd / m ² . Luminance and luminous efficiency of 11.2 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.64, 0.36], and the maximum luminance of the device was 42,910 cd / m ² at a driving voltage of 16V.

Example 7 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1g

After the compound of Formula 1g was synthesized in the same manner as in Step 1 of Example 1, the organic electroluminescent device was manufactured in the same manner as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 3.5 V were 1.2 cd / m ² and 15.2 cd / A, respectively, and the driving voltage of 9 V was 1,034 cd / m ² . Luminance and luminous efficiency of 10.1 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.64, 0.36, and the maximum luminance of the device was 29,018 cd / m ² at a driving voltage of 15V.

Example 8 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1h

After the compound of Formula 1h was synthesized in the same manner as in Step 1 of Example 1, the organic electroluminescent device was manufactured by the same method as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 3.5 V were 1.15 cd / m ² and 13.1 cd / A, respectively, and the driving voltage of 9.5 V was 1,153 cd / m ² . Luminance and luminous efficiency of 9.8 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.65, 0.35], and the maximum luminance of the device was 27,910 cd / m ² at a driving voltage of 15.5 V.

Example 9 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1i

Synthesis of the compound of Formula 1i in the same manner as in Step 1 of Example 1, and then doped in a weight ratio of 8% by weight based on the host material CBP when forming the light emitting layer in the same manner as in Step 2 of Example 1 An organic electroluminescent device was manufactured.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 4 V were 1.05 cd / m ² and 14.8 cd / A, respectively, and the driving voltage of 10 V was 1,053 cd / m ² . Luminance and luminous efficiency of 10.9 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.63, 0.37], and the maximum luminance of the device was 40,192 cd / m ² at a driving voltage of 16V.

Example 10 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1j

After the compound of Formula 1j was synthesized in the same manner as in Step 1 of Example 1, the organic electroluminescent device was manufactured in the same manner as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and the luminous efficiency at the initial driving voltage of 3 V were 1.1 cd / m ² and 13.8 cd / A, respectively, and the driving voltage of 8 V was 1,202 cd / m ² . Luminance and luminous efficiency of 11.1 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.64, 0.36], and the maximum luminance of the device was 37,681 cd / m ² at a driving voltage of 15V.

Example 11 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1k

 Synthesis of the compound of Formula 1k in the same manner as in Step 1 of Example 1, and then doped in a weight ratio of 8% by weight based on the CBP as a host material when forming the light emitting layer in the same manner as in Step 2 of Example 1 An organic electroluminescent device was manufactured.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 3 V were 1.1 cd / m ² and 13.2 cd / A, respectively, and the driving voltage of 8 V was 1,138 cd / m ² . Luminance and luminous efficiency of 10.2 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.65, 0.35], and the maximum luminance of the device was 28,912 cd / m ² at a driving voltage of 15V.

Example 12 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1l

Synthesis of the compound of Formula 1l in the same manner as in Step 1 of Example 1, and then doped in a weight ratio of 8% by weight based on the CBP as a host material when forming the light emitting layer in the same manner as in Step 2 of Example 1 An organic electroluminescent device was manufactured.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 4 V were 1.0 cd / m ² and 15.3 cd / A, respectively, and the driving voltage of 8.5 V was 1,138 cd / m ² . Luminance and luminous efficiency of 11.4 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red as x, y = [0.63, 0.37], and the maximum luminance of the device was 48,281 cd / m ² at a driving voltage of 15 V.

Example 13 Fabrication of Organic Electroluminescent Device Using Compound of Formula 1m

After the compound of Formula 1m was synthesized in the same manner as in Step 1 of Example 1, the organic electroluminescent device was manufactured in the same manner as in Step 2 of Example 1, using the same as a light emitting material.

As a result of measuring the electroluminescence characteristics, it was confirmed that the luminance and luminous efficiency at the initial driving voltage of 4 V were 1.1 cd / m ² and 15.6 cd / A, respectively, and the driving voltage of 8 V was 1,024 cd / m ² . Luminance and luminous efficiency of 11.5 cd / A were shown. In this case, it can be seen that the color coordinates emit light corresponding to red with x, y = [0.63, 0.37], and the maximum luminance of the device was 47,102 cd / m ² at a driving voltage of 15V.

As described above, the iridium organic complex according to the present invention has excellent electrical stability and luminous efficiency, and exhibits light emission in a red region that can realize high luminance and excellent color purity, and thus is useful as a light emitting material of the organic electroluminescent device. Can be utilized.

Claims (7)

Iridium organic complex represented by the following formula (1): Formula 1

Where R ₁ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently hydrogen, halogen, carboxyl, amino, cyano, nitro, C _1-6 linear or branched alkyl, C _6-18 substituted or unsubstituted aryl, C _1-6 straight or branched alkoxy, or C _4-6 hetero ring; R ₂ and R ₃ are each independently hydrogen, halogen, carboxyl, amino, cyano, nitro, C _1-6 straight or branched alkyl, C _6-18 substituted or unsubstituted aryl, C _{1- 6} straight-chain or branched alkoxy, or is a C _4-6 heterocyclic, fused to each other may form an aromatic ring; R ₄ and R ₅ are each independently hydrogen, C _1-6 straight or branched alkyl, halogen-substituted C _1-6 alkyl, C _6-18 substituted or unsubstituted aryl, C _{4- 12} hetero rings, 1 to 3 alkyl or aryl amines, C _1-6 alkoxy, cyano or nitro; X is CH or N. The method of claim 1, An iridium organic complex characterized in that it is selected from compounds of the formula Formula 1a

Formula 1b

Formula 1c

Formula 1d

Formula 1e

Formula 1f

Formula 1g

Formula 1h

Formula 1i

Formula 1j

Chemical Formula 1k

Formula 1l

Formula 1m

An organic electroluminescent device comprising a light emitting layer between an anode, a cathode and a positive electrode, the organic electroluminescent device comprising the iridium organic complex of claim 1 in the light emitting layer. The method of claim 3, wherein An organic electroluminescence device comprising a 4,4-dicarbazole bisphenyl (CBP) of Formula 2 as a host and a doping the iridium organic complex of claim 1 included in the light emitting layer. Formula 2

The method of claim 3, wherein An organic electroluminescent device comprising a structure comprising a charge transport layer between an anode or a cathode and a light emitting layer. The method of claim 5, wherein An organic electroluminescence device comprising a multilayer structure in which transparent electrodes (anodes), hole injection layers, hole transport layers, light emitting layers, electron transport layers, electron injection layers and metal electrodes (cathodes) are sequentially stacked. The method of claim 5, wherein An organic electroluminescent device further comprising a hole blocking layer and an electron blocking layer between the light emitting layer and the electron transporting layer and between the light emitting layer and the hole transporting layer, respectively.

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