An organic metal complex and an organic photoelectric element containing the same

Abstract

The present invention provides an iridium metal complex and an organic photoelectric element containing the same, in particular an organic electroluminescent diode, wherein the structure of the iridium metal complex is shown in formula (I): #imgabs0# wherein X1 and X2 are C and N or N and C; (L^Z) is an auxiliary ligand, which is a bidentate ligand, which is the same as or different from the main ligand on the left side of the above structural formula; the detailed information of the iridium metal complex and the organic photoelectric element shown in formula (I) can be understood through the specific description provided herein. The iridium metal complex provided by the present invention can obtain a high-efficiency, long-life OLED device, and has a good commercial application prospect.

Description

Technical Field

[0001] The invention belongs to the field of organic photoelectricity, and specifically relates to a metal complex and a photoelectric element containing the metal complex, in particular to an organic electroluminescent diode. Background Art

[0002] As a new type of display technology, organic light-emitting diodes (OLEDs) have the unique advantages of self-luminescence, wide viewing angle, low energy consumption, high efficiency, thinness, rich colors, fast response speed, wide applicable temperature range, low driving voltage, flexible, bendable and transparent display panels, and environmental friendliness. They can be used in flat-panel displays and new generation lighting, and can also be used as LCD backlight sources.

[0003] Since its invention in the late 1980s, organic electroluminescent devices have been used in industry. OLED light emission is divided into two modes: fluorescence and phosphorescence. According to theoretical speculation, the ratio of singlet excited state to triplet excited state formed by charge recombination is 1:3. Small molecule fluorescent materials can utilize 25% of the energy, and the remaining 75% of the energy is lost due to the non-luminescent mechanism of triplet excited state. Therefore, it is generally believed that the internal quantum efficiency limit of fluorescent materials is 25%. In 1998, Professor Baldo and Forrest and others discovered that triplet phosphorescence can be used at room temperature and raised the upper limit of the original internal quantum efficiency to 100%. Triplet phosphorescent materials are often metal complexes composed of heavy metal atoms. Using the heavy atom effect, the strong spin-orbit coupling effect makes the originally prohibited triplet energy emit in the form of phosphorescence, and the quantum efficiency is greatly improved.

[0004] At present, almost all the light-emitting layers in organic OLED components use the host-guest light-emitting system, that is, the guest light-emitting material is doped in the host material. Generally speaking, the energy system of the organic host material is larger than that of the guest material, that is, the energy is transferred from the host to the guest, so that the guest material is excited and emits light. The commonly used organic guest material is iridium metal compound. At present, iridium metal compound has become the mainstream in commercial OLED materials, but there are still some technical difficulties, such as OLED requires high efficiency, long life, and lower operating voltage.

[0005] The present invention finds that by changing the structure of the iridium metal compound ligand and introducing a specific OBO-containing ring structure (such as Figure 2 As shown), substituents, etc. can improve the luminous efficiency of the iridium metal compound, while improving the thermal stability and rigidity of the iridium metal compound. Applying such iridium metal compounds to organic optoelectronic devices, especially in organic electroluminescent devices, can improve current efficiency, reduce the operating voltage of components, and obtain long-life organic optoelectronic components. Summary of the invention

[0006] The object of the present invention is to provide an iridium metal complex and an optoelectronic component comprising the same, in particular an organic light-emitting diode.

[0007] The present invention provides an iridium metal complex, characterized in that the structure of the iridium metal complex is as shown in formula (I):

[0008]

[0009] Wherein, X1 and X2 are C and N or N and C; R is independently selected from hydrogen, deuterium, halogen, C1-C18 alkyl, C1-C18 alkoxy, C1-C18 alkylsilyl, C1-C18 alkoxysilyl, C6-C40 aryl, C1-C40 heteroaryl, substituted or unsubstituted aryl ether, substituted or unsubstituted heteroaryl ether, substituted or unsubstituted arylamine, substituted or unsubstituted heteroarylamine, substituted or unsubstituted arylsilyl, substituted or unsubstituted heteroarylsilyl, any one of substituted or unsubstituted aryloxysilyl, substituted or unsubstituted arylacyl, substituted or unsubstituted heteroarylacyl, substituted or unsubstituted phosphinyl; (L^Z) is an auxiliary ligand, which is a bidentate ligand, which is the same as or different from the main ligand on the left side of the above structural formula; all groups may be partially deuterated or fully deuterated; m is selected from 1, 2 or 3, m+n'=3; heteroaryl refers to containing at least one heteroatom among B, N, O, S, P(=O), Si, P; all groups may be partially deuterated or fully deuterated.

[0010] Preferably, in the iridium metal complex formula (I) of the present invention, (L^Z) is selected from one of the following representative structural formulas, but is not limited thereto:

[0011]

[0012] Wherein, Y is selected from O or N; R1 to R3 are independently selected from C1~C18 alkyl, C1~C18 alkoxy, C1~C18 alkylsilyl, C1~C18 alkoxysilyl, C6~C40 aryl, C1~C40 heteroaryl; A2 and B2 are cyclic or non-cyclic selected from C1~C60 alkyl, C1~C60 alkoxy, C1~C60 alkylsilyl, C1~C60 alkoxysilyl, C6~C40 aryl, C1~C40 heteroaryl, A2 and B2 can be mono-substituted or poly-substituted according to the valence bond principle.

[0013] The iridium metal complex structural formula (I) is selected from the following representative structures:

[0014]

[0015] Preferably, in the iridium metal complex of the present invention, A2 and B2 in the iridium metal complex structural formula (I) are selected from one of the following representative structural formulas, but are not limited thereto:

[0016]

[0017] Preferably, in the iridium metal complex of the present invention, (L^Z) in formula (I) is selected from one of the following representative structural formulas, but is not limited thereto:

[0018]

[0019] Wherein, X is selected from NR1, O, S, CR1R2, SiR1R2, O=P-R1 or B-R1; R1 to R3 are independently selected from C1~C18 alkyl, C1~C18 alkoxy, C1~C18 alkylsilyl, C1~C18 alkoxysilyl, C6~C40 aryl, C1~C40 heteroaryl, and may be partially deuterated or fully deuterated.

[0020] Preferably, the iridium metal complex of the present invention is selected from one of the following representative structural formulas, but is not limited thereto:

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[0071] The present invention relates to an iridium metal complex comprising a compound of formula (I) and one or more solvents. The solvent used is not particularly limited. The solvents well known to those skilled in the art can be used, for example, toluene, xylene, mesitylene, tetralin, decalin, bicyclohexane, n-butylbenzene, sec-butylbenzene, tert-butylbenzene and other unsaturated hydrocarbon solvents, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane, chloropentane, bromopentane, hexyl chloride, bromohexane, chlorocyclohexane, bromocyclohexane and other halogenated saturated hydrocarbon solvents, chlorobenzene, dichlorobenzene, trichlorobenzene and other halogenated unsaturated hydrocarbon solvents, tetrahydrofuran, tetrahydropyran and other ether solvents, benzoic acid alkyl esters and other ester solvents.

[0072] The present invention also relates to an organic photoelectric device, comprising: a first electrode;

[0073] a second electrode, facing the first electrode;

[0074] An organic functional layer, sandwiched between the first electrode and the second electrode;

[0075] Wherein, the organic functional layer contains the iridium metal complex.

[0076] The present invention also relates to an organic electroluminescent device, comprising a cathode layer, an anode layer and an organic layer, wherein the organic layer comprises at least one of a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron injection layer and an electron transport layer, wherein the light-emitting layer of the device contains the iridium metal complex.

[0077] The organic electroluminescent device light-emitting layer of the present invention contains the iridium metal complex and the corresponding main material, wherein the mass percentage of the iridium metal complex is 0.1%-60%.

[0078] The organic electroluminescent device described in the present invention is any one of an organic photovoltaic device, an organic light emitting device (OLED), an organic solar cell (OSC), an electronic paper (e-paper), an organic photoreceptor (OPC), an organic thin film transistor (OTFT) and an organic memory element (Organic Memory Element), a lighting device and a display device.

[0079] In the present invention, the organic photoelectric device can be prepared by evaporating metal or conductive oxides and their alloys on a substrate to form an anode by using a method such as sputtering coating, electron beam evaporation, vacuum evaporation, etc.; a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer and an electron transport layer are sequentially evaporated on the surface of the prepared anode, and then a cathode is evaporated. In addition to the above method, an organic electroluminescent device is prepared by evaporating a cathode, an organic layer, and an anode on a substrate in sequence. The organic layer may also include a multilayer structure such as a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer and an electron transport layer. In the present invention, the organic layer is prepared by using a polymer material according to solvent engineering (spin-coating, tape-casting, doctor-blading, screen-printing, inkjet printing or thermal-imaging, etc.) instead of the evaporation method, which can reduce the number of device layers.

[0080] The materials used in the organic electroluminescent device according to the present invention can be divided into top emission, bottom emission or double-sided emission. The compounds of the organic electroluminescent device according to the embodiment of the present invention can be applied to organic solar cells, OLED for lighting, flexible OLED, organic photoreceptors, organic thin film transistors and other electroluminescent devices based on the similar principles of organic light-emitting devices.

[0081] Beneficial effects of the present invention:

[0082] The iridium metal compounds involved in the present invention all have high luminous efficiency. The iridium metal compounds involved in the present invention have good electron and hole receiving capabilities and can improve the energy transmission between the host and the object. Specifically, the organic electroluminescent device made using the iridium metal compound of the present invention as a functional layer, especially as a light-emitting layer, has improved current efficiency and reduced lighting voltage. At the same time, the life of the device is greatly improved, indicating that after most electrons and holes recombine, the energy is effectively transferred to the iridium metal compound for luminescence rather than heat generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 This is a diagram of the structure layer of the organic electroluminescent diode device of the present invention.

[0084] Among them, 110 represents a substrate, 120 represents an anode, 130 represents a hole injection layer, 140 represents a hole transport layer, 150 represents a light-emitting layer, 160 represents a hole blocking layer, 170 represents an electron transport layer, 180 represents an electron injection layer, and 190 represents a cathode.

[0085] Figure 2 The HOMO and LUMO diagrams of the compound Ir-2 of the present invention and the comparative compound Ir-1 obtained by theoretical calculation are shown in FIG. DETAILED DESCRIPTION

[0086] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0087] In a preferred embodiment of the present invention, the OLED device of the present invention contains a hole transport layer, and the hole transport material can be preferably selected from known or unknown materials, and is particularly preferably selected from the following structures, but it does not mean that the present invention is limited to the following structures:

[0088]

[0089] In a preferred embodiment of the present invention, the hole transport layer contained in the OLED device of the present invention comprises one or more p-type dopants. The preferred p-type dopant of the present invention is the following structure, but it does not mean that the present invention is limited to the following structure:

[0090]

[0091] In a preferred embodiment of the present invention, the electron transport layer can be selected from at least one of compounds ET-1 to ET-13, but this does not mean that the present invention is limited to the following structure:

[0092]

[0093] The present invention also provides a preparation comprising the composition and a solvent. The solvent used is not particularly limited, and can be unsaturated hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexane, n-butylbenzene, sec-butylbenzene, tert-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, butyl chloride, butyl bromide, pentyl chloride, pentyl bromide, hexyl chloride, hexyl bromide, cyclohexyl chloride, cyclohexyl bromide, halogenated unsaturated hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, ether solvents such as tetrahydrofuran, tetrahydropyran, and ester solvents such as alkyl benzoate. The preparation is directly used to prepare optoelectronic devices.

[0094] Hereinafter, according to the existing literature and the inventor's related technical reserves, the general synthesis steps of the guest compound involved in formula (I) are as follows:

[0095]

[0096] Ligand 1 General steps,

[0097] (1) Under argon protection, a mixed solution of ligand 1 or L^Z (0.10 mol), IrCl3.3H2O (0.045 mol), 2-ethoxyethanol (300 ml) and water (100 ml) was heated to reflux for 16 to 20 hours until the supernatant was taken and the content of ligand 1 was less than 5% by high performance liquid chromatography. The heating was stopped, the temperature was lowered to room temperature, and the filter cake was filtered with a Buchner funnel. The filter cake was rinsed with a mixture of water and 2-ethoxyethanol and dried to obtain a powder solid bridged dimer with a yield of 41 to 78%.

[0098] (2) Add the dichloro bridged dimer complex (2.2 mmol), ligand L^Z or ligand 1 (2.4 mmol), anhydrous sodium carbonate (1.2 g, 10.8 mmol) and 80 ml of 2-ethoxyethanol into a double-necked round-bottom flask, and then heat and reflux for 6 hours. Stop heating, cool to room temperature, add an appropriate amount of distilled water, and filter out the solid. Dissolve the solid in dichloromethane and pass through a short silica gel column. Remove the solvent under reduced pressure, and concentrate the solid to obtain a final target product by washing with methanol and petroleum ether.

[0099] The preparation method of the iridium metal compound, i.e., the guest compound, and the luminescent properties of the device are explained in detail in conjunction with the following examples. Ligand 1 is obtained by custom synthesis. However, these are only used to illustrate the embodiments of the present invention, so the scope of the present invention is not limited thereto.

[0100] Example 1: Synthesis of Compound 1

[0101]

[0102] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 55%;

[0103] H NMR (400 MHz): 0.99 (t, 12H), 1.03 (q, 8H), 1.12 (s, 6H), 5.08 (s, 1H), 6.98-7.02 (m, 4H), 7.08 (d, 2H), 7.22-7.40 (m, 8H), 8.69 (d, 2H), 9.25 (d, 2H); mass spectrum m / z, theoretical value 972.31; found value M+H: 973.47.

[0104] Example 2: Synthesis of Compound 2

[0105]

[0106] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 49%. Mass spectrum m / z, theoretical value 1140.50; measured value M+H: 1141.61.

[0107] Example 3: Synthesis of Compound 3

[0108]

[0109] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 47%. Mass spectrum m / z, theoretical value 1092.38; measured value M+H: 1093.45.

[0110] Example 4: Synthesis of Compound 4

[0111]

[0112] Referring to the general synthetic route, L^Z represents n-pentane-2,4-dione, and the yield of the final product is 67%. Mass spectrum m / z, theoretical value 832.15; measured value M+H: 833.27.

[0113] Example 5: Synthesis of Compound 5

[0114]

[0115] Referring to the general synthetic route, L^Z represents n-pentane-2,4-dione, and the yield of the final product is 71%. Mass spectrum m / z, theoretical value 832.15; measured value M+H: 833.27.

[0116] Example 6: Synthesis of Compound 6

[0117]

[0118] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 65%; mass spectrum m / z, theoretical value 972.31; measured value M+H: 973.45.

[0119] Example 7: Synthesis of Compound 7

[0120]

[0121] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 61%. Mass spectrum m / z, theoretical value 1140.50; measured value M+H: 1141.63.

[0122] Example 8: Synthesis of Compound 8

[0123]

[0124] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 64%. Mass spectrum m / z, theoretical value 1092.38; measured value M+H: 1093.43.

[0125] Example 9: Synthesis of Compound 9

[0126]

[0127] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 69%. Mass spectrum m / z, theoretical value 1028.37; measured value M+H: 1029.48.

[0128] Example 10: Synthesis of Compound 10

[0129]

[0130] Referring to the general synthetic route, L^Z represents 3,7-diethyl-3,7-methylnonane-4,6-dione, and the yield of the final product is 63%. Mass spectrum m / z, theoretical value 1028.37; measured value M+H: 1029.45.

[0131] Example 11: Synthesis of Compound 11

[0132]

[0133] Referring to the synthetic route in invention patent 202010373366.9, the yield of the final product is 73%. Mass spectrum m / z, theoretical value 900.19; measured value M+H: 901.1.

[0134] Example 12: Synthesis of Compound 12

[0135]

[0136] Referring to the synthetic route in invention patent 202010373366.9, the yield of the final product is 62%. Mass spectrum m / z, theoretical value 1087.27; measured value M+H: 1088.3.

[0137] Fabrication of OLED devices:

[0138] A p-doped material is evaporated on the surface of an ITO glass or an anode with a light-emitting area of ​​2mm×2mm, or the p-doped material is co-evaporated with the compound described in the table at a concentration of 1% to 50% to form a 5-100 nanometer hole injection layer (HIL), a 5-200 nanometer hole transport layer (HTL), and then a 10-100 nanometer light-emitting layer (EML) (which may contain the compound) is formed on the hole transport layer. Finally, an electron transport layer (ETL) of 20-200 nanometers and a cathode of 50-200 nanometers are formed in sequence with the compound described. If necessary, an electron blocking layer (EBL) is added between the HTL and EML layers, and an electron injection layer (EIL) is added between the ETL and the cathode to manufacture an organic light-emitting element.

[0139]

[0140] In the specific embodiment, the structure of the bottom-emitting OLED device is on glass containing ITO, the HIL is HT-1:P-3 (95:5, v / v%), with a thickness of 10 nanometers; the HTL is HT-1, with a thickness of 90 nanometers; the EBL is HT-8, with a thickness of 10 nanometers, the EML is H-1:iridium metal compound (97:3, v / v%), with a thickness of 35 nanometers, and the ETL is ET-13:LiQ (50:50, v / v%), with a thickness of 35 nanometers, and then the cathode Al is evaporated to 70 nanometers. According to the above embodiments and comparative examples, the current efficiency, voltage, life and other characteristics are shown in Table 1 below.

[0141] Table 1

[0142]

[0143] It can be seen from Table 1 that, due to the incorporation of condensed rings into the ligand structure, Device Examples 1 to 6 exhibit good device performance, indicating that the iridium metal complex provided by the present invention has certain commercial application value.

[0144] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An iridium metal complex, characterized in that The structural formula of the iridium metal complex is shown in formula (I): Wherein, X1 and X2 are C and N or N and C; R n Independently selected from hydrogen, halogen, C1-C18 alkyl; m is 2 or 3, m+n'=3; all groups may be partially deuterated or fully deuterated; in the iridium metal complex formula (I), (L^Z) is selected from one of the following representative structural formulas: Wherein, R1 to R3 are independently selected from C1-C18 alkyl groups, which may be partially deuterated or fully deuterated.

2. An iridium metal complex, characterized in that The iridium metal complex is selected from one of the following representative structures:

3. A preparation, characterized in that The invention comprises the iridium metal complex according to any one of claims 1 to 2 and at least one solvent.

4. An organic optoelectronic device, characterized in that: include: a first electrode; A second electrode faces the first electrode; an organic functional layer is sandwiched between the first electrode and the second electrode; wherein the organic functional layer comprises the iridium metal complex according to any one of claims 1 to 2.

5. An organic photoelectric element, comprising a cathode layer, an anode layer and an organic layer, wherein the organic layer comprises at least one of a hole injection layer, a hole transport layer, a light emitting layer or an active layer, an electron injection layer and an electron transport layer, characterized in that: Any one layer of the element contains the iridium metal complex according to any one of claims 1 to 2.

6. The organic photoelectric element according to claim 5, characterized in that: The light-emitting layer contains the iridium metal complex according to any one of claims 1 to 2 and a corresponding host material, wherein the mass percentage of the iridium metal complex is 1% to 50%, and there is no restriction on the host material.

7. The organic optoelectronic device according to claim 4, characterized in that: Organic optoelectronic devices include organic light-emitting devices, electronic paper, organic photoreceptors, organic thin film transistors, lighting and display devices.

8. A display or lighting device, characterized in that: The display or lighting device contains the organic photoelectric element according to claim 5.

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