Organic electroluminescent compound with triazine and carbazolyl and organic light-emitting device

Abstract

The invention discloses an organic electroluminescent compound with triazine and carbazolyl and an organic light-emitting device. The organic electroluminescent compound is shown in the following formula A, wherein R1-R7 in the formula A are independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C5-C30 heteroaryl, and at least one of R1-R7 is deuterium; d1-D10 are respectively and independently selected from hydrogen and deuterium; ar1 and Ar2 are respectively and independently selected from substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C5-C30 heteroaryl groups, and substituent groups are selected from at least one of the following atoms or groups: deuterium, hydroxyl groups, cyano groups, monodeuterium methyl groups, dideuterium methyl groups, trideuterium methyl groups, C1-C4 straight-chain or branched-chain alkyl groups, C6-C18 aryl groups and C5-C24 heteroaryl groups. The 1 # position of the deuterated carbazole in the compound is substituted by phenyl or deuterated phenyl, so that the singlet energy level of the material is greatly improved, the reverse transmission of energy from a doped material to a main body material is effectively avoided, the efficiency of a device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and in particular to an organic electroluminescent compound with triazine and carbazole groups and an organic light-emitting device. Background Art

[0002] Organic light-emitting diodes (OLEDs) are a display technology that uses an electric field to stimulate the emission of fluorescent materials. Their operating principle is that, under the influence of an electric field, holes injected from the positive electrode recombine with electrons injected from the negative electrode in the light-emitting layer, generating light. OLEDs, with their advantages such as low startup voltage, high brightness, wide viewing angle, fast response, and good temperature adaptability, are widely used in mobile phones, tablet computers, TV displays, and lighting.

[0003] The structure of an organic electroluminescent device includes a cathode, an anode, and an organic layer disposed between them. The organic layer structure of OLED devices currently used in the industry is typically multilayered, including, for example, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. For an OLED device containing these layers, when a voltage is applied between the two electrodes, holes are injected from the anode into the organic layer, and electrons are injected from the cathode into the organic layer. When the holes and electrons meet, excitons are formed. When the excitons transfer energy to the dopant material, light is emitted through radiative transitions in the dopant material.

[0004] The invention patent numbered CN119384416A discloses a compound having the following general structure: And discloses the following specific structural formula However, no compound with phenyl substitution at position 1 of carbazole was found.

[0005] The invention patent number "KR1020240131250A" discloses a compound having the following general structure: And specifically discloses the following specific structure;

[0006] However, there is no compound in which the 1-position of carbazole contains a phenyl group and other positions of carbazole are deuterated.

[0007] When these materials are applied to organic electroluminescent devices, the compatibility between the green light hosts is poor, resulting in inefficient energy transfer to the doping material and a decrease in the efficiency of the conductive OLED device. It is necessary to develop organic electroluminescent materials with better performance. Summary of the Invention

[0008] The purpose of the present invention is to solve the above technical problems. The present invention provides an organic electroluminescent compound with triazine and carbazole groups, as shown in the following formula A:

[0009] In formula A, R1-R7 are each independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C5-C30 heteroaryl, and at least one of R1-R7 is deuterium; D1-D10 are each independently selected from hydrogen and deuterium; Ar1 ​​and Ar2 are each independently selected from substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C5-C30 heteroaryl, and the substituent is selected from at least one of the following atoms or groups: deuterium, hydroxyl, cyano, monodeuteriomethyl, dideuteriomethyl, trideuteriomethyl, C1-C4 straight or branched alkyl, C6-C18 aromatic, or C5-C24 heteroaryl.

[0010] As a preferred embodiment of the present invention, in formula A, R1-R7 are independently selected from hydrogen, deuterium, phenyl, and deuterated phenyl, and at least one of R1-R7 is deuterium.

[0011] As a preferred embodiment of the present invention, in formula A, R1-R7 are all deuterium, or one of R1-R7 is phenyl or deuterated phenyl and the others are all deuterium.

[0012] As a preferred embodiment of the present invention, Ar1 and Ar2 are each independently selected from substituted or unsubstituted phenyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, and the substituent is selected from at least one of the following atoms or groups: deuterium, hydroxyl, cyano, monodeuteriomethyl, dideuteriomethyl, trideuteriomethyl, C1-C4 straight or branched alkyl, C6-C18 aromatic, C5-C24 heteroaryl.

[0013] As a preferred embodiment of the present invention, Ar1 and Ar2 are independently selected from: deuterated or undeuterated phenyl, deuterated or undeuterated biphenyl, deuterated or undeuterated dibenzofuranyl.

[0014] As a preferred embodiment of the present invention, the triazine-based organic electroluminescent compound is one of the following structural compounds:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021] The present invention provides an organic electroluminescent device, comprising a first electrode, a second electrode and an organic layer formed between the first electrode and the second electrode, wherein the organic layer contains any one of the above-mentioned organic electroluminescent compounds.

[0022] As a preferred embodiment of the present invention, the organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer; at least one of the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer contains any of the above-mentioned organic electroluminescent compounds.

[0023] As a preferred embodiment of the present invention, the light-emitting layer further contains at least one of the following formulas B or C: wherein Y1 and Y2 are each independently a single bond, a substituted or unsubstituted C6 to C20 arylene group; Y3 and Y4 are each independently a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C24 heteroaryl group; Ar3 to Ar 16 Each is independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C24 heteroaryl group, a cyano group, or a combination thereof, wherein the substituent is a C6 to C20 aryl group.

[0024] As a preferred embodiment of the present invention, the light-emitting layer contains a light-emitting host material, and the light-emitting host material is a mixture of any one of the compounds described above and one or more of compounds P1-P78. The compounds P1-P78 are as follows:

[0025]

[0026]

[0027]

[0028] Beneficial effects of the present invention:

[0029] 1. The substitution of phenyl or deuterated phenyl at position 1 of the deuterated carbazole in the compound of the present invention greatly increases the singlet energy level of the material, thereby effectively avoiding the reverse transfer of energy from the dopant material to the host material, thereby improving the efficiency and life of the device.

[0030] 2. In the present invention, the electron-rich carbazole group in the N-type material structure is deuterated, and the core region (HOMO electron distribution region) of the corresponding P-type is also deuterated. The simultaneous deuteration of the two types of materials greatly improves the chemical stability, photoelectric stability and thermal stability of the material structure, improves the stability of the device, and thus increases the lifespan.

[0031] 3. It can form a good Premix material with the P-type compound of the present invention, has good P / N stability and mass production stability during the evaporation process, and the formed Premix material has a more balanced carrier mobility, expands the recombination area of ​​the exciton, and thus greatly improves the efficiency and life of the device.

[0032] 4. The compound of the present invention has good solubility, which effectively reduces the material preparation cost and the mask cleaning cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic structural diagram of an organic electroluminescent device provided by the present invention;

[0034] The numbers in the figure represent: 1-anode, 2-hole injection layer, 3-hole transport layer, 4-second hole transport layer, 5-light-emitting layer, 6-hole blocking layer, 7-electron transport layer, 8-electron injection layer, 9-cathode.

[0035] Figure 2 is the HPLC spectrum of compound 1 of the present invention.

[0036] Figure 3 The HPLC spectrum of compound 2 of the present invention is shown in FIG.

[0037] Figure 4 is the TGA spectrum of compound 1 of the present invention, Figure 4 It can be seen that the thermal gravimetric loss temperature Td value of compound 1 is 428.42°C.

[0038] Figure 5 is the TGA spectrum of compound 2 of the present invention, Figure 5 It can be seen that the thermal gravimetric loss temperature Td value of compound 2 is 488.35°C.

[0039] Figure 6 is the DSC spectrum of compound 1 of the present invention, Figure 6 It can be seen that the Tm value of compound 1 is 227.09°C.

[0040] Figure 7 is the DSC spectrum of compound 2 of the present invention, Figure 7 It can be seen that the Tm value of compound 2 is 221.94°C.

[0041] Figure 8 is the DSC spectrum of compound 1 of the present invention, Figure 8 It can be seen that the Tg value of compound 1 is 131.26°C.

[0042] Figure 9 is the DSC spectrum of compound 2 of the present invention, Figure 9 It can be seen that the Tg value of compound 2 is 126.64°C. DETAILED DESCRIPTION

[0043] The following further illustrates and describes embodiments of various aspects. It should be understood that the description herein is not intended to limit the claims to the specific aspects described. On the contrary, it is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the present disclosure as defined by the appended claims.

[0044] As used herein, in "deuterated" or "undeuterated," the term "deuterated" means that at least one hydrogen in the group is re-coordinated with deuterium. The term "undeuterated" means that none of the hydrogens in the group are re-coordinated with deuterium.

[0045] As used herein, "aromatic group," "aryl," or "aromatic radical" refers to a group containing one or more aromatic rings, including but not limited to benzene, naphthalene, phenanthrene, fluorene, acenaphthene, pyridine, pyrimidine, pyrrole, furan, thiophene, and the like. The C5-C40 in a C5-C40 aromatic group means that the group contains 5-40 carbon atoms. Aromatic groups can be divided into monocyclic aromatic groups and polycyclic aromatic groups. Specific aromatic groups in the present invention include but are not limited to phenyl, biphenyl, terphenyl, anthracenyl, naphthyl, phenanthrenyl, fluorenyl, dibenzofuranyl, dibenzothiophenyl, 9,9-spirobifluorenyl, 9,9-dimethylfluorenyl, or 9,9-diphenylfluorenyl. Aromatic groups can be substituted or unsubstituted.

[0046] As used herein, "cycloalkyl" refers to a monocyclic or fused ring group ("fused" ring means that each ring in the system shares a pair of adjacent carbon atoms with the other rings in the system) that is entirely carbon, wherein one or more rings are saturated alicyclic rings, generally having 3-20 carbon atoms, preferably 3-12 carbon atoms, and more preferably 3-10 carbon atoms. Cycloalkyl groups can be divided into monocyclic alkyl groups having only one ring and fused cycloalkyl groups having multiple rings. Examples of monocyclic alkyl groups include, but are not limited to, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. Cycloalkyl groups can be substituted or unsubstituted.

[0047] "Cycloalkenyl" herein refers to a monocyclic or fused ring group ("fused" ring means that each ring in the system shares a pair of adjacent carbon atoms with the other rings in the system) of all carbon, wherein one or more rings do not have a completely connected π electron system and contain at least one alkenyl group, which generally has 3-20 carbon atoms, preferably 3-12 carbon atoms, more preferably 3-10 carbon atoms, and examples of cycloalkenyl groups include but are not limited to cyclopentene, cyclohexene, cyclohexadiene, and cycloheptatriene. Cycloalkenyl groups can be substituted or unsubstituted.

[0048] The "deuterated aromatic group" herein refers to an aromatic group in which one or more hydrogen atoms are replaced by deuterium.

[0049] The "deuterated phenyl group" herein refers to a group in which one or more hydrogen atoms in a phenyl group are replaced by deuterium.

[0050] The "heteroaryl" herein refers to a heteroaryl group obtained by replacing one or more carbon atoms in the structure of "aryl" with one or more heteroatoms (such as N, O or S).

[0051] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or those recommended by the manufacturer. All reagents or instruments used, if the manufacturer is not specified, are commercially available conventional products.

[0052] Example 1

[0053] Compound 1

[0054]

[0055] Compound 1 was prepared as follows:

[0056] Step S1:

[0057] Process and post-treatment: Under nitrogen protection, 1-phenyl-deuterated carbazole (25 g, 0.1 mol, 1 eq), halide (25 g, 0.1 mol, 1 eq), DMF 300 ml, and cesium carbonate (82 g, 0.25 mol, 2.5 eq) were added to the reaction flask. After the addition was completed, the reaction solution was heated and refluxed for 12 h. The reaction was completed by HPLC detection. After cooling, 200 ml of water was added for washing, filtered, and the filter cake was dried and purified by column chromatography using a petroleum ether / dichloromethane system to obtain approximately 38.48 g of intermediate 1 with a yield of 80%.

[0058] Step S2:

[0059] Process and post-treatment: Under nitrogen protection, intermediate 1 (38.34 g, 0.08 mol, 1 eq) was added to the reaction flask, 300 ml of ultra-dry tetrahydrofuran was added, the temperature was lowered to -78 ° C, 2.5 M n-butyl lithium (33.6 ml, 0.084 mol, 1.05 eq) was added dropwise, and after the addition was complete, the reaction was kept warm for 1 h, triisopropyl borate (17.47 g, 0.096 mol, 1.2 eq) was added dropwise, and after the addition was complete, the temperature was naturally raised to room temperature, saturated aqueous ammonium chloride solution was added, the liquids were separated, the organic phase was concentrated to dryness, and recrystallized from ethyl acetate to obtain approximately 28.54 g of intermediate 2, with a yield of 80%.

[0060] Step S3:

[0061] Process and post-treatment: Under nitrogen protection, the reaction flask was added with intermediate 2 (28.54g, 0.064mol, 1eq), triazine compound (17.1g, 0.064mol, 1eq), 300ml of toluene, 150ml of ethanol, potassium carbonate (22.08g, 0.16mol, 2.5eq), and Pd(PPh3)4 (0.7392g, 0.00064mol, 1%). After the addition was completed, the reaction solution was heated and refluxed to react overnight. The reaction was completed by HPLC sampling. The reaction solution was cooled and washed with water, separated, and the organic phase was passed through silica gel, concentrated to dryness, and subjected to column chromatography to obtain about 26g, with a yield of 65%.

[0062] Compounds 3, 4, 6, 15, 18, 23, 31, 34, 39, 42, 43, 46, and 85 were obtained in a similar manner. See Table 1 below for details:

[0063] Table 1

[0064]

[0065]

[0066]

[0067] Example 15 Compound 91

[0068]

[0069] Compound 91 was prepared as follows:

[0070] Step S1: For the process and post-processing, see 1-S1.

[0071] Step S2: For the process and post-processing, see 1-S2.

[0072] Step S3: For the process and post-processing, see 1-S3.

[0073] Compounds 9, 10, 12, 52, 93, 106, 108, and 122 were obtained in a similar manner. See Table 2 below for details:

[0074] Table 2

[0075]

[0076]

[0077]

[0078] The above-prepared compounds were synthesized and identified, and the results are shown in Table 3 below:

[0079] Table 3

[0080]

[0081]

[0082] The above materials were subjected to basic performance tests, including thermal weight loss temperature Td and glass transition temperature Tg. The test results are shown in Table 4 below.

[0083] Note: The thermal gravimetric temperature, Td, is the temperature at which the weight loss ratio is 5% in a nitrogen atmosphere, and is measured on a TGA N-1000 thermogravimetric analyzer with a nitrogen flow rate of 10 mL / min. The glass transition temperature, Tg, and melting point, Tm, are measured by differential scanning calorimetry (DSC, Xinke DSCN-650) with a heating rate of 10°C / min.

[0084] Table 4

[0085]

[0086] According to the above data, the compounds synthesized in the present invention have excellent thermal stability, which means that the compounds conforming to the general structural formula of the present invention all have excellent thermal stability and can meet the requirements for use as organic electroluminescent materials.

[0087] Device performance test:

[0088] Application Example 1:

[0089] ITO was used as the reflective layer anode substrate material and its surface was treated with water, acetone, and N2 plasma in sequence. A 10nm layer of HT-1 doped with 5% NDP-9 was deposited on top of the ITO anode substrate to form a hole injection layer (HIL).

[0090] A hole transport layer (HTL) was formed by evaporating 100 nm of HT-1 on the hole injection layer (HIL);

[0091] GP-1 was vacuum-evaporated on the hole transport layer (HTL) to form a second hole transport layer (GPL) with a thickness of 10 nm. Compound 1 prepared in Example 1 of the present invention and compound P-1 were co-evaporated at a ratio of 5:5 as the light-emitting host material, and GD-1 was evaporated as a doping material (the amount of GD-1 was 8% of the total weight of compound 1 and P-1) on the second hole transport layer (GPL) to form a light-emitting layer with a thickness of 20 nm.

[0092] HB-1 was evaporated onto the light-emitting layer to obtain a hole blocking layer (HBL) with a thickness of 20 nm;

[0093] ET-1 and LiQ were co-evaporated onto the hole blocking layer (HBL) in a ratio of 5:5 to obtain an electron transport layer (ETL) with a thickness of 30 nm;

[0094] Magnesium (Mg) and silver (Ag) were mixed in a ratio of 9:1 and evaporated onto the electron transport layer (ETL) to form an electron injection layer (EIL) with a thickness of 50 nm.

[0095] Silver (Ag) is then evaporated onto the electron injection layer to form a 100nm-thick cathode. A 50nm-thick layer of DNTPD is deposited on the cathode sealing layer. Furthermore, the cathode surface is sealed with a UV-curable adhesive and a seal cap containing a desiccant to protect the organic electroluminescent device from atmospheric oxygen or moisture. Thus, an organic electroluminescent device is prepared.

[0096]

[0097]

[0098] Application Example 2-23:

[0099] Compounds 3, 4, 6, 15, 18, 23, 31, 34, 39, 42, 43, 46, 85, 91, 9, 10, 12, 52, 93, 106, 108, and 122 in synthesis examples 2-23 of the present invention were used to replace compound 1 in application example 1 as green light main materials for co-evaporation. The other parts were consistent with application example 1, and the organic electroluminescent devices of application examples 2-93 were prepared accordingly.

[0100] Comparative Examples 1-5:

[0101] The difference from Application Example 1 is that D1-1, D1-2, and D1-3 in "CN119384416A" are used instead of Compound 1 in Application Example 1 as the green light host material for co-evaporation, and the rest is the same as Application Example 1. Based on this, the organic electroluminescent devices of Control Examples 1-3 are produced.

[0102] The difference from Application Example 1 is that D2-1 and D2-2 of "KR1020240131250A" are used instead of Compound 1 in Application Example 1 as the green light host material for co-evaporation. The rest is the same as Application Example 1. Based on this, the organic electroluminescent devices of Control Examples 4 and 5 are produced.

[0103] The characteristics of the organic electroluminescent device manufactured in the above application example and the organic electroluminescent device manufactured in the control example were measured under the condition of a current density of 10 mA / cm2. The results are shown in Table 5 below.

[0104] Table 5

[0105]

[0106]

[0107] As shown in Table 5 above, when the compound of the present invention is applied to an organic electroluminescent device, the luminous efficiency is greatly improved at the same current density, the starting voltage of the device is reduced, and the power consumption of the device is relatively reduced.

[0108] The organic electroluminescent devices prepared in Control Examples 1-5 and Application Examples 1-10 were subjected to luminescence lifetime tests to obtain T97% data (the time it takes for the luminescence brightness to drop to 97% of the initial brightness). The test equipment was a TEO light-emitting device lifetime test system. The results are shown in Table 7:

[0109] Table 7:

[0110]

[0111]

[0112] As can be seen from Table 7 above, when the compound of the present invention is applied to an organic electroluminescent device, the service life is greatly improved at the same current density, and the compound has broad application prospects.

[0113] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An organic electroluminescent compound containing triazine and carbazole groups, characterized in that: As shown in formula A below: In formula A, R1-R7 are independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl, and at least one of R1-R7 is deuterium; D1-D 10 Each is independently selected from hydrogen and deuterium; Ar1 ​​and Ar2 are each independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl, and the substituent is selected from at least one of the following atoms or groups: deuterium, hydroxyl, cyano, monodeuteriomethyl, dideuteriomethyl, trideuteriomethyl, C1-C4 straight or branched alkyl, C6-C18 aromatic, C5-C24 heteroaryl.

2. The organic electroluminescent compound having triazine and carbazole groups according to claim 1, wherein: In formula A, R1-R7 are independently selected from hydrogen, deuterium, phenyl, and deuterated phenyl, and at least one of R1-R7 is deuterium.

3. The organic electroluminescent compound having triazine and carbazole groups according to claim 1, wherein: In formula A, R1-R7 are all deuterium, or one of R1-R7 is phenyl or deuterated phenyl and the others are all deuterium.

4. The organic electroluminescent compound having triazine and carbazole groups according to claim 1, wherein: Ar1 and Ar2 are each independently selected from substituted or unsubstituted phenyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, and the substituent is selected from at least one of the following atoms or groups: deuterium, hydroxyl, cyano, monodeuteriomethyl, dideuteriomethyl, trideuteriomethyl, C1-C4 straight chain or branched alkyl, C6-C18 aromatic group, C5-C24 heteroaryl group.

5. The organic electroluminescent compound having triazine and carbazole groups according to claim 1, wherein: Ar1 and Ar2 are each independently selected from: deuterated or undeuterated phenyl, deuterated or undeuterated biphenyl, deuterated or undeuterated dibenzofuranyl.

6. The organic electroluminescent compound having triazine and carbazole groups according to claim 1, wherein: The triazine-based organic electroluminescent compound is one of the following structural compounds:

7. An organic electroluminescent device, characterized in that: The device comprises a first electrode, a second electrode and an organic layer formed between the first electrode and the second electrode, wherein the organic layer contains the organic electroluminescent compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, wherein: The organic layer comprises a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer; at least one of the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer contains the organic electroluminescent compound according to any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 8, characterized in that: The light-emitting layer further contains at least one of the following formulas B or C: wherein Y1 and Y2 are each independently a single bond, a substituted or unsubstituted C6 to C20 arylene group; Y3 and Y4 are each independently a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C24 heteroaryl group; Ar3 to Ar 16 Each is independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C24 heteroaryl group, a cyano group, or a combination thereof, wherein the substituent is a C6 to C20 aryl group.

10. The organic electroluminescent device according to claim 9, wherein: The light-emitting layer contains a light-emitting host material, which is a mixture of the compound according to any one of claims 1 to 6 and one or more compounds P1 to P78. The compounds P1 to P78 are as follows:

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