Iridium complexes and organic light-emitting devices

Abstract

The present invention discloses an iridium complex and an organic light-emitting device, belonging to the field of display technology. The chemical structure of the iridium complex is as follows: #imgabs0#p≥0, R m represents a first substituent, wherein the first substituent is selected from at least one of halogen, -CF3, -CN, substituted or unsubstituted C1-C6 alkyl; q≥0, R n represents a second substituent selected from at least one of halogen, -CF3, -CN, substituted or unsubstituted C1-C6 alkyl; t≥0, R a represents a third substituent, wherein the third substituent is selected from one of fluorine, -CF3, and -CN. When the iridium complex is used as a red light dopant, it not only more effectively improves the luminous efficiency and luminous lifetime, but also has stronger thermal stability.

Description

Technical Field

[0001] The present invention relates to the field of display technology, in particular to iridium complexes and organic light-emitting devices. Background Art

[0002] Organic light-emitting diodes (OLEDs) are semiconductor light-emitting devices based on organic light-emitting materials. OLED devices include a light-emitting layer based on the same material. By varying the material, the type of light emitted can be adjusted. Phosphorescent materials effectively utilize triplet excitons, theoretically increasing their internal quantum efficiency from 25% to 100% compared to fluorescent materials.

[0003] Iridium complex is a common organic electroluminescent phosphorescent material with the advantages of good phosphorescence emission, high phosphorescence emission efficiency, wide emission spectrum and strong stability. It is a widely used organic electroluminescent phosphorescent material.

[0004] However, due to the narrow energy gap of red-light iridium complexes, it is difficult to match the energy levels between the light-emitting layer and the carrier transport layer based on them, and concentration quenching is prone to occur. Therefore, it is necessary to improve red-light iridium complexes. Summary of the Invention

[0005] In view of this, the embodiments of the present invention provide an iridium complex and an organic light-emitting device, which can solve the above technical problems.

[0006] Specifically, the following technical solutions are included:

[0007] In one aspect, an iridium complex is provided, the chemical structural formula of the iridium complex being as follows:

[0008]

[0009] Where p≥0, R m represents a first substituent, wherein the first substituent is selected from at least one of halogen, -CF3, -CN, and a substituted or unsubstituted C1-C6 alkyl group;

[0010] q≥0, R n represents a second substituent, wherein the second substituent is selected from at least one of halogen, -CF3, -CN, and a substituted or unsubstituted C1-C6 alkyl group;

[0011] t≥0, R a represents a third substituent, wherein the third substituent is selected from one of fluorine, -CF3, and -CN.

[0012] In some possible implementations, for the substituted C1-C6 alkyl group, the corresponding substituent includes deuterium, halogen, -CF3 or -CN.

[0013] In some possible implementations, the first substituent R m The number is 1-3.

[0014] In some possible implementations, the first substituent R m The number of the first substituent R is 1. m Selected from -F, -CF3 or -CN.

[0015] In some possible implementations, the first substituent R m The number of is 2 or 3, and the 2 or 3 first substituents are the same or different;

[0016] The first substituent R m Selected from -F, -CF3 or -CN.

[0017] In some possible implementations, the second substituent R n The number of the second substituent R is 1-4. n When the number is multiple, the multiple second substituents R n Same or different;

[0018] The second substituent R n Selected from C1-C6 alkyl, -F, -CF3 or -CN.

[0019] In some possible implementations, the C1-C6 alkyl group includes methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl.

[0020] In some possible implementations, the third substituent R a The number is 1-2;

[0021] The third substituent R a When the number of the third substituent R is 1, a Located in the para or meta position;

[0022] The third substituent R a When the number is 2, the two third substituents R a are the same or different, and the two third substituents R a All are located in the intervening position.

[0023] In some possible implementations, the third substituent R a Selected from -F or -CF3.

[0024] On the other hand, an organic light-emitting device is provided. The organic light-emitting device includes a light-emitting layer. The raw materials for preparing the light-emitting layer include any one of the above-mentioned iridium complexes.

[0025] The beneficial effects of the technical solution provided by the embodiment of the present invention include at least:

[0026] The iridium complex provided in the embodiment of the present invention, combined with its chemical structure, can be seen that the iridium complex adopts a main ligand mainly composed of phenylbenzo[F]isoquinoline and an auxiliary ligand mainly composed of a dicarbonyl group, and the main ligand has a first substituent R m and the second substituent R n , the auxiliary ligand has a third substituent R a The combination of the main ligand and the auxiliary ligand makes the iridium complex, when used as a red light dopant, not only more effectively improve the luminescence efficiency and luminescence life, but also has stronger thermal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic structural diagram of an exemplary organic light-emitting device provided in an embodiment of the present invention.

[0029] The reference numerals represent:

[0030] 1- anode, 2- hole injection layer, 3- hole transport layer, 4- electron blocking layer, 5- light emitting layer,

[0031] 6-electron transport layer, 7-electron injection layer, 8-cathode. DETAILED DESCRIPTION

[0032] In order to make the technical solutions and advantages of the present application clearer, the implementation methods of the present application will be described in further detail below with reference to the accompanying drawings.

[0033] Organic light-emitting diodes (OLEDs) are semiconductor light-emitting devices based on organic light-emitting materials. OLED devices consist of at least a hole transport layer, a light-emitting layer, and an electron transport layer. Holes generated by the anode travel through the hole transport layer to the light-emitting layer, while electrons generated by the cathode travel through the electron transport layer to the light-emitting layer. The holes and electrons form excitons in the light-emitting layer, generating light. By varying the light-emitting material, the type of light emitted can be adjusted.

[0034] Typically, 25% of excitons are in the singlet excited state, and the remaining 75% are in the triplet excited state. The radiative transition pathways corresponding to these two excitons are singlet fluorescence and triplet phosphorescence, respectively. Phosphorescent materials can effectively utilize triplet excitons, and theoretically, the internal quantum efficiency of phosphorescent materials can be increased from 25% to 100% compared to fluorescent materials. Therefore, high-efficiency phosphorescent organic electroluminescent devices have attracted significant attention for their use in devices such as flat-panel displays and portable displays.

[0035] Common phosphorescent materials include red, green, and blue phosphorescent materials. Iridium complexes are a widely used class of organic electroluminescent phosphorescent materials. The high atomic number of iridium results in strong spin-orbit coupling in iridium complexes, which facilitates phosphorescence. The large d-orbital energy level splitting of the iridium metal ion prevents metal-ligand charge transfer (MLCT) interactions with the ligand, enhancing phosphorescence efficiency. The trivalent iridium ion forms a highly stable neutral molecule with the ligand, making it suitable for fabricating light-emitting devices using vacuum evaporation or solution processing. Iridium complexes emit light with colors that span the entire visible spectrum and exhibit excellent stability, meeting the requirements for electroluminescent materials. Consequently, iridium complexes, with their excellent phosphorescence properties, high efficiency, broad emission spectrum, and strong stability, have become a key research focus for organic electroluminescent phosphorescent materials.

[0036] However, due to the narrow energy gap of red-light iridium complexes, it is difficult to match the energy levels between the light-emitting layer and the carrier transport layer based on them, and concentration quenching is prone to occur. Therefore, it is necessary to improve red-light iridium complexes.

[0037] An embodiment of the present invention provides an iridium complex, the chemical structural formula of the iridium complex is as follows:

[0038]

[0039] Where p≥0, R m represents a first substituent, wherein the first substituent is selected from at least one of halogen, -CF3, -CN, and a substituted or unsubstituted C1-C6 alkyl group;

[0040] q≥0, R n represents a second substituent, wherein the second substituent is selected from at least one of halogen, -CF3, -CN, and a substituted or unsubstituted C1-C6 alkyl group;

[0041] t≥0, R a represents a third substituent, wherein the third substituent is selected from one of fluorine, -CF3, and -CN.

[0042] It can be understood that for the iridium complex provided in the embodiment of the present invention, The main ligand includes phenylbenzo[F]isoquinoline, which plays the role of electronic transition energy level. Wherein, the "*" in the chemical formula is the binding site of the group and iridium (Ir).

[0043] It is a dicarbonyl auxiliary ligand used to fine-tune the emission wavelength, improve sublimation properties, thermal stability, and enhance the luminous efficiency of the material. The "*" in the chemical formula represents the binding site of the group with iridium (Ir).

[0044] The iridium complex provided in the embodiment of the present invention, combined with its chemical structure, can be seen that the iridium complex adopts a main ligand mainly composed of phenylbenzo[F]isoquinoline and an auxiliary ligand mainly composed of a dicarbonyl group, and the main ligand has a first substituent R m and the second substituent R n , the auxiliary ligand has a third substituent R a The combination of the main ligand and the auxiliary ligand makes the iridium complex, when used as a red light dopant, not only more effectively improve the luminescence efficiency and luminescence life, but also has stronger thermal stability.

[0045] In some examples, p, q, and t are not 0 at the same time. For example, p, q, and t can all be non-zero; or, any one of p, q, and t can be 0, and the other two can be non-zero; or, any two of p, q, and t can be 0, and the other one can be non-zero.

[0046] In some examples, p is 0, 1, 2, 3, or 4, and t is 0, 1, 2, 3, or 4.

[0047] In some examples, q is 0, 1, 2, 3, or 4.

[0048] In some examples, p is 0, 1, or 2, and t is 0, 1, or 2.

[0049] As an example, p is 0 and t is 0, 1, or 2.

[0050] As an example, p is 1 and t is 0, 1 or 2, further, t is 1 or 2.

[0051] As an example, p is 2 and t is 0, 1 or 2.

[0052] In some examples, for the substituted C1-C6 alkyl mentioned above, the corresponding substituent includes deuterium, halogen, -CF3 or -CN, wherein the halogen includes fluorine, chlorine, bromine or iodine.

[0053] The C1-C6 alkyl mentioned above refers to a straight-chain or branched alkyl group containing 1-6 carbon atoms, including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 2,3-dimethylpropyl and 1-ethylpropyl, cyclopentyl, cyclohexyl, 2-methyl-3-pentyl, 3,3-dimethyl-2-butyl, etc.

[0054] Preferably, the C1-C6 alkyl group may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, or the like.

[0055] In the iridium complex provided by the embodiment of the present invention, the first substituent R m The number of the first substituent R is 1-3, that is, the first substituent R m The number of digits is 1, 2 or 3.

[0056] In some examples, the first substituent R m The number of substituents is 1, and the first substituent R m Selected from -F, -CF3 or -CN.

[0057] In other examples, the first substituent R m The number of R is 2 or 3, 2 or 3 first substituents R m are the same or different, and the first substituent R m Selected from -F, -CF3 or -CN.

[0058] In the iridium complex provided in the embodiment of the present invention, the second substituent R n The number of the second substituent R is 1-4, that is, n The number of the second substituent R is 1, 2, 3 or 4. n When the number of is multiple (ie ≥ 2), multiple second substituents R n The same or different; the second substituent R n Selected from C1-C6 alkyl, -F, -CF3 or -CN.

[0059] As a preferred example, the second substituent R n is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, -F, -CF3 or -CN.

[0060] In combination with the above description of the first substituent and the second substituent, the present invention provides some applicable primary ligands for the iridium complex. The chemical structural formulas of these primary ligands are as follows:

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] In some implementations, the third substituent R a The number of substituents is 1-2. For example, the third substituent R a When the number of the third substituent R is 1, a Located at the para or meta position. The third substituent R a When the number of is 2, the two third substituents R a Located at the meta position, and two third substituents R a Same or different.

[0067] In some examples, the third substituent R a Selected from -F or -CF3, this can further reduce the sublimation temperature, improve device stability and extend service life.

[0068] In combination with the above description of the third substituent, the present invention provides some suitable auxiliary ligands for the iridium complex. The chemical structural formulas of these auxiliary ligands are as follows:

[0069]

[0070]

[0071] The iridium complex provided in the embodiment of the present invention can be obtained by combining any one of the main ligands RD-1 to RD-90 with any one of the auxiliary ligands RP-1 to RP-24.

[0072] In some implementations, the following primary ligands and the following auxiliary ligands may be preferably combined to obtain an iridium complex with better overall performance. The primary ligand is selected from any one of RD-2, RD-3, RD-6, RD-10, RD-12, RD-15, RD-23, RD-32, RD-33, RD-45, RD-63, and RD-90; and the auxiliary ligand is selected from any one of RP-2, RP-4, RP-5, RP-10, RP-14, and RP-20.

[0073] The iridium complex obtained by combining the above-mentioned main ligand and auxiliary ligand is beneficial to improving the luminous efficiency, causing the spectrum to red-shift, and can be used as an infrared light source. It also has good stability and a long service life.

[0074] In some examples, the present invention provides some typical iridium complexes. The chemical structural formulas of these iridium complexes are shown below. In each of the following iridium complexes, the third substituent R a Selected from F or -CF3:

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] On the other hand, an embodiment of the present invention further provides a method for preparing an iridium complex, the method for preparing the iridium complex comprising:

[0085] A primary ligand compound and an auxiliary ligand compound are provided, wherein the primary ligand compound is used to provide a primary ligand for the iridium complex, and the auxiliary ligand compound is used to provide an auxiliary ligand for the iridium complex.

[0086] The primary ligand compound is reacted with trivalent iridium to prepare a dimer.

[0087] The dimer is reacted with an auxiliary ligand compound to obtain an iridium complex, wherein the reaction can be carried out in the presence of potassium carbonate or sodium carbonate.

[0088] The chemical structure of the main ligand compound is shown below:

[0089]

[0090] The chemical structure of the dimer is shown below:

[0091]

[0092] The chemical structure of the auxiliary ligand compound is shown below:

[0093]

[0094] In another aspect, an embodiment of the present invention further provides an organic light-emitting device, which includes a light-emitting layer, and a raw material for preparing the light-emitting layer includes the above-mentioned iridium complex.

[0095] The organic light-emitting device provided in an embodiment of the present invention is capable of emitting red light. Based on the use of the above-mentioned iridium complex including an oxygen-containing heterocycle, the luminous efficiency and luminous lifetime of the organic light-emitting device are significantly improved, and the organic light-emitting device also has stronger thermal stability.

[0096] The iridium complex can be used as a red light-emitting dopant, or emissive dopant, in the light-emitting layer, synergizing with the host luminescent material in the light-emitting layer to produce luminescence. In some examples, the mass ratio of the host luminescent material to the iridium complex is 90-99:5, for example, 91:5, 92:5, 93:5, 94:5, 95:5, 96:5, 97:5, etc.

[0097] Exemplarily, the host light-emitting material includes at least one of the following groups: triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, aza-dibenzoselenophene.

[0098] The organic light-emitting device provided by the embodiment of the present invention includes an anode, a cathode and an organic layer, wherein the organic layer includes at least a light-emitting layer, and the organic layer may further include at least one layer of a hole injection layer, a hole transport layer, a hole blocking layer, an electron injection layer, and an electron transport layer.

[0099] For example, if Figure 1 As shown, the organic light-emitting device provided by the embodiment of the present invention includes an anode 1, a hole injection layer 2, a hole transport layer 3, an electron blocking layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7 and a cathode 8 stacked in sequence from bottom to top, wherein the anode 1 is formed on a substrate, and the substrate can be, for example, a glass substrate, a ceramic substrate, etc.

[0100] The anode 1 , the hole injection layer 2 , the hole transport layer 3 , the electron blocking layer 4 , the electron transport layer 6 , the electron injection layer 7 and the cathode 8 can each be made of materials commonly used in the art and will not be described in detail here.

[0101] The hole injection layer 2, the hole transport layer 3, the electron blocking layer 4, the electron transport layer 6, and the electron injection layer 7 can be formed by vacuum evaporation, molecular beam evaporation, solvent-dissolved dip coating, spin coating, rod coating, and inkjet printing. The anode 1 and the cathode 8 can be prepared by evaporation or sputtering.

[0102] In some examples, the organic light-emitting device provided by the embodiments of the present invention can be used in any of the following electronic devices for display or light emission: computers, tablet computers, televisions, phones, virtual reality or augmented reality displays, etc.

[0103] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the examples, if specific techniques or conditions are not specified, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially. In the following examples, if not clearly stated, "%" refers to weight percentage.

[0104] Example 1

[0105] This embodiment 1 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-1. The preparation steps of the iridium complex RDP-1 and the related preparation equations are shown below.

[0106]

[0107] Prepare Equation 1

[0108] Referring to the preparation formula (1), 3.82 g of the primary ligand RD-2 and 2.02 g of iridium trichloride trihydrate were added to a round-bottom flask. Then, 30 mL of water and 90 mL of ethylene glycol ethyl ether were added. Under nitrogen, the mixture was refluxed and stirred at 115°C for 12 hours. Heating was then stopped. The resulting mixture was filtered, and the filter cake was collected. The filter cake was washed sequentially with water, ethanol, and methyl tert-ether to obtain a dark red iridium dimer. The resulting iridium dimer was added directly to a round-bottom flask without further treatment. 100 mL of dichloromethane was added, followed by 4.50 g of potassium carbonate and 7.20 g of the auxiliary ligand RP-2. The mixture was stirred at room temperature for 12 hours, and then stirring was stopped. The solvent in the product solution was evaporated to dryness, and 6.83 g of a red powdery solid was obtained by column chromatography, which was the iridium complex RDP-1. HPLC (iPrOH 10%, MeOH 90%, 1 mL / min, 365 nm) analysis showed that the purity of the iridium complex RDP-1 was 99.72%.

[0109] Example 2

[0110] This embodiment 2 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-5. The preparation formula of the iridium complex RDP-5 is shown below.

[0111]

[0112] Prepare Equation 2

[0113] Referring to Preparation Formula 2, according to the method described in Example 1, only the raw materials were replaced to obtain 7.06 g of a red powdery solid, namely, the iridium complex RDP-5. HPLC analysis showed that the purity of the iridium complex RDP-20 was 99.53%.

[0114] Example 3

[0115] This embodiment 3 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-20. The preparation formula of the iridium complex RDP-20 is shown below.

[0116]

[0117] Prepare Equation 3

[0118] Referring to Preparation Formula 3, according to the method described in Example 1, only the raw materials were replaced to prepare 6.44 g of a red powdery solid, namely, the iridium complex RDP-20. HPLC analysis showed that the purity of the iridium complex RDP-20 was 99.82%.

[0119] Example 4

[0120] This embodiment 4 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-41. The preparation formula of the iridium complex RDP-41 is shown below.

[0121]

[0122] Prepare Equation 4

[0123] Referring to Preparation Formula 4, according to the method described in Example 1, only the raw materials were replaced to prepare 6.89 g of red powdery solid, which is the iridium complex RDP-41. HPLC analysis showed that the purity of the iridium complex RDP-41 was 99.65%.

[0124] Example 5

[0125] This Example 5 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-31. The preparation formula of the iridium complex RDP-31 is shown below.

[0126]

[0127] Prepare Equation 5

[0128] Referring to Preparation Formula 5, according to the method described in Example 1, only the raw materials were replaced to prepare 6.39 g of a red powdery solid, namely, the iridium complex RDP-31. HPLC analysis showed that the purity of the iridium complex RDP-31 was 99.65%.

[0129] Example 6

[0130] This Example 6 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-49. The preparation formula of the iridium complex RDP-49 is shown below.

[0131]

[0132] Prepare Equation 6

[0133] Referring to Preparation Formula 6, according to the method described in Example 1, only the raw materials were replaced to prepare 4.22 g of a red powdery solid, namely, the iridium complex RDP-49. HPLC analysis showed that the purity of the iridium complex RDP-49 was 99.8%.

[0134] Example 7

[0135] This Example 7 provides an iridium complex, the chemical structural formula of which is shown in the above-mentioned RDP-50. The preparation formula of the iridium complex RDP-50 is shown below.

[0136]

[0137] Prepare Equation 7

[0138] Referring to Preparation Formula 7, according to the method described in Example 1, only the raw materials were replaced to prepare 5.31 g of a red powdery solid, namely, the iridium complex RDP-50. HPLC analysis showed that the purity of the iridium complex RDP-50 was 99.51%.

[0139] Application Example 1

[0140] In this application example 1, an organic electroluminescent device is prepared based on the iridium complex RD-1 prepared in Example 1, which includes the following layers stacked in sequence: glass / anode / hole injection layer / hole transport layer / electron blocking layer / luminescent layer / electron transport layer / electron injection layer / cathode.

[0141] The preparation method of the organic electroluminescent device is as follows:

[0142] (1) A transparent conductive ITO glass substrate with an anode (China Southern Glass Group Co., Ltd.) was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, and then washed in ethanol, acetone, and deionized water in sequence. It was baked in a clean environment to completely remove moisture, cleaned with ultraviolet photosynthetic ozone, and then treated with oxygen plasma for 30 seconds.

[0143] (2) The transparent conductive ITO glass substrate with the anode after the above pretreatment is placed in a vacuum chamber, evacuated, and the compound HIL is evaporated on the surface of the ITO anode as a hole injection layer at a deposition rate of 0.1 nm / s.

[0144] (3) Compound HT was evaporated on the surface of the hole injection layer to form a hole transport layer with a thickness of 100 nm. The evaporation rate was 0.1 nm / s.

[0145] (4) Compound EB was evaporated on the surface of the hole transport layer to form an electron blocking layer with a thickness of 10 nm. The evaporation rate was 0.1 nm / s.

[0146] (5) A 40 nm thick light-emitting layer was evaporated on the surface of the electron blocking layer, wherein 95% by weight of compound RH was used as the main light-emitting material and 5% by weight of iridium complex RD-25 was used as the doping guest material at an evaporation rate of 0.1 nm / s.

[0147] (6) A 35 nm thick compound ET:Liq (weight ratio of 50:50) was evaporated on the surface of the light-emitting layer as an electron transport layer at a deposition rate of 0.1 nm / s.

[0148] (7) LiQ with a thickness of 1 nm was evaporated on the surface of the electron transport layer as the electron injection layer and Al with a thickness of 100 nm was evaporated as the cathode.

[0149] The chemical structures of the compounds involved in the organic electroluminescent device are shown below:

[0150]

[0151] Comparative Example 1

[0152] The difference between Comparative Example 1 and Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by compound Ir-1.

[0153] The chemical structure of compound Ir-1 is shown below:

[0154]

[0155] Comparative Example 2

[0156] The difference between Comparative Example 2 and Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by compound Ir-2.

[0157] The chemical structure of compound Ir-2 is shown below:

[0158]

[0159] Application Example 2

[0160] The difference from Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by the iridium complex RDP-5, and the other preparation processes are the same.

[0161] Application Example 3

[0162] The difference from Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by the iridium complex RDP-20, and the other preparation processes are the same.

[0163] Application Example 4

[0164] The difference from Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by the iridium complex RDP-41, and the other preparation processes are the same.

[0165] Application Example 5

[0166] The difference from Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by the iridium complex RDP-31, and the other preparation processes are the same.

[0167] Application Example 6

[0168] The difference from Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by the iridium complex RDP-49, and the other preparation processes are the same.

[0169] Application Example 7

[0170] The difference from Application Example 1 is that, when preparing the organic electroluminescent device, the iridium complex RDP-1 is replaced by the iridium complex RDP-50, and the other preparation processes are the same.

[0171] Test Case

[0172] Based on the Photo Research PR650 spectrometer, the above-mentioned organic electroluminescent devices were tested at 10mA / cm 2 The working voltage, current efficiency and CIE coordinates under the current density of 50mA / cm 2The LT(150) value is the ratio of the luminance after 150 hours of operation at a current density of 1000 nm to the initial luminance, where the initial luminance is defined as 100%. The LT(150) value represents the degree of luminance decay relative to the initial luminance after 150 hours of operation, and thus characterizes the stability of the organic electroluminescent device. The test results are shown in Table 1.

[0173] Table 1

[0174] project Iridium complexes Voltage (V) Current efficiency (cd / A) LT(150)(%) Example 1 RDP-1 3.42 21.73 92.29 Example 2 RDP-5 3.43 22.88 93.54 Example 3 RDP-20 3.54 21.06 91.61 Example 4 RDP-41 3.48 22.49 93.37 Example 5 RDP-31 3.38 24.04 96.50 Example 6 RDP-49 3.45 21.22 96.13 Example 7 RDP-50 3.56 20.68 90.39 Comparative Example 1 Ir-1 3.51 18.37 75.65 Comparative Example 2 Ir-2 3.64 15.73 81.90

[0175] As can be seen from Table 1, by using the iridium complex provided by the embodiment of the present invention, the operating voltage of the organic electroluminescent device can be reduced, the luminous efficiency can be improved, the stability of the device can be improved, and the device life can be effectively extended.

[0176] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An iridium complex, characterized in that The chemical structural formula of the iridium complex is shown below: Where p is 0, 1, 2, 3 or 4, R m represents a first substituent, wherein the first substituent is selected from at least one of halogen, -CF3, -CN, and a substituted or unsubstituted C1-C6 alkyl group; q is 0, 1, 2, 3, or 4, R n represents a second substituent, wherein the second substituent is selected from at least one of halogen, -CF3, -CN, and a substituted or unsubstituted C1-C6 alkyl group; t is 1 or 2, R a represents a third substituent, wherein the third substituent is selected from one of fluorine and -CF3; The third substituent R a When the number of the third substituent R is 1, a Located in the para or meta position; The third substituent R a When the number is 2, the two third substituents R a are the same or different, and the two third substituents R a All are located in the metaposition; For substituted C1-C6 alkyl, the corresponding substituent is deuterium, halogen, -CF3 or -CN.

2. The iridium complex according to claim 1, characterized in that The first substituent R m The number is 1-3.

3. The iridium complex according to claim 2, characterized in that The first substituent R m The number of the first substituent R is 1. m Selected from -F, -CF3 or -CN.

4. The iridium complex according to claim 2, characterized in that The first substituent R m The number of is 2 or 3, and the 2 or 3 first substituents are the same or different; The first substituent R m Selected from -F, -CF3 or -CN.

5. The iridium complex according to claim 1, characterized in that The second substituent R n The number of the second substituent R is 1-4. n When the number is multiple, the multiple second substituents R n Same or different; The second substituent R n Selected from C1-C6 alkyl, -F, -CF3 or -CN.

6. The iridium complex according to claim 5, characterized in that The C1-C6 alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tert-butyl.

7. An organic light-emitting device, characterized in that: The organic light-emitting device comprises a light-emitting layer, and the raw materials for preparing the light-emitting layer comprise the iridium complex according to any one of claims 1 to 6.

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