A compound containing triazine and carbazole structure and application thereof

Abstract

The application relates to a compound containing a triazine and carbazole structure and an application thereof, and belongs to the technical field of semiconductors. The application provides a compound structure as shown in a general formula (1). After the compound is applied to a light-emitting layer of an OLED device, lower device voltage and higher device efficiency can be achieved, and the service life of the device can be greatly improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a compound containing triazine and carbazole structures and its applications. Background Technology

[0002] In organic light-emitting diodes (OLEDs), a hole transport region can exist between the anode and the emissive layer, and an electron transport region can exist between the emissive layer and the cathode. Holes from the anode can migrate to the emissive layer through the hole transport region, while electrons from the cathode can migrate to the emissive layer through the electron transport region. Holes and electrons recombine in the emissive layer to generate excitons. Based on the spin coupling effect of heavy metal atoms, organometallic compound materials can directly transition from the triplet state to the ground state, theoretically achieving 100% internal quantum yield.

[0003] Nevertheless, for triple-state phosphorescent OLEDs, there remains a need for improvement in device voltage, current efficiency, and lifetime. The performance of the host material in the emissive layer typically has a significant impact on these key performance characteristics of organic electroluminescent devices. According to existing technologies, compounds used as host materials usually contain triazine groups. When existing triazine derivatives are used as host materials, there is a need for improvements in device voltage, current efficiency, and device lifetime. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention provides a compound containing triazine and carbazole structures and its applications. This invention provides a host alternative material with low voltage, high efficiency, and especially longer lifespan.

[0005] The technical solution of this invention is as follows:

[0006] A compound containing triazine and carbazole structures, the structure of which is shown in general formula (1):

[0007]

[0008] In general formula (1), R1 represents the structure shown in formula 1-1, formula 1-2 or formula 1-3;

[0009]

[0010] L is represented by the structure shown in Equation 1-4, Equation 1-5, Equation 1-6 or Equation 1-7;

[0011]

[0012]

[0013] R2 is represented by the structure shown in Equation 1-8, Equation 1-9, Equation 1-10 or Equation 1-11;

[0014]

[0015] In general formula (1), the hydrogen atoms in phenyl, L, R1, and R2 can also be replaced by deuterium.

[0016] The structures of the compounds containing triazine and carbazole are represented by any one of general formulas (2-1) to (2-7):

[0017]

[0018] In general formulas (2-1) to (2-7), the meanings of R1 and R2 are the same as those defined above;

[0019] In general formulas (2-1) to (2-7), hydrogen atoms can also be replaced by deuterium.

[0020] In a preferred embodiment, the hydrogen atoms in the phenyl group, L, R1, and R2 of the general formula (1) may be wholly or partially substituted with deuterium. In a preferred embodiment, the structure of the compound is represented by any one of general formulas (3-1) to (3-5):

[0021]

[0022] In general formulas (3-1) to (3-5), the meanings of R1 and R2 are the same as those defined above;

[0023] In general formulas (3-1) to (3-5), hydrogen atoms can also be replaced by deuterium.

[0024] In a preferred embodiment, the compound containing triazine and carbazole structures has any one of the following structures:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] An organic electroluminescent device includes a cathode, an anode, and a functional layer, wherein the functional layer is located between the cathode and the anode, and at least one functional layer contains the compound containing triazine and carbazole structures.

[0032] In a preferred embodiment, the functional layer includes a light-emitting layer containing the aforementioned compound with triazine and carbazole structures;

[0033] Preferably, the light-emitting layer comprises a host material and a dopant material, wherein the host material contains the compound containing triazine and carbazole structures.

[0034] In a preferred embodiment, the main material of the light-emitting layer is formed by mixing the compound containing triazine and carbazole structures with any one or more of compounds GH-1 to GH-170, wherein the specific structures of compounds GH-1 to GH-170 are as follows:

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] An illumination or display element comprising the aforementioned organic electroluminescent device.

[0045] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0046] 1) Starting from the bridging group L, this invention discovers that a specific bridging group L can significantly change the material properties, providing a main alternative material with low voltage, high efficiency, and long lifespan. Compared with compounds in the prior art, it has a longer room temperature lifespan and high temperature lifespan, while having lower voltage and higher current efficiency, which helps to improve the overall performance of the device. In particular, the combination of the two materials can greatly improve the device lifespan.

[0047] 2) The compounds provided by this invention, by introducing deuterium atoms, can help improve the device and extend its lifespan when applied to the light-emitting layer. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the structure of an OLED device (Top device) in which the materials listed in this invention are applied;

[0049] Wherein, 1 is a transparent substrate layer, 2 is an anode layer, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an electron blocking layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, 10 is a cathode layer, and 11 is a CPL layer. Detailed Implementation

[0050] All raw materials involved in the synthesis embodiments of this invention can be purchased from the market.

[0051] The principles and features of the present invention are described below with reference to the accompanying drawings and embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0052] Any numerical range listed herein is intended to include all subranges with the same numerical precision within the listed range. For example, "1.0 to 10.0" means including all subranges (and inclusive) between the listed minimum value of 1.0 and the listed maximum value of 10.0, that is, all subranges with a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0. Any maximum numerical limit listed herein is intended to include all smaller numerical limits included herein, and any minimum numerical limit listed herein is intended to include all larger numerical limits included herein. Therefore, the applicant reserves the right to amend this specification, including the claims, to expressly describe any subranges falling within the scope expressly described herein.

[0053] In the accompanying drawings, for clarity, the dimensions of layers and regions may be exaggerated. It will also be understood that when a layer or element is referred to as being "above" another layer or substrate, the layer or element may be directly above that other layer or substrate, or intermediate layers may be present. Furthermore, it will be understood that when a layer is referred to as being "between" two layers, the layer may be the only layer between the two layers, or one or more intermediate layers may be present. The same reference numerals throughout the drawings denote the same elements.

[0054] In this invention, the terms "upper," "lower," "top," and "bottom," used to describe electrodes, organic electroluminescent devices, and other structures, indicate orientation only in a specific state and do not imply that the structure can only exist in that orientation. Conversely, if the structure can be repositioned, such as by inverting it, the orientation of the structure changes accordingly. Specifically, in this invention, the "bottom" or "lower" side of the electrode refers to the side of the electrode closer to the substrate during fabrication, while the opposite side farther from the substrate is the "top" or "upper" side.

[0055] Synthesis of intermediate-8B

[0056]

[0057] Add starting material-1 (10.0 mmol) to a flask, followed by starting material-2 (10.0 mmol), K2CO3 (50.0 mmol), toluene (150 mL), Pd2(dba)3 (0.3 mmol), and S-Phos (0.6 mmol); reflux overnight under nitrogen protection. After the reaction is complete and cooled to room temperature, dilute the reaction solution with ethyl acetate, wash the organic phase with saturated brine, dry with anhydrous sodium sulfate, filter and concentrate the organic phase, and purify the residue by silica gel column chromatography to obtain intermediate-8B;

[0058] Intermediates 1A to 8A, 1B and 2B are all commercially available or can be prepared by conventional synthetic methods in the art.

[0059] Example 1: Synthesis of Compound 5:

[0060]

[0061] Intermediate-1A (5.0 mmol) was added to a flask, followed by intermediate-1B (5.0 mmol), saturated aqueous solution of K₂CO₃ (25.0 mmol), THF (80 mL), and Pd(PPh₃)₄ (0.2 mmol). The mixture was refluxed under nitrogen protection for 36 hours. After the reaction was completed and cooled to room temperature, the mixture was extracted with dichloromethane (150 mL × 3), dried over anhydrous sodium sulfate, filtered, and the organic phase was concentrated. The residue was purified by silica gel column chromatography to give compound 5.

[0062] The following target compounds were synthesized according to the preparation process in Example 1; the reaction conditions were the same, except that intermediates A and B listed in Table 1 were used.

[0063] Table 1

[0064]

[0065]

[0066] Device Example 1

[0067] like Figure 1As shown, the transparent substrate layer 1 is a transparent PI film. The anode layer 2 (ITO (15nm) / Ag (150nm) / ITO (15nm)) is washed sequentially with a cleaning agent (SemiClean M-L20), pure water, and dried, followed by ultraviolet-ozone washing to remove organic residues from the anode layer surface. After the above washing, HT-1 and P-1 are deposited as a hole injection layer 3 using a vacuum evaporation apparatus, with a film thickness of 10nm and a mass ratio of HT-1 to P-1 of 97:3. Next, HT-1 is deposited as a hole transport layer 4 with a thickness of 130nm. Subsequently, EB-1 is deposited as an electron blocking layer 5 with a thickness of 40nm. After the electron blocking layer materials are deposited, the light-emitting layer 6 of the OLED light-emitting device is fabricated. Its structure includes compound 5 and GH-2 as the main materials, and GD-1 as a dopant material with a doping ratio of 6% (mass ratio). The light-emitting layer film thickness is 40nm. Following the aforementioned light-emitting layer 6, HB-1 is vacuum-deposited to a thickness of 5 nm; this layer serves as the hole-blocking layer 7. Following the hole-blocking layer 7, ET-1 and Liq are vacuum-deposited at a mass ratio of 1:1, resulting in a thickness of 35 nm; this layer serves as the electron transport layer 8. On the electron transport layer 8, a 1 nm thick LiF layer is fabricated using a vacuum evaporation apparatus; this layer serves as the electron injection layer 9. On the electron injection layer 9, a 15 nm thick Mg:Ag electrode layer is fabricated using a vacuum evaporation apparatus, with a Mg:Ag mass ratio of 1:9; this layer serves as the cathode layer 10. On the cathode layer 10, CP-1 is vacuum-deposited as the CPL layer 11, with a thickness of 70 nm. This yields the organic electroluminescent device 1.

[0068] The molecular structural formulas of the relevant materials are shown in Table 2 below:

[0069] Table 2

[0070]

[0071] After completing the OLED light-emitting device as described above, the anode and cathode were connected using a known driving circuit, and the device's voltage, current efficiency, emission spectrum, and lifetime were measured. Examples and comparisons of devices prepared using the same method are shown in Table 3; the difference lies in that different N-type host materials were used to replace compound 5, and different P-type host materials were used to replace GH-2. The test results for the voltage, current efficiency, and lifetime of the resulting devices are shown in Table 4.

[0072] Table 3

[0073]

[0074]

[0075] Table 4

[0076]

[0077]

[0078] Note: Voltage and current efficiency are based on a current density of 10 mA / cm². 2 The test was conducted under the following conditions using an IVL (current-voltage-brightness) testing system (Suzhou Fosstar Scientific Instruments Co., Ltd.); the lifetime testing system was the EAS-62C OLED device lifetime tester from System Technology Co., Ltd., Japan; LT95 refers to the condition at 20mA / cm². 2 The time it takes for the device brightness to decay to 95%.

[0079] As can be seen from the device data results in Table 4, compared with devices 1-4, the compounds of the present invention, when applied to devices, have a significantly lower device voltage than compounds Ref-1 to Ref-4, and the device efficiency and device lifetime are significantly improved compared with the comparative compounds Ref-1 to Ref-4, resulting in a significant improvement in the overall performance of OLED.

[0080] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compound containing a triazine and a carbazole structure, characterized in that, The structure of the compound is shown in general formula (1): General formula (1) In general formula (1), R1 represents the structure shown in formula 1-1, formula 1-2 or formula 1-3; L is represented by the structure shown in Equation 1-4 or Equation 1-6; R2 is represented by the structure shown in Equation 1-8; In general formula (1), the hydrogen atoms in phenyl, L, R1, and R2 can also be replaced by deuterium.

2. The compound containing triazine and carbazole structures according to claim 1, characterized in that, The structure of the compound is represented by any one of the general formulas (2-1), (2-2), (2-5), and (2-6): In general formulas (2-1), (2-2), (2-5), and (2-6), the meanings of R1 and R2 are the same as those defined in claim 1; In general formulas (2-1), (2-2), (2-5), and (2-6), hydrogen atoms can also be replaced by deuterium.

3. The compound containing triazine and carbazole structures according to claim 1, characterized in that, In the general formula (1), all or part of the hydrogen atoms in the phenyl, L, R1, and R2 are replaced by deuterium.

4. The compound containing triazine and carbazole structures according to claim 1, characterized in that, The structure of the compound is represented by any one of the general formulas (3-1) to (3-5): In general formulas (3-1) to (3-5), the meanings of R1 and R2 are the same as those defined in claim 1; In general formulas (3-1) to (3-5), hydrogen atoms can also be replaced by deuterium.

5. The compound containing triazine and carbazole structures according to claim 1, characterized in that, The specific structure of the compound is any one of the following structures: 。 6. An organic electroluminescent device, comprising a cathode, an anode, and a functional layer, wherein the functional layer is located between the cathode and the anode, characterized in that, At least one functional layer contains the compound containing triazine and carbazole structures as described in any one of claims 1 to 5.

7. The organic electroluminescent device according to claim 6, wherein the functional layer comprises a light-emitting layer, characterized in that, The light-emitting layer contains the compound containing triazine and carbazole structures as described in any one of claims 1 to 5.

8. The organic electroluminescent device according to claim 7, characterized in that, The light-emitting layer comprises a host material and a dopant material, wherein the host material contains a compound containing a triazine and a carbazole structure as described in any one of claims 1 to 5.

9. The organic electroluminescent device according to claim 8, characterized in that, The main material of the light-emitting layer is formed by mixing the compound containing triazine and carbazole structures as described in any one of claims 1 to 5 with any one or more of compounds GH-1 to GH-170, wherein the specific structures of compounds GH-1 to GH-170 are as follows: 。 10. A lighting or display element, characterized in that, The lighting or display element comprises any one of claims 6-9. The organic electroluminescent device described.

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