Organic metal iridium complex luminescent material and organic electroluminescent device

Abstract

The invention belongs to the technical field of organic photoelectric materials, and discloses an organic metal iridium complex light-emitting material and an organic electroluminescent device.According to the organic metal iridium complex light-emitting material, after triphenylsilyl is connected into a ligand of Lb, due to the fact that the triphenylsilyl has the large steric hindrance effect and the hyperconjugation effect, the light-emitting effect of the organic metal iridium complex light-emitting material is improved; therefore, the electron distribution can be regulated and controlled, the excited state can be stabilized, the stability of the material is enhanced, and the properties of high luminous efficiency and long service life are obtained. Meanwhile, by introducing other substituents into La and Lb ligands, the wavelength and electron distribution of the organic metal iridium complex material are further adjusted, so that the driving voltage of the organic electroluminescent device prepared when the organic metal iridium complex is used as a luminescent layer doping material is obviously reduced, the luminous efficiency is obviously improved, and the service life is obviously prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic materials, and more particularly, to an organoiridium metal complex luminescent material and an organic electroluminescent device. Background Art

[0002] An organic electroluminescent (OLED) device is a self-luminous device. Due to its characteristics such as low driving voltage, high brightness, fast response time, wide viewing angle, high resolution, simple process, flexibility and bendability, it has attracted much attention in the fields of new display technology and lighting technology.

[0003] The application fields of OLED technology are constantly expanding. In addition to applications in traditional fields such as smart phones and TVs, OLEDs have also begun to be applied in fields such as wearable devices, in-vehicle displays, and medical devices. With the advent of the 5G era and the increasing use of applications such as mobile phone videos and games by people, the requirements for screen displays are also getting higher and higher, which has also promoted the development of OLED materials to a certain extent. Among OLED materials, organometallic luminescent materials have gradually become one of the core materials of its display technology.

[0004] Compared with other luminescent materials, organometallic luminescent materials have better luminous efficiency and brightness, and at the same time have the characteristics of wide viewing angle and fast response speed. Therefore, they have developed rapidly in recent years. Among many transition metal materials, iridium (Ir), platinum (Pt), etc. with d6 and d8 electron structures can generate strong spin-orbit coupling, increasing the intersystem crossing probability from singlet state to triplet state. Therefore, the phosphorescence efficiency is greatly improved, the phosphorescence lifetime is shortened, phosphorescence quenching is reduced, and phosphorescence emission at room temperature is achieved. Organometallic luminescent materials with iridium as the core have gradually become a research hotspot in this field due to their relatively short triplet lifetime and high luminous brightness.

[0005] Currently, by adjusting the ligand types and structures of organometallic iridium complex luminescent materials, changes in emission wavelength and performance can be achieved, thereby obtaining high-efficiency red, green, and blue luminescent materials. Currently, there are many studies on green organometallic iridium complex luminescent materials and they are relatively mature. However, it is still a challenge to develop an organometallic iridium complex luminescent material with high luminous efficiency and long lifespan. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an organometallic iridium complex luminescent material and an organic electroluminescent device. This organometallic iridium complex luminescent material is through L bIntroduce triphenylsilyl into the ligand, and use its steric hindrance effect and hyperconjugation effect to regulate the electron distribution and stabilize the excited state, thereby enhancing the stability of the material and obtaining the properties of high luminous efficiency and long service life.

[0007] To solve the above problems, the present invention provides the following technical solutions:

[0008] In the first aspect, the present invention provides an organometallic iridium complex luminescent material with the general formula Ir(L a ) 2 (L b ) 1 , having the compound structure shown in Formula I:

[0009] ,

[0010] Formula I

[0011] Among them, L a and L b are both ligands, L a has the structure shown in Formula 1, and L b has the structure shown in Formula 2;

[0012]

[0013] Formula 1 Formula 2

[0014] X 1 ~X 4 are the same or different and are independently selected from CR x ;

[0015] X 1 ~X 4 at least one of the R x in CR x has the -L-R a structure, L represents a single bond, and the structure of R a is shown in Formula II:

[0016]

[0017] Formula II

[0018] R x can be the same or different and are independently selected from one or more of hydrogen, deuterium, hydroxyl group, nitro group, amino group, sulfonic acid group, alkyl group, cycloalkyl group, aryl group, heteroaryl group, alkoxy group, alkylamino group, alkenyl group or alkynyl group, heterocyclic group, fused ring group, spiro ring group, silyl group and germanium alkyl group; any two adjacent substituents can be connected to each other;

[0019] R 1 ~R 4, R 5 ~R 7 Each independently selected from one or more of hydrogen, deuterium, hydroxyl, nitro, amino, sulfonic acid group, alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, alkylamino, alkenyl or alkynyl, heterocyclic group, fused ring group, spiro ring group, silyl, germyl; wherein any two adjacent substituents can be connected to each other.

[0020] In some embodiments of the present invention, R 1 ~R 4 , R 5 ~R 7 The substituents at the position can be the same or different; R 1 ~R 4 , R 5 ~R 7 The substituent position is any position of the benzene ring where it is located.

[0021] In some embodiments of the present invention, R 1 ~R 3 The number of substituents is 0 to 4; R 4 The number of substituents is 0 to 2; R 5 ~R 7 The number of substituents is 0 to 5.

[0022] In some embodiments of the present invention, the R 1 ~R 4 , R 5 ~R 7 , R x Each independently represents hydrogen, deuterium, substituted or unsubstituted alkyl having 1 - 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 - 20 carbon atoms, substituted or unsubstituted alkoxy having 1 - 20 carbon atoms, substituted or unsubstituted heterocyclic group having 2 - 20 carbon atoms, substituted or unsubstituted aryl having 6 - 20 carbon atoms, substituted or unsubstituted heteroaryl having 3 - 20 carbon atoms, substituted or unsubstituted spiro ring group having 5 - 20 carbon atoms, substituted or unsubstituted silyl having 1 - 10 carbon atoms, substituted or unsubstituted germyl having 1 - 15 carbon atoms.

[0023] In some embodiments of the present invention, the substituted or unsubstituted alkyl having 1 - 20 carbon atoms includes any one or more of methyl, ethyl, propyl, isopropyl, butyl, tert - butyl, isobutyl, sec - butyl, pentyl, isopentyl, neopentyl, hexyl, 1 - methylpentyl, 2 - methylpentyl, 3 - methylpentyl, 2,3 - dimethylbutyl, 2,2 - dimethylbut, heptyl, 2 - methylhexyl, octyl, nonyl, decyl, undecane to eicosane.

[0024] In some embodiments of the present invention, the substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms includes any one or more of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl to cycloeicosyl.

[0025] In some embodiments of the present invention, the substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms includes any one or more of methoxy, ethoxy, propoxy, butoxy to eicosyloxy, phenoxy, isopropoxy, tert-butoxy, pentyloxy.

[0026] In some embodiments of the present invention, the substituted or unsubstituted heterocyclic group having 2 to 20 carbon atoms includes an aromatic or non-aromatic cyclic group containing at least one heteroatom, where the heteroatom is selected from one or more combinations of O, S, N, P, B, Si, and Ge.

[0027] For example, oxirane, thiirane, substituted or unsubstituted pyrazole, substituted or unsubstituted imidazole, substituted or unsubstituted oxazole, substituted or unsubstituted thiazole, substituted or unsubstituted tetrahydrothiophene, substituted or unsubstituted pyrazine, substituted or unsubstituted pyridazine, substituted or unsubstituted benzimidazole, substituted or unsubstituted benzothiazole.

[0028] In some embodiments of the present invention, the substituted or unsubstituted aryl group having 6 to 20 carbon atoms includes any one or more of phenyl, tolyl, chlorophenyl, bromophenyl, fluorophenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl.

[0029] In some embodiments of the present invention, the substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms includes substituted or unsubstituted pyridyl, substituted or unsubstituted furyl, substituted or unsubstituted thienyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted benzofuryl, substituted or unsubstituted benzothienyl, substituted or unsubstituted indolyl, substituted or unsubstituted quinoline and isoquinoline groups, substituted or unsubstituted carbazolyl, substituted or unsubstituted dibenzofuryl, substituted or unsubstituted dibenzothienyl.

[0030] In some embodiments of the present invention, the substituted or unsubstituted spiro group having 5 to 20 carbon atoms includes any one or more of spiro[4.4]nonyl, spiro[5.5]undecyl, bicyclo[2.2.1]heptyl, bicyclo[3.3.1]nonyl, spirobifluorene, spirofluoreneoxanthene, spiro(indenothiophene)fluorene, spiro(cyclopentadithiophene)fluorene, small-ring spiroalkyl.

[0031] In some embodiments of the present invention, the substituted or unsubstituted silyl group having 1 to 10 carbon atoms includes any one or more of trimethylsilyl, triethylsilyl, tripropylsilyl, trimethylenepropylsilyl, tridecylsilyl, isopropylsilyl, tert-butylsilyl, neopentylsilyl, 3,3-dimethylhexylsilyl, cyclohexylsilyl, phenylsilyl, and triphenylsilyl.

[0032] In some embodiments of the present invention, the substituted or unsubstituted germanium group having 1 to 15 carbon atoms includes any one or more of trimethylgermyl, triethylgermyl, tripropylgermyl, isopropylgermyl, tert-butylgermyl, neopentylgermyl, cyclohexylgermyl, and phenylgermyl.

[0033] In some embodiments of the present invention, the R 1 ~R 4 ,R 5 ~R 7 ,R x hydrogen atoms in the substituents can be deuterated.

[0034] In some embodiments of the present invention, the specific structure of the organometallic iridium complex luminescent material is selected from any one of the following, but not limited thereto:

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] 。

[0067] In a second aspect, the present invention also provides a method for preparing an organometallic iridium complex luminescent material. When the compound having the structure shown in Formula II appears at the X 1 position, the synthesis route is as follows:

[0068]

[0069] When Formula II appears at the X 2 , X 3 , X 4 position, the synthesis route is the same as the above synthesis route.

[0070] The specific synthesis steps are as follows:

[0071] 1. Add ethylene glycol monoethyl ether and water into a three-necked flask, put the compound with the structure shown in Formula III into the reaction system, displace nitrogen, then add iridium trichloride, reflux the reaction under nitrogen protection, and then cool to room temperature. A precipitate will form. Filter the precipitate by suction, and wash and dry it successively with water, absolute ethanol, and petroleum ether to obtain the compound with the structure shown in Intermediate Formula IV.

[0072] 2. Weigh the compound with the structure shown in Intermediate Formula IV, add silver trifluoromethanesulfonate, then add dichloromethane and methanol to the system. After displacing nitrogen, react at room temperature. Finally, through column chromatography (short column), concentrate the filtrate to a solid to obtain the iridium complex intermediate compound with the structure shown in Formula V.

[0073] 3. Weigh the compound with the structure shown in Intermediate Formula V, add the compound with the structure shown in Ligand Formula VI, and then add absolute ethanol to the system. After displacing nitrogen, react at a certain temperature, then filter by suction, wash with alcohol, and dry to obtain the crude product. Finally, use dichloromethane and petroleum ether as eluents and perform silica gel column chromatography to obtain the final product compound with the structure shown in Formula I-a.

[0074] In a third aspect, the present invention further provides an organic electroluminescent device, which includes a first electrode, a second electrode, and an organic functional layer disposed between the first electrode and the second electrode. The organic functional layer includes a hole transport region, a light-emitting layer, and an electron transport region; the light-emitting layer includes a host material and a doping material, and the doping material includes the above-mentioned organometallic iridium complex light-emitting material.

[0075] In an embodiment of the present invention, the first electrode deposits the electrode material on the substrate by physical vapor deposition methods such as sputtering and thermal evaporation.

[0076] Among them, the materials of the first electrode can generally be divided into three categories. The first category is transparent conductive oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO 2 )), zinc oxide (ZnO), etc., which can be used as anodes; the second category is metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), etc., which can be used as cathodes; the third category is composite structures such as the ITO / Ag / ITO three-layer structure, which reduces the resistance and enhances the conductivity through the intermediate metal.

[0077] In an embodiment of the present invention, the organic functional layer is generally formed on the electrode by vacuum thermal evaporation or solution processing (such as spin coating, inkjet printing), and the materials used as the organic material layer can be organic small molecules, organic macromolecules, or polymers.

[0078] Specifically, the organic functional layer includes a hole transport layer, an electron transport layer, a light-emitting layer, and an auxiliary functional layer.

[0079] In an embodiment of the present invention, the hole transport layer is located between the anode and the light-emitting layer, and can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds.

[0080] In an embodiment of the present invention, a hole injection layer (HIL) and an electron blocking layer (EBL) can also be added to the hole transport layer.

[0081] In an embodiment of the present invention, the material of the hole transport layer can be phthalocyanine derivatives, conductive polymers, or polymers containing conductive dopants such as poly(phenylene vinylene), polyaniline / dodecylbenzenesulfonic acid, poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate), polyaniline / camphorsulfonic acid, polyaniline / poly(4-styrenesulfonate), aromatic amine derivatives, etc.

[0082] In an embodiment of the present invention, the hole injection layer is located between the anode and the hole transport layer, and the material used can be a compound with the structure shown in Formula A or Formula B. The specific structural formula is as follows:

[0083] 。

[0084] The light-emitting layer generally includes a host material and a doping material. The host material provides a carrier transport channel, and the materials used can be CBP, Mcp, etc.; the doping material improves the light-emitting efficiency, and is generally a red, green, or blue phosphorescent material, such as the organic iridium metal complex light-emitting material with the structure shown in Formula I of this application.

[0085] In an embodiment of the present invention, the electron transport layer is generally a single-layer structure, and the material of the electron transport layer can be a single compound or a combination of multiple compounds, such as Alq 3 (aluminum tris(8-hydroxyquinoline)), Znq (zinc tris(8-hydroxyquinoline)), Bebq (bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum), TPBi (1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene), Bphen (4,7-diphenyl-1,10-phenanthroline), or a new material introducing heterocycles such as pyridine and triazine or phosphoxy groups (such as TPBI).

[0086] In an embodiment of the present invention, an electron injection layer and a hole blocking layer can also be added to the electron transport layer.

[0087] In one embodiment of the present invention, the electron injection layer is located between the electron transport layer and the cathode, and the material of the electron injection layer may be one or more of LiF, NaCl, CsF, Li 2 O, Cs 2 CO 3 , BaO, Na, Li, Ca.

[0088] Fourthly, the present invention also provides an application of an organic electroluminescent device having the above-mentioned organometallic iridium complex luminescent material in the fields of mobile phone displays, wearable devices, vehicle-mounted displays, medical devices, etc.

[0089] Compared with the prior art, the present invention has the following beneficial effects:

[0090] The organometallic iridium complex luminescent material provided by the present invention, after introducing triphenylsilyl into the ligand of L b , due to the large steric hindrance effect and hyperconjugation effect of triphenylsilyl, the electron distribution can be regulated and the excited state can be stabilized, the stability of the material can be enhanced, and the properties of high luminous efficiency and long service life can be obtained. At the same time, by introducing other substituents into the ligands of L a and L b , the wavelength and electron distribution of the organometallic iridium complex material are further adjusted, so that the driving voltage of the organic electroluminescent device prepared when the organometallic iridium complex is used as a doping material for the light-emitting layer is significantly reduced, and the luminous efficiency and lifespan are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 FIG. is the nuclear magnetic resonance hydrogen spectrum of the organometallic iridium complex Ⅰ-33 in Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0092] The technical solutions of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only used to illustrate and explain the present invention exemplarily, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0093] Unless otherwise specified, the raw materials and reagents used in the following examples and device preparation examples are all commercially available products.

[0094] Example 1

[0095] This synthesis example provides an organometallic iridium complex Ⅰ-33, that is, a compound numbered Ⅰ-33, and the specific synthesis steps are as follows:

[0096] Step 1: Synthesis of Intermediate 1

[0097]

[0098] Add 2-bromo-5-tert-butylpyridine (1 eq) (CAS No.: 1142197-19-0), (7-bromodibenzo[b,d]furan-4-yl)boronic acid (1.1 eq) (CAS No.: 2324746-51-0) and anhydrous potassium carbonate (3 eq) into a three-necked flask, then add toluene 20 times the mass of the compound shown in Formula III, ethanol 10 times and water 10 times as solvents. After displacing nitrogen twice, add Pd(pph 3 ) 4 (0.03 eq), displace nitrogen twice again, react at 100 °C for 24 h, and then purify by column chromatography (eluent: hexane and ethyl acetate) to obtain Intermediate 1 (yield: 63.7%).

[0099] Step 2: Synthesis of Intermediate 2 (Formula VI-1)

[0100]

[0101] Dissolve Intermediate 1 (1 eq) in anhydrous THF, cool it to -78 °C using liquid nitrogen, then slowly dropwise add n-butyllithium (2 eq), let it warm up to room temperature naturally, and react overnight. The next day, add triphenylsilane (1.5 eq) (CAS No.: 34525-04-7), react at room temperature for 3 h, and then slowly heat up to reflux and react for 3 h. After the reaction is completed, cool it to room temperature, then slowly add saturated MgSO 4 aqueous solution and extract three times with ethyl acetate. Then remove the solvent from the organic layer by a rotary evaporator and obtain the compound shown in Formula VI-1 by column chromatography (yield: 57.4%).

[0102] MS(ESI, m / Z): [M+H]+: 559.93.

[0103] Step 3: Synthesis of Formula I-33

[0104] 1. Put the compound (2.5 eq) with the structure of Formula III-1 (CAS: 27012-22-2) and IrCl 3 ·3H 2 O (1 eq) into a three-necked flask, then add ethylene glycol monoethyl ether 15 times the mass of the compound shown in Formula VII and pure water 3 times. After displacing nitrogen twice, reflux and react at 120 °C for 48 hours, then cool to room temperature, and a precipitate will form. Filter the precipitate by suction, wash it successively with anhydrous ethanol and petroleum ether, and dry it to obtain the bridged ligand shown in Formula IV-1 (yield: 56.1%).

[0105]

[0106] 2. Weigh the intermediate compound with the structure shown in Formula Ⅳ-1 (1 eq) and silver trifluoromethanesulfonate (2.2 eq), add them to a three-necked flask, then add 20 times the mass of methylene chloride and 3 times the mass of methanol of Formula Ⅶ-1 to the system. Under nitrogen protection, reflux for 30 hours, cool to room temperature, and then purify and concentrate through a silica gel funnel to obtain the iridium ligand compound intermediate shown in Formula Ⅴ-1 (yield: 89.3%).

[0107] 。

[0108] 3. Weigh the intermediate compound with the structure shown in Formula Ⅴ-1 (1 eq) and the ligand compound with the structure shown in Formula Ⅵ-1 (2.5 eq) into a three-necked flask, then add 20 times the mass of anhydrous ethanol of the compound with the structure shown in Formula Ⅴ-1 to the system. After displacing nitrogen twice, reflux and react at 80 °C for 48 hours. After cooling to room temperature, perform suction filtration, wash with alcohol, dry, and obtain the final compound shown in Formula Ⅰ-33 (yield: 23.7%) through column chromatography (eluent: methylene chloride and hexane), and its HPLC purity is greater than 99%.

[0109] 。

[0110] MS(ESI, m / Z): [M + H]+: 1087.55

[0111] The NMR data is as Figure 1 shown

[0112] Device Preparation Example 1

[0113] Prepare the organic electroluminescent device with the compound shown in Formula Ⅰ-33, and the preparation method is as follows:

[0114] 1) On the anode, cut the ITO-patterned glass substrate into a size of 50 mm × 50 mm × 0.5 mm, ultrasonically treat it with deionized water and isopropyl alcohol for 10 minutes in sequence, and then expose it to ultraviolet light and ozone for 30 minutes for cleaning.

[0115] 2) Load the obtained glass substrate onto a vacuum deposition device. First, deposit Formula A on the anode as a hole injection layer, and the deposition thickness is 100 Å. Then, deposit the hole transport layer of the compound with the structure shown in Formula C with a thickness of 900 Å on the hole injection layer.

[0116] , ,

[0117] Formula C Formula D

[0118] 3) Prepare a light-emitting layer by mixing the host material 4,4'-N,N'-biphenyldicarbazole ("CBP") and the doping material of the structure shown in Formula I-33 in a mass ratio of 9:1, and the evaporation thickness is 400 Å. Then, evaporate a TPBi (Formula D) electron transport layer with a thickness of 400 Å on the light-emitting layer, evaporate a LiF electron injection layer with a thickness of 10 Å on the electron transport layer, and finally evaporate a cathode material Al with a thickness of 1500 Å on the electron injection layer to obtain an organic electroluminescent device.

[0119] Referring to Preparation Example 1 of the light-emitting device, replace the doping material of the structure shown in Formula I-33 in the organic electroluminescent device with Compounds of Formula I-1, I-25, I-35, I-68, I-119, I-151, I-277, I-361, I-486, and I-577, and prepare organic electroluminescent devices therefrom, denoted as Device Preparation Examples 2-11, as shown in Table 1 for details.

[0120] Comparative Example 1

[0121] Prepare an organic electroluminescent device by the same method as in Device Preparation Example 1, and replace the doping material of the structure shown in Formula I-33 in the light-emitting layer with Comparative Compound 1, the structure of which is as follows:

[0122] 。

[0123] Comparative Compound 1

[0124] Comparative Example 2

[0125] Prepare an organic electroluminescent device by the same method as in Device Preparation Example 1, and replace the doping material of the structure shown in Formula I-33 in the light-emitting layer with Comparative Compound 2, the structure of which is as follows:

[0126] 。

[0127] Comparative Compound 2

[0128] Comparative Example 3

[0129] Prepare an organic electroluminescent device by the same method as in Device Preparation Example 1, and replace the doping material of the structure shown in Formula I-33 in the light-emitting layer with Comparative Compound 3, the structure of which is as follows:

[0130] 。

[0131] Comparative Compound 3

[0132] To further illustrate the luminescence performance of the organometallic luminescent material prepared by the present invention, the luminescence characteristics of the organic light-emitting devices prepared in Device Preparation Examples 1-11 and the devices obtained in Comparative Examples 1-3 were tested. The measurement was carried out using a KEITHLEY2400 source measurement unit and a CS-2000 spectro-radiance meter to evaluate the driving voltage, luminous efficiency and lifespan. The results are shown in Table 1.

[0133] Table 1 Luminescence detection data of the organic electroluminescent devices prepared in Device Preparation Examples 1-11 and Comparative Examples 1-3

[0134]

[0135] As can be seen from Table 2, when the luminescence brightness is the same, compared with Comparative Examples 1 and 2, the driving voltage of Device Preparation Examples 1-11 decreases, and the efficiency and service life increase. The reason is mainly that the steric effect of the triphenylsilyl group of the compound shown in Formula I-33 in Device Preparation Example 1 reduces the interaction between the host and the guest, and inhibits the formation of the intermolecular charge transfer complex between the electron-transporting host material and the doping material. In addition, the electron-withdrawing effect of the triphenylsilyl group reduces the electron cloud density of the silicon atom and enhances the triplet state stability of the material.

[0136] Therefore, the organic electroluminescent device prepared by using the compound provided by the present invention as the luminescent layer doping material has better luminous efficiency and longer service time.

[0137] Those skilled in the art will clearly see that the present invention can have many modifications and variations without departing from the spirit and scope of the present invention. Therefore, it can be expected that the present invention covers the modifications and variations of the present invention provided within the scope of the appended claims and their equivalents.

[0138] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic metal iridium complex luminescent material, characterized in that: The general formula is Ir(L a )2(L b ) 1, the compound structure is shown in formula I: ， Formula I Among them, L a and L b All are ligands, L a Having the structure shown in Formula 1, L b Having the structure shown in Formula 2; Formula 1 Formula 2 X1~X4 are the same or different and are independently selected from CR x ; At least one CR is present in X1~X4 x R x With -LR a structure, L represents a single bond, R a The structure is shown in Formula II: ； Formula II Among them, the R x the same or different, independently selected from one or more of hydrogen, deuterium, hydroxyl, nitro, amino, sulfonic acid, alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, alkylamino, olefin or alkyne, heterocyclic, fused ring, spirocyclic, silane and germyl; any two adjacent substituents may be connected to each other; The R1-R4 and R5-R7 are each independently selected from one or more of hydrogen, deuterium, hydroxyl, nitro, amino, sulfonic acid, alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, alkylamino, olefin or alkyne, heterocyclic, condensed ring, spirocyclic, silane and germyl groups; wherein any two adjacent substituents may be connected to each other.

2. The organometallic iridium complex luminescent material according to claim 1, characterized in that: The substituents at the positions of R1~R4, R5~R7 are the same or different; the positions of R1~R4, R5~R7 substituents are any positions of the benzene ring; the number of R1~R3 ​​substituents is 0~4; the number of R4 substituents is 0~2; the number of R5~R7 substituents is 0~5.

3. The organometallic iridium complex luminescent material according to claim 1, characterized in that: R1~R4, R5~R7, R x Each independently represents hydrogen, deuterium, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 20 carbon atoms, substituted or unsubstituted alkoxy having 1 to 20 carbon atoms, substituted or unsubstituted heterocyclic group having 2 to 20 carbon atoms, substituted or unsubstituted aryl group having 6 to 20 carbon atoms, substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms, substituted or unsubstituted spirocyclic group having 5 to 20 carbon atoms, substituted or unsubstituted silanyl group having 1 to 10 carbon atoms, or substituted or unsubstituted germyl group having 1 to 15 carbon atoms.

4. The organometallic iridium complex luminescent material according to claim 3, characterized in that: The substituted or unsubstituted alkyl group having 1 to 20 carbon atoms includes one or more of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl, sec-butyl, pentyl, isopentyl, neopentyl, hexyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 2,3-dimethylbutyl, 2,2-dimethylbutyl, heptyl, 2-methylhexyl, octyl, nonyl, decyl, undecane to eicosane; The substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms includes one or more of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and cycloeicosyl; The substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms includes one or more of methoxy, ethoxy, propoxy, butoxy to eicosyl, phenoxy, isopropoxy, tert-butoxy, and neopentyloxy.

5. The organometallic iridium complex luminescent material according to claim 3, characterized in that: The substituted or unsubstituted heterocyclic group having 2 to 20 carbon atoms is an aromatic or non-aromatic cyclic group containing at least one heteroatom, wherein the heteroatom is selected from one or more combinations of O, S, N, P, B, Si and Ge; The substituted or unsubstituted aryl group having 6 to 20 carbon atoms includes one or more of phenyl, tolyl, chlorophenyl, bromophenyl, fluorophenyl, biphenyl, terphenyl, naphthyl, anthracenyl, and phenanthryl.

6. The organometallic iridium complex luminescent material according to claim 3, characterized in that: The substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms includes a substituted or unsubstituted pyridyl group, a substituted or unsubstituted furyl group, a substituted or unsubstituted thienyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothienyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted quinoline group and an isoquinoline group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted dibenzothienyl group; The substituted or unsubstituted spirocyclic group having 5 to 20 carbon atoms includes one or more of spiro[4.4]nonyl, spiro[5.5]undecyl, bicyclo[2.2.1]heptyl, bicyclo[3.3.1]nonyl, spirobifluorenyl, spirofluoreneoxanthenyl, spiro(indenothiophene)fluorenyl, spiro(cyclopentadithiophene)fluorenyl, and small ring spiroalkyl; The substituted or unsubstituted silyl group having 1 to 10 carbon atoms comprises one or more of trimethylsilyl, triethylsilyl, tripropylsilyl, trimethylenepropanesilyl, triacontylsilyl, isopropylsilyl, tert-butylsilyl, neopentylsilyl, 3,3-dimethylhexylsilyl, cyclohexylsilyl, phenylsilyl, and triphenylsilyl; The substituted or unsubstituted germanyl group having 1 to 15 carbon atoms includes any one or more of trimethylgermanyl, triethylgermanyl, tripropylgermanyl, isopropylgermanyl, tert-butylgermanyl, neopentylgermanyl, cyclohexylgermanyl, and phenylgermanyl; R1~R4, R5~R7, R x The hydrogen atoms in the substituent groups may be deuterated.

7. The organometallic iridium complex luminescent material according to claim 5, characterized in that: The substituted or unsubstituted heterocyclic group having 2 to 20 carbon atoms is oxirane, thiirane, substituted or unsubstituted pyrazole, substituted or unsubstituted imidazole, substituted or unsubstituted oxazole, substituted or unsubstituted thiazole, substituted or unsubstituted tetrahydrothiophene, substituted or unsubstituted pyrazine, substituted or unsubstituted pyridazine, substituted or unsubstituted benzimidazole, substituted or unsubstituted benzothiazole.

8. The organometallic iridium complex luminescent material according to any one of claims 1 to 7, characterized in that: The specific structure of the organometallic iridium complex luminescent material is selected from any one of the following: 。 9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic functional layer arranged between the first electrode and the second electrode, wherein the organic functional layer comprises a hole transport region, a light-emitting layer and an electron transport region; the light-emitting layer comprises a main material and a doping material, wherein the doping material comprises the organic metal iridium complex light-emitting material according to any one of claims 1 to 8.

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