A triazine compound, an organic electroluminescence device, and a display apparatus

Abstract

The application provides a triazine compound, an organic electroluminescent device and a display device, and relates to the technical field of organic electroluminescent materials.The triazine compound has a structure as shown in formula (I) and is suitable for use as an electron transport material of an OLED light-emitting device, so that the OLED light-emitting device has a lower driving voltage, a higher current efficiency and a longer service life.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescent materials technology, specifically relating to a triazine compound, an organic electroluminescent device, and a display device. Background Technology

[0002] Organic electroluminescence (EL) refers to the phenomenon where organic materials directly convert electrical energy into light energy under the influence of an electric field. Organic electroluminescent devices are self-emissive light-emitting devices that utilize this principle. They possess characteristics such as self-illumination, vibrant and bright colors, thinness, light weight, fast response speed, wide viewing angle, low driving voltage, tolerance to harsh natural conditions, and the ability to be made into flexible panels. As a result, they have gradually become the most advantageous technology in the next generation of flat panel displays.

[0003] Organic electroluminescent devices have a sandwich-like structure, including electrode material films and organic functional materials sandwiched between different electrode films or on their own. These various functional materials are stacked together according to their intended use to form the organic electroluminescent device. As a current-carrying device, when a voltage is applied to the two electrodes of the organic electroluminescent device, positive and negative charges are generated in the organic functional material films through the action of an electric field. These positive and negative charges then recombine in the light-emitting layer to produce light; this process is called electroluminescence.

[0004] The structure of an organic light-emitting diode (OLED) consists of an anode, a cathode, and an organic layer between them. To improve the efficiency and stability of OLEDs, the organic material layer comprises multiple layers with different materials, such as a hole injection layer (HIL), a hole transport layer (HTL), a hole blocking layer, a light-emitting layer, an electron transport layer (ETL), and an electron injection layer (EIL). Currently, organic light emission has become a mainstream display technology, and correspondingly, various novel OLED materials have been developed. The electron transport performance of electron transport materials is a major obstacle to the widespread practical application of OLED technology, directly limiting the device's luminous efficiency, lifespan, and operating voltage. Therefore, continuous research and innovation of efficient and long-lifespan organic light-emitting compounds are crucial for continuously improving the performance of OLEDs. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a triazine compound, an organic electroluminescent device, and a display device, solving the technical problems of high driving voltage, low current efficiency, and short lifespan of OLED light-emitting devices made from existing electron transport materials.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] In a first aspect, the present invention provides a triazine compound having the structure shown in formula (I):

[0010]

[0011] Among them, X1, X2, and X3 are each independently selected from N or CR, and at least one of X1, X2, and X3 is selected from N;

[0012] R is selected from one or a combination of two of H, phenyl, naphthyl, biphenyl, fluoranyl, triphenylene, dibenzofuranyl, dibenzothiophene, 9,9-dimethylfluorenyl, and carbazole.

[0013] L is selected from one or a combination of two of the following: single bond, phenylene, naphthylene, biphenylene, fluoranylene, triphenylene, dibenzofuranyl, dibenzothiophene, 9,9-dimethylfluorenyl, and carbazolyl.

[0014] Ar1 and Ar2 are independently selected from one or a combination of two of the following: phenyl, naphthyl, biphenyl, fluoranyl, triphenylene, dibenzofuranyl, dibenzothiophenyl, 9,9-dimethylfluorenyl, and carbazoleyl.

[0015] The hydrogen atoms in the compound of formula (I) are each independently replaced by deuterium atoms.

[0016] In this invention, by designing and searching for the molecular structure of triazine compounds, the obtained triazine compounds are suitable as electron transport materials for OLED light-emitting devices, enabling OLED light-emitting devices to have lower driving voltage, higher current efficiency and longer lifespan.

[0017] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0018] Preferably, the triazine compound is selected from any one of the following compounds:

[0019]

[0020] The definitions of each symbol are the same as above.

[0021] Preferably, X1, X2, and X3 are all selected from N atoms.

[0022] Preferably, at least one of Ar1 and Ar2 is selected from carbazolyl.

[0023] Preferably, the triazine compound L is not selected from single bonds and conforms to general formulas I-1, I-2, and I-3.

[0024] Preferably, the triazine compound L is selected from benzoxazole.

[0025] As a preferred embodiment of the present invention, the triazine compound is selected from any one of the following compounds:

[0026]

[0027]

[0028] The hydrogen atoms in the above compounds can be replaced by deuterium atoms independently.

[0029] In a second aspect, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer material comprises a triazine compound as described in the first aspect.

[0030] As a preferred embodiment of the present invention, the organic thin film layer includes an electron transport layer, and the electron transport layer material includes triazine compounds as described in the first aspect.

[0031] Thirdly, the present invention provides a display device comprising the organic electroluminescent device as described in the second aspect.

[0032] (III) Beneficial Effects

[0033] This invention provides a triazine compound, an organic electroluminescent device, and a display device. Compared with the prior art, it has the following advantages:

[0034] In this invention, by designing and searching for the molecular structure of triazine compounds, the prepared triazine compounds are suitable as electron transport materials for OLED light-emitting devices, enabling OLED light-emitting devices to have lower driving voltage, higher current efficiency and longer lifespan. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0037] Synthesis Example 1

[0038] This synthetic example provides a method for preparing compound P1, the specific preparation method of which is as follows:

[0039]

[0040] Under nitrogen protection, 60 mL of toluene, 20 mL of ethanol, and 20 mL of water were added sequentially to a three-necked flask. Then, 3.0 g of the boric acid compound shown in P1-1, 2.7 g of the intermediate shown in P1-2, 2.12 g of sodium carbonate, and 0.23 g of tetrakis(triphenylphosphine)palladium were added. The mixture was slowly heated to 60 °C and reacted for 2 h, then heated to 80 °C and reacted for 6 h. After cooling to room temperature, the solid was filtered to obtain a solid. The solid was washed sequentially with water and methanol, dried, and then separated by silica gel column chromatography. The eluent was petroleum ether:ethyl acetate:THF = 20:1:4 (volume ratio) to give 3.9 g of compound P1.

[0041] The mass-to-charge ratio (m / z) of compound P1 was measured to be 485.16 by mass spectrometry.

[0042] Synthesis Examples 2-13

[0043] Following the preparation method of compound P1, P1-2 were replaced with other chlorinated or brominated compounds for the reaction. Other chlorinated or brominated compounds are detailed in Table 1. Compounds P2-P13 were prepared, and the mass spectra of compounds P2-P13 were measured. The mass-to-charge ratio (m / z) of compounds P2-P13 was recorded, as detailed in Table 1.

[0044] Table 1 Preparation parameters of compounds P2-P13

[0045]

[0046]

[0047]

[0048] Other compounds for which specific synthesis steps are not listed can be prepared using common knowledge in the art, in conjunction with the above examples.

[0049] The specific structures of several materials used in the device embodiments of the present invention are as follows:

[0050]

[0051] D1 synthesis:

[0052]

[0053] Compound D1 was prepared using the same synthetic method as compound 1. The mass spectrum of D1 was measured to be m / z: 666.22.

[0054] Device Example 1

[0055] This embodiment of the device provides an organic electroluminescent device with the following structure: ITO / HIL02 (100nm) / HT (40nm) / light-emitting layer (30nm): BH:D-4 3% / electron transport material (30nm) / LiF (0.5nm) / Al (150nm).

[0056] The fabrication method of organic electroluminescent devices is as follows:

[0057] The material was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~1×10 -6 Pa is sequentially vacuum-deposited onto the cleaned ITO substrate. The light-emitting layer (30nm): BH:D-43% / refers to the fact that in the device, BH and D-4 are co-evaporated in a volume ratio of 97:3 to form the light-emitting layer, with a thickness of 30nm.

[0058] The electron transport layer material is compound P1 provided in Example 1 of this invention.

[0059] Device Examples 2-13

[0060] Device Examples 2-13 each provide an organic electroluminescent device. The only difference between them and Device Example 1 is that the electron transport layer material is different. For details of the specific materials, please refer to Table 1 below. Other conditions are the same as those in Device Example 1.

[0061] Device Comparison Examples 1-3

[0062] Comparative Examples 1-3 each provide an organic electroluminescent device, which differs from Device Example 1 only in the electron transport layer material. The specific materials are detailed in Table 1 below, and other conditions are the same as those in Device Example 1.

[0063] Performance testing

[0064] The luminance, driving voltage, current efficiency, and LT95 of the organic electroluminescent devices provided above were tested. The voltage and current efficiency are calculated based on a luminance of 1000 cd / m². 2 The corresponding value, LT95, refers to maintaining an initial device current density of 10 mA / cm². 2 The time required for the device efficiency to drop to 95% of the efficiency corresponding to the initial current density, while LT95 is a relative value for voltage, current efficiency, and efficiency. Specific test results are shown in Table 2.

[0065] Table 2 Performance Test Results

[0066]

[0067] As shown in Table 2, when the electron transport layer materials X1, X2, and X3 of the device are all selected from N atoms, the device voltage decreases when comparing device Example 1 and device Example 13.

[0068] As can be seen from device examples 4, 5, and 7, when at least one of the electron transport layer materials Ar1 and Ar2 is selected from carbazole-based materials, the current efficiency increases.

[0069] As can be seen from device examples 8-11, when the electron transport layer material L of the device is not selected from single bonds, the device voltage decreases, and when it conforms to general formulas I-1, I-2, and I-3, the voltage decreases further.

[0070] As can be seen from Device Example 12, when the electron transport layer material L of the device is selected from succinate, the device has a good lifespan.

[0071] In summary, compared with existing technologies, it has the following beneficial effects:

[0072] In this invention, by designing and searching for the molecular structure of triazine compounds, the prepared triazine compounds are suitable as electron transport materials for OLED light-emitting devices, enabling OLED light-emitting devices to have lower driving voltage, higher current efficiency and longer lifespan.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A triazine compound, characterized in that, The triazine compound is selected from any of the following compounds: 。 2. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes the triazine compound as described in claim 1.

3. The organic electroluminescent device as described in claim 2, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic thin film layer disposed between the anode and the cathode, wherein the organic thin film layer material includes the aforementioned triazine compound.

4. The organic electroluminescent device as described in claim 2, characterized in that, The organic thin film layer includes an electron transport layer, and the electron transport layer material includes the aforementioned triazine compound.

5. A display device, characterized in that, The display device includes the organic electroluminescent device as described in claim 2.

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