KR20090073850A - Organometallic complex compounds for photoelectric device and photoelectric device comprising the same - Google Patents

Abstract

An organometallic complex compound is provided to ensure excellent solubility by introducing a benzimidazole-based compound having a bulky stereostructure as a ligand of the organometallic complex compound. A metal complex compound for an organic photoelectric device is represented by chemical formula 1 and comprises a benzimidazole derivative ligand. The organic photoelectric device comprises an organic thin film layer positioned between a pair of electrodes. The organic thin film layer comprises a metalorganic compound. The organic thin film layer comprises a light emitting layer including an organometallic complex compound as a dopant.

Description

ORGANOMETALLIC COMPLEX COMPOUNDS FOR PHOTOELECTRIC DEVICE AND PHOTOELECTRIC DEVICE COMPRISING THE SAME}

The present invention relates to an organometallic complex compound for an organic photoelectric device, and an organic photoelectric device including the same, and more particularly, to introduce a benzimidazole compound having a bulk three-dimensional structure as a ligand of a metal complex compound. By suppressing the interaction between molecules, the present invention relates to an organometallic complex compound for an organic photoelectric device having excellent solubility, and an organic photoelectric device including the same.

Organic photoelectric devices are attracting attention as next generation display devices. The organic photoelectric device can be driven at a low voltage and can solve the drawbacks of the TFT-LCD, such as thinning, wide viewing angle, and fast response speed. In addition, compared to other display devices, the medium size or less may have the same or higher image quality than that of the TFT-LCD, and the manufacturing process is simple.

In the organic photoelectric device, an organic light emitting material is formed in a space between a lower plate having a form in which an ITO transparent electrode pattern is formed as an anode electrode on a transparent glass substrate and an upper plate in which a metal electrode is formed as a cathode electrode on the substrate. And a display device that emits light while a current flows through the organic light emitting material when a predetermined voltage is applied between the metal electrode and the metal electrode.

The organic light emitting material used in such an organic photoelectric device was developed by Eastman Kodak in 1987 for the first time to develop an organic light emitting material using a low molecular aromatic diamine and an aluminum complex as a material for forming a light emitting layer (Applied Physics Letters). 51, 913, 1987), and in 1987, CW Tang et al. Reported the first devices with practical performance (Applied Physics Letters, 51 (12), 913-915, 1987).

The organic photoelectric device is a self-luminous display device capable of driving low voltage, having a wide viewing angle, excellent contrast, and fast response speed.

The organic photoelectric device generally has a structure formed on a glass substrate in order of an anode electrode made of a transparent electrode, an organic thin film layer including a light emitting region, and a cathode electrode made of a metal electrode.

In this case, the organic thin film layer may include a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer or an electron injection layer, and may further include an electron blocking layer or a hole blocking layer due to the light emission characteristics of the light emitting layer.

When an electric field is applied to the organic photoelectric device having such a structure, holes and electrons are injected from the anode electrode and the cathode electrode, respectively, and the injected holes and electrons are recombined in the light emitting layer through the respective hole transport layer and the electron transport layer to emit light. (exitons) The formed light exciton emits light while transitioning to ground states, in which a light emitting layer (dopant) is doped into the light emitting layer (host) to increase the efficiency and stability of the light emitting state.

In the organic photoelectric device having the structure as described above, the light emitting material may be divided into a fluorescent material using an exciton in a singlet state and a phosphorescent material using a triplet state according to its light emitting mechanism, and not only a fluorescent light emitting material but also a phosphorescent material. Luminescent materials can also be used as luminescent materials in organic photoelectric devices (DFO'Brien et al., Applied Physics Letters, 74 (3), 442-444, 1999; MA Baldo et al., Applied Physics letters, 75 (1), 4- 6,1999).

The phosphorescence emission is a mechanism in which electrons transfer from the ground state to the excited state, and then the singlet excitons are non-luminescently transferred to the triplet excitons through intersystem crossing, and then the triplet excitons are emitted to the ground state. Is done.

At this time, the lifetime of the triplet excitons cannot be transferred directly to the ground state (spin forbidden), so the process of transition to the ground state after the flipping of the electron spin proceeds, so the lifetime (luminescence time) is higher than that of fluorescence. 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 mechanical terms, when the holes injected from the anode and the electrons injected from the cathode recombine to form a light-emitting excitons in the organic photoelectric device, the generation ratio of the singlet and triplet is 1: 3 in the OLED device. Triplet luminescence excitons are generated three times more than singlet luminescence excitons.

Therefore, in the case of fluorescence, the probability of singlet excited state is 25% (triple excited state 75%), and the luminous efficiency is limited, whereas phosphorescence can be used to triplet excited state and 75% singlet excited state. Theoretically, the internal quantum efficiency can be up to 100%. Therefore, in the case of using the phosphorescent material, there is an advantage that can achieve a light emission efficiency about three times higher than the fluorescent light emitting material.

As a molecular structure that is easy to phosphorescence emission, it is a molecular structure that is easy to intercalate to introduce heavy metals such as Ir, Pt, Rh, Pd, etc. in this case, in this case, the spin generated by the heavy atom effect (heavy atom effect) Spin-orbital coupling results in a mixture of triplet and singlet states, which allows forbidden transitions and effectively phosphorescent at room temperature.

Among these, the iridium organometallic complex is attracting attention as a material having excellent phosphorescence emission efficiency and phosphorescence emission materials using the same have been reported (Sergey Lamansky etc. Inorg. Chem., 40, 1704-1711, 2001 & J. Am. Chem. Soc., 123, 4304-4312, 2001).

The phosphorescent organic metal complex has been mainly developed for the development of low molecular weight materials that can form the device by the vacuum deposition method, and in the case of the polymer material is a wet process such as spin coating, inkjet printing, casting method Configure

Wet processes using polymers are easier to fabricate devices than vacuum evaporation, and have more advantages in terms of cost and size, but have the disadvantage that polymer materials are lower than low molecular materials in terms of lifetime, luminous efficiency and color purity.

Therefore, in order to overcome such a problem, there is a demand for the development of a material capable of constituting a device by a wet process with low molecular weight and high solubility.

SUMMARY OF THE INVENTION An object of the present invention is to introduce a benzimidazole compound having a bulk conformation as a ligand of an organometallic complex compound, thereby inhibiting the interaction between molecules, thereby providing an organometallic complex compound for an organic photoelectric device having excellent solubility. It is.

Still another object of the present invention is to provide an organic photoelectric device comprising the organometallic complex compound for an organic photoelectric device.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by the average person from the following description.

According to one embodiment of the present invention, represented by the following Chemical Formula 1, an organometallic complex compound for an organic photoelectric device including a benzimidazole derivative ligand.

[Formula 1]

(In Formula 1,

N is an integer of 1 to 3,

M is a metal forming an octahedral complex,

L is a monovalent anionic bidentate ligand coordinated to M through sp ² carbon and a heteroatom, or a monovalent anionic bidentate ligand coordinated to M through heteroatom and heteroatom,

R ₁ to R ₅ are each independently a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, substituted or unsubstituted A substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted amino group having 2 to 20 carbon atoms, and a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,

R ₁ to R ₅ are each present as an independent substituent, or are fused with each other to form a ring,

R ₆ is a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted Or an unsubstituted amino group having 2 to 20 carbon atoms and a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and n ₆ is an integer of 0 to 4)

According to another embodiment of the present invention, an organic thin film layer is disposed between a pair of electrodes, and the organic thin film layer provides an organic photoelectric device including the organometallic complex compound.

Other specific details of embodiments of the present invention are included in the following detailed description.

The metal complex compound for an organic photoelectric device of the present invention introduces a benzimidazole compound having a bulk structure as a ligand of the metal complex compound to inhibit the interaction between molecules, thereby providing excellent solubility. In addition, by using the metal complex compound having excellent solubility, an organic light emitting device having a high luminous efficiency can be manufactured even through a wet process.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

According to one embodiment of the present invention, represented by the following Chemical Formula 1, an organometallic complex compound for an organic photoelectric device including a benzimidazole derivative ligand.

[Formula 1]

(In Formula 1,

N is an integer of 1 to 3,

M is a metal forming an octahedral complex,

L is a monovalent anionic bidentate ligand coordinated to M through sp ² carbon and a heteroatom, or a monovalent anionic bidentate ligand coordinated to M through heteroatom and heteroatom,

R ₁ to R ₅ are each independently a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, substituted or unsubstituted A substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted amino group having 2 to 20 carbon atoms, and a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,

R ₁ to R ₅ are each present as an independent substituent, or are fused with each other to form a ring,

R ₆ is a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted Or an unsubstituted amino group having 2 to 20 carbon atoms and a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and n ₆ is an integer of 0 to 4)

Substituted herein, unless specified otherwise, a hydrogen atom is a halogen group, an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, and Mean substituted with any one of the substituents selected from the group consisting of a combination of these.

In addition, in the present specification, hetero means a carbon atom substituted with any one hetero atom selected from the group consisting of N, O, S, and P unless otherwise specified.

At least one of R ₁ to R ₄ is a substituted or unsubstituted carbazole group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted arylamine group having 6 to 30 carbon atoms, a substituted or unsubstituted C 12 to 30 It is preferable that it is a C1-C30 aryl group substituted by any one substituent selected from the group which consists of the biarylphenyl group of these, and its combination.

When at least one of the R ₁ to R ₄ is the substituted aryl group, R ₁ to R ₅ is preferably any one selected from the group consisting of substituents represented by the following formulas (2) to (6).

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

(In Chemical Formulas 2 to 6

X ₂₁ to X ₂₈ , X ₃₁ to X ₃₈ , and X ₅₁ to X ₆₆ are each independently any one selected from the group consisting of CR ₁₈ , and N,

R ₁₈ and R ″ are each independently a hydrogen atom, a halogen atom, R ₁₆ , OR ₁₆ , N (R ₁₆ ) ₂ , P (R ₁₆ ) ₂ , P (OR ₁₆ ) ₂ , POR ₁₆ , PO ₂ R ₁₆ , PO ₃ R ₁₆ , SR ₁₆ , Si (R ₁₆ ) ₃ , Si (CH ₃ ) ₂ R ₁₆ , Si (Ph) ₂ R ₁₆ , B (R ₁₆ ) ₂ , B (OR ₁₆ ) ₂ , C ( O) R ₁₆ , C (O) OR ₁₆ , C (O) N (R ₁₆ ) ₂ , CN, NO ₂ , SOR ₁₆ , SO ₂ R ₁₆ , and SO ₃ R ₁₆ ,

R ₁₆ is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted carbon atom 1 to 30 A heteroalkyl group selected from the group consisting of a substituted or unsubstituted aryl group having 3 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms,

R 'is a group consisting of a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 2 to 30 carbon atoms, and a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms. Is any one selected from

Ar ₁ to Ar ₄ is selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms)

L is preferably any one selected from the group consisting of ligands represented by the following formulas (7) to (13).

[Formula 7] [Formula 8] [Formula 9] [Formula 10]

    [Formula 11] [Formula 12] [Formula 13]

(In the above formulas 7 to 13,

R ₁ to R ₃ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted fluorene group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted biarylphenyl group , R ₁₆ , OR ₁₆ , N (R ₁₆ ) ₂ , P (R ₁₆ ) ₂ , P (OR ₁₆ ) ₂ , POR ₁₆ , PO ₂ R ₁₆ , PO ₃ R ₁₆ , SR ₁₆ , Si (R ₁₆ ) ₃ , Si (CH ₃ ) ₂ R ₁₆ , Si (Ph) ₂ R ₁₆ , B (R ₁₆ ) ₂ , B (OR ₁₆ ) ₂ , C (O) R ₁₆ , C (O) OR ₁₆ , C (O) Any one selected from the group consisting of N (R ₁₆ ) ₂ , CN, NO ₂ , SO ₂ , SOR ₁₆ , SO ₂ R ₁₆ , and SO ₃ R ₁₆ ,

R ₁₆ is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted carbon group 1 to 30 Any one selected from the group consisting of 30 heteroalkyl groups, substituted or unsubstituted aryl groups having 3 to 40 carbon atoms, and substituted or unsubstituted heteroaryl groups having 3 to 40 carbon atoms,

N ₁ is an integer of 1 to 3, n ₂ , n ₄ , and n ₅ are an integer of 1 to 4, n ₃ is an integer of 1 to 2)

The M is preferably any one selected from the group consisting of Group 9 elements of the Periodic Table forming the octahedral complex, and Group 10 elements, and any one element selected from the group consisting of Ir, Pt, Rh, and Pd It is more preferable that it is and even more preferable that it is Ir.

The organometallic complex compound for an organic photoelectric device represented by Formula 1 is more preferably a compound represented by Formula 14 or Formula 15 below, but is not limited thereto.

[Formula 14]

[Formula 15]

According to another embodiment of the present invention, an organic thin film layer is disposed between a pair of electrodes, and the organic thin film layer provides an organic photoelectric device including the polymer. The organic photoelectric device is preferably an organic light emitting device.

The organic photoelectric device includes a first electrode formed on a substrate, an organic thin film layer formed on the first electrode and including an organic metal complex compound for an organic photoelectric device, and a second electrode formed on the organic thin film layer.

The first electrode may preferably use a transparent conductive metal oxide such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

As the said board | substrate, a glass substrate, a flexible board | substrate, etc. can be used preferably.

Wherein the organic thin film layer is formed on the first electrode layer and the first buffer layer for injecting and transporting holes, the light emitting layer formed on the first buffer layer, formed on the light emitting layer, at least one of the second buffer layer for injecting, transporting electrons It may further comprise a layer. Layers constituting the organic thin film layer may include an organometallic complex compound according to an embodiment of the present invention.

Preferably, the light emitting layer includes the organometallic complex compound as a dopant, and in this case, the organometallic complex compound may be included in an amount of 1 to 10% by weight based on the whole of the light emitting layer. When the content of the organometallic complex compound is within the above range, energy transfer from the host to the dopant occurs efficiently, which is preferable.

The first buffer layer may include any one layer selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, and a combination thereof, wherein the second buffer layer is an electron injection layer, an electron transport layer, an electron It may comprise a barrier layer, and any one layer selected from the group consisting of a combination thereof.

The organometallic complex compound is excellent in solubility, and when the organic thin film layer is prepared using the organometallic complex, the organometallic complex compound may be easily prepared by wet processes such as spin coating, inkjet, and casting.

1 is a view schematically showing a cross-sectional view of an organic photoelectric device 1 according to an embodiment of the present invention. Referring to FIG. 1, the organic photoelectric device 1 may include a first electrode 12 made of a transparent conductive metal oxide, an organic thin film layer 10 including a light emitting region, and a second electrode 16. This is a structure formed on the substrate 11. However, the configuration of the organic photoelectric device according to the embodiment of the present invention is not limited thereto.

The substrate 11 may be formed of a glass substrate or a flexible substrate having flexibility.

The first electrode 12 is formed on the substrate 11. The first electrode 12 may be formed of a transparent conductive metal oxide, and may use ITO or IZO as the transparent conductive metal oxide.

The organic thin film layer 10 is formed on the first electrode 12. The organic thin film layer 10 includes a light emitting layer 14, a first buffer layer 13, and a second buffer layer 15. At least one layer of the constituent layers of the organic thin film layer 10 includes an organometallic complex compound according to an embodiment of the present invention.

The first and second buffer layers 13 and 15 may include a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer, and further include an electron blocking layer or a hole blocking layer due to light emission characteristics of the light emitting layer 14. can do.

The second electrode 16 is formed on the second buffer layer 15. The second electrode 16 includes lithium (Li), magnesium (Mg), calcium (Ca), aluminum (Al), Al: Li, Ba: Li, or Ca: Li having a small work function. Can be used.

When an electric field is applied to the organic photoelectric device 1, holes and electrons are injected from the first electrode 12 and the second electrode 16, respectively, and the injected holes and electrons are emitted from the light emitting layer 14 of the organic thin film layer 10. ) And recombination to form luminescent excitons. The light emitter emits light as it transitions to ground states.

The following presents specific embodiments of the present invention. However, the embodiments described below are merely for illustrating or explaining the present invention in detail, and thus the present invention is not limited thereto.

( Production Example : Organometallic complexes  Preparation of compounds)

( Production Example  1: represented by Formula 14 Organometallic complexes  Synthesis of compounds)

An organometallic complex compound represented by Chemical Formula 14 was synthesized in the same manner as in Scheme 1 below.

Scheme 1

Under a nitrogen atmosphere, 3.0 g (1.0 eq, 8.59 mmol) of 1-phenyl-2- (3'-bromophenyl) -benzimidazole and 9- (3- (4,4,5,5-tetramethyl-1 3.50 g (1.2 eq, 9.45 mmol) of 3,2-dioxaborolan-2-yl) phenyl) -9H-carbazole was dissolved in 100 ml of tetrahydrofuran, and then 40 ml of a 2 molar potassium carbonate aqueous solution was added dropwise. . 0.30 g (0.03 eq, 0.26 mmol) of tetra (triphenylphosphino) palladium was added dropwise as a catalyst to reflux for 12 hours.

After completion of the reaction, tetra (triphenylphosphino) palladium was removed through celite filtration, and then extracted with toluene. The organic layer was concentrated and separated by silica gel column chromatography to synthesize ligand 1.

50 ml of glycerol was added to 1.02 g (1.5 eq, 2.00 mmol) of the ligand 1 and 0.8 g (1.0 eq, 1.33 mmol) of bis (2-phenylpyridine) acetylacetonate iridium, followed by 24 hours at 200 ^o C under a nitrogen atmosphere. It was refluxed. The reaction solution was poured into 800 ml of distilled water, stirred for about 10 minutes, washed with distilled water and filtered under reduced pressure. The crystal obtained after the filter was dissolved in chloroform again, separated by silica gel comlum chromatography, and then recrystallized with n-hexane to synthesize an iridium complex having a benzimidazole-based bulk ligand.

Elemental analysis was performed on the prepared iridium complex. Calculated: C, 70.08; H, 3. 99; Ir, 19.01; N, 6.93. Found: C, 70.13; H, 3.92; Ir, 19.00; N, 6.94.

( Production Example  2: represented by Formula 15 Organometallic complexes  Synthesis of compounds)

Scheme 2

Under nitrogen atmosphere, 3.0 g (1.0 eq, 8.59 mmol) of 1-phenyl-2- (3'-bromophenyl) -benzimidazole and 9,9 '-(5- ( p- (4,4,5, 5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl) -1,3-phenylene) bis (9H-carbazole) 5.77 g (1.2 eq, 9.45 mmol) was added to tetrahydrofuran. After dissolving in 100 ml, 40 ml of 2 mol potassium carbonate aqueous solution was added dropwise.

0.30 g (0.03 eq, 0.26 mmol) of tetra (triphenylphosphino) palladium was added dropwise as a catalyst to reflux for 12 hours.

After completion of the reaction, tetra (triphenylphosphino) palladium was removed through celite filtration, and then extracted with toluene.

The organic layer was concentrated and separated by silica gel column chromatography to synthesize Ligand 2.

The ligand 2 0.94g (1.5eq, 1.25mmol) and bis (2-phenylpyridine) acetylacetonate iridium 0.5g (1.0eq, 0.83mmol) was placed in a 50ml glycerol, for 24 hours at 200 ^o C in a nitrogen atmosphere It was refluxed.

The reaction solution was poured into 800 ml of distilled water, stirred for about 10 minutes, washed with distilled water and filtered under reduced pressure.

The crystal obtained after the filter was dissolved in chloroform again, separated by silica gel column chromatography, and then recrystallized with n-hexane to obtain an iridium complex having a benzimidazole-based bulk ligand.

Elemental analysis was performed on the prepared iridium complex. Calculated: C, 78.55; H, 4. 25; Ir, 10.39; N, 6.81. Found: C, 78.63; H, 4. 27; Ir, 10.34; N, 6.76.

( Example : Organic photoelectric device  Produce)

( Example  One)

A first electrode was formed on a glass substrate having a size of 15 Ω / cm ² , 1200 Å by Corning Corporation using ITO and having a size of 20 mm × 20 mm × 0.7 mm.

The substrate on which the first electrode was formed was ultrasonically cleaned for 5 minutes in isopropyl alcohol and pure water, followed by UV ozone cleaning for 30 minutes.

Poly (ethylenedioxy) thiophene (PEDOT) was spin-coated on the first electrode. An emission layer was formed on the PEDOT.

As the host material of the light emitting layer, poly vinylcarbazole (PVK) and 4,4'-N, N'-dicarbazolebiphenyl (4,4'-N, N'-dicarbazolebiphenyl, CBP) are 1: A mixture of 1 was used, and each of the organometallic complex compounds prepared in Preparation Example 1 was used as a dopant 7%. The light emitting layer was spin coated to a thickness of 500 kPa.

Bis (2-methyl-8-quinolinolate) -4- (phenylphenolate) aluminum (bis (2-methyl-8-quinolinolate) -4- (phenylphenolate) aluminum, BAlq) was vacuum deposited on the light emitting layer. A hole blocking layer having a thickness of 50 μs was formed. Subsequently, tris (8-hydroxy-quinolate) aluminum (Alq ₃ ) was vacuum deposited on the hole blocking layer to form an electron transport layer having a thickness of 200 Å.

An organic photoelectric device was manufactured by sequentially vacuum depositing LiF to a thickness of 10 kW as an electron injection layer on the electron transport layer and to a thickness of 1000 kW of Al as a second electrode.

( Example  2)

An organic photoelectric device was manufactured in the same manner as in Example 1, except that the organometallic complex compound prepared in Preparation Example 2 was used as a dopant.

( Comparative example  One)

Except for using tris (2-4 (4-tolyl) phenylpyridine) iridium (tris (2-4 (4-tolyl) phenylpyridine) iridium, Ir (mppy) ₃ ) as a dopant, the same procedure as in Example 1 To produce an organic photoelectric device.

( Organic photoelectric device  Performance measurement)

In order to understand the characteristics of the fabricated organic photoelectric device, the initial driving voltage (turn-on voltage), the driving voltage (V), the luminous efficiency (cd / A) and the power efficiency (lm / at a luminance of 1000 cd / m ² W) was measured, and the results are shown in Table 1 below.

In addition, the PL intensity (photoluminescence intensity) of the organometallic complex compounds prepared in Preparation Example 1, Preparation Example 2, and Comparative Example 1 was measured, and the results are also shown in Table 1 below.

TABLE 1

compound PL intensity (nm) Initial drive voltage (V) Luminance (at 1000cd / m ² ) Color coordinates (x, y) Drive voltage (V) Luminous Efficiency (cd / A) Power efficiency (lm / W) Max Luminous Efficiency (cd / A) Max Power Efficiency (lm / W) Comparative Example 1 (Ir (mppy) ₃ ) 516 4.40 8.20 16.16 6.19 16.21 6.79 0.31, 0.61 Example 1 (Formula 14) 512 4.40 8.40 20.02 7.49 20.69 10.85 0.35, 0.60 Example 2 (Formula 15) 513 4.40 8.40 15.08 5.64 15.67 6.82 0.34, 0.60

Referring to Table 1, although the organic photoelectric device of Examples 1 and 2 is an organic photoelectric device manufactured by a spin coating method, which is a wet process rather than a vacuum deposition method, the color coordinates are from (x, y) = (0.35, 0.60) to (x, y) = (0.34, 0.60) is emitting light corresponding to pure green, the luminous efficiency at 1000cd / m ² is 20.69 cd / A to 15.67 cd / A Ir (mppy) of Comparative Example 1 Better than ₃ or equivalent.

In addition, the organic photoelectric device of Examples 1 and 2 showed a power efficiency of 7.49 lm / w to 5.64 lm / w, which is superior to or equivalent to that of the organic photoelectric device of Comparative Example 1.

In addition, the organic photoelectric devices of Examples 1 and 2 have very low initial driving voltage of 4.4 V, and the maximum luminous efficiency and the maximum power efficiency were also better than or equal to those of the organic photoelectric device of Comparative Example 1.

As described above, the organic photoelectric device using the organometallic complex compound according to the embodiment of the present invention introduces a benzimidazole compound having a bulk steric structure into the ligand of the metal complex compound, thereby resulting in an intermolecular distance. As the crystallinity is reduced and the intermolecular interaction is suppressed, electrical characteristics such as power efficiency or initial driving voltage, and light emission characteristics are improved.

Also, green Ir (ppy) ₃ (where ppy is 2-phenylpyridine) or Ir (ppy) ₂ (acac) (where ppy is 2-phenylpyridine) is known among the phosphorescent organic metal complex compounds. Unlike 2-phenylpyridine, and acac is pentane-2,4-dione, the organometallic complex compound of the present invention is very soluble in organic solvents such as toluene, chloroform and chlorobenzene even at room temperature. Good solubility characteristics were shown.

Therefore, the organometallic complex compound according to the embodiment of the present invention is expected to be useful as a light emitting material of the organic photoelectric device.

The present invention is not limited to the above embodiments, but may be manufactured in various forms, and a person skilled in the art to which the present invention pertains has another specific form without changing the technical spirit or essential features of the present invention. It will be appreciated that the present invention may be practiced as. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

1 is an exploded perspective view of an organic photoelectric device according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: organic photoelectric device 10: organic thin film layer

11 substrate 12 first electrode

13: first buffer layer 14: light emitting layer

15: second buffer layer 16: second electrode

Claims (11)

A metal complex compound for an organic photoelectric device, represented by the following Chemical Formula 1, comprising a benzimidazole derivative ligand. [Formula 1]

(In Formula 1, N is an integer of 1 to 3, M is a metal forming an octahedral complex, L is a monovalent anionic bidentate ligand coordinated to M through sp ² carbon and a heteroatom, or a monovalent anionic bidentate ligand coordinated to M through heteroatom and heteroatom, R ₁ to R ₅ are each independently a hydrogen atom, a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, substituted or unsubstituted A substituent selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted amino group having 2 to 20 carbon atoms, and a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, R ₁ to R ₅ are each present as an independent substituent, or are fused with each other to form a ring, R ₆ is a halogen atom, a nitro group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted Or an unsubstituted amino group having 2 to 20 carbon atoms and a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and n ₆ is an integer of 0 to 4, The substituted is any one selected from the group consisting of a halogen atom, a cyano group, a hydroxy group, an amino group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms. Substituted with a substituent of) The method of claim 1, At least one of the R ₁ to R ₄ is a substituted or unsubstituted carbazole group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted biarylphenyl group, and combinations thereof An organometallic complex compound for an organic photoelectric device which is an aryl group having 1 to 30 carbon atoms substituted with any one substituent selected from the group consisting of. The method of claim 1, At least one of the R ₁ to R ₅ is any one selected from the group consisting of a substituent represented by the formula 2 to 6 organometallic complex compound for an organic photoelectric device. [Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

(In Chemical Formulas 2 to 6 X ₂₁ to X ₂₈ , X ₃₁ to X ₃₈ , and X ₅₁ to X ₆₆ are each independently any one selected from the group consisting of CR ₁₈ , and N, R ₁₈ and R ″ are each independently a hydrogen atom, a halogen atom, R ₁₆ , OR ₁₆ , N (R ₁₆ ) ₂ , P (R ₁₆ ) ₂ , P (OR ₁₆ ) ₂ , POR ₁₆ , PO ₂ R ₁₆ , PO ₃ R ₁₆ , SR ₁₆ , Si (R ₁₆ ) ₃ , Si (CH ₃ ) ₂ R ₁₆ , Si (Ph) ₂ R ₁₆ , B (R ₁₆ ) ₂ , B (OR ₁₆ ) ₂ , C ( O) R ₁₆ , C (O) OR ₁₆ , C (O) N (R ₁₆ ) ₂ , CN, NO ₂ , SOR ₁₆ , SO ₂ R ₁₆ , and SO ₃ R ₁₆ , R ₁₆ is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted carbon atom 1 to 30 Is a heteroalkyl group selected from the group consisting of a substituted or unsubstituted aryl group having 3 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms, R 'is a group consisting of a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylene group having 2 to 30 carbon atoms, and a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms. Is any one selected from Ar ₁ to Ar ₄ is any one selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, The substituted is any one selected from the group consisting of a halogen atom, a cyano group, a hydroxy group, an amino group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms. Substituted with a substituent of) The method of claim 1, Wherein L is any one selected from the group consisting of a ligand represented by the formula 7 to 13 metal complex compound for an organic photoelectric device. [Formula 7] [Formula 8] [Formula 9] [Formula 10]

    [Formula 11] [Formula 12] [Formula 13]

(In the above formulas 7 to 13, R ₁ to R ₃ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted fluorene group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted biarylphenyl group , R ₁₆ , OR ₁₆ , N (R ₁₆ ) ₂ , P (R ₁₆ ) ₂ , P (OR ₁₆ ) ₂ , POR ₁₆ , PO ₂ R ₁₆ , PO ₃ R ₁₆ , SR ₁₆ , Si (R ₁₆ ) ₃ , Si (CH ₃ ) ₂ R ₁₆ , Si (Ph) ₂ R ₁₆ , B (R ₁₆ ) ₂ , B (OR ₁₆ ) ₂ , C (O) R ₁₆ , C (O) OR ₁₆ , C (O) Any one selected from the group consisting of N (R ₁₆ ) ₂ , CN, NO ₂ , SO ₂ , SOR ₁₆ , SO ₂ R ₁₆ , and SO ₃ R ₁₆ , R ₁₆ is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted carbon group 1 to 30 Any one selected from the group consisting of 30 heteroalkyl groups, substituted or unsubstituted aryl groups having 3 to 40 carbon atoms, and substituted or unsubstituted heteroaryl groups having 3 to 40 carbon atoms, N ₁ is an integer of 1 to 3, n ₂ , n ₄ , and n ₅ are an integer of 1 to 4, n ₃ is an integer of 1 to 2, The substituted is any one selected from the group consisting of a halogen atom, a cyano group, a hydroxy group, an amino group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms. Substituted with a substituent of) The method of claim 1, M is an organometallic complex compound for an organic photoelectric device, which is any one element selected from the group consisting of Group 9 elements and Period 10 elements of the periodic table. The method of claim 5, The M is an organometallic complex compound for an organic photoelectric device which is any one element selected from the group consisting of Ir, Pt, Rh, and Pd. The method of claim 1, The organometallic complex compound for an organic photoelectric device represented by Formula 1 is any one selected from the group consisting of a compound represented by Formula 14 and a compound represented by Formula 15. [Formula 14]

[Formula 15]

An organic thin film layer positioned between the pair of electrodes, The organic thin film layer is an organic photoelectric device comprising an organometallic complex compound according to any one of claims 1 to 7. The method of claim 8, The organic thin film layer includes a light emitting layer including the organometallic complex compound as a dopant, The dopant is contained in 1 to 10% by weight relative to the entire light emitting layer. The method of claim 8, The organic thin film layer further comprises any one layer selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, and a combination thereof. The method of claim 8, The organic thin film layer is an organic photoelectric device further comprises any one selected from the group consisting of an electron injection layer, an electron transport layer, an electron blocking layer, and combinations thereof.

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