A compound, an organic light emitting device, and a display apparatus

Abstract

The application discloses a compound, an organic light-emitting device and a display device, and belongs to the field of OLED materials.The compound has a structure shown in formula I.The compound has good thermal stability and film stability, excellent light emission performance, and can be used for preparing an OLED light-emitting device, especially as a light-emitting layer material in the OLED device, and can effectively improve the light emission efficiency and service life of the organic light-emitting device.

Description

Technical Field

[0001] This invention relates to a compound that can be used in organic light-emitting elements and organic light-emitting devices and display devices using the compound, and more particularly to a triazine compound that can be used as a light-emitting layer in an organic light-emitting element to achieve element characteristics such as high luminous efficiency, long lifespan and low voltage drive, as well as organic light-emitting devices using the compound and organic light-emitting elements and display devices including the compound. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are display components that utilize self-emissive properties. They have a wider viewing angle and are thinner, lighter, and faster than liquid crystal displays. They can also achieve flexible displays, making them highly anticipated for use as full-color display components or lighting equipment.

[0003] Organic light emission typically refers to the phenomenon of converting electrical energy into light energy using organic materials. Organic light-emitting devices that utilize organic light emission usually have a structure that includes an anode, a cathode, and an organic layer sandwiched between the anode and the cathode.

[0004] To improve the efficiency and stability of organic light-emitting elements (OLEDs), the organic layer is often composed of a multi-layered structure made of different materials. For example, it may consist of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. When a voltage is applied between the two electrodes in this OLED structure, holes from the anode are injected into the organic layer, and electrons from the cathode are also injected into the organic layer. When the injected holes and electrons meet in the light-emitting layer, they form excitons. When these excitons release energy and transition to the ground state, they emit photons, thus producing light. This type of OLED is widely recognized for its self-emissive nature, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and high-speed response.

[0005] Currently, research on organic electroluminescent materials has been widely carried out in academia and industry. Among them, luminescent materials are an important component of organic electroluminescent devices. However, there is still much room for improvement in the stability and luminescent performance of luminescent materials, which restricts the industrialization of luminescent devices. Therefore, designing and searching for a compound as a novel OLED material to overcome its shortcomings in practical applications is a key focus and future research trend in OLED materials research. Summary of the Invention

[0006] The purpose of this invention is to provide a compound and an organic light-emitting device and display device using the compound. The compound has good thermal stability, and the light-emitting device prepared using the compound has high luminous efficiency and long service life.

[0007] This invention provides a compound with the general structural formula shown in Formula I:

[0008]

[0009] Where X is selected from O, S, or

[0010] Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C6. 30 Aromatic hydrocarbon groups or C3-C 30 Aromatic heterocyclic groups;

[0011] R1 and R2 are each independently selected from substituted or unsubstituted C1 to C2. 12 alkyl group, substituted or unsubstituted C6-C 30 Aromatic hydrocarbon groups or C3-C 30 Aromatic heterocyclic groups;

[0012] Furthermore, the hydrogen atoms in compound I can be independently replaced by deuterium atoms, F, CN, and C1~C. 12 Alkyl, C1-C 12 Alkyl groups or C6-C 30 Aryl or C3~C 30 A substitution in an aromatic heterocyclic group.

[0013] Preferably, C6 to C 30 The aromatic hydrocarbon group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, indole, fluorenyl, perylene, phenanthryl, pyrene, fluoranyl, or benzophenanthryl.

[0014] Preferably, C3 to C 30 The heteroatom in an aromatic heterocyclic group is selected from oxygen, sulfur, nitrogen, or silicon.

[0015] Preferably, C3 to C 30 The aromatic heterocyclic group is selected from any one of triazinyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazoyl, silfluorenyl, benzofuran-dibenzothiophenyl, benzofuran-dibenzofuranyl, benzofuran-carbazoyl, and benzofuran-thiophenyl.

[0016] Preferably, C3 to C 30 The aromatic heterocyclic group is preferably one of dibenzofuranyl, dibenzothiophenyl, or carbazoleyl.

[0017] Preferably, the substituents in Ar1, Ar2, R1, and R2 are each independently selected from C1-C4 alkane groups and C6-C4 alkane groups. 12 At least one of the aryl groups.

[0018] Preferably, the compound is as shown in any one of formulas 1 to 160:

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] This invention lists some specific structural forms of the compounds, but the compounds described in this invention are not limited to these listed chemical structures. Any structure based on the structure shown in Formula I, where Ar1, Ar2, and X satisfy the above-mentioned limiting conditions should be included.

[0027] Secondly, the present invention provides an intermediate for preparing the compound of the present invention, having the following structure:

[0028]

[0029] Thirdly, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising the compound as described in the first aspect.

[0030] Preferably, the organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode;

[0031] The material of the organic layer includes compounds as described in the first aspect.

[0032] Preferably, the organic layer includes a light-emitting layer;

[0033] The main material of the light-emitting layer includes the compounds described in the first aspect.

[0034] Fourthly, the present invention provides a display device comprising the organic electroluminescent device as described in the second aspect.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] This invention designs the structure of compounds to obtain compounds with good luminescent properties, which can be used to prepare organic electroluminescent devices. In particular, as a light-emitting layer material in organic electroluminescent devices, it can effectively reduce the driving voltage of organic electroluminescent devices and improve the current efficiency of organic electroluminescent devices. Detailed Implementation

[0037] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0038] Preparation Example 1: Synthesis of Intermediate 1

[0039]

[0040] 0.1 mol of 1,6-dibromodibenzofuran, 0.3 mol of o-chloroaniline, 0.3 mol of sodium tert-butoxide, 0.01 mol of palladium acetate, 0.05 mol of tri-tert-butylphosphine (a 10% toluene solution containing 0.05 mol of pure tri-tert-butylphosphine) and 500 mL of xylene were added to a reaction flask. The mixture was refluxed under nitrogen protection for 20 h. The reaction was then stopped, cooled, and the mixture was separated and washed with water. The organic phase was concentrated to dryness, and 100 mL of ethanol was added. The mixture was refluxed for 2 h and then cooled to room temperature and filtered to obtain intermediate 1-1.

[0041] Mass spectrometry of intermediate 1-1 was measured, m / z: 418.06.

[0042] 0.04 mol of intermediate 1-1, 0.008 mol of palladium acetate, 0.24 mol of cesium carbonate, 0.16 mol of tricyclohexylphosphine-boron tetrafluoride salt, and 200 mL of N,N-dimethylacetamide were added to a reaction flask. The mixture was heated to reflux for 12 h under nitrogen protection. The reaction was then stopped, and the mixture was cooled to room temperature. The reaction solution was poured into 500 mL of water, stirred for 30 min, and then filtered directly. The obtained solid was dissolved in toluene and passed through a silica gel column. The filtrate was concentrated and recrystallized from ethanol to obtain intermediate 1.

[0043] Mass spectrometry analysis of intermediate 1 yielded the following results: m / z: 346.11. Analyzed elemental composition (%): C, 83.20; H, 4.05; N, 8.13.

[0044] Intermediate 1 was subjected to NMR analysis, and the data are as follows: 1H-NMR (Bruker, Switzerland, Avance II 400MHz NMR spectrometer, CDCl3), δ8.58 (s, 1H), δ8.23 (m, 2H), δ8.09 (s, 1H), δ7.62 (d, 1H), δ7.53 (d, 1H), δ7.38 (m, 2H), δ7.30 (d, 1H), δ7.22~7.09 (m, 5H).

[0045] Synthesis of intermediate 2 in Preparation Example 2

[0046]

[0047] Referring to Preparation Example 1, 1,6-dibromodibenzofuran was replaced with 1-iodo-6-bromo-dibenzothiophene in Preparation Example 1, while other operations remained unchanged, to prepare intermediate 2-1.

[0048] Mass spectrometry analysis of intermediate 2-1 yielded the following results: m / z: 434.04.

[0049] Intermediate 2 was then prepared by referring to the method used to prepare intermediate 1 in Example 1.

[0050] The intermediate 2 was analyzed by mass spectrometry, and the mass spectrometry results are as follows: mass spectrometry m / z: 362.09.

[0051] Synthesis of intermediate 3 in Preparation Example 3

[0052]

[0053] Referring to Preparation Example 1, 1,6-dibromodibenzofuran was replaced with 1,5-diiodo-9,9-dimethylfluorene in Preparation Example 1, while other operations remained unchanged, to prepare intermediate 3-1.

[0054] Mass spectrometry was performed on intermediate 3-1, and the results are as follows: m / z: 444.12.

[0055] Intermediate 3 was then prepared by referring to the method used to prepare intermediate 1 in Example 1.

[0056] The intermediate 3 was analyzed by mass spectrometry, and the mass spectrometry results are as follows: mass spectrometry m / z: 372.16.

[0057] Synthesis Example 1: Synthesis of Compound 1

[0058]

[0059] 0.01 mol of intermediate 1, 0.03 mol of bromobenzene, 0.05 mol of sodium tert-butoxide, 0.005 mol of tris(dibenzylacetone)palladium, 0.005 mol of tri-tert-butylphosphine (a 10% toluene solution containing 0.005 mol of pure tri-tert-butylphosphine), and 30 mL of xylene were added to a reaction flask. The mixture was heated to reflux under nitrogen protection for 6 h. The reaction was then stopped, cooled, and directly filtered. The resulting filter cake was washed with water and ethanol, dried, dissolved in toluene, and passed through a column. The filtrate was concentrated and recrystallized from toluene to obtain compound 1.

[0060] The mass spectrometry results of compound 1 are as follows: m / z: 498.17.

[0061] Synthesis Example 2: Synthesis of Compound 4

[0062]

[0063] Referring to Synthesis Example 1, bromobenzene in Synthesis Example 1 was replaced with 4-bromobiphenyl, while other operations remained unchanged, to obtain compound 4.

[0064] The mass spectrometry results for compound 4 are as follows: m / z: 650.24.

[0065] Synthesis Example 3: Synthesis of Compound 35

[0066]

[0067] Referring to Synthesis Example 1, bromobenzene in Synthesis Example 1 was replaced with 3,5-diphenyl-1-bromobenzene, and intermediate 1 in Synthesis Example 1 was replaced with intermediate 2, with other operations remaining unchanged, to obtain compound 35.

[0068] The mass spectrometry results of compound 35 are as follows: m / z: 818.28.

[0069] Synthesis Example 4: Synthesis of Compound 121

[0070]

[0071] Referring to Synthesis Example 1, bromobenzene in Synthesis Example 1 was replaced with 2-bromo-9,9-dimethylfluorene, and intermediate 1 in Synthesis Example 1 was replaced with intermediate 3, with other operations remaining unchanged, to obtain compound 121.

[0072] The mass spectrometry results of compound 121 are as follows: m / z: 756.35.

[0073] Other compounds can be obtained using similar synthetic methods.

[0074] In this invention, the specific structure of the materials used in the following device application examples is as follows:

[0075]

[0076] In this invention, N-1 is used as the N-type host material, the compound described in this invention is used as the P-type host material, and P-1, P-2, P-3, P-4, P-5, and P-6 are used as comparative P-type host materials. Organic electroluminescent devices are fabricated using Firpic as the light-emitting layer doping material. Specific device embodiments are as follows.

[0077] Device Example 1

[0078] The device embodiment provides an organic electroluminescent device, using compound 1 provided in synthesis embodiment 1 of the present invention as the main material of the P-type light-emitting layer; the structure of the organic electroluminescent device is as follows:

[0079] ITO / HT (40nm) / Emitting layer host material (compound 1:N-1):Firpic 5% (30nm) / TPBI (30nm) / LiF (0.5nm) / Al (150nm).

[0080] The fabrication method of the above-mentioned organic electroluminescent device is as follows:

[0081] The glass substrate coated with an ITO transparent conductive layer (as the anode) was ultrasonically treated in a cleaning agent, then rinsed in deionized water, then ultrasonically degreased in a mixed solvent of acetone and ethanol, then baked in a clean environment until completely dehydrated, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the surface properties and enhance the bonding ability with the hole layer.

[0082] The glass substrate with the anode was placed in a vacuum chamber and evacuated to 1×10-5 to 9×10-4 Pa. A hole transport layer HT was vacuum-deposited on the anode film at a deposition rate of 0.1 nm / s and a film thickness of 40 nm.

[0083] The host material and dopant material Firpic are vacuum-deposited on the hole transport layer to serve as the light-emitting layer of the organic electroluminescent device. The deposition rate is 0.1 nm / s and the total film thickness is 30 nm. The host material of the light-emitting layer (compound 1:N-1):Firpic 5% (30 nm) refers to the co-evaporation of compound 1:N-1:Firpic in the device at a mass ratio of 60:35:5 to form the light-emitting layer, and the thickness of the light-emitting layer is 30 nm.

[0084] Electron transport layers (TPBI) were sequentially vacuum-deposited on top of the light-emitting layer at a deposition rate of 0.1 nm / s and a film thickness of 30 nm.

[0085] 0.5 nm of LiF was vacuum-deposited on the electron transport layer, and 150 nm of Al was used as the electron injection layer and cathode.

[0086] Device Examples 2-10

[0087] Device Examples 2-10 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the P-type main material of the light-emitting layer is different (see Table 1 below), while other conditions are the same as those in Device Example 1.

[0088] Device Comparison Examples 1-4

[0089] Comparative Examples 1-4 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the P-type main material of the light-emitting layer is different (see Table 1 below), while other conditions are the same as Device Example 1.

[0090] Performance testing

[0091] Test Methods: The driving voltage, current efficiency, and lifetime (LT95) of the OLED devices provided above were tested using the OLED-1000 multi-channel accelerated aging lifetime and color performance analysis system manufactured by Hangzhou Yuanfang. LT95 refers to the time required for the brightness to decrease to 95% of its original brightness while maintaining an initial brightness of 1000 nits at a constant current density. Test items included the brightness, driving voltage, and current efficiency of the organic electroluminescent device. The driving voltage, current efficiency, and LT95 data were all based on a brightness of 1000 cd / m². 2 The relative values ​​at different times. The performance test results of organic electroluminescent devices are shown in Table 1 below:

[0092] Table 1

[0093]

[0094]

[0095] As can be seen from the above, this invention, through structural design, obtains a compound suitable as the main material for the P-type light-emitting layer. The organic electroluminescent device prepared thereby has a lower driving voltage, higher current efficiency, and longer service life.

[0096] Device Examples 11-15

[0097] Device Examples 11-15 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the P-type main material of the light-emitting layer is different (see Table 2 below), while other conditions are the same as those in Device Example 1.

[0098] Device Comparison Example 5

[0099] Comparative Example 5 provides an organic electroluminescent device, which differs from Example 1 only in that the P-type body material of the light-emitting layer is different (see Table 2 below). All other conditions are the same as those in Example 1.

[0100] The performance of the organic electroluminescent devices provided in Device Examples 11-15 and Device Comparative Examples was tested using the same methods as above. The test results are detailed in Table 2 below.

[0101] Table 2

[0102]

[0103]

[0104] As can be seen from the above, this invention, through structural design, obtains a compound suitable for the P-type host material of the light-emitting layer. The organic electroluminescent device prepared thereby has a lower driving voltage, higher current efficiency, and longer service life.

[0105] Device Examples 16-20

[0106] Device Examples 16-20 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the P-type main material of the light-emitting layer is different (see Table 3 below), while other conditions are the same as those in Device Example 1.

[0107] Device Comparison Example 6

[0108] Comparative Example 6 provides an organic electroluminescent device, which differs from Device Example 1 only in that the P-type main material of the light-emitting layer is different (see Table 3 below), while other conditions are the same as Device Example 1.

[0109] The performance of the organic electroluminescent devices provided in Device Examples 16-20 and Device Comparative Examples was tested using the same methods as above. The test results are detailed in Table 3 below.

[0110] Table 3

[0111]

[0112] As can be seen from the above, this invention, through structural design, obtains a compound suitable as the main material for the P-type light-emitting layer. The organic electroluminescent device prepared thereby has a lower driving voltage, higher current efficiency, and longer service life.

[0113] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A compound, characterized in that, Its general structural formula is shown in Formula I: Formula I Where X is selected from ; Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6~C. 30 Aromatic hydrocarbon groups or C3~C 30 The aromatic heterocyclic group, C6~C 30 The aromatic hydrocarbon group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, and phenanthrene, wherein the C3~C 30 The aromatic heterocyclic group is selected from one of silylfluorenyl, dibenzofuranyl, and dibenzothiopheneyl; the substituents in Ar1 and Ar2 are each independently selected from at least one of C1-C4 alkane groups; R1 and R2 are each independently selected from methyl groups; Furthermore, the hydrogen atoms in compound I can be replaced by deuterium atoms.

2. The compound according to claim 1, characterized in that, The structure of the compound represented by Formula I is shown below: ； Furthermore, the hydrogen atoms in the above compounds can be completely or partially replaced by deuterium atoms.

3. An intermediate, characterized in that, It has the following structure: The intermediate is used to synthesize the compound according to claim 1 or 2.

4. An organic light-emitting device, characterized in that, It includes the compound as described in claim 1 or 2.

5. The organic light-emitting device according to claim 4, characterized in that, The organic light-emitting device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode; the organic layer comprises the compound according to claim 1 or 2.

6. The organic light-emitting device according to claim 5, characterized in that, The organic layer is a light-emitting layer, and the main material of the light-emitting layer includes the aforementioned compound.

7. A display device, characterized in that, Includes the organic light-emitting device according to any one of claims 4 to 6.

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