Organic electroluminescent material and use thereof

Abstract

The present invention provides a compound having the structure of Formula (1): wherein the various moieties are as defined in the specification. Also provided are organic electroluminescent devices comprising the compound.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201910767252.X (filed on February 26, 2021, invention title: Organic electroluminescent materials and their applications). Technical Field

[0002] This invention relates to an organic compound that can be used in organic electroluminescent devices, particularly as a host material for the light-emitting layer or a hole-blocking layer material; the invention also relates to the application of the compound in organic electroluminescent devices, and organic electroluminescent devices comprising the compound. Background Technology

[0003] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them ideal for fabrication on flexible substrates, allowing for the design and production of aesthetically pleasing and stylish optoelectronic products, offering unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, and organic sensors. OLEDs, in particular, have developed rapidly and have already achieved commercial success in the information display field. OLEDs can provide highly saturated red, green, and blue colors, and full-color displays made with them do not require an additional backlight, offering advantages such as vibrant colors, thinness, and flexibility.

[0004] The core of an OLED device is a thin-film structure containing various organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as light-emitting host materials and light-emitting guest materials (dyes). When an electric current is applied, electrons and holes are injected and transported to the light-emitting region, where they recombine, thereby generating excitons and emitting light.

[0005] Various organic materials have been developed and combined with unique device structures to improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency, and delay device decay. For quantum mechanical reasons, common fluorescent emitters primarily utilize singlet excitons generated when electrons and holes combine to emit light, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can simultaneously utilize triplet and singlet excitons to emit light, and are called phosphorescent emitters, with energy conversion efficiencies up to four times higher than traditional fluorescent emitters. Thermally excited delayed fluorescence (TADF) technology promotes the transition from triplet to singlet excitons, achieving high luminescence efficiency without the use of metal complexes, while still effectively utilizing triplet excitons.

[0006] As OLED products gradually enter the market, people have increasingly higher requirements for their performance. Current OLED materials and device structures cannot fully solve the problems related to efficiency, lifespan, and cost of OLED products. Through careful consideration and continuous experimentation, the researchers of this invention have discovered an ingenious molecular design scheme, which is described in detail below. Surprisingly, the compounds disclosed in this invention are highly suitable for application in OLEDs and for improving device performance. Summary of the Invention

[0007] This invention discloses a class of compounds with a large conjugated system structure containing a seven-membered ring, which can improve the charge transport performance of materials and simultaneously adjust the HOMO / LUMO energy levels in order to balance carrier transport and improve the performance of OLED devices.

[0008] On the one hand, the present invention provides a compound having the structure shown in general formula (1):

[0009]

[0010] in,

[0011] X and Y are independently selected from oxygen, sulfur, selenium, and BR. a NR b CR c R d SiR e R f CR g R h -CR i R j ;

[0012] Z 1 -Z 10 Each independently for CR z Or N;

[0013] R 1 Represents 0 to 2 identical or different substituents; R 2 Represents 0 to 2 identical or different substituents;

[0014] R 3 Represents 0 to 3 identical or different substituents; R 4 Represents 0 to 3 identical or different substituents;

[0015] R a R c R d R e R f R g R h R i Rj R z R 1 R 2 R e and R 4 Each of them is independently selected from hydrogen, halogen, C1-C12 alkyl, C3-C12 cycloalkyl, C1-C12 alkoxy, C2-C12 cycloalkoxy, silyl, carbonyl, acyl, ester, cyano, amino, C6-C30 aryl, C3-C30 heteroaryl, or combinations thereof;

[0016] R b It is selected from halogens, C1-C12 alkyl groups, C3-C12 cycloalkyl groups, C1-C12 alkoxy groups, C2-C12 cycloalkoxy groups, silyl groups, carbonyl groups, acyl groups, ester groups, cyano groups, amino groups, C6-C30 aryl groups, C3-C30 heteroaryl groups, or combinations thereof;

[0017] Any two adjacent substituents can be linked together to form a ring, such as a five-membered aromatic ring or a six-membered aromatic ring;

[0018] When R a R b R c R d R e R f R g R h R i R j Or R z When any one of them exists in multiples, they may be the same or different.

[0019] In some embodiments, the compound has the following structure:

[0020]

[0021] Each group is defined as in general formula (1).

[0022] In some implementation schemes, R b The following groups are selected, and can be attached to the N atom at any substituted position:

[0023]

[0024] In some embodiments, the compound has a structure selected from P1-P236:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] As another aspect of the present invention, the present invention also provides the application of the compound described above in an organic electroluminescent device.

[0037] As another aspect of the present invention, the present invention also provides an organic electroluminescent device, comprising a first electrode, a second electrode, and one or more organic material layers inserted between the first electrode and the second electrode, wherein at least one of the organic material layers contains a compound of the present invention.

[0038] In some embodiments, the light-emitting layer and / or hole-blocking layer of the organic electroluminescent device contain the compounds of the present invention.

[0039] In some embodiments, the compounds of the present invention are used as the light-emitting host in the light-emitting layer.

[0040] In some embodiments, the compounds of the present invention are used as hole-blocking layers. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0042] In this specification, alkyl, alkoxy, and silyl groups may contain 1-12 carbon atoms, cycloalkyl and cycloalkoxy groups may contain 3-12 carbon atoms, aryl groups may contain 6-30 carbon atoms, and heteroaryl groups may contain 3-30 carbon atoms.

[0043] Compounds for which no synthetic method is mentioned in this invention are all raw materials obtained through commercial channels. Solvents and reagents used in this invention, such as dichloromethane, petroleum ether, ethanol, tetrahydrofuran, N,N-dimethylacetamide, anhydrous magnesium sulfate, carbazole, benzimidazole, etc., can all be purchased from the domestic chemical market, for example, from Sinopharm Reagent Company, TCI Company, Shanghai Bid Pharmaceutical Company, and Bailingwei Reagent Company.

[0044] The present invention will be described in detail below with several specific embodiments. The compounds of the present invention can be synthesized with reference to the specific synthesis examples shown below. However, it should be noted that obtaining the compounds is not limited to the synthesis methods and raw materials used in the present invention. Those skilled in the art can also select other methods or routes to obtain the novel compounds proposed in the present invention. The compounds for which synthesis methods are not mentioned in the present invention are all raw material products obtained through commercial means, or self-made using these raw material products according to known methods.

[0045] The intermediates and compounds in this invention were analyzed and detected using mass spectrometry (ZAB-HS type mass spectrometer, manufactured by Micromass, UK).

[0046] Synthesis Examples

[0047] Representative synthetic route 1:

[0048]

[0049] Representative synthetic pathway 1-1:

[0050] Representative synthetic pathways 1-2:

[0051]

[0052] Representative synthetic pathways 1-3:

[0053] Representative synthetic route 2:

[0054]

[0055] Representative synthetic route 3:

[0056]

[0057] M1 Synthesis

[0058]

[0059] Under a nitrogen atmosphere, 66.60 g (200 mmol) of 1-bromo-8-iodonaphthalene, 36.00 g (200 mmol) of 2-(methoxycarbonyl)phenylboronic acid, 2.30 g (2 mmol) of tetra(triphenylphosphine)palladium, 55.2 g (400 mmol) of potassium carbonate, 1200 ml of 1,4-dioxane, and 400 ml of distilled water were placed in a 3 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate M1-1 (53.75 g) was obtained by column chromatography. Calculated molecular weight: 314.20; Measured C / Z: 314.2.

[0060]

[0061] Under a nitrogen atmosphere, M1-1 (47.13 g, 150 mmol) and 500 mL of tetrahydrofuran were placed in a 2 L reaction vessel and cooled to 0 °C. Methylmagnesium bromide (110.48 g, 600 mmol) was slowly added. The reaction was allowed to return to room temperature for 12 h, followed by the addition of saturated NH4Cl aqueous solution and stirring for 15 min. The mixture was extracted with ethyl acetate, and the concentrated organic phases were combined. Intermediate M1-2 (44.68 g) was obtained by column chromatography. Calculated molecular weight: 341.25; Measured C / Z: 341.2.

[0062]

[0063] Under a nitrogen atmosphere, M1-2 (40.95 g, 120 mmol) and 400 mL of dichloromethane were placed in a 1 L reaction vessel, cooled to 0 °C, and methanesulfonic acid (11.52 g, 120 mmol) was added. The reaction was carried out for 12 h. Water was added and stirred for 1 h. The organic phases were extracted and combined. The concentrated organic phases were separated by column chromatography to obtain intermediate M1 27.54 g. Calculated molecular weight: 323.23, measured C / Z: 323.2.

[0064] Synthesis example 1:

[0065] Synthesis of P16

[0066]

[0067] Under a nitrogen atmosphere, M1 (16.16 g, 50 mmol), 2-(methoxycarbonyl)phenylboronic acid (9.00 g, 50 mmol), tetrakis(triphenylphosphine)palladium (1.15 g, 1 mmol), potassium carbonate (13.8 g, 100 mmol), 300 ml of 1,4-dioxane, and 100 ml of distilled water were placed in a 1 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate P16-1 (15.78 g) was obtained by column chromatography. Calculated molecular weight: 378.47; Measured C / Z: 378.5.

[0068]

[0069] Under a nitrogen atmosphere, P16-1 (15.14 g, 40 mmol) and 200 mL of tetrahydrofuran were placed in a 2 L reaction vessel and cooled to 0 °C. Methylmagnesium bromide (29.46 g, 160 mmol) was slowly added. The reaction was allowed to return to room temperature for 12 h, followed by the addition of saturated NH4Cl aqueous solution and stirring for 15 min. The mixture was extracted with ethyl acetate, and the concentrated organic phases were combined. Column chromatography was used to separate intermediate P16-2 (11.78 g). Calculated molecular weight: 378.52; Measured C / Z: 378.5.

[0070]

[0071] Under a nitrogen atmosphere, P16-2 (11.36 g, 30 mmol) and 150 mL of dichloromethane were placed in a 1 L reaction vessel, cooled to 0 °C, and methanesulfonic acid (2.88 g, 30 mmol) was added. The reaction was carried out for 12 h. Water was added and stirred for 1 h. The organic phases were extracted and combined. The intermediate P16-3 (7.29 g) was obtained by column chromatography. Calculated molecular weight: 360.50, measured C / Z: 360.5.

[0072]

[0073] Under a nitrogen atmosphere, P16-3 (7.21 g, 20 mmol), sodium chloride (23.38 g, 400 mmol), aluminum trichloride (193.14 g, 800 mmol), and 500 ml of benzene were placed in a 2 L reaction vessel and refluxed for 12 h. After cooling to room temperature, excess AlCl3 was removed with a saturated aqueous solution of NaHCO3, and the concentrated organic phases were combined. Compound P163.04 g was obtained by column chromatography. Calculated molecular weight: 358.48; Measured C / Z: 358.5.

[0074] Synthesis example 2:

[0075] Synthesis of P18

[0076]

[0077] Under a nitrogen atmosphere, M1 (32.32 g, 100 mmol), 2-methylthiophenylboronic acid (16.80 g, 100 mmol), tetrakis(triphenylphosphine)palladium (1.15 g, 1 mmol), potassium carbonate (27.6 g, 200 mmol), 600 ml of 1,4-dioxane, and 200 ml of distilled water were placed in a 1 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate P18-1 (30.55 g) was obtained by column chromatography. Calculated molecular weight: 366.52; Measured C / Z: 366.5.

[0078]

[0079] Under a nitrogen atmosphere, P18-1 (29.32 g, 80 mmol) and 300 ml of acetic acid were placed in a 1 L reaction vessel. H2O2 (8.16 g, 240 mmol) was dissolved in 50 ml of acetic acid and slowly added dropwise to the solution. The reaction was carried out at room temperature for 8 h. After the reaction was complete, the mixtures were combined and concentrated to remove the acetic acid. Column chromatography was used to separate intermediate P18-2 (20.41 g). Calculated molecular weight: 382.52; Measured C / Z: 382.5.

[0080]

[0081] Under a nitrogen atmosphere, P18-2 (19.13 g, 50 mmol) and 75 ml of trifluoromethanesulfonic acid were placed in a 500 ml reaction vessel and stirred at room temperature for 24 h. Then, 40 ml of pyridine and 5 ml of water were added, and the mixture was refluxed for 30 min. After returning to room temperature, the mixture was extracted with dichloromethane, and the concentrated organic phases were combined. Column chromatography was used to separate intermediate P18-3 (11.22 g). Calculated molecular weight: 350.48; Measured C / Z: 350.5.

[0082]

[0083] Under a nitrogen atmosphere, P18-3 (10.52 g, 30 mmol), sodium chloride (35.06 g, 600 mmol), aluminum trichloride (289.68 g, 1200 mmol), and 1000 ml of benzene were placed in a 2 L reaction vessel and refluxed for 12 h. After cooling to room temperature, excess AlCl3 was removed with a saturated aqueous solution of NaHCO3, and the concentrated organic phases were combined. Column chromatography was used to separate P18-3 to obtain 4.25 g. Calculated molecular weight: 348.46; Measured C / Z: 348.5.

[0084] Synthesis example 3:

[0085] Synthesis of P174

[0086]

[0087] Under a nitrogen atmosphere, M1 (32.32 g, 100 mmol), 2-nitrophenylboronic acid (16.70 g, 100 mmol), tetrakis(triphenylphosphine)palladium (1.15 g, 1 mmol), potassium carbonate (27.6 g, 200 mmol), 600 ml of 1,4-dioxane, and 200 ml of distilled water were placed in a 1 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate P174-1 (29.38 g) was obtained by column chromatography. Calculated molecular weight: 366.52; Measured C / Z: 366.5.

[0088]

[0089] Under a nitrogen atmosphere, P174-1 (29.32 g, 80 mmol), triphenylphosphine (52.46 g, 200 mmol), and o-dichlorobenzene (300 mL) were placed in a 1 L reaction vessel and refluxed at 180 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate P174-2 (22.68 g) was obtained by column chromatography. Calculated molecular weight: 333.43; Measured C / Z: 333.4.

[0090]

[0091] Under a nitrogen atmosphere, P174-2 (20.00 g, 60 mmol), sodium chloride (70.13 g, 1200 mmol), aluminum trichloride (579.43 g, 2400 mmol), and 1500 ml of benzene were placed in a 3 L reaction vessel and refluxed for 12 h. After cooling to room temperature, excess AlCl3 was removed with a saturated aqueous solution of NaHCO3, and the concentrated organic phases were combined. The intermediate P174-38.76 g was obtained by column chromatography. Calculated molecular weight: 331.42; Measured C / Z: 331.4.

[0092]

[0093] Under a nitrogen atmosphere, M1 (6.63 g, 20 mmol), 2-chloro-4-phenylquinazoline (4.81 g, 20 mmol), cesium carbonate (13.04 g, 40 mmol), and 100 ml of DMF were placed in a 250 ml reaction vessel and refluxed for 12 h. After cooling to room temperature, the concentrated organic phases were combined. P174 (4.77 g) was obtained by column chromatography. Calculated molecular weight: 535.65; Measured C / Z: 535.6.

[0094] M2 Synthesis

[0095]

[0096] Under a nitrogen atmosphere, 66.60 g (200 mmol) of 1-bromo-8-iodonaphthalene, 33.60 g (200 mmol) of 2-methylthiophenylboronic acid, 2.30 g (2 mmol) of tetrakis(triphenylphosphine)palladium, 55.2 g (400 mmol) of potassium carbonate, 1200 ml of 1,4-dioxane, and 400 ml of distilled water were placed in a 3 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate M2-1 (48.12 g) was obtained by column chromatography. Calculated molecular weight: 329.26; Measured C / Z: 329.3.

[0097]

[0098] Under a nitrogen atmosphere, M2-1 (47.74 g, 145 mmol) and 600 ml of acetic acid were placed in a 2 L reaction vessel. H2O2 (14.79 g, 435 mmol) was dissolved in 150 ml of acetic acid and slowly added dropwise to the solution. The reaction was carried out at room temperature for 8 h. After the reaction was complete, the mixtures were combined and concentrated to remove the acetic acid. Column chromatography was used to separate intermediate M2-2 (36.21 g). Calculated molecular weight: 345.25; Measured C / Z: 345.2.

[0099]

[0100] Under a nitrogen atmosphere, M2-2 (34.52 g, 100 mmol) and 150 mL of trifluoromethanesulfonic acid were placed in a 1 L reaction vessel and stirred at room temperature for 24 h. Then, 80 mL of pyridine and 10 mL of water were added, and the mixture was refluxed for 30 min. After returning to room temperature, the mixture was extracted with dichloromethane, and the concentrated organic phases were combined. Column chromatography was used to separate intermediate M2 (14.38 g). Calculated molecular weight: 313.21; Measured C / Z: 313.2.

[0101] Synthesis example 4:

[0102] P90 Synthesis

[0103] Replacing M1 with M2 in Synthesis Example 3, while keeping everything else unchanged, yielded P90. Calculated molecular weight: 525.63, measured C / Z: 525.6.

[0104] M3 Synthesis

[0105]

[0106] Under a nitrogen atmosphere, 66.60 g (200 mmol) of 1-bromo-8-iodonaphthalene, 33.40 g (200 mmol) of 2-nitrophenylboronic acid, 2.30 g (2 mmol) of tetrakis(triphenylphosphine)palladium, 55.2 g (400 mmol) of potassium carbonate, 1200 ml of 1,4-dioxane, and 400 ml of distilled water were placed in a 3 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate M3-1 (53.04 g) was obtained by column chromatography. Calculated molecular weight: 328.17; Measured C / Z: 328.2.

[0107]

[0108] Under a nitrogen atmosphere, M3-1 (52.51 g, 160 mmol), triphenylphosphine (104.92 g, 400 mmol), and o-dichlorobenzene (600 mL) were placed in a 2 L reaction vessel and refluxed at 180 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate M3-2 (34.57 g) was obtained by column chromatography. Calculated molecular weight: 296.17; Measured C / Z: 296.2.

[0109]

[0110] Under a nitrogen atmosphere, M3-2 (32.58 g, 110 mmol), iodobenzene (22.44 g, 110 mmol), cuprous iodide (20.95 g, 110 mmol), o-phenanthroline (19.82 g, 110 mmol), potassium phosphate (46.64 g, 220 mmol), and 500 mL of xylene were placed in a 2 L reaction vessel and refluxed for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate M3 (33.91 g) was obtained by column chromatography. Calculated molecular weight: 372.27; Measured C / Z: 372.3.

[0111] Synthesis example 5:

[0112] Synthesis of P204

[0113] Replacing M1 with M3 and 2-chloro-4-phenylquinazoline with 2-chloro-4,6-diphenyltriazine in Synthesis Example 3, while keeping everything else unchanged, yielded P204. Calculated molecular weight: 611.71, measured C / Z: 611.7.

[0114] Synthesis example 6:

[0115] Synthesis of P208

[0116] Replacing M1 with M3 in Synthesis Example 3, while keeping everything else unchanged, yielded P208. Calculated molecular weight: 584.68, measured C / Z: 584.7.

[0117] Synthesis example 7:

[0118] Synthesis of P213

[0119]

[0120] Under a nitrogen atmosphere, 2-chloro-4-phenylquinazoline (7.22 g, 30 mmol), 4-fluorophenylboronic acid (4.20 g, 30 mmol), tetrakis(triphenylphosphine)palladium (0.69 g, 0.6 mmol), potassium carbonate (16.56 g, 60 mmol), 100 ml of dioxane, and 30 ml of distilled water were placed in a 500 ml reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate P213-1 (8.04 g) was obtained by column chromatography. M: 300.3.

[0121] In Synthesis Example 3, M1 was replaced with M3, and 2-chloro-4-phenylquinazoline was replaced with P213-1, while other parameters remained unchanged, resulting in P213. Calculated molecular weight: 660.78, measured C / Z: 660.8.

[0122] Synthetic Comparative Example 1:

[0123] Synthesis of D2

[0124]

[0125] Under a nitrogen atmosphere, M1 (32.32 g, 100 mmol), 2-methylthiophenylboronic acid (16.80 g, 100 mmol), tetrakis(triphenylphosphine)palladium (1.15 g, 1 mmol), potassium carbonate (27.6 g, 200 mmol), 600 ml of 1,4-dioxane, and 200 ml of distilled water were placed in a 1 L reaction vessel and refluxed at 100 °C for 12 h. After cooling to room temperature, the concentrated organic phases were combined. Intermediate D2-1 (30.55 g) was obtained by column chromatography. Calculated molecular weight: 366.52; Measured C / Z: 366.5.

[0126]

[0127] Under a nitrogen atmosphere, D2-1 (29.32 g, 80 mmol) and 300 ml of acetic acid were placed in a 1 L reaction vessel. H2O2 (8.16 g, 240 mmol) was dissolved in 50 ml of acetic acid and slowly added dropwise to the solution. The reaction was carried out at room temperature for 8 h. After the reaction was complete, the mixtures were combined and concentrated to remove the acetic acid. Column chromatography was used to separate intermediate D2-2 (20.41 g). Calculated molecular weight: 382.52; Measured C / Z: 382.5.

[0128]

[0129] Under a nitrogen atmosphere, D2-2 (19.13 g, 50 mmol) and 75 ml of trifluoromethanesulfonic acid were placed in a 500 ml reaction vessel and stirred at room temperature for 24 h. Then, 40 ml of pyridine and 5 ml of water were added, and the mixture was refluxed for 30 min. After returning to room temperature, the mixture was extracted with dichloromethane, and the concentrated organic phases were combined. Column chromatography was used to separate intermediate D2 (11.22 g). Calculated molecular weight: 350.48; Measured C / Z: 350.5.

[0130] Device Examples

[0131] Implementation

[0132] An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0133] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0134] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), and zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as the cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), and magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0135] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0136] The hole transport region is located between the anode and the light-emitting layer. The hole transport region 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. The hole transport region can also be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0137] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives as shown in HT-1 to HT-34 below; or any combination thereof.

[0138]

[0139]

[0140]

[0141] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-34 mentioned above, or one or more compounds of HI1 to HI3 mentioned below; it can also be one or more compounds of HT-1 to HT-34 doped with one or more compounds of HI1 to HI3 mentioned below.

[0142]

[0143] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0144] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0145] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0146]

[0147]

[0148]

[0149] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0150]

[0151]

[0152] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0153]

[0154]

[0155] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1-YPD-11 listed below.

[0156]

[0157]

[0158] The OLED organic material layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0159] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-57 listed below.

[0160]

[0161]

[0162]

[0163] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0164] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0165] The fabrication process of the organic electroluminescent device in this embodiment is as follows:

[0166] Example 1

[0167] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0168] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶. -5 Pa, on the aforementioned anolyte film, a 10 nm HT-4:HI-3 (97 / 3, w / w) mixture was vacuum thermally deposited as a hole injection layer, a 60 nm HT-4 compound as a hole transport layer, a 40 nm P174:RPD-8 (100:3, w / w) binary mixture as a light-emitting layer, a 25 nm ET-46:ET-57 (50 / 50, w / w) mixture as an electron transport layer, a 1 nm LiF layer as an electron injection layer, and a 150 nm aluminum metal as a cathode. The total deposition rate of all organic layers and LiF was controlled at 0.1 nm / s, and the deposition rate of the metal electrode was controlled at 1 nm / s.

[0169] Examples 2-5

[0170] Organic electroluminescent devices were prepared according to the method described in Example 1, except that P174 was replaced with P90, P204, P208 and P213 respectively.

[0171] Comparative Example 1

[0172] Organic electroluminescent devices were prepared according to the method described in Example 1, except that P174 was replaced with the following compound:

[0173]

[0174] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0175] Under the same brightness, the driving voltage, current efficiency, and lifetime of the organic electroluminescent devices prepared in Examples 1-5 and Comparative Example 1 were measured using a digital source meter and a luminance meter. Specifically, the voltage was increased at a rate of 0.1V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 3000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: using a luminance meter at 10000 cd / m² 2 At a constant current, the brightness of the organic electroluminescent device decreased to 9500 cd / m² under the specified brightness. 2 The time is in hours.

[0176] The performance of organic electroluminescent devices is shown in Table 1 below:

[0177] Table 1. Performance of the organic electroluminescent devices in Examples 1-5 and Comparative Example 1

[0178]

[0179] The above results show that the novel organic material of the present invention, when used in organic electroluminescent devices, can effectively reduce the start-up and stop voltage while maintaining good efficiency and improving the service life of the material, making it a high-performance red light host material.

[0180] Example 6

[0181] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0182] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶.-5 Pa, on the aforementioned anolyte film, a 10 nm HT-4:HIL-3 (97 / 3, w / w) mixture was vacuum thermally deposited as a hole injection layer, a 60 nm HT-4 compound as a hole transport layer, a 40 nm GPH-62:RPD-8 (100:3, w / w) binary mixture as a light-emitting layer, a 5 nm P2O4 compound as a hole blocking layer, a 25 nm ET-46:ET-57 (50 / 50, w / w) mixture as an electron transport layer, a 1 nm LiF layer as an electron injection layer, and a 150 nm aluminum metal as a cathode. The total deposition rate of all organic layers and LiF was controlled at 0.1 nm / s, and the deposition rate of the metal electrode was controlled at 1 nm / s.

[0183] Examples 7-8

[0184] Organic electroluminescent devices were prepared according to the method described in Example 6, except that P204 was replaced with P208 or P213 respectively.

[0185] Comparative Example 2

[0186] Organic electroluminescent devices were prepared according to the method described in Example 6, except that P204 was replaced with the following compound:

[0187]

[0188] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0189] Under the same brightness, the driving voltage, current efficiency, and lifetime of the organic electroluminescent devices prepared in Examples 6-8 and Comparative Example 2 were measured using a digital source meter and a luminance meter. Specifically, the voltage was increased at a rate of 0.1V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 3000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: using a luminance meter at 10000 cd / m² 2 At a constant current, the brightness of the organic electroluminescent device decreased to 9500 cd / m² under the specified brightness. 2 The time is in hours.

[0190] The performance of organic electroluminescent devices is shown in Table 2 below:

[0191] Table 2. Performance of the organic electroluminescent devices in Examples 6-8 and Comparative Example 2

[0192]

[0193] The above results indicate that the novel organic material of this invention can also be used as a hole blocking layer material, which can improve the current efficiency and service life of the device while maintaining good reduction of start-up and drop voltage.

[0194] Examples 9-10

[0195] Organic electroluminescent devices were prepared according to the method described in Example 6, except that P204 was replaced with P16 or P18 respectively.

[0196] Comparative Example 3

[0197] Organic electroluminescent devices were prepared according to the method described in Example 6, except that P204 was replaced with the compound prepared in Comparative Example 1 as shown below:

[0198]

[0199] The performance of organic electroluminescent devices is shown in Table 3 below.

[0200] Table 3. Performance of the organic electroluminescent devices in Examples 9 and 10 and Comparative Example 3

[0201]

[0202] The above results indicate that materials such as P16 and P18, which lack electron-withdrawing groups, can also be used as hole-blocking layer materials. Compared with D2, these compounds with a large conjugated structure containing a seven-membered ring can improve device lifetime while maintaining good turn-on and turn-off voltage and current efficiency.

[0203] Although the invention has been described in conjunction with embodiments, the invention is not limited to the above embodiments. It should be understood that various modifications and improvements can be made by those skilled in the art under the guidance of the inventive concept, and the appended claims summarize the scope of the invention.

Claims

1. A compound having a structure shown in any of the following general formulas: in, R c and R d Independently selected from C1-C12 alkyl groups and C3-C12 cycloalkyl groups, R 1 R 2 R 3 and R 4 It is hydrogen; When R c R d When any one of them exists in multiple forms, they may be the same or different. R b Selected from the following groups, which are attached to the N atom at any substituted position: #imgpt3#.

2. The compound according to claim 1, having a structure selected from the following:

3. A compound having a structure selected from the following:

4. The application of the compound according to any one of claims 1 to 3 in organic electroluminescent devices.

5. An organic electroluminescent device comprising a first electrode, a second electrode, and one or more organic material layers inserted between the first electrode and the second electrode, wherein at least one of the organic material layers contains a compound according to any one of claims 1 to 3.

6. The organic electroluminescent device according to claim 5, wherein the organic material layer of the compound according to any one of claims 1 to 3 is a light-emitting layer and / or a hole-blocking layer.

7. The organic electroluminescent device according to claim 5 or 6, wherein the compound according to any one of claims 1 to 3 is used as the light-emitting host in the light-emitting layer.

Images