Crosslinking agent, light emitting device and display panel and method for manufacturing the same

Abstract

The application provides a crosslinking agent, a light-emitting device, a display panel and a preparation method thereof. The crosslinking agent comprises an electroactive group and a crosslinking group, the electroactive group and the crosslinking group are bonded, and the crosslinking group is located on at least part of the side of the electroactive group. According to the crosslinking agent provided by the embodiment of the application, the electroactive group has conductivity, which is conducive to the transmission of electrons or holes. When the crosslinking agent is applied to a light-emitting functional layer of a light-emitting device, the transmission performance of the light-emitting functional layer for electrons or holes can be improved, the voltage of the light-emitting device can be reduced, and the power consumption of the light-emitting device can be saved. The crosslinking group can be crosslinked with other materials in the light-emitting functional layer, which is conducive to the patterning of the film layer and the improvement of the stability of the light-emitting device, facilitates the manufacturing of the light-emitting device, and improves the yield of the light-emitting device.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to crosslinking agents, light-emitting devices, display panels, and methods for their preparation. Background Technology

[0002] Quantum dot light-emitting diodes (QLEDs) possess advantages such as high color gamut, long potential lifespan, good viewing angle, and low cost, making them a highly promising future display technology. QLED devices have enormous potential in improving the color gamut of display panels. However, due to limitations in related technologies, current QLED devices still cannot fully meet the demands. Summary of the Invention

[0003] In view of this, embodiments of this application provide a crosslinking agent, a light-emitting device, and a display panel, and a method for preparing the same.

[0004] The first aspect of this application provides a crosslinking agent, comprising:

[0005] An electroactive group and a crosslinking group are bonded together, and the crosslinking group is located on at least a portion of the periphery of the electroactive group.

[0006] In one embodiment, the electroactive group includes at least one of fluorene, carbazole, aniline, imidazole, pyridine, triazine, and pyrimidine.

[0007] In one embodiment, the electroactive group includes At least one of them;

[0008] R1, R2, R3, R4, R5, R6, R7 and R8 each independently include at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms;

[0009] Preferably, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic amino group having 2 to 40 carbon atoms is substituted with F. The following substitutions may be made: , Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic amino group having 2 to 40 carbon atoms are replaced by O or S.

[0010] In one embodiment, the crosslinking group includes a photocrosslinking group;

[0011] Preferably, the crosslinking groups include: At least one of them;

[0012] Ar4, Ar5, Ar6, and Ar7 each independently include aromatic or heteroaromatic rings;

[0013] R9, R 10 R 11 R 12 Each independently includes at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms;

[0014] Preferably, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic amino group having 2 to 40 carbon atoms is substituted with F. The following substitutions may be made: , Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic amino group having 2 to 40 carbon atoms are replaced by O or S.

[0015] In one embodiment, the crosslinking agent comprises a structure as shown in formula (1):

[0016]

[0017] Among them, the electroactive groups include Ar, and the crosslinking groups include X and Y;

[0018] Ar includes at least one of the structures shown in equations (1-1) to (1-3):

[0019]

[0020] In equations (1-1) to (1-3), * represents a site that can bond with X and Y;

[0021] X and * represent the sites, Ar1 to Ar3, and R. 13 ~R 15 At least one site in the matrix is ​​bonded, and / or, Y is bonded to the site indicated by *, Ar1 to Ar3, and R. 13 ~R 15 At least one site of bonding;

[0022] Ar1, Ar2, and Ar3 each independently include At least one of them;

[0023] X and Y each include independently At least one of them;

[0024] Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 R 14 and R 15 Each independently includes at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms;

[0025] Ar4, Ar5, Ar6, and Ar7 each independently include aromatic or heteroaromatic rings;

[0026] R 13 R 14 and R 15 The number of each is independently at least one;

[0027] i+m+n≤18, i, m and n are not all 0 at the same time;

[0028] Preferably, i+m+n≤9.

[0029] In one embodiment, in the same crosslinking agent molecule structure, the sum of the number of X and the number of Y is greater than or equal to 2 and less than or equal to 20.

[0030] Preferably, the sum of the number of X and the number of Y is greater than or equal to 2 and less than or equal to 8;

[0031] Preferably, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic amino group having 2 to 40 carbon atoms is substituted with F. The following substitutions may be made: , Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic amino group having 2 to 40 carbon atoms are replaced by O or S.

[0032] In one embodiment, the crosslinking agent comprises a structure shown in at least one of formulas (2-1) to (2-36):

[0033]

[0034]

[0035]

[0036] The second aspect of this application provides a method for preparing a crosslinking agent, comprising: causing a first compound and a second compound to undergo a coupling reaction to obtain a crosslinking agent, wherein the crosslinking agent includes a bonded electroactive group and a crosslinking group, and the crosslinking group is located on at least a portion of the periphery of the electroactive group;

[0037] Wherein, the first compound includes an electroactive group, and the second compound includes a crosslinking group; or, the electroactive group includes a first sub-electroactive group and a second sub-electroactive group, and the crosslinking group includes a first sub-crosslinking group and a second sub-crosslinking group; or, the first compound includes an electroactive group and a first sub-crosslinking group, and the second compound includes a second sub-electroactive group and a second sub-crosslinking group; or, the first compound includes a crosslinking group and a first sub-electroactive group, and the second compound includes a second sub-electroactive group.

[0038] In one embodiment, the coupling reaction includes the Suzuki coupling reaction.

[0039] A third aspect of this application provides a light-emitting device, comprising:

[0040] A first electrode layer, a light-emitting functional layer, and a second electrode layer are stacked together.

[0041] The raw materials for the light-emitting functional layer include the aforementioned crosslinking agent, or the crosslinking agent prepared by the aforementioned preparation method.

[0042] In one embodiment, the light-emitting functional layer includes at least one light-emitting layer, and the light-emitting layer includes a crosslinking agent;

[0043] Preferably, the crosslinking agent accounts for 1 to 30% of the total mass of the light-emitting layer;

[0044] Preferably, the light-emitting layer comprises a quantum dot light-emitting layer.

[0045] In one embodiment, the light-emitting functional layer further includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer located between the first electrode layer and the light-emitting layer;

[0046] Preferably, at least one of the hole injection layer, hole transport layer and electron blocking layer includes a crosslinking agent, wherein the electroactive group in the crosslinking agent includes at least one of fluorene, carbazole and aniline;

[0047] Preferably, the hole injection layer includes a crosslinking agent, the mass of which accounts for 1 to 30% of the total mass of the hole injection layer; and / or, the hole transport layer includes a crosslinking agent, the mass of which accounts for 1 to 30% of the total mass of the hole transport layer; and / or, the electron blocking layer includes a crosslinking agent, the mass of which accounts for 1 to 30% of the total mass of the electron blocking layer.

[0048] Preferably, the light-emitting functional layer further includes a hole injection layer, a hole transport layer and an electron blocking layer stacked sequentially, wherein the hole injection layer is located on the side of the hole transport layer closer to the first electrode layer;

[0049] Preferably, the light-emitting functional layer further includes a crosslinking layer located between the light-emitting layer and the electron blocking layer, or between the electron blocking layer and the hole transport layer, or between the hole transport layer and the hole injection layer, wherein the crosslinking layer includes a crosslinking agent.

[0050] In one embodiment, the light-emitting functional layer further includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer located between the second electrode layer and the light-emitting layer;

[0051] Preferably, at least one of the electron injection layer, electron transport layer, and hole blocking layer includes a crosslinking agent, wherein the electroactive group in the crosslinking agent includes at least one of imidazole, pyridine, triazine, and pyrimidine;

[0052] Preferably, the electron injection layer includes a crosslinking agent, the mass of which accounts for 1 to 30% of the total mass of the electron injection layer; and / or, the electron transport layer includes a crosslinking agent, the mass of which accounts for 1 to 30% of the total mass of the electron transport layer; and / or, the hole blocking layer includes a crosslinking agent, the mass of which accounts for 1 to 30% of the total mass of the hole blocking layer.

[0053] Preferably, the light-emitting functional layer further includes an electron injection layer, an electron transport layer and a hole blocking layer stacked sequentially, wherein the electron injection layer is located on the side of the electron transport layer closer to the second electrode layer;

[0054] Preferably, the light-emitting functional layer further includes a crosslinking layer located between the light-emitting layer and the hole-blocking layer, or between the hole-blocking layer and the electron transport layer, or between the electron transport layer and the electron injection layer, wherein the crosslinking layer includes a crosslinking agent.

[0055] A fourth aspect of this application provides a display panel, including:

[0056] Array substrate;

[0057] A pixel defining layer is located on one side of the array substrate, and the pixel defining layer includes multiple openings;

[0058] Multiple of the aforementioned light-emitting devices, some of which are located in the opening.

[0059] In one embodiment, the light-emitting functional layer includes a hole injection layer, a hole transport layer, an electron blocking layer and at least one light-emitting layer stacked sequentially, wherein the hole injection layer is located on the side of the hole transport layer near the first electrode layer;

[0060] In adjacent light-emitting devices, hole injection layers are spaced apart, and / or hole transport layers are spaced apart.

[0061] The fifth aspect of this application provides a method for manufacturing a display panel, comprising:

[0062] A first electrode layer is fabricated on one side of the array substrate;

[0063] A pixel defining layer is prepared on the side of the first electrode layer away from the array substrate. The pixel defining layer includes a plurality of openings, and the first electrode layer is at least partially exposed to the openings.

[0064] A light-emitting functional layer and a second electrode layer are sequentially fabricated in the opening;

[0065] The raw materials for the light-emitting functional layer include the aforementioned crosslinking agent, or the crosslinking agent prepared by the aforementioned preparation method.

[0066] In one embodiment, fabricating a light-emitting functional layer in the opening includes:

[0067] A hole injection layer, a hole transport layer, an electron blocking layer, and at least one light-emitting layer are sequentially prepared in the opening, wherein the raw material for at least one of the hole injection layer, hole transport layer, electron blocking layer, and light-emitting layer includes a crosslinking agent.

[0068] Preferably, preparing the hole injection layer in the opening includes:

[0069] A full-layer hole injection material layer is prepared on the side of the pixel defining layer away from the array substrate. The hole injection material layer includes a crosslinking agent.

[0070] The hole injection material layer is patterned using photolithography to obtain a hole injection layer with spaced intervals.

[0071] Preferably, after preparing the hole injection layer in the opening, preparing the hole transport layer in the opening includes:

[0072] A whole-layer hole transport material layer is prepared on the side of the hole injection layer away from the array substrate. The hole transport material layer includes a crosslinking agent.

[0073] The hole transport material layer is patterned using photolithography to obtain a hole transport layer with spaced intervals.

[0074] Preferably, after fabricating the hole transport layer in the opening, fabricating the light-emitting layer in the opening includes:

[0075] A whole-layer light-emitting material layer is prepared on the side of the hole transport layer away from the array substrate, and the light-emitting material layer includes a crosslinking agent;

[0076] The luminescent material layer is patterned using photolithography to obtain spaced luminescent layers.

[0077] According to the crosslinking agent provided in the embodiments of this application, the electroactive groups are conductive, which facilitates the transport of electrons or holes. Applying the crosslinking agent to the light-emitting functional layer of a light-emitting device improves the electron or hole transport performance of the light-emitting functional layer, reduces the voltage of the light-emitting device, and saves power consumption. The crosslinking groups can crosslink with other materials in the light-emitting functional layer, improving the stability of the light-emitting device while also facilitating the patterning of the film layer, simplifying the fabrication of the light-emitting device, and improving the yield of the light-emitting device. Attached Figure Description

[0078] Figure 1 This is a schematic diagram of the crosslinking agent in one embodiment of this application.

[0079] Figure 2 This is a schematic diagram of the structure of a light-emitting device in one embodiment of this application.

[0080] Figure 3 This is a schematic diagram of the structure of the light-emitting device in another embodiment of this application.

[0081] Figure 4 A schematic diagram of the structure of the display panel in one embodiment of this application.

[0082] Figure 5 This is a schematic diagram of the structure of the display panel in another embodiment of this application.

[0083] Figure 6 A schematic diagram of the manufacturing process of the display panel in one embodiment of this application.

[0084] Figure 7 The above are voltage-current density curves of the light-emitting devices in Example 1 and Comparative Example 1.

[0085] Figure 8 The voltage-brightness curves of the light-emitting devices in Example 1 and Comparative Example 1 are shown.

[0086] Figure 9 The voltage-brightness curves of the light-emitting devices in Example 21 and Comparative Example 2 are shown.

[0087] Figure 10 The voltage-brightness curves are for the light-emitting devices of Example 26 and Comparative Example 3. Detailed Implementation

[0088] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0089] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In some instances, methods and means well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.

[0090] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0091] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0092] The first aspect of this application provides a crosslinking agent, as described above. Figure 1The schematic diagram of the crosslinking agent shown includes: an electroactive group 100 and a crosslinking group 200, which are bonded together, and the crosslinking group 200 is located on at least a portion of the periphery of the electroactive group 100.

[0093] According to the crosslinking agent provided in the embodiments of this application, the electroactive group 100 is conductive, which facilitates the transport of electrons or holes. Applying the crosslinking agent to the light-emitting functional layer of the light-emitting device helps to improve the electron or hole transport performance of the light-emitting functional layer, reduce the voltage of the light-emitting device, and save power consumption. The crosslinking group 200 can crosslink with other materials in the light-emitting functional layer, improving the stability of the light-emitting device while also facilitating the patterning of the film layer, simplifying the fabrication of the light-emitting device, and improving the yield of the light-emitting device.

[0094] For example, when a crosslinking agent is applied to the light-emitting layer of a light-emitting device, the crosslinking agent and the main material of the light-emitting layer will crosslink together under light irradiation. After crosslinking, it will not be developed by the developer. At this time, the positions where the light-emitting layer needs to be retained are light-irradiated, while the positions where the light-emitting layer does not need to be retained are not light-irradiated. After development, a patterned light-emitting layer is obtained.

[0095] In one embodiment, the electroactive group 100 includes at least one selected from fluorene, carbazole, aniline, imidazole, pyridine, triazine, and pyrimidine. Fluorene, carbazole, and aniline possess hole transport properties, and applying the crosslinking agent to the light-emitting device is beneficial for improving the hole transport properties of the light-emitting device; imidazole, pyridine, triazine, and pyrimidine possess electron transport properties, and applying the crosslinking agent to the light-emitting device is beneficial for improving the electron transport properties of the light-emitting device.

[0096] For example, crosslinking agents including fluorene, carbazole, and aniline can be applied to the hole injection layer and hole transport layer of a light-emitting device, and can also be applied to the light-emitting layer of the light-emitting device. For example, when the crosslinking agent is applied to the hole injection layer and hole transport layer of the light-emitting device, because the crosslinking agent possesses hole transport properties, the hole mobility in the hole injection layer and hole transport layer does not decrease significantly, thereby reducing the voltage of the light-emitting device. For example, when the crosslinking agent is applied to the light-emitting layer of the light-emitting device, the carrier imbalance phenomenon of fewer holes and more electrons in the light-emitting device can be improved, thus enhancing device performance.

[0097] For example, crosslinking agents including imidazole, pyridine, triazine, and pyrimidine can be applied to the electron injection layer and electron transport layer of a light-emitting device, and can also be applied to the light-emitting layer of a light-emitting device. For example, when the crosslinking agent is applied to the electron injection layer and electron transport layer of a light-emitting device, because the crosslinking agent has electron transport properties, the hole mobility of the electron injection layer and electron transport layer will not decrease significantly, thereby reducing the voltage of the light-emitting device.

[0098] In one embodiment, the electroactive group includes At least one of the following: R1, R2, R3, R4, R5, R6, R7 and R8 each independently include at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms and a cyclic amino group having 2 to 40 carbon atoms.

[0099] In one embodiment, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched .... At least one H atom in a cyclic amino group with 0 carbon atoms is replaced by F, Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or

[0100] Alternatively, at least two non-adjacent CH2 groups in a cyclic amine group having 2 to 40 carbon atoms are replaced by O or S. This enhances the electron or hole transport properties of the crosslinking agent.

[0101] In one embodiment, the crosslinking group 200 includes a photocrosslinking group.

[0102] For example, the raw materials for the hole injection layer include a crosslinking agent and conventional hole injection layer raw materials. A complete hole injection material layer is prepared using a vapor deposition method. The hole injection material layer is irradiated with ultraviolet light, and then developed using a developer to obtain the hole injection layer. It is understood that when the hole injection material layer is irradiated with ultraviolet light, the crosslinking groups 200 crosslink with the conventional hole injection layer raw materials under ultraviolet light irradiation. This allows the hole injection material layer irradiated with ultraviolet light to resist etching by the developer, while the hole injection material layer not irradiated with ultraviolet light cannot resist etching and is etched away, thus achieving the patterning of the hole injection material layer and obtaining the hole injection layer.

[0103] For example, the raw materials for the hole transport layer include a crosslinking agent and conventional hole transport layer raw materials. A monolithic hole transport material layer is prepared using a vapor deposition method. The hole transport material layer is irradiated with ultraviolet light, and then developed using a developer to obtain the hole transport layer. It is understood that when the hole transport material layer is irradiated with ultraviolet light, the crosslinking groups 200 crosslink with the conventional hole transport layer raw materials under ultraviolet light irradiation. This allows the hole transport material layer irradiated with ultraviolet light to resist etching by the developer, while the hole transport material layer not irradiated with ultraviolet light cannot resist etching and is etched away, thus achieving the patterning of the hole transport material layer and obtaining the hole transport layer.

[0104] For example, the raw materials for the light-emitting layer include a crosslinking agent and conventional light-emitting layer raw materials. A whole-layer light-emitting material layer is prepared using a vapor deposition method. The light-emitting material layer is irradiated with ultraviolet light, and then developed using a developer to obtain the light-emitting layer. It is understood that when the light-emitting material layer is irradiated with ultraviolet light, the crosslinking groups 200 crosslink with the conventional light-emitting layer raw materials under ultraviolet light irradiation. This allows the light-emitting material layer irradiated with ultraviolet light to resist etching by the developer, while the light-emitting material layer not irradiated with ultraviolet light cannot resist etching and is etched away, thus achieving patterning of the light-emitting material layer and obtaining the light-emitting layer.

[0105] It is understandable that the number of crosslinking groups in the same crosslinking agent molecule is greater than or equal to two. This facilitates the crosslinking of the crosslinking agent with other organic materials.

[0106] In one embodiment, the crosslinking group includes: At least one of the following: Ar4, Ar5, Ar6, and Ar7, each independently comprising an aromatic or heteroaromatic ring; R9, R 10 R 11 R 12Each group independently includes at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms. Therefore, the crosslinking groups have a suitable structural size, facilitating hole hopping to or from the electroactive groups, improving the hole transport performance of the light-emitting device, reducing the voltage of the light-emitting device, and improving its performance; furthermore, the crosslinking effect of the aforementioned crosslinking groups is excellent under ultraviolet light irradiation.

[0107] In one embodiment, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched .... At least one H atom in a cyclic amino group with 0 carbon atoms is replaced by F, Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or

[0108] Alternatively, at least two non-adjacent CH2 groups in a cyclic amine group having 2 to 40 carbon atoms are replaced by O or S. This results in a crosslinking agent exhibiting superior crosslinking properties.

[0109] In one embodiment, the crosslinking agent comprises a structure as shown in formula (1):

[0110] Electroactive groups include Ar, and crosslinking groups include X and Y;

[0111] Wherein, Ar includes at least one of the structures shown in equations (1-1) to (1-3):

[0112]

[0113] In equations (1-1) to (1-3), * represents a site that can bond with X and Y;

[0114] X and * represent the sites, Ar1 to Ar3, and R. 13 ~R 15 At least one site in the matrix is ​​bonded, and / or, Y is bonded to the site indicated by *, Ar1 to Ar3, and R. 13 ~R 15 At least one site of bonding;

[0115] Ar1, Ar2, and Ar3 each independently include At least one of them;

[0116] X and Y each include independently At least one of the following: R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 R 14 and R 15 Each independently includes at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms; Ar4, Ar5, Ar6, and Ar7 each independently include an aromatic or heteroaromatic ring; R 13 R 14 and R 15 The number of each is at least one; i+m+n≤18 (for example, it can be 1, 2, 4, 6, 8, 10, 12, 14, 16 or 18, etc.), and i, m and n are not all 0 at the same time.

[0117] For example, the structural formulas of Ar1, Ar2, and Ar3 can be the same or different. For example, i, m, and n not being 0 simultaneously includes: one of i, m, and n being non-zero; two of i, m, and n being non-zero; and all three of i, m, and n being non-zero.

[0118] In a preferred embodiment, i+m+n≤9.

[0119] In one embodiment, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched .... At least one H atom in a cyclic amino group with 0 carbon atoms is replaced by F, Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or

[0120] Alternatively, at least two non-adjacent CH2 groups in a cyclic amine group having 2 to 40 carbon atoms are replaced by O or S. Exemplarily, in the same crosslinking agent molecule structure, the number of X and Y can be the same or different. The structural formulas of X and Y can be the same or different.

[0121] For example, the same crosslinking agent molecule structure may include multiple X and multiple Y groups. In one embodiment, the sum of the number of X groups and the number of Y groups in the same crosslinking agent molecule structure is greater than or equal to 2 and less than or equal to 20 (e.g., it can be 2, 4, 6, 8, 10, 12, 14, 16, 18, or 20, etc.); preferably, the sum of the number of X groups and the number of Y groups is greater than or equal to 2 and less than or equal to 8. Thus, in the same crosslinking agent molecule structure, the number of crosslinking groups is appropriate, the crosslinking performance is excellent, and it hardly affects the jumping of holes to the electroactive groups or the jumping of holes out of the electroactive groups.

[0122] In one embodiment, the crosslinking agent comprises at least one structure shown in formulas (2-1) to (2-36):

[0123]

[0124]

[0125]

[0126] Therefore, the above-mentioned crosslinking agent has strong electroactivity, which is conducive to holes jumping to the electroactive groups or to holes jumping out of the electroactive groups, thereby improving the hole transport performance of the light-emitting device, reducing the voltage of the light-emitting device, and improving the performance of the light-emitting device; moreover, the crosslinking effect of the above-mentioned crosslinking groups is excellent under ultraviolet light irradiation.

[0127] In existing technologies, the crosslinking agents used lack electroactivity. When applied to the hole injection layer and hole transport layer, the hole mobility in these layers decreases significantly, resulting in higher voltage and energy consumption in the light-emitting device. However, in this application, when the crosslinking agent of this embodiment is applied to the hole injection layer and hole transport layer of the light-emitting device, the hole mobility in these layers does not decrease significantly due to the crosslinking agent's hole transport properties, thus reducing the voltage of the light-emitting device. For example, applying the crosslinking agent to the light-emitting layer of a light-emitting device can improve the carrier imbalance phenomenon of fewer holes and more electrons, thereby enhancing device performance.

[0128] A second aspect of this application provides a method for preparing a crosslinking agent, comprising: subjecting a first compound and a second compound to a coupling reaction to obtain a crosslinking agent, the crosslinking agent comprising bonded electroactive groups and crosslinking groups, the crosslinking groups being located on at least a portion of the periphery of the electroactive groups; wherein the first compound comprises an electroactive group and the second compound comprises a crosslinking group; or, the electroactive groups comprise a first sub-electroactive group and a second sub-electroactive group, the crosslinking groups comprise a first sub-crosslinking group and a second sub-crosslinking group, the first compound comprising a first sub-electroactive group and a first sub-crosslinking group, the second compound comprising a second sub-electroactive group and a second sub-crosslinking group; or, the first compound comprises an electroactive group and a first sub-crosslinking group, the second compound comprising a second sub-crosslinking group; or, the first compound comprises a crosslinking group and a first sub-electroactive group, the second compound comprising a second sub-electroactive group.

[0129] Exemplary, the first compound includes, but is not limited to, etc.; the second compound includes, but is not limited to, wait.

[0130] Exemplary examples include, but are not limited to, the Suzuki coupling reaction. It is understood that the Suzuki coupling reaction can also be referred to as the Suzuki coupling reaction. Exemplary examples include the following steps: mixing a first compound and a second compound (the molar ratio of the first compound and the second compound can be (1-2):(1-2)), using a mixture of tetrahydrofuran, ethanol, and deionized water as a solvent, and using Na2CO3 and Pd(PPh3)4 as catalysts, heating under nitrogen protection (the heating temperature can be 50-70°C) for a period of time to obtain the crosslinking agent.

[0131] For example, the preparation method of the crosslinking agent having structural formula 2-32 is as follows: Add to a 500 mL round-bottom flask... (8.48 mmol, 1 eq), (9.34 mmol, 1.1 eq) was reacted with a mixture of tetrahydrofuran (160 mL), ethanol (60 mL), and deionized water (100 mL) as solvent, and Na₂CO₃ (67.84 mmol, 8 eq) and Pd(PPh₃)₄ (1.27 mmol, 0.15 eq) as catalysts. The reaction was carried out under nitrogen protection at 60 °C in the dark for 36 hours. After cooling, the mixture was filtered, and the filter cake was washed successively with saturated brine and ethanol. Further processing using conventional methods yielded the crosslinking agent (71% yield, HPLC purity 99.56%). Mass spectrometry (MALDI-TOF-MS) results: m / z: 1019.75. Elemental analysis results: Theoretical values ​​(%): C, 85.93; H, 6.82; N, 4.12; O, 3.14. Experimental values ​​(%): C, 85.73; H, 6.60; N, 4.42; O, 3.26.

[0132] For example, the preparation method of the crosslinking agent having structural formula 2-33 is as follows: add to a 500 mL round-bottom flask (8.48 mmol, 1 eq), (9.34mmol,

[0133] 1.1 eq), using a mixture of tetrahydrofuran (160 mL), ethanol (60 mL), and deionized water (100 mL) as solvent, with Na₂CO₃ (67.84 mmol, 8 eq) and Pd(PPh₃)₄ (1.27 mmol, 0.15 eq) as catalysts, the mixture was heated to 60 °C and reacted in the dark for 36 hours under nitrogen protection. After cooling, the mixture was filtered, and the filter cake was washed successively with saturated brine and ethanol. Further processing using conventional methods yielded the crosslinking agent (76% yield, HPLC purity 99.66%). MALDI-TOF-MS results: m / z: 889.61. Elemental analysis results: Theoretical values ​​(%): C, 68.07; H, 4.14; F, 16.89; N, 10.90. Experimental values ​​(%): C, 68.05; H, 4.16; F, 16.79; N, 11.00.

[0134] For example, the preparation method of the crosslinking agent having structural formula 2-34 is as follows: add to a 500 mL round-bottom flask (8.48 mmol, 1 eq), (9.34 mmol, 1.1 eq) was prepared using a mixture of tetrahydrofuran (160 mL), ethanol (60 mL), and deionized water (100 mL) as solvent. Na₂CO₃ (67.84 mmol, 8 eq) and Pd(PPh₃)₄ (1.27 mmol, 0.15 eq) were added as catalysts. The reaction was carried out under nitrogen protection at 60 °C in the dark for 36 hours. After cooling, the mixture was filtered, and the filter cake was washed successively with saturated brine and ethanol. Further processing using conventional methods yielded the crosslinking agent (85% yield, HPLC purity 99.33%). MALDI-TOF-MS results: m / z: 1003.71. Elemental analysis results: Theoretical values ​​(%): C, 86.11; H, 6.52; N, 4.18; O, 3.19. Experimental values ​​(%): C, 86.11; H, 6.67; N, 4.11; O, 3.11.

[0135] For example, the preparation method of a crosslinking agent having structural formula 2-35 is as follows: Add [the following to a 500 mL round-bottom flask] (33.92 mmol, 4 eq), (8.48 mmol, 1 eq) was prepared using a mixture of tetrahydrofuran (160 mL), ethanol (60 mL), and deionized water (100 mL) as solvent. Na₂CO₃ (67.84 mmol, 8 eq) and Pd(PPh₃)₄ (1.27 mmol, 0.15 eq) were added as catalysts. The reaction was carried out under nitrogen protection at 60 °C in the dark for 36 hours. After cooling, the mixture was filtered, and the filter cake was washed successively with saturated brine and ethanol. Further processing using conventional methods yielded the crosslinking agent (62% yield, HPLC purity 99.13%). MALDI-TOF-MS results: m / z: 1653.93. Elemental analysis results: Theoretical values ​​(%): C, 87.13; H, 6.58; N, 3.39; O, 2.90. Experimental values ​​(%): C, 87.10; H, 6.48; N, 3.49; O, 3.03.

[0136] For example, the preparation method of the crosslinking agent having structural formula 2-36 is as follows: add to a 500 mL round-bottom flask (33.92 mmol, 4 eq), (8.48 mmol, 1 eq) was prepared using a mixture of tetrahydrofuran (160 mL), ethanol (60 mL), and deionized water (100 mL) as solvent. Na₂CO₃ (67.84 mmol, 8 eq) and Pd(PPh₃)₄ (1.27 mmol, 0.15 eq) were added as catalysts. The reaction was carried out under nitrogen protection at 60 °C in the dark for 36 hours. After cooling, the mixture was filtered, and the filter cake was washed successively with saturated brine and ethanol. Further processing using conventional methods yielded the crosslinking agent (51% yield, HPLC purity 99.09%). MALDI-TOF-MS results: m / z: 1651.22. Elemental analysis results: Theoretical values ​​(%): C, 87.24; H, 6.47; N, 3.39; O, 2.91. Experimental values ​​(%): C, 87.05; H, 6.53; N, 3.52; O, 3.00.

[0137] It is understandable that the preparation method of crosslinking agents with structural formulas 2-1 to 2-31 can refer to the preparation method shown in the example above. The ratio of raw materials, the selected solvent and heating temperature can be selected according to the actual situation.

[0138] A third aspect of this application provides a light-emitting device, as shown in the reference... Figure 2 The schematic diagram of the light-emitting device shown includes: a first electrode layer 110, a light-emitting functional layer 120, and a second electrode layer 130 stacked together; the raw material of the light-emitting functional layer 120 includes the crosslinking agent mentioned above, or the crosslinking agent prepared by the preparation method mentioned above.

[0139] It should be noted that the crosslinking agent is the same as described above, and will not be elaborated further here.

[0140] For example, one of the first electrode layer 110 and the second electrode layer 130 is an anode, and the other of the first electrode layer 110 and the second electrode layer 130 is a cathode.

[0141] It should be noted that the number of layers in the light-emitting functional layer 120 is at least one light-emitting layer 124 (EML). (Refer to...) Figure 3 The schematic diagram of the light-emitting device shown indicates that the light-emitting functional layer 120 may further include at least one of the following: a hole injection layer 121 (HIL), a hole transport layer 122 (HTL), and an electron-blocking layer 123 (EBL) located between the anode and the light-emitting layer 124 (EML); and at least one of the following: an electron injection layer 125 (EIL), an electron transport layer 126 (ETL), and a hole-blocking layer 127 (HBL) located between the cathode and the light-emitting layer 124 (EML).

[0142] For example, the number of layers in the light-emitting functional layer 120 is at least one light-emitting layer 124. This should be interpreted broadly, and may include, for example, the following situations: 1. Multiple light-emitting layers 124 are stacked; 2. Between the electron transport layer 126 and the electron injection layer 125, the light-emitting functional layer 120 further includes at least one light-emitting functional unit. The light-emitting functional unit includes an n-type charge generation layer, a p-type charge generation layer, a second hole transport layer, a second electron blocking layer, a second light-emitting layer, a second hole blocking layer, and a second electron transport layer stacked in sequence. The n-type charge generation layer is located on the side of the p-type charge generation layer closer to the electron transport layer 126. The second light-emitting layer in the multiple light-emitting functional units and the light-emitting layer 124 constitute a multi-layer light-emitting layer.

[0143] In one embodiment, the light-emitting layer includes a crosslinking agent. Exemplarily, the raw materials for the light-emitting layer include a crosslinking agent and conventional light-emitting layer raw materials. A monolithic light-emitting material layer is prepared using a vapor deposition method. The light-emitting material layer is irradiated with ultraviolet light, and then developed using a developer to obtain the light-emitting layer. It is understood that when the light-emitting material layer is irradiated with ultraviolet light, the crosslinking groups 200 crosslink with the conventional light-emitting layer raw materials under ultraviolet light irradiation. This allows the light-emitting material layer irradiated with ultraviolet light to resist etching by the developer, while the light-emitting material layer not irradiated with ultraviolet light cannot resist etching and is etched away, thus achieving patterning of the light-emitting material layer and obtaining the light-emitting layer. When the crosslinking agent is applied to the light-emitting layer of a light-emitting device, it can improve the carrier imbalance phenomenon of fewer holes and more electrons in the light-emitting device, thereby improving device performance.

[0144] In one embodiment, the crosslinking agent accounts for 1% to 30% of the total mass of the light-emitting layer (e.g., 1%, 5%, 10%, 15%, 20%, 25%, or 30%). Therefore, a suitable content of crosslinking agent in the light-emitting layer can improve the carrier imbalance phenomenon of fewer holes and more electrons in the light-emitting device, thereby enhancing device performance.

[0145] In one embodiment, the light-emitting layer comprises a quantum dot light-emitting layer. Therefore, the light-emitting device has advantages such as high color gamut, long potential lifetime, good viewing angle, and low cost.

[0146] In one embodiment, refer to Figure 3 The light-emitting functional layer 120 further includes at least one of a hole injection layer 121, a hole transport layer 122, and an electron blocking layer 123 located between the first electrode layer 110 and the light-emitting layer 124.

[0147] In one embodiment, at least one of the hole injection layer 121, the hole transport layer 122, and the electron blocking layer 123 includes a crosslinking agent, wherein the electroactive group in the crosslinking agent includes at least one of fluorene, carbazole, and aniline. This facilitates hole transport in the light-emitting device. In one embodiment, the hole injection layer includes a crosslinking agent. Exemplarily, the raw materials for the hole injection layer include a crosslinking agent and conventional hole injection layer raw materials. A whole-layer hole injection material layer is prepared using a vapor deposition method, the hole injection material layer is irradiated with ultraviolet light, and the ultraviolet-irradiated hole injection material layer is developed using a developer to obtain the hole injection layer. It is understood that when the hole injection material layer is irradiated with ultraviolet light, the crosslinking groups crosslink with the conventional hole injection layer raw materials under ultraviolet light irradiation, making the ultraviolet-irradiated hole injection material layer resistant to etching by the developer, while the unirradiated hole injection material layer cannot resist etching by the developer and is etched away, thus achieving patterning of the hole injection material layer and obtaining the hole injection layer. Because the crosslinking agent has hole transport properties, the hole mobility of the hole injection layer does not decrease significantly, which in turn reduces the voltage of the light-emitting device.

[0148] For example, the crosslinking agent accounts for 1% to 30% of the total mass of the hole injection layer (e.g., 1%, 5%, 10%, 15%, 20%, 25%, or 30%). Thus, with a suitable crosslinking agent content, the hole mobility of the hole injection layer is relatively high, resulting in a relatively low voltage for the light-emitting device.

[0149] In one embodiment, the hole transport layer includes a crosslinking agent. Exemplarily, the raw materials for the hole transport layer include a crosslinking agent and conventional hole transport layer raw materials. A monolithic hole transport material layer is prepared using a vapor deposition method. The hole transport material layer is irradiated with ultraviolet light, and then developed using a developer to obtain the hole transport layer. It is understood that when the hole transport material layer is irradiated with ultraviolet light, the crosslinking groups crosslink with the conventional hole transport layer raw materials under ultraviolet light irradiation. This allows the hole transport material layer irradiated with ultraviolet light to resist etching by the developer, while the hole transport material layer not irradiated with ultraviolet light cannot resist etching and is etched away, thus achieving patterning of the hole transport material layer and obtaining the hole transport layer. Because the crosslinking agent possesses hole transport properties, the hole mobility of the hole transport layer does not decrease significantly, thereby reducing the voltage of the light-emitting device.

[0150] For example, the crosslinking agent accounts for 1% to 30% of the total mass of the hole transport layer (e.g., 1%, 5%, 10%, 15%, 20%, 25%, or 30%). Thus, with a suitable crosslinking agent content, the hole mobility of the hole transport layer is relatively high, resulting in a relatively low voltage for the light-emitting device.

[0151] In one embodiment, the electron blocking layer includes a crosslinking agent. Exemplarily, the raw materials for the electron blocking layer include a crosslinking agent and conventional electron blocking layer raw materials. A monolithic electron blocking material layer is prepared using a vapor deposition method, the electron blocking material layer is irradiated with ultraviolet light, and the irradiated electron blocking material layer is developed with a developer to obtain the electron blocking layer. It is understood that when the electron blocking material layer is irradiated with ultraviolet light, the crosslinking groups crosslink with the conventional electron blocking layer raw materials under ultraviolet light irradiation. This allows the irradiated electron blocking material layer to resist etching by the developer, while the unirradiated electron blocking material layer cannot resist etching and is etched away, thus achieving patterning of the electron blocking material layer and obtaining the electron blocking layer. Because the crosslinking agent possesses hole transport properties, the hole mobility of the electron blocking layer does not decrease significantly, thereby reducing the voltage of the light-emitting device.

[0152] For example, the crosslinking agent accounts for 1% to 30% of the total mass of the electron blocking layer (e.g., 1%, 5%, 10%, 15%, 20%, 25%, or 30%). Thus, with a suitable crosslinking agent content, the hole mobility of the electron blocking layer is relatively high, resulting in a relatively low voltage for the light-emitting device.

[0153] In one embodiment, the light-emitting functional layer 120 further includes a hole injection layer 121, a hole transport layer 122, and an electron blocking layer 123. The hole injection layer 121 is located on the side of the hole transport layer 122 near the first electrode layer 110. The light-emitting functional layer 120 also includes a crosslinking layer located between the light-emitting layer 124 and the electron blocking layer 123, or between the electron blocking layer 123 and the hole transport layer 122, or between the hole transport layer 122 and the hole injection layer 121. The crosslinking layer includes a crosslinking agent. Thus, the electroactive groups in the crosslinking layer facilitate hole transport, and the crosslinking layer can improve the hole transport performance of the light-emitting device and reduce the voltage of the light-emitting device.

[0154] In one embodiment, the light-emitting functional layer 120 further includes an electron injection layer 125, an electron transport layer 126, and a hole blocking layer 127 stacked sequentially, with the electron injection layer 125 located on the side of the electron transport layer 126 near the second electrode layer 130.

[0155] In one embodiment, at least one of the electron injection layer 125, the electron transport layer 126, and the hole blocking layer 127 includes a crosslinking agent, wherein the electroactive groups in the crosslinking agent include at least one of imidazole, pyridine, triazine, and pyrimidine. This facilitates electron transport in the light-emitting device.

[0156] In one embodiment, the electron injection layer 125 includes a crosslinking agent; the mass of the crosslinking agent accounts for 1 to 30% of the total mass of the electron injection layer 125 (e.g., it can be 1%, 5%, 10%, 15%, 20%, 25%, or 30%, etc.).

[0157] In one embodiment, the electron transport layer 126 includes a crosslinking agent; the mass of the crosslinking agent accounts for 1 to 30% of the total mass of the electron transport layer (e.g., 1%, 5%, 10%, 15%, 20%, 25%, or 30%, etc.).

[0158] In one embodiment, the hole blocking layer 127 includes a crosslinking agent; the mass of the crosslinking agent accounts for 1 to 30% of the total mass of the hole blocking layer (e.g., 1%, 5%, 10%, 15%, 20%, 25%, or 30%, etc.).

[0159] In one embodiment, the light-emitting functional layer 120 further includes a crosslinking layer located between the light-emitting layer 124 and the hole blocking layer 127, or between the hole blocking layer 127 and the electron transport layer 126, or between the electron transport layer 126 and the electron injection layer 125, and the crosslinking layer includes a crosslinking agent.

[0160] It is understood that the electroactive groups include at least one of fluorene, carbazole, aniline, imidazole, pyridine, triazine, and pyrimidine. Fluorene, carbazole, and aniline facilitate hole transport, while imidazole, pyridine, triazine, and pyrimidine facilitate electron transport. For example, the crosslinking agent in the light-emitting layer 124 may include at least one of fluorene, carbazole, aniline, imidazole, pyridine, triazine, and pyrimidine; the crosslinking agent in the electron injection layer 125, electron transport layer 126, and hole blocking layer 127 includes at least one of imidazole, pyridine, triazine, and pyrimidine; and the hole injection layer 121, hole transport layer 122, and electron blocking layer 123 include at least one of fluorene, carbazole, and aniline.

[0161] For example, the light-emitting device can be an organic light-emitting diode (OLED), a micro light-emitting diode (Micro LED), a quantum dot light-emitting diode (QLED), etc. The light-emitting device can be a light-emitting device of various colors, such as a red light-emitting device R, a green light-emitting device G, a blue light-emitting device B, etc.

[0162] A fourth aspect of this application provides a display panel, referring to... Figure 4 and Figure 5The schematic diagram of the display panel shown includes: an array substrate 10; a pixel defining layer 20 located on one side of the array substrate 10, the pixel defining layer 20 including a plurality of openings 21; and a plurality of the aforementioned light-emitting devices 30, some of which are located in the openings 21.

[0163] It should be noted that the light-emitting device is the same as described above, and will not be elaborated further here.

[0164] In one embodiment, refer to Figure 4 The light-emitting device 30 includes a first electrode layer 110, a light-emitting functional layer 120, and a second electrode layer 130 stacked together. The light-emitting functional layer 120 has at least one light-emitting layer 124. The light-emitting functional layer 120 also includes a hole injection layer 121, a hole transport layer 122, and an electron blocking layer 123. The hole injection layer 121 is located on the side of the hole transport layer 122 closest to the first electrode layer 110. In adjacent light-emitting devices 30, the hole injection layers 121 are spaced apart, and / or the hole transport layers 122 are spaced apart. This helps to reduce the residue of the light-emitting layer 124 during the manufacturing process.

[0165] For example, the light-emitting device can be an organic light-emitting diode (OLED), a micro light-emitting diode (Micro LED), a quantum dot light-emitting diode (QLED), etc. The light-emitting device can be a light-emitting device of various colors, such as a red light-emitting device R, a green light-emitting device G, a blue light-emitting device B, etc.

[0166] It is understandable that when fabricating light-emitting devices of different colors, an etching process is used to remove the film material corresponding to the unwanted light-emitting device. During the removal process, the light-emitting layer material will remain. The spacing between the hole injection layer 121 and the hole transport layer 122 helps to reduce the residue of the light-emitting layer 124 during the fabrication process.

[0167] For example, the light-emitting device 30 also has an encapsulation layer on the side facing away from the array substrate 10. The encapsulation layer can be a thin-film encapsulation layer. The encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked in sequence. The first inorganic encapsulation layer, the organic encapsulation layer, and the second inorganic encapsulation layer are conventional structures and materials, and are not considered improvements in this application. They will not be described in detail here.

[0168] Exemplarily, the array substrate 10 may be a substrate. In some embodiments, the substrate may be a glass substrate. In some embodiments, the substrate may include an organic resin material such as epoxy resin, triazine, silicone resin, or polyimide. For example, the substrate may be an FR4 type printed circuit board (PCB), or a flexible PCB that is easily deformable. In some embodiments, the substrate may include a ceramic material such as silicon nitride, aluminum nitride, or aluminum oxide, or include a metal or metal compound. For example, the substrate may be a metal core PCB (MCPCB) or a metal copper clad laminate (MCCL).

[0169] The fifth aspect of this application provides a method for manufacturing a display panel, referring to... Figure 6 The diagram shows a process flow chart for manufacturing a display panel, which includes the following steps.

[0170] S100: A first electrode layer is fabricated on one side of the array substrate.

[0171] It should be noted that the array substrate and the first electrode layer are the same as described above, and will not be repeated here.

[0172] For example, a whole layer of first electrode material can be prepared on one side of the array substrate, and the first electrode material layer can be patterned to obtain the first electrode layer.

[0173] S200: A pixel defining layer is prepared on the side of the first electrode layer away from the array substrate. The pixel defining layer includes a plurality of openings, and the first electrode layer is at least partially exposed to the openings.

[0174] It should be noted that the pixel delimitation layer is the same as described above, and will not be elaborated on further here.

[0175] S300: A light-emitting functional layer and a second electrode layer are sequentially fabricated in the opening.

[0176] It should be noted that the light-emitting functional layer and the second electrode layer are the same as described above, and will not be repeated here.

[0177] For example, fabricating a pixel defining layer on the side of the first electrode layer away from the array substrate includes: fabricating a whole pixel defining material layer on the side of the first electrode layer away from the array substrate, wherein the whole pixel defining material layer is an inorganic material; and performing a dry etching process to pattern the pixel defining material layer to obtain the pixel defining layer.

[0178] The raw materials for the light-emitting functional layer include the crosslinking agent described above, or the crosslinking agent prepared by the preparation method described above.

[0179] It should be noted that the crosslinking agent is the same as described above, and will not be elaborated further here.

[0180] In one embodiment, preparing a light-emitting functional layer in an opening includes: sequentially preparing a hole injection layer, a hole transport layer, an electron blocking layer, and at least one light-emitting layer in the opening, wherein the raw material for at least one of the hole injection layer, the hole transport layer, the electron blocking layer, and the light-emitting layer includes a crosslinking agent.

[0181] In one embodiment, preparing a hole injection layer in an opening includes: preparing a full-layer hole injection material layer on the side of the pixel defining layer away from the array substrate, the hole injection material layer including a crosslinking agent; and patterning the hole injection material layer using a photolithography process to obtain a spaced hole injection layer.

[0182] In one embodiment, after preparing a hole injection layer in the opening, preparing a hole transport layer in the opening includes: preparing a full-layer hole transport material layer on the side of the pixel defining layer away from the array substrate, the hole transport material layer including a crosslinking agent; and patterning the hole transport material layer using a photolithography process to obtain a spaced hole transport layer.

[0183] In one embodiment, after fabricating a hole transport layer in the opening, fabricating a light-emitting layer in the opening includes: fabricating a whole-layer light-emitting material layer on the side of the pixel defining layer away from the array substrate, the light-emitting material layer including a crosslinking agent; and patterning the light-emitting material layer using a photolithography process to obtain spaced light-emitting layers.

[0184] In one embodiment, the sequential fabrication of a hole injection layer, a hole transport layer, an electron blocking layer, and a light-emitting layer within an opening includes the following steps: fabricating a full-layer hole injection material layer on the side of the pixel defining layer facing away from the array substrate; fabricating a full-layer hole transport material layer on the side of the hole injection material layer facing away from the array substrate; fabricating a full-layer electron blocking material layer on the side of the hole transport material layer facing away from the array substrate; fabricating a full-layer light-emitting material layer on the side of the electron blocking material layer facing away from the array substrate; and patterning the hole injection material layer, hole transport material layer, electron blocking material layer, and light-emitting material layer using a photolithography process to obtain the hole injection layer, hole transport layer, electron blocking layer, and light-emitting layer.

[0185] In one embodiment, the plurality of light-emitting devices include a first light-emitting device, a second light-emitting device, and a third light-emitting device. The steps for sequentially fabricating a hole injection layer, a hole transport layer, an electron blocking layer, and a light-emitting layer within the opening are as follows:

[0186] A hole injection material layer, a hole transport material layer, an electron blocking material layer, and a light-emitting material layer of the first light-emitting device are sequentially fabricated on the side of the pixel defining layer away from the array substrate. The hole injection material layer, the hole transport material layer, the electron blocking material layer, and the light-emitting material layer are patterned to obtain the hole injection layer, the hole transport layer, the electron blocking layer, and the light-emitting layer of the first light-emitting device.

[0187] A hole injection material layer, a hole transport material layer, an electron blocking material layer, and a light-emitting material layer of a second light-emitting device are sequentially fabricated on the side of the pixel defining layer away from the array substrate. The hole injection material layer, hole transport material layer, electron blocking material layer, and light-emitting material layer are patterned to obtain the hole injection layer, hole transport layer, electron blocking layer, and light-emitting layer of the second light-emitting device.

[0188] A hole injection material layer, a hole transport material layer, an electron blocking material layer, and a light-emitting material layer of a third light-emitting device are sequentially fabricated on the side of the pixel defining layer away from the array substrate. The hole injection material layer, hole transport material layer, electron blocking material layer, and light-emitting material layer are patterned to obtain the hole injection layer, hole transport layer, electron blocking layer, and light-emitting layer of the third light-emitting device.

[0189] It is understandable that the first, second, and third light-emitting devices can each be independently red light-emitting device R, green light-emitting device G, and blue light-emitting device B; the preparation order of the three light-emitting devices, red light-emitting device R, green light-emitting device G, and blue light-emitting device B, is not restricted, and can be flexibly selected according to the actual situation as long as the requirements can be met.

[0190] The present application will be further described below with reference to specific embodiments. It should be noted that the following embodiments are only used to explain the present application and should not be construed as limiting the present application.

[0191] Example 1

[0192] The method for preparing the red light-emitting device in this embodiment is as follows:

[0193] On an indium tin oxide (ITO) substrate (anode), after UV ozone treatment for 5 min, a hole injection layer with a thickness of 40 nm was obtained by spin-coating poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and annealing at 120 °C for 30 min. Then, compound (2-31) (10 wt%) was used: poly[(N,N'-(4-n-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine)-ALT-(9,9-di-n-octylfluorenyl-2,7-phenylene oxide)-[2-31]-[3-(4-n-butylphenyl)-N,N'-diphenyl-1,4-phenylenediamine)-ALT-(9,9-di-n-octylfluorenyl-2,7-phenylene oxide) ...[3-(4-n-butyl A mixed hole transport material solution of [-di-based](TFB) was spin-coated and exposed using a 365nm light source. The solution was then soaked in toluene for 10 seconds and spin-dried. Next, a red quantum dot solution was spin-coated, followed by annealing at 100°C for 30 minutes to obtain a 20nm thick red quantum dot emitting layer. A zinc oxide (ZnO) solution was then spin-coated and annealed at 80°C for 30 minutes to obtain a 50nm thick electron transport layer. Finally, a 100nm thick aluminum (Al) electrode was vapor-deposited as the cathode.

[0194] Examples 2-14: The preparation method of the light-emitting device is basically the same as that of Example 1, except that the type of crosslinking agent in the hole transport layer is different, as detailed in Table 1 below.

[0195] Examples 15-20: The preparation method of the light-emitting device is basically the same as that of Example 1, except that the content of crosslinking agent in the hole transport layer is different, as detailed in Table 1 below.

[0196] Comparative Example 1: The fabrication method of the light-emitting device is basically the same as that of Example 1, except that the crosslinking agent in the hole transport layer is replaced with D1, as detailed in Table 1 below. The molecular formula of D1 is...

[0197] The voltage, external quantum efficiency (EQE), and lifetime of the light-emitting devices of Examples 1-20 and Comparative Example 1 are shown in Table 1 below.

[0198] Table 1

[0199]

[0200] For details of the voltage-current density curves of the light-emitting devices in Example 1 and Comparative Example 1, please refer to... Figure 7 For details, please refer to the voltage-brightness curve. Figure 8 As can be seen from the data in Table 1, the light-emitting devices using the crosslinking agent of this application have superior performance.

[0201] Examples 21-25 and Comparative Example 2

[0202] The fabrication method of the light-emitting device is basically the same as in Example 1, except that the material of the light-emitting layer is the same as that of the green light-emitting layer, and the type of crosslinking agent in the hole transport layer is different, as detailed in Table 2 below.

[0203] Table 2

[0204]

[0205] For details of the voltage-brightness curves of the light-emitting devices in Example 21 and Comparative Example 2, please refer to [the provided text]. Figure 9 As can be seen from the data in Table 2, the light-emitting devices using the crosslinking agent of this application have superior performance.

[0206] Examples 26-30 and Comparative Example 3

[0207] The fabrication method of the light-emitting device is basically the same as that in Example 1, except that the material of the light-emitting layer is the same as that of the blue light-emitting layer, and the type of crosslinking agent in the hole transport layer is different, as detailed in Table 3 below.

[0208] Table 3

[0209]

[0210] For details of the voltage-brightness curves of the light-emitting devices in Example 26 and Comparative Example 3, please refer to [the provided text]. Figure 10 As can be seen from the data in Table 3, the light-emitting devices using the crosslinking agent of this application have superior performance.

[0211] Example 31 The method for preparing the red light-emitting device in this example is as follows:

[0212] On an indium tin oxide (ITO) substrate (anode), after UV ozone treatment for 5 min, a hole injection layer with a thickness of 40 nm was obtained by spin-coating poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and annealing at 120 °C for 30 min. Then, a hole injection layer with a thickness of 40 nm was obtained by spin-coating using TFB as a hole transport material solution. Next, a red quantum dot solution of compound (2-32) (4 wt%) was used for spin-coating, followed by exposure to a 365 nm light source and development with n-octane solution to obtain a red quantum dot emitting layer with a thickness of 20 nm. Then, a zinc oxide (ZnO) solution was used for spin-coating and annealing at 80 °C for 30 min to obtain an electron transport layer with a thickness of 50 nm. Finally, an aluminum (Al) electrode with a thickness of 100 nm was deposited as the cathode.

[0213] Examples 32-44: The preparation method of the light-emitting device is basically the same as that of Example 31, except that the type of crosslinking agent in the light-emitting layer is different, as detailed in Table 4 below.

[0214] Examples 45-50: The preparation method of the light-emitting device is basically the same as that of Example 31, except that the content of crosslinking agent in the light-emitting layer is different, as detailed in Table 4 below.

[0215] Comparative Example 4: The fabrication method of the light-emitting device is basically the same as that of Example 31, except that the crosslinking agent in the light-emitting layer is replaced with D1, as detailed in Table 1 below. The molecular formula of D1 is...

[0216] The voltage, external quantum efficiency (EQE), and lifetime of the light-emitting devices in Examples 31-50 and Comparative Example 4 are shown in Table 4 below.

[0217] Table 4

[0218]

[0219] Examples 51-55 and Comparative Example 5

[0220] The preparation method of the light-emitting device is basically the same as that in Example 31, except that the material of the light-emitting layer is the same as that of the green light-emitting layer, and the type of crosslinking agent in the light-emitting layer is different, as detailed in Table 5 below.

[0221] Table 5

[0222]

[0223] Examples 56-60 and Comparative Example 6

[0224] The preparation method of the light-emitting device is basically the same as that in Example 31, except that the material of the light-emitting layer is the same as that of the blue light-emitting layer, and the type of crosslinking agent in the light-emitting layer is different, as detailed in Table 6 below.

[0225] Table 6

[0226]

[0227] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0228] The above description has been given for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A crosslinking agent, characterized in that, include: An electroactive group and a crosslinking group, wherein the electroactive group and the crosslinking group are bonded together, and the crosslinking group is located on at least a portion of the periphery of the electroactive group.

2. The crosslinking agent according to claim 1, characterized in that, The electroactive group includes at least one of fluorene, carbazole, aniline, imidazole, pyridine, triazine, and pyrimidine.

3. The crosslinking agent according to claim 1, characterized in that, The electroactive groups include At least one of them; R1, R2, R3, R4, R5, R6, R7 and R8 each independently include at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms; Preferably, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic amino group having 2 to 40 carbon atoms is substituted with F. The following substitutions may be made: , Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic amino group having 2 to 40 carbon atoms are replaced by O or S.

4. The crosslinking agent according to claim 1, characterized in that, The crosslinking groups include photocrosslinking groups; Preferably, the crosslinking groups include: At least one of them; Ar4, Ar5, Ar6, and Ar7 each independently include an aromatic or heteroaromatic ring; The R9, R 10 R 11 R 12 Each independently includes at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms; Preferably, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic amino group having 2 to 40 carbon atoms is substituted with F. The following substitutions may be made: , Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic amino group having 2 to 40 carbon atoms are replaced by O or S.

5. The crosslinking agent according to any one of claims 1 to 4, characterized in that, The crosslinking agent comprises a structure as shown in formula (1): Wherein, the electroactive group includes Ar, and the crosslinking group includes X and Y; The Ar includes at least one of the structures shown in equations (1-1) to (1-3): In equations (1-1) to (1-3), * represents a site that can bond with X and Y; The X and the * represent the site, Ar1 to Ar3, and R. 13 ~R 15 At least one site in the matrix is ​​bonded, and / or, the Y is bonded to the site represented by the *, the Ar1 to Ar3 and R. 13 ~R 15 At least one site of bonding; Ar1, Ar2, and Ar3 each independently include At least one of them; X and Y each include independently At least one of them; Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 R 14 and R 15 Each independently includes at least one of H, F, Cl, Br, I, CN, NO2, a straight-chain alkyl group having 1 to 40 carbon atoms, a branched alkyl group having 3 to 40 carbon atoms, a cyclic alkyl group having 3 to 40 carbon atoms, a branched alkyl group having 2 to 40 carbon atoms, and a cyclic amino group having 2 to 40 carbon atoms; Ar4, Ar5, Ar6, and Ar7 each independently include aromatic or heteroaromatic rings; The R 13 R 14 and R 15 The number of each is independently at least one; i+m+n≤18, i, m and n are not all 0 at the same time; Preferably, i+m+n≤9.

6. The crosslinking agent according to claim 5, characterized in that, In the same crosslinking agent molecule structure, the sum of the number of X and the number of Y is greater than or equal to 2 and less than or equal to 20; Preferably, the sum of the number of X and the number of Y is greater than or equal to 2 and less than or equal to 8; Preferably, at least one H atom in a straight-chain alkyl group having 1 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic alkyl group having 3 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a branched alkyl group having 2 to 40 carbon atoms is substituted with F, Cl, Br, I, CN, or NO2; and / or, at least one H atom in a cyclic amino group having 2 to 40 carbon atoms is substituted with F. The following substitutions may be made: , Cl, Br, I, CN, or NO2; and / or, at least two non-adjacent CH2 groups in a straight-chain alkyl group having 1 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic alkyl group having 3 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a branched alkyl group having 2 to 40 carbon atoms are replaced by O or S; and / or, at least two non-adjacent CH2 groups in a cyclic amino group having 2 to 40 carbon atoms are replaced by O or S.

7. The crosslinking agent according to claim 6, characterized in that, The crosslinking agent comprises at least one structure as shown in formulas (2-1) to (2-36):

8. A method for preparing a crosslinking agent, characterized in that, include: A coupling reaction is carried out between the first compound and the second compound to obtain the crosslinking agent, the crosslinking agent comprising bonded electroactive groups and crosslinking groups, the crosslinking groups being located on at least a portion of the periphery of the electroactive groups; Wherein, the first compound includes the electroactive group, and the second compound includes the crosslinking group; or, the electroactive group includes a first sub-electroactive group and a second sub-electroactive group, and the crosslinking group includes a first sub-crosslinking group and a second sub-crosslinking group, the first compound includes the first sub-electroactive group and the first sub-crosslinking group, and the second compound includes the second sub-electroactive group and the second sub-crosslinking group; or, the first compound includes the crosslinking group and the first sub-electroactive group, and the second compound includes the second sub-electroactive group.

9. The preparation method according to claim 8, characterized in that, The coupling reaction includes the Suzuki coupling reaction.

10. A light-emitting device, characterized in that, include: A first electrode layer, a light-emitting functional layer, and a second electrode layer are stacked together. The raw material of the light-emitting functional layer includes the crosslinking agent as described in any one of claims 1 to 7, or the crosslinking agent prepared by the preparation method described in claim 8 or 9.

11. The light-emitting device according to claim 10, characterized in that, The light-emitting functional layer includes at least one light-emitting layer, and the light-emitting layer includes the crosslinking agent; Preferably, the crosslinking agent accounts for 1 to 30% of the total mass of the light-emitting layer; Preferably, the light-emitting layer comprises a quantum dot light-emitting layer.

12. The light-emitting device according to claim 11, characterized in that, The light-emitting functional layer further includes at least one of a hole injection layer, a hole transport layer, and an electron blocking layer located between the first electrode layer and the light-emitting layer; Preferably, at least one of the hole injection layer, hole transport layer and electron blocking layer includes the crosslinking agent, and the electroactive group in the crosslinking agent includes at least one of fluorene, carbazole and aniline; Preferably, the hole injection layer includes the crosslinking agent, the mass of which accounts for 1-30% of the total mass of the hole injection layer; and / or, the hole transport layer includes the crosslinking agent, the mass of which accounts for 1-30% of the total mass of the hole transport layer; and / or, the electron blocking layer includes the crosslinking agent, the mass of which accounts for 1-30% of the total mass of the electron blocking layer. Preferably, the light-emitting functional layer further includes the hole injection layer, the hole transport layer and the electron blocking layer stacked sequentially, wherein the hole injection layer is located on the side of the hole transport layer closer to the first electrode layer; Preferably, the light-emitting functional layer further includes a crosslinking layer located between the light-emitting layer and the electron blocking layer, or between the electron blocking layer and the hole transport layer, or between the hole transport layer and the hole injection layer, wherein the crosslinking layer includes the crosslinking agent.

13. The light-emitting device according to claim 11, characterized in that, The light-emitting functional layer further includes at least one of an electron injection layer, an electron transport layer, and a hole blocking layer located between the second electrode layer and the light-emitting layer; Preferably, at least one of the electron injection layer, electron transport layer, and hole blocking layer includes the crosslinking agent, wherein the electroactive group in the crosslinking agent includes at least one of imidazole, pyridine, triazine, and pyrimidine; Preferably, the electron injection layer includes the crosslinking agent, the mass of which accounts for 1-30% of the total mass of the electron injection layer; and / or, the electron transport layer includes the crosslinking agent, the mass of which accounts for 1-30% of the total mass of the electron transport layer; and / or, the hole blocking layer includes the crosslinking agent, the mass of which accounts for 1-30% of the total mass of the hole blocking layer. Preferably, the light-emitting functional layer further includes the electron injection layer, the electron transport layer and the hole blocking layer stacked sequentially, wherein the electron injection layer is located on the side of the electron transport layer closer to the second electrode layer; Preferably, the light-emitting functional layer further includes a crosslinking layer located between the light-emitting layer and the hole-blocking layer, or between the hole-blocking layer and the electron transport layer, or between the electron transport layer and the electron injection layer, wherein the crosslinking layer includes the crosslinking agent.

14. A display panel, characterized in that, include: Array substrate; A pixel defining layer is located on one side of the array substrate, and the pixel defining layer includes a plurality of openings; The light-emitting device according to any one of claims 10 to 13, wherein a portion of the light-emitting device is located in the opening.

15. The display panel according to claim 14, characterized in that, The light-emitting functional layer includes a hole injection layer, a hole transport layer, an electron blocking layer and at least one light-emitting layer stacked in sequence, wherein the hole injection layer is located on the side of the hole transport layer close to the first electrode layer; In adjacent light-emitting devices, the hole injection layers are spaced apart, and / or the hole transport layers are spaced apart.

16. A method for manufacturing a display panel, characterized in that, include: A first electrode layer is fabricated on one side of the array substrate; A pixel defining layer is formed on the side of the first electrode layer opposite to the array substrate. The pixel defining layer includes a plurality of openings, and the first electrode layer is at least partially exposed to the openings. A light-emitting functional layer and a second electrode layer are sequentially fabricated in the opening; The raw material of the light-emitting functional layer includes the crosslinking agent as described in any one of claims 1 to 7, or the crosslinking agent prepared by the preparation method described in claim 8 or 9.

17. The preparation method according to claim 16, characterized in that, Fabricating a light-emitting functional layer in the opening includes: A hole injection layer, a hole transport layer, an electron blocking layer, and at least one light-emitting layer are sequentially prepared in the opening, wherein the raw material for at least one of the hole injection layer, hole transport layer, electron blocking layer, and light-emitting layer includes the crosslinking agent; Preferably, preparing the hole injection layer in the opening includes: A full-layer hole injection material layer is prepared on the side of the pixel defining layer opposite to the array substrate, the hole injection material layer including the crosslinking agent; The hole injection material layer is patterned using photolithography to obtain the hole injection layer with intervals. Preferably, after preparing a hole injection layer in the opening, preparing a hole transport layer in the opening includes: A full-layer hole transport material layer is prepared on the side of the hole injection layer opposite to the array substrate, the hole transport material layer including the crosslinking agent; The hole transport material layer is patterned using photolithography to obtain the hole transport layer with spaced intervals. Preferably, after fabricating a hole transport layer in the opening, fabricating a light-emitting layer in the opening includes: A whole-layer light-emitting material layer is prepared on the side of the hole transport layer opposite to the array substrate, the light-emitting material layer including the crosslinking agent; The light-emitting material layer is patterned using a photolithography process to obtain the light-emitting layers spaced apart.

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