Functional layer forming material, functional layer preparation method and light-emitting device

Abstract

A functional layer forming material, a functional layer preparation method and a light-emitting device relate to the technical field of display and are used for improving the efficiency of a light-emitting substrate. The functional layer forming material comprises a functional material and a cross-linking material. Wherein the ratio of the mass of the cross-linking material to the mass of the functional material is greater than 0 and less than or equal to 15%. The cross-linked material is configured to react with the functional material under a first preset condition to generate a cross-linked functional material. In the cross-linked functional material, a chain segment corresponding to the functional material is a first chain segment, and a chain segment corresponding to the cross-linked material is a second chain segment. Under a second preset condition, the crosslinking functional material can be subjected to decomposition reaction; in the decomposition reaction, the position where the crosslinking functional material is decomposed is located at the joint of the first chain segment and the second chain segment or located in the middle of the second chain segment. The energy layer forming material is used for preparing a functional layer.

Description

Technical Field

[0001] The present disclosure relates to the field of display technologies, and in particular, to a functional layer forming material, a method for preparing a functional layer, and a light-emitting device. Background Art

[0002] Quantum dots (QDs) are novel light-emitting materials with advantages such as high optical color purity, high luminescence quantum efficiency, tunable emission color, and long service life, and have become a research hotspot for novel light-emitting materials for light-emitting diodes (LEDs). Therefore, quantum dot light-emitting diodes (QLEDs) using quantum dot light-emitting materials as the light-emitting layer have become the main direction of research on novel display devices. Summary of the Invention

[0003] An object of an embodiment of the present disclosure is to provide a functional layer forming material, a method for preparing a functional layer, and a light-emitting device, which are used to improve the efficiency of a light-emitting substrate.

[0004] To achieve the above object, the embodiments of the present disclosure provide the following technical solutions:

[0005] On the one hand, a functional layer forming material is provided. The functional layer forming material includes a functional material and a crosslinking material. Wherein, the ratio of the mass of the crosslinking material to the mass of the functional material is greater than 0 and less than or equal to 15%. The crosslinking material is configured to react with the functional material under a first preset condition to generate a crosslinked functional material. In the crosslinked functional material, the segment corresponding to the functional material is the first segment, and the segment corresponding to the crosslinking material is the second segment. Under a second preset condition, the crosslinked functional material can undergo a decomposition reaction; in the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment, or in the middle of the second segment.

[0006] It can be understood that since the crosslinking material can react with the functional material under the first preset condition to generate a crosslinked functional material, and the functional crosslinked material can undergo a decomposition reaction under the second preset condition, the crosslinking material can be used as a reversible crosslinking agent for the functional material. When a photolithography sacrificial layer photolithography process is used to prepare a light-emitting substrate, the functional layer can be used as a front film layer of a quantum dot light-emitting layer. After the necessary development process is completed, by applying the second preset condition, the crosslinked functional material is decomposed, so that at least part of the crosslinked functional material decomposes to achieve de-crosslinking. Thus, compared with the case where the crosslinked functional material does not decompose, the crosslinked functional material in the material of the formed functional layer can be relatively less.

[0007] In this case, when the prepared light-emitting substrate is operating normally (e.g., for electroluminescence), the material of the functional layer can be in a non-crosslinked (or de-crosslinked) state. Compared with the case where the crosslinked functional material does not decompose, the function of the functional layer (e.g., carrier transport function, carrier injection function, or carrier blocking function) is less affected by the change in electrical properties (e.g., energy level, carrier transport rate, or carrier injection rate) caused by crosslinking, resulting in a higher current density and efficiency of the light-emitting device, less efficiency decay of the light-emitting device, enabling the electrical properties of the light-emitting device to reach a level consistent with or closer to that of the light-emitting substrate in the non-crosslinked case, and improving the electrical properties and efficiency of the light-emitting substrate prepared by the photolithography sacrificial layer process.

[0008] In some embodiments, the crosslinked functional material includes a plurality of first segments and a plurality of second segments. In the decomposition reaction, when the decomposition position of the crosslinked functional material is at the connection between the first segment and the second segment, after the decomposition reaction, a part of the first segment and a part of the second segment remain connected. In the decomposition reaction, when the decomposition position of the crosslinked functional material is in the middle of the second segment, after the decomposition reaction, a part of the second segment does not decompose.

[0009] In some embodiments, the crosslinking material includes a plurality of first groups and at least one second group. The plurality of first groups are located at the ends of the crosslinking material and can react with the functional material under a first preset condition. The at least one second group is located in the middle of the crosslinking material and can decompose under a second preset condition.

[0010] In some embodiments, the first group is a first photosensitive group, and the first preset condition includes irradiating with a first light.

[0011] In some embodiments, the plurality of first groups are the same or different and are each independently selected from any one of benzophenone group, azide group, diazo group, and bisaziridine group.

[0012] In some embodiments, the crosslinking material and the functional material undergo a hydrocarbon insertion reaction or an addition reaction to form a crosslinked functional material.

[0013] In some embodiments, the second group is a second photosensitive group, and the second preset condition includes irradiating with a second light. When the first group is a first photosensitive group, the second light is different from the first light.

[0014] In some embodiments, the second group has the structure shown in the following formula (IA-1).

[0015]

[0016] Wherein, * is the first connection site.

[0017] In some embodiments, the second group is a first thermosensitive group, and the second preset condition includes applying a heating means.

[0018] In some embodiments, when the crosslinking material includes a second group, the second group is any one of an azo group, a peroxy group, a persulfide group, an acetyl ketone group, and a methylthiophenol group. When the crosslinking material includes a plurality of second groups, the plurality of second groups are the same or different and are each independently selected from any one of an azo group, a peroxy group, a persulfide group, an acetyl ketone group, and a methylthiophenol group.

[0019] In some embodiments, when the second group is an azo group, the second group has a structure represented by the following general formula (IA-2).

[0020]

[0021] Wherein, * is a first connection site. R1, R2, R3, and R4 are the same or different and are each independently selected from any one of hydrogen, a substituted or unsubstituted saturated or unsaturated straight-chain or branched alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted ester group having 1 to 40 carbon atoms, a substituted or unsubstituted nitrile group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 members, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 members, or may be connected to an adjacent group to form a substituted or unsubstituted ring having 3 to 40 members.

[0022] In some embodiments, R1 and R4 are the same and are each selected from any one of the structures represented by the following formulas (IA-2-1) to (IA-2-7).

[0023]

[0024] Wherein, a, b, and c are the same or different and are each independently selected from any one of 0, 1, 2, and 3.

[0025] In some embodiments, R2 and R3 are the same and are each selected from any one of the structures represented by the following formulas (IA-2-8) to (IA-2-16).

[0026]

[0027] Wherein, d and e are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5, and 6.

[0028] In some embodiments, when the second group is a peroxy group, the second group is selected from any one of the structures represented by the following formulas (IA-3) to (IA-8);

[0029]

[0030] Among them, * is the first linking site. f, g, h, and i are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5, and 6.

[0031] In some embodiments, when the second group is a persulfur group, the second group is selected from any one of the structures shown in the following formulas (IA-9) to

[0032] (IA-14);

[0033]

[0034]

[0035] Among them, * is the first linking site. j, k, m, and n are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5, and 6.

[0036] In some embodiments, when the second group is an acetyl ketone group, the second group is the structure shown in the following formula (IA-15);

[0037]

[0038] Among them, * is the first linking site.

[0039] In some embodiments, when the second group is a methanethiol group, the second group is the structure shown in the following general formula (IA-16).

[0040]

[0041] Among them, * is the first linking site.

[0042] In some embodiments, the crosslinked material is selected from any one of the structures shown in the following general formulas (I) and (II).

[0043]

[0044] G is selected from any one of the structures shown in the following general formula (IB).

[0045]

[0046] Among them, J is the first group. # is the second linking site. A is the second group; when the second group includes the first linking site, the first linking site is linked to the second linking site. L1, L2, and L3 are the same or different and are each independently selected from any one of a substituted or unsubstituted amide group having 1 to 40 carbon atoms, a substituted or unsubstituted ester group having 1 to 40 carbon atoms, a substituted or unsubstituted saturated or unsaturated straight-chain or branched alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms. E1 and E2 are the same or different and are each independently selected from any one of carbon, oxygen, sulfur, selenium, sulfur, phosphorus, a substituted or unsubstituted saturated or unsaturated straight-chain or branched alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms. x, y, and w are the same or different and are each independently selected from any one of 1, 2, 3, 4, 5, and 6. z is selected from any one of 2, 3, 4, 5, and 6.

[0047] In some embodiments, L1, L2, and L3 are the same or different and are each independently selected from any one of the structures represented by the following general formulas (IC-1) to (IC-3);

[0048]

[0049] Among them, R5 and R6 are the same or different and are each independently selected from any one of a substituted or unsubstituted saturated or unsaturated straight-chain or branched alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted nitrile group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms; moreover, among R5 and R6, at least one is a saturated substituted or unsubstituted straight-chain or branched alkyl group having 1 to 6 carbon atoms.

[0050] In some embodiments, E1 and E2 are the same or different and are each independently selected from any one of the structures represented by the following general formulas (ID-1) to (ID-6).

[0051]

[0052]

[0053] Among them, L is L1, L2, or L3. p, r, and s are the same or different and are each independently selected from any one of 1, 2, 3, 4, 5, and 6.

[0054] On the other hand, a method for preparing a functional layer is provided. The method for preparing the functional layer includes: providing a functional layer forming material; the functional layer forming material includes: a functional material and a crosslinking material; the ratio of the mass of the crosslinking material to the mass of the functional material is greater than 0 and less than or equal to 15%. Under a first preset condition, the crosslinking material and the functional material react to generate a crosslinked functional material; in the crosslinked functional material, the segment corresponding to the functional material is the first segment, and the segment corresponding to the crosslinking material is the second segment. Under a second preset condition, the crosslinked functional material undergoes a decomposition reaction to form a functional layer; in the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment, or in the middle of the second segment.

[0055] The beneficial effects achievable by the method for preparing a functional layer provided by some embodiments of the present disclosure are the same as those achievable by a functional layer forming material provided by the above technical solution, and will not be elaborated herein.

[0056] In some embodiments, the first preset condition is an exposure condition. While forming the functional layer, a quantum dot light-emitting layer is also formed.

[0057] The method for preparing the functional layer specifically includes: forming a first initial functional layer, and the material of the first initial functional layer includes the functional layer forming material. Exposing the first initial functional layer, and the exposed part of the first initial functional layer forms a second initial functional layer, and the material of the second initial functional layer includes the crosslinked functional material. Developing the unexposed part of the first initial functional layer. And under a second preset condition, causing the crosslinked functional material in the second initial functional layer to undergo a decomposition reaction.

[0058] The method for preparing a quantum dot light-emitting layer includes: forming an initial quantum dot light-emitting layer. Exposing the initial quantum dot light-emitting layer. And developing the initial quantum dot light-emitting layer.

[0059] Among them, developing the unexposed part of the first initial functional layer and developing the initial quantum dot light-emitting layer are performed after exposing the first initial functional layer and before causing the crosslinked functional material in the second initial functional layer to undergo a decomposition reaction under a second preset condition.

[0060] On another aspect, a light-emitting device is provided. The light-emitting device includes an anode, a cathode, and a functional layer located between the anode and the cathode. The forming material of the functional layer includes the functional layer forming material as described in any of the above embodiments.

[0061] The beneficial effects achievable by the light-emitting device provided by some embodiments of the present disclosure are the same as those achievable by a functional layer forming material provided by the above technical solution, and will not be elaborated herein.

[0062] In some examples, the functional layer includes one or more of a quantum dot light-emitting layer, a hole transport layer, a hole injection layer, an electron blocking layer, an electron transport layer, an electron injection layer, and a hole blocking layer.

[0063] In some embodiments, the functional layer is located between the anode and the quantum dot light-emitting layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] To more clearly illustrate the technical solutions in the present disclosure, the following will briefly introduce the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings in the following description are only the drawings of some embodiments of the present disclosure, and those of ordinary skill in the art can also obtain other drawings based on these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams and do not limit the actual sizes of the products involved in the embodiments of the present disclosure, the actual processes of the methods, the actual timings of the signals, etc.

[0065] Figure 1 It is a step diagram of a method for preparing a light-emitting substrate according to some embodiments of the present disclosure;

[0066] Figure 2 It is a structural diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0067] Figure 3 It is another step diagram of a method for preparing a light-emitting substrate according to some embodiments of the present disclosure;

[0068] Figure 4 It is another structural diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0069] Figure 5 It is a structural diagram of a light-emitting device according to some embodiments of the present disclosure;

[0070] Figure 6 It is a data comparison diagram of the external quantum efficiency of a light-emitting device according to some embodiments of the present disclosure;

[0071] Figure 7 It is a structural diagram of a single-hole device according to some embodiments of the present disclosure;

[0072] Figure 8 It is a graph showing the change of the current density of a single-hole device with voltage according to some embodiments of the present disclosure;

[0073] Figure 9 It is a graph showing the change of the current density of a light-emitting device with voltage according to some embodiments of the present disclosure;

[0074] Figure 10 It is another structural diagram of a light-emitting device according to some embodiments of the present disclosure;

[0075] Figure 11 A flowchart of a method for preparing a functional layer provided by some embodiments of the present disclosure;

[0076] Figure 12 A step diagram of a method for preparing a functional layer provided by some embodiments of the present disclosure. Detailed implementation manners

[0077] Next, the technical solutions in some embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the present disclosure.

[0078] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular form "comprises" and the present participle form "comprising", are interpreted as open and inclusive meanings, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples", etc., are intended to indicate that the specific features, structures, materials or characteristics related to the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0079] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "a plurality" is two or more.

[0080] "At least one of A, B, and C" has the same meaning as "at least one of A, B, or C", and both include the following combinations of A, B, and C: only A, only B, only C, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0081] "A and / or B" includes the following three combinations: only A, only B, and the combination of A and B.

[0082] As used herein, "about", "substantially" or "approximately" includes the recited value and the average value within an acceptable deviation range of the specific value, where the acceptable deviation range is determined by one of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system).

[0083] As used herein, "parallel", "perpendicular", "equal" include the recited situation and situations similar to the recited situation, where the range of the similar situation is within an acceptable deviation range, and the acceptable deviation range is determined by one of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and approximate parallel, where the acceptable deviation range of approximate parallel can be, for example, within 5° deviation; "perpendicular" includes absolute perpendicular and approximate perpendicular, where the acceptable deviation range of approximate perpendicular can also be, for example, within 5° deviation. "Equal" includes absolute equal and approximate equal, where the acceptable deviation range of approximate equal can be, for example, the difference between the two equal values is less than or equal to 5% of either one of them.

[0084] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can be that the layer or element is directly on the other layer or substrate, or there can also be an intermediate layer between the layer or element and the other layer or substrate.

[0085] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of the layers and the area of the regions are enlarged for clarity. Therefore, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances can be envisioned. Thus, the exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but include shape deviations caused by, for example, manufacturing. For example, an etched region shown as rectangular will generally have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shape of the regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0086] It should be noted that, for example, 1 / 2 shown in the drawings of the present disclosure means that both Structure 1 and Structure 2 can refer to this structure. For example, 20 / R in the drawings means that both the light-emitting device 20 and the red light-emitting device R can be represented by this structure. Other similar reference numerals appearing in the drawings also follow the above description.

[0087] Based on the quantum confinement effect, quantum dots (QDs) have excellent luminescent properties such as broadband absorption, narrowband emission, and continuously tunable peak positions. At the same time, QDs have solution processability, which avoids the use of expensive vacuum equipment. As a result, quantum dot light-emitting diodes (QLEDs) using QDs as luminescent materials are considered to be the most promising next-generation self-luminous display technologies and are widely used in display lighting, solar cells, and photodetection and other fields, such as in new high-resolution display devices (electroluminescent or photoluminescent). Compared with organic light-emitting diode (OLED) devices, QLED devices have the advantages of lower power consumption, higher color purity, and wider color gamut.

[0088] In the preparation method of QLED devices, the precise preparation of the devices in the sub-pixel region is the prerequisite for achieving high-resolution display on the QLED light-emitting substrate. When using the solution method to prepare the quantum dot light-emitting layer of QLED devices, patterning is to pixelate the solution-state QDs. The preparation technologies for the light-emitting layer of quantum dot light-emitting diodes mainly include inkjet printing technology, lithography technology, transfer printing technology, etc., and lithography technology is a more promising method for preparing high-resolution quantum dot light-emitting diodes.

[0089] Lithography technology, that is, a technology to achieve QD patterning by means of exposure and development. Using photosensitive QD materials and realizing the direct patterning preparation of QD thin films on the substrate through mature lithography and development processes is an effective way to achieve high pixel density (high resolution) on the QLED light-emitting substrate. Exemplarily, surface ligands with photoreactivity endow QDs with the function of direct lithographic patterning. The main principle is to utilize photoreactions such as the decomposition or crosslinking of photosensitive groups to change the colloidal stability of QDs before and after the photoreaction, and achieve the purpose of selective patterning through development.

[0090] As Figure 1 shown, an exemplary preparation process for the quantum dot light-emitting layer 14 of a light-emitting substrate 10 is introduced. Please refer to Figure 1 the last small figure (i.e., the small figure corresponding to step S8) in it. The light-emitting substrate 10 includes: a substrate 11, a pixel defining layer 12 disposed on the substrate 11, and a plurality of light-emitting devices, and each light-emitting device includes a quantum dot light-emitting layer 14. Among them, the pixel defining layer 12 has a plurality of openings Q, and the plurality of light-emitting devices can be arranged in one-to-one correspondence with the plurality of openings Q.

[0091] Exemplarily, multiple light-emitting devices include: a red light-emitting device R, a green light-emitting device G, and a blue light-emitting device B. The following describes the process of sequentially forming the quantum dot light-emitting layer 14R of the red light-emitting device R, the quantum dot light-emitting layer 14G of the green light-emitting device G, and the quantum dot light-emitting layer 14B of the blue light-emitting device B.

[0092] As Figure 1 shown, this process includes steps: S1 to S8.

[0093] To improve the efficiency of electron and hole injection into the quantum dot light-emitting layer 14, a front film layer 13A is further provided between the substrate 11 and the quantum dot light-emitting layer 14. The front film layer 13A is, for example, one or two of an electron injection layer, an electron transport layer, and a hole blocking layer, or one or two of a hole injection layer, a hole transport layer, and an electron blocking layer.

[0094] S1: Coat a red quantum dot (Red Quantum Dot, RQD) light-emitting material on the side of the front film layer 13A away from the substrate 11 to form a red initial quantum dot light-emitting layer 14Ri. Expose the red initial quantum dot light-emitting layer 14Ri. The area where the red light-emitting device R is to be preformed is the exposed area, and the red initial quantum dot light-emitting layer 14Ri in the exposed area forms the quantum dot light-emitting layer 14R of the red light-emitting device R.

[0095] S2: Develop to remove the red initial quantum dot light-emitting layer 14Ri in areas other than the exposed area in S2.

[0096] S3: Coat a green quantum dot (Green Quantum Dot, GQD) light-emitting material on the quantum dot light-emitting layer 14R of the red light-emitting device R and on the side of the front film layer 13A away from the substrate 11 to form a green initial quantum dot light-emitting layer 14Gi.

[0097] S4: Expose the green initial quantum dot light-emitting layer 14Gi. The area where the green light-emitting device G is to be preformed is the exposed area, and the green initial quantum dot light-emitting layer 14Gi in the exposed area forms the quantum dot light-emitting layer 14G of the green light-emitting device G.

[0098] S5: Develop to remove the green initial quantum dot light-emitting layer 14Gi in areas other than the exposed area in S4.

[0099] S6: Coat a blue quantum dot (Blue Quantum Dot, BQD) light-emitting material on the quantum dot light-emitting layer 14G of the green light-emitting device G, the quantum dot light-emitting layer 14R of the red light-emitting device R, and on the side of the front film layer 13A away from the substrate 11 to form a blue initial quantum dot light-emitting layer 14Bi.

[0100] S7: Expose the blue initial quantum dot light-emitting layer 14Bi. The region where the blue light-emitting device B is pre-formed is the exposed region, and the blue initial quantum dot light-emitting layer 14Bi in the exposed region forms the quantum dot light-emitting layer 14B of the blue light-emitting device B.

[0101] S8: Develop, and remove the blue initial quantum dot light-emitting layer 14Bi in regions other than the exposed region in S7.

[0102] However, in the actual process of fabricating the quantum dot light-emitting layer 14 of the light-emitting substrate 1, as Figure 2 shown, due to certain interactions between the quantum dot light-emitting material and the materials of the film layers adjacent thereto, which include but are not limited to van der Waals forces, electrostatic forces, gravitational forces, capillary forces, etc., there is a problem that the quantum dot light-emitting material of the previous color (such as the red quantum dot light-emitting material) is not completely eluted in this patterning method. In this way, there will be residues of the quantum dot light-emitting material of the previous color (such as the red quantum dot light-emitting material) on the side of the quantum dot light-emitting layer of the next color (such as the quantum dot light-emitting layer 14G of the green light-emitting device G) close to the substrate 11. At the same time, there is also a problem that the quantum dot light-emitting material of the next color (such as the blue quantum dot light-emitting material) is not completely eluted in this patterning method. In this way, there will be residues of the quantum dot light-emitting material of the next color (such as the blue quantum dot light-emitting material) on the side of the quantum dot light-emitting layer of the previous color (such as the quantum dot light-emitting layer 14G of the green light-emitting device G) away from the substrate 11.

[0103] Exemplarily, as Figure 2 shown, taking the sequential formation of the quantum dot light-emitting layer 14R of the red light-emitting device R, the quantum dot light-emitting layer 14G of the green light-emitting device G, and the quantum dot light-emitting layer 14B of the blue light-emitting device B as an example, on the side of the quantum dot light-emitting layer 14R of the red light-emitting device R away from the substrate 11, there will be a residual layer G0 formed by the green quantum dot light-emitting material and a residual layer B0 formed by the blue quantum dot light-emitting material. On the side of the quantum dot light-emitting layer 14G of the green light-emitting device G close to the substrate 11, there will be a residual layer R0 formed by the red quantum dot light-emitting material, and on the side of the quantum dot light-emitting layer 14G of the green light-emitting device G away from the substrate 11, there will be a residual layer B0 formed by the blue quantum dot light-emitting material. On the side of the quantum dot light-emitting layer 14B of the blue light-emitting device B close to the substrate 11, there will be a residual layer R0 formed by the red quantum dot light-emitting material and a residual layer G0 formed by the green quantum dot light-emitting material.

[0104] Such residual layers formed by the quantum dot light-emitting material will cause color mixing problems. When the light-emitting device is lit, there is an easy problem of impure emission spectra, thus affecting the device performance.

[0105] Therefore, in order to overcome the problem of impure emission spectra in the light-emitting substrate. In some embodiments, asFigure 3 and Figure 4 As shown in Figure 4 , a photolithography process using a photolithography sacrificial layer is adopted. Specifically, a material that can undergo a crosslinking reaction under light irradiation is used as the material for the front film layer of the quantum dot light-emitting layer, so that the front film layer of the quantum dot light-emitting layer serves as an auxiliary sacrificial layer to remove a part of the quantum dot light-emitting material in the regions other than the region where the target opening is located, so as to avoid the formation of residues of the quantum dot light-emitting material in the regions other than the region where the target opening is located. In this way, the problem that there are residues of the quantum dot light-emitting material of the previous color on the side close to the substrate of the quantum dot light-emitting layer of the next color, and there are residues of the quantum dot light-emitting material of the next color on the side far from the substrate of the quantum dot light-emitting layer of the previous color can be solved, and further, the color mixing problem caused by the residual layer formed by the quantum dot light-emitting material can be solved.

[0106] As Figure 3 shown in Figure 3 , taking the preparation process when forming the quantum dot light-emitting layer 14R of the red light-emitting device R, the quantum dot light-emitting layer 14G of the green light-emitting device G, and the quantum dot light-emitting layer 14B of the blue light-emitting device B in sequence with the hole transport layer as the photolithography sacrificial layer as an example, a preparation process of the quantum dot light-emitting layer 14 of a light-emitting substrate 10 is introduced exemplarily. This process includes steps: M1 to M12.

[0107] M1: Coat and form a first initial hole transport layer 151i on the side of the front film layer 13B far from the substrate 11. The material of the first initial hole transport layer 151i includes: a first hole transport material and a second photosensitive material. The front film layer 13B is, for example, an anode or a hole injection layer.

[0108] M2: Coat and form a red initial quantum dot light-emitting layer 14Ri on the side of the first initial hole transport layer 151i far from the substrate 11. The material of the red initial quantum dot light-emitting layer 14Ri includes: a red quantum dot light-emitting material and a first photosensitive material. Expose the first region W1 where the red light-emitting device R is located.

[0109] In some examples, in M2, the first region W1 is exposed, so that the red quantum dot light-emitting material and the first photosensitive material in the first region W1 crosslink to generate a red crosslinked quantum dot light-emitting material, and at the same time, the first hole transport material and the second photosensitive material in the first region W1 crosslink to generate a first crosslinked hole transport material.

[0110] In other examples, M1 further includes: exposing the first region W1 where the red light-emitting device R is located, so that the first hole transport material and the second photosensitive material in the first region W1 crosslink to generate a first crosslinked hole transport material. In this case, in M2, the first region W1 is exposed, so that the red quantum dot light-emitting material and the first photosensitive material in the first region W1 crosslink to generate a red crosslinked quantum dot light-emitting material.

[0111] M3: Use a first solvent to dissolve a part of the red initial quantum dot light-emitting layer 14Ri located in the second region W2, and remove the part of the red initial quantum dot light-emitting layer 14Ri located in the second region W2. Here, the second region W2 is the remaining region of the plurality of light-emitting devices 20 other than the region where the red light-emitting device R is located.

[0112] Exemplarily, there will be residues of the red quantum dot light-emitting material and the first photosensitive material near the substrate 11, and a first temporary residue layer 31 will remain in the second region W2.

[0113] M4: Use a second solvent to dissolve a part of the first initial hole transport layer 151i located in the second region W2, remove the part of the first initial hole transport layer 151i located in the second region W2 and away from the substrate 11, and retain the part of the first initial hole transport layer 151i located in the second region W2 and near the substrate 11 to form a first initial residue pattern 32. And obtain the first hole transport layer 151 and the quantum dot light-emitting layer 14R of the red light-emitting device R.

[0114] In some examples, the light-emitting substrate 10 further includes a pixel definition layer 12, and the first initial residue pattern 32 is formed on the side of the pixel definition layer 12 away from the substrate 11 at the same time.

[0115] It should be understood that when removing the part of the first initial hole transport layer 151i located in the second region W2 and away from the substrate 11, the first temporary residue layer 31 is also removed, which can effectively prevent the residue of the red quantum dot light-emitting material in the second region W2.

[0116] M5: Coat and form a second initial hole transport layer 152i on the side of the quantum dot light-emitting layer 14R of the red light-emitting device R and away from the substrate 11 where the first initial residue pattern 32 is formed. The material of the second initial hole transport layer 152i includes: a second hole transport material and a fourth photosensitive material.

[0117] M6: Form a green initial quantum dot light-emitting layer 14Gi on the side of the second initial hole transport layer 152i away from the substrate 11. The material of the green initial quantum dot light-emitting layer 14Gi includes: a green quantum dot light-emitting material and a third photosensitive material. Expose the third region W3 where the green light-emitting device G is located.

[0118] Here, for the description of the exposure method of the second initial hole transport layer 152i and the green initial quantum dot light-emitting layer 14Gi, please refer to the description of the exposure method of the first initial hole transport layer 151i and the red initial quantum dot light-emitting layer 14Ri in M1 and M2, which will not be elaborated here.

[0119] In some examples, when exposing the third region W3 where the green light-emitting device G is located, the first initial residual pattern 32 located in the third region W3 is converted into a first residual pattern 32A.

[0120] M7: Use a third solvent to dissolve a part of the green initial quantum dot light-emitting layer 14Gi located in the fourth region W4, and remove the part of the green initial quantum dot light-emitting layer 14Gi located in the fourth region W4. Among them, the fourth region W4 is the remaining regions other than the region where the green light-emitting device G is located among the plurality of light-emitting devices 20.

[0121] Exemplarily, there will be residues in the parts of the green quantum dot light-emitting material and the third photosensitive material close to the substrate 11, and a second temporary residual layer 33 will remain in the fourth region W4.

[0122] M8: Use a fourth solvent to dissolve a part of the second initial hole transport layer 152i located in the fourth region W4, remove the part of the green initial quantum dot light-emitting layer 14Gi located in the fourth region W4 and away from the substrate 11 side, and retain the part of the second initial hole transport layer 152i located in the fourth region W4 and close to the substrate 11 side, form a second initial residual pattern 34, and obtain the second hole transport layer 152 and the quantum dot light-emitting layer 14G of the green light-emitting device G.

[0123] In some examples, the light-emitting substrate 10 further includes a pixel defining layer 12, and a second initial residual pattern 34 is simultaneously formed on the side of the pixel defining layer 12 away from the substrate 11.

[0124] It should be understood that when removing the part of the second initial hole transport layer 152i located in the fourth region W4 and away from the substrate 11 side, the second temporary residual layer 33 is also removed. It can effectively prevent the residue of the green quantum dot light-emitting material in the fourth region W4.

[0125] M9: Coat and form a third initial hole transport layer 153i on the side of the quantum dot light-emitting layer 14R of the red light-emitting device R, the quantum dot light-emitting layer 14G of the green light-emitting device R and the second initial residual pattern 34 away from the substrate 11. The material of the third initial hole transport layer 153i includes: a third hole transport material and a sixth photosensitive material.

[0126] M10: Form a blue initial quantum dot light-emitting layer 14Bi on the side of the third initial hole transport layer 153i away from the substrate 11. The material of the blue initial quantum dot light-emitting layer 14Bi includes: a blue quantum dot light-emitting material and a fifth photosensitive material. Expose the fifth region W5 where the blue light-emitting device B is located.

[0127] Here, for the description of the exposure method of the third initial hole transport layer 153i and the blue initial quantum dot light-emitting layer 14Bi, please refer to the description of the exposure method of the first initial hole transport layer 151i and the red initial quantum dot light-emitting layer 14Ri in M1 and M2, which will not be elaborated here.

[0128] In some examples, when exposing the fifth region W5 where the blue light-emitting device B is located, the first initial residual pattern 32 located in the fifth region W5 is converted into the first residual pattern 32A, and the second initial residual pattern 34 located in the fifth region W5 is converted into the second residual pattern 34A.

[0129] M11: Use the fifth solvent to dissolve the part of the blue initial quantum dot light-emitting layer 14Bi located in the sixth region W6, and remove the part of the blue initial quantum dot light-emitting layer 14Bi located in the sixth region W6. Among them, the sixth region W6 is the remaining regions of the plurality of light-emitting devices 20 except the region where the blue light-emitting device B is located.

[0130] Exemplarily, there will be residues of the blue quantum dot light-emitting material and the fifth photosensitive material near the substrate 11, and a third temporary residual layer 35 will remain in the sixth region W6.

[0131] M12: Use the sixth solvent to dissolve the part of the third initial hole transport layer 153i located in the sixth region W6, remove the part of the blue initial quantum dot light-emitting layer 14Bi located in the sixth region W6 and away from the substrate 11, and retain the part of the third initial hole transport layer 153i located in the sixth region W6 and near the substrate 11 to form a third initial residual pattern 36, and obtain the third hole transport layer 153 and the quantum dot light-emitting layer 14B of the blue light-emitting device B.

[0132] In some examples, the light-emitting substrate 10 further includes a pixel definition layer 12, and the third initial residual pattern 36 is simultaneously formed on the side of the pixel definition layer 12 away from the substrate 11.

[0133] It should be understood that when removing the part of the third initial hole transport layer 153i located in the sixth region W6 and away from the substrate 11, the third temporary residual layer 35 is also removed. It can effectively prevent the residue of the blue quantum dot light-emitting material in the sixth region W6.

[0134] From the above preparation process, it can be seen that in the light-emitting substrate prepared by the photolithography process using the photolithography sacrificial layer, the material of the functional layer corresponding to the auxiliary sacrificial layer is a crosslinked material. For example, as Figure 4As shown, in the light-emitting substrate 10, the first hole transport layer 151 is an auxiliary sacrificial layer for the quantum dot light-emitting layer 14R, and the material of the first hole transport layer 151 is a first cross-linked hole transport material; the second hole transport layer 152 is an auxiliary sacrificial layer for the quantum dot light-emitting layer 14G, and the material of the second hole transport layer 152 is a second cross-linked hole transport material; the third hole transport layer 153 is an auxiliary sacrificial layer for the quantum dot light-emitting layer 14B, and the material of the third hole transport layer 153 is a third cross-linked hole transport material.

[0135] In some implementation manners, when the material of the functional layer is a cross-linked material, the current density of the light-emitting device will decrease, and the efficiency of the light-emitting device will decay. Therefore, in order to enable the photolithography process of the photolithography sacrificial layer to be better produced, applied, and promoted, a reversible cross-linking strategy needs to be proposed to improve the efficiency of the light-emitting device prepared by the above photolithography process.

[0136] To illustrate the above problems more clearly, the influence of the material of the functional layer being a cross-linked material on the efficiency of the light-emitting device is illustrated by the following experimental examples.

[0137] The first group of test examples

[0138] In the following Examples 1 to 3, as Figure 5 shown, the light-emitting device 20 includes an anode 16, a hole injection layer 18, a hole transport layer 15, a quantum dot light-emitting layer 14, an electron transport layer 19, and a cathode 17 that are stacked in sequence.

[0139] In the following Examples 1 to 3, the material of the anode 16 is indium tin oxide (ITO) with a thickness of about 100 nm; the material of the hole injection layer 18 is poly(3,4-ethylenedioxythiophene) (PEDOT) with a thickness of about 40 nm; the material of the hole transport layer 15 includes 1,2,4,5-tetrakis(trifluoromethyl)benzene (TFB) and a photosensitive cross-linking agent (shown in the following formula (CL)), and the mass ratio of the two is 95:5, and the thickness of the hole transport layer 15 is about 30 nm; the material of the quantum dot light-emitting layer 14 is a red quantum dot material CdSe / ZnS (a material without a photosensitive cross-linking function) with a thickness of about 30 nm; the material of the electron transport layer 19 is ZnMgO with a thickness of about 50 nm; the material of the cathode 17 is Al with a thickness of about 150 nm.

[0140]

[0141] It should be noted that, as described in the thickness of each film layer in the above embodiments (for example, the thickness of the anode 16), "about" includes the stated value and the average value within an acceptable deviation range of a specific value (for example: 100 nm), where the acceptable deviation range is, for example, ±10% to ±15%. The same applies hereinafter.

[0142] In the following Examples 1 to 3, the preparation processes and conditions of the film layers other than the hole transport layer 15 and the quantum dot light-emitting layer 14 are the same. The preparation processes of the hole transport layer 15 and the quantum dot light-emitting layer 14 in Examples 1 to 3 are described below respectively.

[0143] In Example 1, the preparation process of the hole transport layer 15 is the solution coating method without exposure treatment; the preparation process of the quantum dot light-emitting layer 14 is the solution coating method without exposure treatment.

[0144] In Example 2, the preparation process of the hole transport layer 15 is the solution coating method and is treated by ultraviolet exposure with a high-pressure mercury lamp (hereinafter simply referred to as UV-HT); the preparation process of the quantum dot light-emitting layer 14 is the solution coating method without exposure treatment.

[0145] In Example 3, the preparation process of the hole transport layer 15 is the solution coating method and is treated by ultraviolet exposure with a high-pressure mercury lamp (hereinafter simply referred to as UV-HT); the preparation process of the quantum dot light-emitting layer 14 is the solution coating method and is treated by ultraviolet exposure with a high-pressure mercury lamp (hereinafter simply referred to as UV-QD).

[0146] The external quantum efficiency (EQE) of the light-emitting devices in Examples 1 to 3 was measured, and the results are as Figure 6 shown.

[0147] Comparing Example 1 with Example 2, please refer to Figure 6 , after the UV-HT treatment, the external quantum efficiency of the light-emitting device decreased from 25.6% ± 1% to 22% ± 1%, a decrease of about 3%, and the reduction rate was about 14%. Comparing Example 1 with Example 3, please refer to Figure 6, after UV-HT and UV-QD treatment, the external quantum efficiency of the light-emitting device decreased from 25.6% ± 1% to 15.8% ± 0.6%, a decrease of about 10%, and the decrease rate was about 38%. This is because in Example 2, after UV-HT treatment, crosslinking reaction occurred between TFB and the photosensitive crosslinking agent in the hole transport layer, generating crosslinked hole transport material; in Example 3, in addition to UV-HT treatment, UV-QD treatment was also carried out. Since the quantum dot light-emitting layer does not completely absorb photons, some photons will pass through the quantum dot light-emitting layer and enter the hole transport layer, further crosslinking TFB and the photosensitive crosslinking agent in the hole transport layer to generate more crosslinked hole transport material. When the crosslinked hole transport material in the hole transport layer is relatively high, the hole transport rate of the light-emitting device will decrease. Therefore, in Example 2 and Example 3, the external quantum efficiency of the light-emitting device decreased, and moreover, compared with Example 2, the decrease rate of the external quantum efficiency of the light-emitting device in Example 3 was higher.

[0148] The second group of test examples

[0149] In the following Examples 4 to 6, as Figure 7 shown, the single-hole device 40 (Hole Only Device, HOD device) includes an anode 16, a hole injection layer 18A, a hole transport layer 15A, a quantum dot light-emitting layer 14, a hole transport layer 15B, a hole injection layer 18B, and a cathode 17 stacked in sequence.

[0150] In the following Examples 4 to 6, the material of the anode 16 is ITO for all, and the thickness is about 100 nm; the material of the hole injection layer 18A is PEDOT for all, and the thickness is about 40 nm; the material of the hole transport layer 15A includes TFB and a photosensitive crosslinking agent (the structure is shown in the above formula (CL)) for all, and the mass ratio of the two is 95:5, and the thickness of the hole transport layer 15A is about 30 nm; the material of the quantum dot light-emitting layer 14 is a red quantum dot material CdSe / ZnS (a material without photosensitive crosslinking function) for all, and the thickness is about 30 nm; the material of the hole transport layer 15B is a vapor-depositable small molecule hole transport material 4,4',4”-tris(carbazol-9-yl)triphenylamine (TCTA) for all, and the thickness is about 40 nm; the material of the hole injection layer 18B is MoOx for all, and the thickness is about 15 nm; the material of the cathode 17 is Al for all, and the thickness is about 150 nm.

[0151] In the following Examples 4 to 6, the preparation processes and conditions of the other film layers except the hole transport layer 15A and the quantum dot light-emitting layer 14 are the same. Among them, the preparation processes of the hole transport layer 15A and the quantum dot light-emitting layer 14 in Example 4 are the same as those of the hole transport layer 15 and the quantum dot light-emitting layer 14 in Example 1; the preparation processes of the hole transport layer 15A and the quantum dot light-emitting layer 14 in Example 5 are the same as those of the hole transport layer 15 and the quantum dot light-emitting layer 14 in Example 2; the preparation processes of the hole transport layer 15A and the quantum dot light-emitting layer 14 in Example 6 are the same as those of the hole transport layer 15 and the quantum dot light-emitting layer 14 in Example 3.

[0152] It should be understood that Example 4 can be used as the HOD device corresponding to Example 1, Example 5 can be used as the HOD device corresponding to Example 2, and Example 6 can be used as the HOD device corresponding to Example 3.

[0153] The hole current density of the HOD devices in Examples 4 to 6 was measured, and the change curve of the obtained hole current density (unit: mA / cm 2 ) with voltage (unit: V) is as Figure 8 shown.

[0154] Comparing Example 4, Example 5 and Example 6, please refer to Figure 8 . At the same voltage, the hole current densities of the HOD device 40 from large to small are: Example 4, Example 5, Example 6. This is because in Example 5 and Example 6, after UV-HT treatment, the TFB and the photosensitive crosslinking agent in the hole transport layer 15A will undergo a crosslinking reaction to generate a crosslinked hole transport material. Moreover, in Example 6, in addition to UV-HT treatment, UV-QD treatment is also performed, which further crosslinks the TFB and the photosensitive crosslinking agent in the hole transport layer 15A to generate more crosslinked hole transport materials. When the crosslinked hole transport material in the hole transport layer 15A is relatively high, the hole transport rate of the HOD device 40 will decrease to some extent. Therefore, in Example 5 and Example 6, the hole current density of the HOD device 40 decreases to some extent, and the decrease rate of the hole current density of the HOD device 40 in Example 6 is higher than that in Example 5.

[0155] The third group of test examples

[0156] Example 7 is provided. In Example 7, the structure of the light-emitting device 20 is the same as that of the light-emitting devices in Examples 1 to 3, and is all as Figure 5 shown.

[0157] In Example 7, the material and thickness of the anode 16, the material and thickness of the hole injection layer 18, the thickness of the hole transport layer 15, the material and thickness of the quantum dot light-emitting layer 14, the material and thickness of the electron transport layer 19, and the material and thickness of the cathode 17 are the same as those in Examples 1 to 3. Different from Examples 1 to 3, the material of the hole transport layer 15 is TFB and it does not contain a photosensitive crosslinking agent.

[0158] In Example 7, the preparation processes and conditions of the other film layers except the hole transport layer 15 and the quantum dot light-emitting layer 14 are the same as those in Examples 1 to 3.

[0159] In Example 7, the preparation process of the hole transport layer 15 is the solution coating method and it is treated by ultraviolet exposure of a high-pressure mercury lamp (hereinafter referred to as UV-HT); the preparation process of the quantum dot light-emitting layer 14 is the solution coating method and it is treated by ultraviolet exposure of a high-pressure mercury lamp (hereinafter referred to as UV-QD).

[0160] The curves of the current density (unit: mA / cm 2 ) versus voltage (unit: V) of the light-emitting devices in Examples 1 to 3 and Example 7 are as Figure 9 shown.

[0161] Comparing Examples 1 to 3 with Example 7, please refer to Figure 9 . At the same voltage, the current densities of the light-emitting device 20 from large to small are: Example 7, Example 1, Example 2, Example 3. This is because in Examples 2 and 3, after being treated by UV-HT and UV-QD, crosslinked hole transport materials are generated, and moreover, compared with Example 2, there are more crosslinked hole transport materials in Example 3. In Example 1, the hole transport layer 15 contains a photosensitive crosslinking agent, but it is not treated by UV-HT or UV-QD, and no crosslinked hole transport materials are generated; in Example 7, the hole transport layer 15 does not contain a photosensitive crosslinking agent, and even after being treated by UV-HT and UV-QD, no crosslinked hole transport materials will be generated. The current densities of Example 1 and Example 7 are both at a relatively high level, indicating that in the case where the hole transport layer 15 does not include a photosensitive crosslinking agent, even if the light-emitting device 20 is normally exposed according to the exposure process, the current density can be restored to the current density level of the non-crosslinked light-emitting device 20 (i.e., Example 1).

[0162] It can be seen from the above first group of test examples to the third group of test examples that when the material of the functional layer is a crosslinked material, the current density of the light-emitting device will decrease, resulting in a decline in the efficiency of the light-emitting device.

[0163] Based on this, some embodiments of the present disclosure provide a functional layer forming material. The functional layer forming material includes a functional material and a crosslinking material. Wherein, the ratio of the mass of the crosslinking material to the mass of the functional material is greater than 0 and less than or equal to 15%. The crosslinking material is configured to react with the functional material under a first preset condition to generate a crosslinked functional material. In the crosslinked functional material, the segment corresponding to the functional material is the first segment, and the segment corresponding to the crosslinking material is the second segment. Under a second preset condition, the crosslinked functional material can undergo a decomposition reaction; in the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment, or in the middle of the second segment.

[0164] It should be understood that the functional material is the material in the above-mentioned functional layer forming material that can realize the functions of the functional layer, and such functions are, for example, any one or a combination of carrier transport, carrier injection, and carrier blocking. Among them, the carriers are, for example, holes or electrons.

[0165] In some examples, as Figure 10 shown, the functional material is a material for a hole transport functional layer, for example, any one of the materials of the hole transport layer 15, the hole injection layer 18, and the electron blocking layer 51; in other examples, the functional material is a material for an electron transport functional layer, for example, any one of the materials of the electron transport layer 19, the electron injection layer 53, and the hole blocking layer 52. That is to say, regarding the type of the functional material, there is no limitation here, as long as it meets the requirement that the functional material is an organic material and can react with the crosslinking material to generate a crosslinked functional material.

[0166] Here, the ratio of the mass of the crosslinking material to the mass of the functional material is greater than 0 and less than or equal to 15%. By setting it in this way, the amount of the crosslinking material in the functional layer forming material can be reduced, the influence of the crosslinking material on the performance of the functional material can be minimized, and the performance of the crosslinked functional material can reach a level close to that of the functional material.

[0167] For example, the functional material is a hole transport material, and the crosslinked functional material is a crosslinked hole transport material. When the ratio of the mass of the crosslinking material to the mass of the hole transport material is greater than 0 and less than or equal to 15%, compared with the case where the ratio of the mass of the crosslinking material to the mass of the hole transport material is greater than 15%, on the one hand, the stacking manner of the crosslinked hole transport material molecules after film formation is closer to that of the hole transport material molecules after film formation, and on the other hand, the energy level of the crosslinked hole transport material is closer to that of the hole transport material. In this way, the hole transport ability of the crosslinked hole transport material can be closer to that of the hole transport material.

[0168] Exemplarily, the ratio of the mass of the crosslinked material to the mass of the functional material is greater than 0.2% and less than or equal to 10%.

[0169] Exemplarily, the ratio of the mass of the crosslinked material to the mass of the functional material is greater than 0.2% and less than or equal to 5%.

[0170] Exemplarily, the ratio of the mass of the crosslinked material to the mass of the functional material is greater than or equal to 0.2% and less than or equal to 1%.

[0171] Exemplarily, the ratio of the mass of the crosslinked material to the mass of the functional material can be 0.2%, 0.5%, 0.8%, 1.0%, 1.5%, 2.5%, 3.5%, 4.2%, 5.0%, 8%, 10%, 13% or 15%, etc.

[0172] It should be noted that in the functional layer forming material, the ratio of the mass of the crosslinked material to the mass of the functional material can be obtained by separately measuring the mass of the functional material and the mass of the crosslinked material in the functional layer forming material and calculating. Here, there are no restrictions on the testing means and measurement methods for the mass of the functional material and the mass of the crosslinked material in the functional layer forming material.

[0173] In some examples, the mass of the functional material and the mass of the crosslinked material in the functional layer forming material can be measured by nuclear magnetic resonance hydrogen spectroscopy (H Nuclear Magnetic Resonance Spectra, HNMR) or nuclear magnetic resonance carbon spectroscopy (C Nuclear Magnetic Resonance Spectra, CNMR). For example, the mass of the functional material is obtained by calculating the peak area of the characteristic peak of the functional material, and the mass of the crosslinked material is obtained by calculating the peak area of the characteristic peak of the crosslinked material.

[0174] In other examples, the mass of the functional material and the mass of the crosslinked material in the functional layer forming material can be measured by high performance liquid chromatography (High Performance Liquid Chromatography, HPLC). For example, the mass of the functional material is obtained by calculating the peak area of the characteristic peak of the functional material, and the mass of the crosslinked material is obtained by calculating the peak area of the characteristic peak of the crosslinked material.

[0175] Exemplarily, when the crosslinked material and the functional material can react to generate a crosslinked functional material; moreover, when the crosslinked functional material can undergo a decomposition reaction, the preparation method of the functional layer can include:

[0176] R1: Under the first preset condition, the crosslinking material and the functional material can react to form a crosslinked functional material. Moreover, in the molecular structure of the crosslinked functional material, there is a first segment corresponding to the functional material and a second segment corresponding to the crosslinking material.

[0177] R2: Under the second preset condition, the crosslinked functional material undergoes a decomposition reaction.

[0178] It should be understood that in R1, the reaction between the crosslinking material and the functional material is a crosslinking reaction. Since the crosslinking reaction occurs with a certain degree of randomness, the number of first segments or the number of second segments in a certain crosslinked functional material can be one or multiple. That is to say, there is no limit here on the number of first segments and the number of second segments in the crosslinked functional material.

[0179] In R2, the position where the crosslinked functional material decomposes can be at least the following three positions: one is in the middle of the first segment; the second is at the connection between the first segment and the second segment; the third is in the middle of the second segment. Here, in the second segment, other positions except the end structure can be included in the range of the middle of the second segment.

[0180] It can be understood that when the position where the crosslinked functional material decomposes is in the middle of the first segment, in the material of the functional layer formed, the first segment corresponding to the functional material is disconnected, which may have an adverse effect on the function of the functional layer. Therefore, by setting the position where the crosslinked functional material decomposes in the decomposition reaction at the connection between the first segment and the second segment, or in the middle of the second segment, the structure of the first segment and / or the functional material can be retained in the material of the functional layer, and the performance of the functional layer can be maintained at a relatively high level, which is beneficial to improving the electrical performance and efficiency of the light-emitting substrate.

[0181] In some examples, the crosslinked functional material includes multiple first segments and multiple second segments. In the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment. In this case, the process of the crosslinking reaction between the crosslinking material and the functional material to form the crosslinked functional material and the decomposition reaction of the crosslinked functional material can be shown as the following formula (1).

[0182]

[0183] In other examples, the crosslinked functional material includes multiple first segments and multiple second segments. In the decomposition reaction, the position where the crosslinked functional material decomposes is in the middle of the second segment. In this case, the process of the crosslinking reaction between the crosslinking material and the functional material to form the crosslinked functional material and the decomposition reaction of the crosslinked functional material can be shown as the following formula (2).

[0184]

[0185] It should be noted that in Formula (1) and Formula (2), represents the crosslinkable group of the functional material (which can also be understood as the crosslinking site), that is, the part that reacts with the first group of the crosslinking material.

[0186] Understandably, since the crosslinking material can react with the functional material under the first preset condition to generate a crosslinked functional material, and the functional crosslinked material can undergo a decomposition reaction under the second preset condition, the crosslinking material can be used as a reversible crosslinking agent for the functional material. When preparing a light-emitting substrate by a photolithography sacrificial layer photolithography process, the functional layer can be used as the front film layer of the quantum dot light-emitting layer. After the necessary development process is completed, step R2 is performed. By applying the second preset condition, at least part of the crosslinked functional material undergoes decomposition to achieve de-crosslinking. In this way, compared with the case where the crosslinked functional material does not decompose, the crosslinked functional material in the formed functional layer material can be relatively less.

[0187] In this case, when the prepared light-emitting substrate is operating normally (such as electroluminescence), the material of the functional layer can be in a non-crosslinked (or de-crosslinked) state. Compared with the case where the crosslinked functional material does not decompose, the function of the functional layer (such as carrier transport function, carrier injection function or carrier blocking function) is less affected by the change of electrical properties (such as energy level, carrier transport rate or carrier injection rate) caused by crosslinking, so that the current density and efficiency of the light-emitting device are higher, the efficiency decay of the light-emitting device is less, the electrical properties of the light-emitting device can reach a level consistent with or closer to that of the light-emitting substrate in the non-crosslinked case, and the electrical properties and efficiency of the light-emitting substrate prepared by the photolithography sacrificial layer photolithography process can be improved.

[0188] Moreover, the time for performing step R2 can be flexibly controlled, as long as it is after the necessary development process is completed (such as after the quantum dot light-emitting layer of each light-emitting device is developed), which can improve the feasibility of forming the functional layer and fabricating the light-emitting device.

[0189] In some examples, as shown in Formula (1) and Formula (2), in the decomposition reaction, the degree of de-crosslinking of the crosslinked functional material is relatively high. In other examples, in the decomposition reaction, the degree of de-crosslinking of the crosslinked functional material is relatively low, which can also be understood as that the crosslinked functional material undergoes partial de-crosslinking. The case where the crosslinked functional material undergoes partial de-crosslinking will be introduced exemplarily below.

[0190] In some embodiments, the crosslinked functional material includes a plurality of first segments and a plurality of second segments. In the decomposition reaction, when the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment, after the decomposition reaction, a part of the first segment and a part of the second segment remain connected. In the decomposition reaction, when the position where the crosslinked functional material decomposes is in the middle of the second segment, after the decomposition reaction, a part of the second segment does not decompose.

[0191] It should be understood that when a part of the first segment and a part of the second segment remain connected, or a part of the second segment does not decompose, the material of the functional layer includes both the crosslinked functional material and the product after the decomposition reaction of the crosslinked functional material (hereinafter simply referred to as the de-crosslinked product). Moreover, compared with the crosslinked functional material, the performance of the de-crosslinked product (such as the hole transport performance) is at a relatively high level.

[0192] It can be understood that when more crosslinked functional materials undergo decomposition reactions, the degree of de-crosslinking of the crosslinked functional materials is higher. At this time, the performance of the functional layer (such as the hole transport performance) is at a relatively high level. Therefore, when a part of the first segment and a part of the second segment remain connected, or a part of the second segment does not decompose, by regulating the proportion of the crosslinked functional materials that undergo decomposition reactions, the performance of the functional layer (such as the carrier transport, carrier injection function, or carrier blocking function) can be regulated, so as to realize the regulation of the carrier transport, injection, or blocking performance of the light-emitting device.

[0193] Exemplarily, the way to regulate the proportion of the crosslinked functional materials that undergo decomposition reactions can be to control the time and intensity of the decomposition reaction within a certain range.

[0194] The crosslinking reaction between the functional material and the crosslinking material, as well as the reaction position and reaction degree of the decomposition reaction of the crosslinked functional material, have been introduced above by way of example. Next, some possible implementation manners of the crosslinking reaction between the functional material and the crosslinking material, as well as the decomposition reaction of the crosslinked functional material, will be introduced by way of example.

[0195] In some examples, the process of the crosslinking reaction between the crosslinking material and the functional material to generate the crosslinked functional material, and the decomposition reaction of the crosslinked functional material is as shown in the above formula (1). As a possible implementation manner, the functional material can be modified so that the functional material has a set group, and the set group can undergo a crosslinking reaction with the crosslinking material under a first preset condition to generate the crosslinked functional material, and the crosslinked functional material can undergo a decomposition reaction under a second preset condition to regenerate the crosslinking material and the functional material.

[0196] Exemplarily, the set group is a photosensitive group. The first preset condition includes irradiating a fourth light ray, and the second preset condition includes irradiating a fifth light ray. The wavelength band where the fourth light ray is located does not overlap with the wavelength band where the fifth light ray is located.

[0197] Exemplarily, the set group is a thermosensitive group. The first preset condition includes heating to a first reaction temperature, and the second preset condition includes heating to a second reaction temperature. The first reaction temperature is different from the second reaction temperature. For example, the second reaction temperature is greater than the first reaction temperature.

[0198] In some other examples, the crosslinking material reacts with the functional material to form a crosslinked functional material; and the process of the crosslinked functional material undergoing a decomposition reaction is as shown in the above formula (2); some embodiments in this case will be introduced exemplarily below.

[0199] In some embodiments, as shown in formula (2), the crosslinking material includes a plurality of first groups and at least one second group. The plurality of first groups are located at the ends of the crosslinking material and can react with the functional material under the first preset condition. At least one second group is located in the middle of the crosslinking material and can decompose under the second preset condition.

[0200] It can be understood that based on the above structure, on the one hand, by using the first group, the crosslinking material can react with the functional material. Moreover, when the crosslinking material includes a plurality of first groups, one crosslinking material molecule can react with a plurality of functional material molecules to achieve the purpose of crosslinking. On the other hand, when the crosslinking material includes at least one second group, at least one second group is also included in the second segment corresponding to the crosslinking material. In this way, by using at least one second group, the crosslinked functional material containing the second segment can undergo a decomposition reaction, and since the second group is located in the middle of the second segment, the position where the crosslinked functional material decomposes is located in the middle of the second segment.

[0201] In some examples, the crosslinking material includes one second group. At this time, as shown in formula (2), when a decomposition reaction occurs, the second segment can be decomposed into two sub-segments, and the two sub-segments can be respectively connected to two first segments. In another example, the crosslinking material includes a plurality of second groups. At this time, when a decomposition reaction occurs, the second segment can be decomposed into at least three sub-segments. When the second segment is a straight-chain segment, among the at least three sub-segments, the two sub-segments located at the ends can be respectively connected to two first segments; when the second segment is a branched-chain segment, the at least three sub-segments can be connected to at least three first segments.

[0202] In the above embodiments, there are no limitations on the type of the first preset condition and the type of the reaction that occurs between the crosslinking material and the functional material, as long as the requirement of generating the crosslinked functional material is satisfied.

[0203] For example, the first group is the second thermosensitive group, and the first preset condition includes applying a heating means. At this time, the functional layer forming material can be heated to cause the functional material to react with the crosslinking material to generate a crosslinked functional material.

[0204] In some embodiments, the first group is the first photosensitive group, and the first preset condition includes irradiating the first light.

[0205] Here, the first group being the first photosensitive group means that the first group is a photosensitive reaction group / functional group, and is at least configured to react with the functional material under the illumination condition of light with a specific wavelength or wavelength band.

[0206] It can be understood that through the above settings, by irradiating the first light, the functional material can react with the crosslinking material to generate a crosslinked functional material. In this way, on the one hand, the reaction conditions for generating the crosslinked functional material can be matched with the preparation process of the quantum dot light-emitting substrate in some embodiments of the present disclosure (such as steps M1-M2, M5-M6, or M9-M10 in the foregoing preparation method), improving the feasibility of generating the crosslinked functional material; on the other hand, the first preset condition can be easily applied.

[0207] In some examples, the first preset condition is to irradiate the first light, and the first light is, for example, ultraviolet light. In other examples, in addition to irradiating the first light, the first preset condition further includes one or more of, for example, introducing an inert gas and adding a certain reaction assistant. In other words, there are no limitations on other conditions in the first preset condition except for irradiating the first light.

[0208] In some embodiments, the plurality of first groups are the same or different, and are each independently selected from any one of benzophenone group, azide group, diazo group, and bisaziridine group.

[0209] It can be understood that the benzophenone group, azide group, diazo group, and bisaziridine group are all photosensitive groups. When the first group is selected from any one of the benzophenone group, azide group, diazo group, and bisaziridine group, the first group can be used to cause the functional material to react with the crosslinking material under the condition of irradiating the first light to generate a crosslinked functional material, making the reaction conditions for generating the crosslinked functional material easy to apply and matching the preparation process of the quantum dot light-emitting substrate in some embodiments.

[0210] In some embodiments, the crosslinking material and the functional material undergo a C-H insertion reaction to generate a crosslinked functional material.

[0211] Understandably, since the functional material is an organic material, it mostly contains carbon-hydrogen bonds. By setting up the carbon-hydrogen insertion reaction between the crosslinking material and the functional material, the feasibility of generating the crosslinked functional material can be improved, enabling a greater variety of selectable functional materials.

[0212] In some examples, the first group is a first photosensitive group, and the first photosensitive group is a benzophenone group. The structure of the crosslinking material can be shown as the following formula (3). The carbon-hydrogen insertion reaction occurs between the crosslinking material and the functional material, and this carbon-hydrogen insertion reaction can be shown as the following formula (4).

[0213]

[0214] It should be noted that formula (3) shows one benzophenone group in the crosslinking material molecule, and formula (4) shows the reaction that occurs between this benzophenone group and the functional material molecule. It should be understood that, as described above, the crosslinking material molecule also includes at least one first group present in Ra. The first group is, for example, any one of a benzophenone group, an azide group, a diazo group, and a bisaziridine group. Here, regarding the types of other first groups other than the benzophenone group shown in formula (3), as well as the other structures in Ra other than the first group (such as the second group described in detail below and the structure of the molecular skeleton), no limitations are set here. Among them, in the case where the other first group other than the benzophenone group shown in formula (3) is not a benzophenone group, regarding the reaction between the first group and the functional material molecule, reference can be made to the reactions described in detail below, and no further elaboration will be provided here.

[0215] In some examples, the first group is a first photosensitive group, and the first photosensitive group is an azide group. The structure of the crosslinking material can be shown as the following formula (5). The carbon-hydrogen insertion reaction occurs between the crosslinking material and the functional material, and this carbon-hydrogen insertion reaction can be shown as the following formula (6).

[0216]

[0217] Equation (5) shows an azide group in the crosslinked material molecule, and Equation (6) shows the reaction that this azide group undergoes with the functional material molecule. It should be understood that, as described above, the crosslinked material molecule further includes at least one first group present in Rb, and the first group is, for example, any one of benzophenone group, azide group, diazo group, and bisaziridine group. Here, regarding the types of other first groups other than the azide group shown in Equation (5), the types of substituents X1, X2, X3, and X4, and other structures in Rb other than the first group (such as the second group described in detail below and the structure of the molecular skeleton), no limitations are set here. Among them, when other first groups other than the azide group shown in Equation (5) are not azide groups, regarding the reaction of the first group with the functional material molecule, reference can be made to the reactions described above or in detail below, and no further elaboration will be provided here.

[0218] In some examples, the first group is a first photosensitive group, the first photosensitive group is a diazo group, and the structure of the crosslinked material can be shown as the following Equation (7). The crosslinked material and the functional material undergo a C-H insertion reaction, and this C-H insertion reaction can be shown as the following Equation (8).

[0219]

[0220] Equation (7) shows a diazo group in the crosslinked material molecule, and Equation (8) shows the reaction that this diazo group undergoes with the functional material molecule. It should be understood that, as described above, the crosslinked material molecule further includes at least one first group present in Rc and / or Rd, and the first group is, for example, any one of benzophenone group, azide group, diazo group, and bisaziridine group. Here, regarding the types of other first groups other than the diazo group shown in Equation (7), and other structures in Rc and Rd other than the first group (such as the second group described in detail below and the structure of the molecular skeleton), no limitations are set here. Among them, when other first groups other than the diazo group shown in Equation (7) are not diazo groups, regarding the reaction of the first group with the functional material molecule, reference can be made to the reactions described above or in detail below, and no further elaboration will be provided here.

[0221] In some examples, the first group is a first photosensitive group, the first photosensitive group is a bisaziridine group, and the structure of the crosslinked material can be shown as the following Equation (9). The crosslinked material and the functional material can undergo a C-H insertion reaction, and this C-H insertion reaction can be shown as the following Equation (10).

[0222]

[0223]

[0224] Equation (9) shows a bisaziridine group in the crosslinked material molecule, and Equation (10) shows the reaction of this bisaziridine group with the functional material molecule. It should be understood that, as described above, the crosslinked material molecule further includes at least one first group present in Re and / or Rf. The first group is, for example, any one of benzophenone group, azide group, diazo group, and bisaziridine group. Here, regarding the types of other first groups other than the bisaziridine group shown in Equation (9), and other structures in Re and Rf other than the first group (such as the second group described in detail below, and the structure of the molecular backbone), no limitations are set here. Among them, when the other first group other than the bisaziridine group shown in Equation (9) is not a bisaziridine group, regarding the reaction of the first group with the functional material molecule, regarding the reactions that can be referred to the foregoing or described in detail below, no further elaboration will be made here.

[0225] It should be noted that the structural formulas listed above are examples of the structure of the crosslinked material and the C-H insertion reaction that occurs between the crosslinked material and the functional material, and are not limitations on the structure of the crosslinked material and the C-H insertion reaction that occurs between the crosslinked material and the functional material. Moreover, (x) in the above structural formulas is a substitute name for each structure or reaction formula, and is not part of the structure or reaction formula. Among them, x takes a positive integer; the reaction condition UV represents ultraviolet light irradiation. represents other structures in the functional material except for the C-H bond part.

[0226] In some embodiments, the crosslinked material and the functional material undergo an addition reaction to form a crosslinked functional material.

[0227] It can be understood that when the functional material contains an unsaturated segment in its chain segment, the functional material contains unsaturated bonds such as alkenyl, alkenylene, alkynyl, or alkynylene groups. By setting the addition reaction between the crosslinked material and the functional material, the functional material can react with the crosslinked material to form a crosslinked functional material, which can improve the feasibility of forming the crosslinked functional material and make the crosslinked material applicable to functional materials containing unsaturated segments.

[0228] In some examples, the first group is a benzophenone group, and the structure of the crosslinked material can be as shown in the above formula (3). In this case, the crosslinked material and the functional material undergo an addition reaction, and this addition reaction can be as shown in the following formula (11) or formula (12).

[0229]

[0230] In some examples, the first group is an azide group, and the structure of the crosslinked material can be as shown in the above formula (4). In this case, the crosslinked material and the functional material undergo an addition reaction, and this addition reaction can be as shown in the following formula (13) or formula (14).

[0231]

[0232] In some examples, the first group is a diazo group, and the structure of the crosslinked material can be as shown in the above formula (5). In this case, an addition reaction occurs between the crosslinked material and the functional material, and this addition reaction can be as shown in the following formula (15) or formula (16).

[0233]

[0234] In some examples, the first group is a bisaziridine group, and the structure of the crosslinked material can be as shown in the above formula (6). In this case, an addition reaction occurs between the crosslinked material and the functional material, and this addition reaction can be as shown in the following formula (17) or formula (18).

[0235]

[0236] It should be noted that in formulas (11), (13), (15), and (17), the reactions that occur between the functional material and the crosslinked material are shown when the alkenyl group of the functional material is located in the middle of the molecular chain of the functional material and at the end of the molecular chain of the functional material. In practical applications, the alkenyl group of the functional material can be only located in the middle of the molecular chain of the functional material, or only at the end of the molecular chain of the functional material, or, alternatively, a part of the alkenyl group can be located in the middle of the molecular chain of the functional material and another part of the alkenyl group can be located at the end of the molecular chain of the functional material, without any limitation here; moreover, when the alkenyl group of the functional material is only located in the middle of the molecular chain of the functional material and only at the end of the molecular chain of the functional material, the situations of the addition reactions that occur between the functional material and the crosslinked material can be referred to formulas (11), (13), (15), and (17), and will not be elaborated here.

[0237] It should be noted that the structural formulas listed above are examples of the addition reactions that occur between the crosslinked material and the functional material, and are not limitations on the structure of the crosslinked material and the addition reactions that occur between the crosslinked material and the functional material. Moreover, (x) in the above structural formulas is a reference number for each structure or reaction formula, and is not a part of the structure or reaction formula, where x is a positive integer; the reaction condition UV represents ultraviolet light irradiation, represents other structures in the functional material except for the unsaturated bond part.

[0238] The above is an exemplary description of the first group and the reaction between the first group and the functional material when the crosslinked material includes the first group. Next, an exemplary description will be given of the second group and the decomposition reaction of the crosslinked functional material when the crosslinked material includes the second group.

[0239] In some embodiments, the second group is a second photosensitive group, and the second preset condition includes irradiating with a second light. When the first group is a first photosensitive group, the second light is different from the first light.

[0240] Here, the second group being a second photosensitive group means that the second group is a photosensitive type of cleavable group / functional group or bond-breaking group / functional group, and is at least configured to: under the illumination condition of light with a specific wavelength or wavelength band, undergo a cleavage reaction or a bond-breaking reaction.

[0241] Here, the second light being different from the first light means that the wavelength or wavelength band of the first light does not overlap with the wavelength or wavelength band of the second light. For example, the wavelength of the first light is a first wavelength value, the wavelength of the second light is a second wavelength value, the first wavelength value is different from the second wavelength value, and there is a certain difference between the two.

[0242] It can be understood that through the above settings, by irradiating with the second light, the crosslinked functional material can undergo a decomposition reaction, and the position where the crosslinked functional material decomposes is located in the middle of the second segment, making it easy to apply the second preset condition. Moreover, when the first group is a first photosensitive group, by setting the second light to be different from the first light, the influence of the second preset condition on the functional material and crosslinked material that may exist in the functional layer can be reduced.

[0243] In some examples, the second preset condition is irradiating with a second light, and the second light is, for example, ultraviolet light. In other examples, in addition to irradiating with the second light, the second preset condition further includes one or more of, for example, introducing an inert gas and adding a certain reaction assistant. In other words, there are no limitations on other conditions in the second preset condition except for irradiating with the second light.

[0244] In some examples, the functional layer forming material is a hole transport layer forming material, and a quantum dot light-emitting layer is provided on one side of the hole transport layer. Among them, the forming material of the quantum dot light-emitting layer forms a quantum dot light-emitting layer (the material of the quantum dot light-emitting layer, for example, contains a crosslinked quantum dot light-emitting material) under the action of a third light. In this case, the second light and the third light can be the same or different, and there are no limitations here.

[0245] In some embodiments, the second group has the structure shown in the following formula (IA-1).

[0246]

[0247] Among them, * is the first connection site.

[0248] It should be understood that through the first connection site, the second group can be connected to other structures in the crosslinked material molecule, for example, connected to the second connection site # described in detail below.

[0249] In some examples, under the second preset condition (i.e., irradiating the second light), the decomposition reaction of the second group with the structure shown in formula (IA-1) can be as shown in the following formula (19).

[0250]

[0251] Exemplarily, the UV in formula (19) can be a mixed ultraviolet light irradiation of 250 nm to 400 nm, or it can also be an ultraviolet light irradiation with a specific wavelength (such as 254 nm or 365 nm).

[0252] It should be noted that formula (19) schematically shows the main products in the reaction, and for some small molecule products that may be generated in the reaction, they are not shown in formula (19).

[0253] It can be understood that when the second group has the structure shown in formula (IA-1), the second group is the second photosensitive group. Thus, by irradiating the second light, the second segment of the crosslinked functional material molecule can be decomposed (for example, decomposed into at least two sub-segments), and the position where the crosslinked functional material decomposes is in the middle of the second segment. For example: as shown in formula (19), the connection relationship between one of the first connection sites and the product shown in formula (19) is released, achieving the purpose of decomposing the second segment.

[0254] In some embodiments, the second group is the first thermosensitive group, and the second preset condition includes applying a heating means.

[0255] Here, the second group being the first thermosensitive group means that the second group is a thermosensitive cleavable group / functional group or bondable group / functional group, and is at least configured to: under the condition of applying a heating means, undergo a cleavage reaction or a bond-breaking reaction.

[0256] It can be understood that through the above settings, by heating the crosslinked functional material to a set temperature, the crosslinked functional material can undergo a decomposition reaction, and the position where the crosslinked functional material decomposes is in the middle of the second segment. Thus, firstly, the second preset condition is easy to apply; secondly, the decomposition reaction of the crosslinked functional material can be completed during the thermal annealing process after other functional layers are completed, or it can also be completed when the device is thermally annealed as a whole after the device is fabricated; thus, the decomposition of the crosslinked functional material can be achieved without adding new processes, improving the process feasibility.

[0257] In some examples, the second preset condition is to heat to a set temperature and maintain the set temperature for a set time. In other examples, in addition to heating to the set temperature and maintaining the set temperature for the set time, the second preset condition further includes one or more of, for example, light avoidance, introduction of an inert gas, and addition of a certain reaction auxiliary agent. In other words, there are no restrictions here on other conditions in the second preset condition except for applying heating means.

[0258] In some embodiments, when the crosslinking material includes a second group, the second group is any one of an azo group, a peroxide group, a persulfide group, an acetyl ketone group, and a methylthiophenol group. When the crosslinking material includes a plurality of second groups, the plurality of second groups are the same or different and are each independently selected from any one of an azo group, a peroxide group, a persulfide group, an acetyl ketone group, and a methylthiophenol group.

[0259] It can be understood that the azo group, the peroxide group, the persulfide group, the acetyl ketone group, and the methylthiophenol group are all thermosensitive groups, and can undergo a decomposition reaction (such as a bond-breaking reaction or a cleavage reaction) under the second preset condition (including applying a heating condition), and can decompose the second segment of the crosslinking functional material molecule (for example, decompose into at least two sub-segments), and the position where the crosslinking functional material decomposes is in the middle of the second segment.

[0260] In some embodiments, when the second group is an azo group, the second group has the structure shown in the following general formula (IA-2).

[0261]

[0262] Wherein, * is the first connection site.

[0263] R1, R2, R3, and R4 are the same or different and are each independently selected from any one of hydrogen, a substituted or unsubstituted saturated or unsaturated straight-chain or branched-chain alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted ester group having 1 to 40 carbon atoms, a substituted or unsubstituted nitrile group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 members, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 members, or may be connected to an adjacent group to form a substituted or unsubstituted ring having 3 to 40 members.

[0264] Here, for the description of the first connection site, reference may be made to the description of the first connection site in formula (IA-1), which will not be elaborated here.

[0265] Among them, the straight-chain alkyl group of Cx refers to a straight-chain alkyl group with x carbon (C) atoms in total, where x is a positive integer, and the same applies hereinafter. For the understanding of other groups such as branched-chain alkyl groups of Cx, ester groups of Cx, etc., reference can be made to the above content and will not be elaborated here. Moreover, the phenyl group refers to the general term of the remaining group after removing the hydrogen atom of one carbon atom on the benzene ring. For the understanding of other groups such as aryl groups, heteroaryl groups, ester groups, etc., reference can be made to the above content and will not be elaborated here. Furthermore, the heteroaryl group of Z atoms refers to a heteroaryl group with Z atoms in the ring, where Z is a positive integer, and the same applies hereinafter. For the understanding of other groups such as heterocyclic groups of Z atoms, rings of Z atoms, etc., reference can be made to the above content and will not be elaborated here.

[0266] When any one of R1, R2, R3 or R4 is selected from a substituted saturated or unsaturated straight-chain or branched-chain alkyl group of C1-C40, a substituted ester group of C1-C40, a substituted nitrile group of C1-C40, a substituted cycloalkyl group of C3-C40, a substituted heterocyclic group of 3 to 40 members, a substituted aryl group of C6-C40, and a substituted heteroaryl group of 5 to 40 members, there is no limitation on the type and number of substituents here.

[0267] It can be understood that the structure shown in the general formula (IA-2) contains an azo group, which can undergo a decomposition reaction (such as a bond-breaking reaction or a cleavage reaction) under the action of a second preset condition, causing the crosslinked functional material to decompose, and the position where the decomposition occurs is in the middle of the second chain segment.

[0268] In some embodiments, R1 and R4 are the same and are selected from any one of the structures shown in the following formulas (IA-2-1) to (IA-2-7).

[0269]

[0270] Among them, a, b, and c are the same or different and are each independently selected from any one of 0, 1, 2, and 3.

[0271] It can be understood that when R1 and R4 are selected from any one of the structures shown in the following general formulas (IA-2-1) to (IA-2-7), the molecular weight of the second group is relatively low, which can make the molecular weight of the crosslinked material relatively low. First, it can reduce the steric hindrance effect when the crosslinked material and the functional material undergo a crosslinking reaction. Second, it can make the molar amount of the crosslinked material in the functional layer forming material relatively large, thereby enhancing the crosslinking function of the crosslinked material.

[0272] In some embodiments, R2 and R3 are the same and are selected from any one of the structures shown in the following formulas (IA-2-8) to (IA-2-16).

[0273]

[0274]

[0275] Among them, d and e are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5, and 6.

[0276] It can be understood that, similarly to the above, when R2 and R3 are selected from any one of the structures shown in the following general formulas (IA-2-1) to (IA-2-7), the molecular weight of the second group is relatively low, which can reduce the steric effect during the cross-linking reaction between the cross-linking material and the functional material, and at the same time can improve the cross-linking function of the cross-linking material.

[0277] Exemplarily, when R1 and R4 are the same and R2 and R3 are the same, the decomposition reaction of the second group can be as shown in formula (20).

[0278]

[0279] Among them, R2’ is the remaining structure after removing a hydrogen atom from R2.

[0280] Exemplarily, when the first group is an azide group, the second group is an azo group, and the azo group is selected from one of the structures shown in the general formula (IA-2), the cross-linking reaction between the cross-linking material and the functional material, and the decomposition reaction of the cross-linked functional material can be as shown in formula (23).

[0281]

[0282] It should be understood that when the cross-linked functional material in formula (23) undergoes a decomposition reaction, product 1 and product 2 can be generated, or two product 3 can be generated.

[0283] Exemplarily, when the first group is a benzophenone group, the second group is an azo group, and the azo group is selected from one of the structures shown in the general formula (IA-2), the cross-linking reaction between the cross-linking material and the functional material, and the decomposition reaction of the cross-linked functional material can be as shown in formula (24).

[0284]

[0285] It should be understood that when the cross-linked functional material in formula (24) undergoes a decomposition reaction, product 4 and product 5 can be generated, or two product 6 can be generated.

[0286] It should be noted that in formulas (23) and (24), represents the functional material molecule, and the same applies hereinafter.

[0287] In some embodiments, when the second group is a peroxy group, the second group is selected from any one of the structures represented by the following formulas (IA-3) to (IA-8).

[0288]

[0289] Wherein, * is the first connection site.

[0290] f, g, h, and i are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5, and 6.

[0291] Here, for the description of the first connection site, reference may be made to the description of the first connection site in formula (IA-1), which will not be elaborated herein.

[0292] It can be understood that the structures represented by the general formulas (IA-3) to (IA-8) all contain a peroxy group, and this peroxy group can undergo a decomposition reaction (such as a bond-breaking reaction or a cleavage reaction) under the action of a second preset condition, causing the crosslinked functional material to decompose, and the position where the decomposition occurs is in the middle of the second segment.

[0293] Exemplarily, when the second group is the structure represented by formula (IA-3), the decomposition reaction of the second group can be as shown in formula (21).

[0294]

[0295] Exemplarily, when the second group is the structure represented by formula (IA-5), the decomposition reaction of the second group can be as shown in formula (22).

[0296]

[0297] It should be noted that formula (22) schematically shows the main structure of the second group, and for some of the carbon-hydrogen structures in the second group, they are not shown in formula (22).

[0298] Exemplarily, when the first group is a benzophenone group, the second group is an azo group, and the azo group is selected from one of the structures represented by the general formula (IA-2), the crosslinking reaction that occurs between the crosslinking material and the functional material, and the decomposition reaction that occurs to the crosslinked functional material can be as shown in formula (25).

[0299]

[0300] It should be understood that when the crosslinked functional material in formula (25) undergoes a decomposition reaction, product 7 or product 8 can be generated.

[0301] In some embodiments, when the second group is a persulfur group, the second group is selected from any one of the structures represented by the following formulas (IA-9) to

[0302] (IA-14);

[0303]

[0304] wherein, * is the first connection site.

[0305] j, k, m and n are the same or different, and are each independently selected from any one of 0, 1, 2, 3, 4, 5 and 6.

[0306] Here, for the description of the first connection site, reference may be made to the description of the first connection site in formula (IA-1), which will not be elaborated here.

[0307] It can be understood that the structures represented by the general formulas (IA-9) to (IA-14) all contain a persulfur group, and this persulfur group can undergo a decomposition reaction (such as a bond-breaking reaction or a cleavage reaction) under the action of a second preset condition, causing the crosslinked functional material to decompose, and the position where the decomposition occurs is in the middle of the second segment.

[0308] In some embodiments, when the second group is an acetyl ketone group, the second group is a structure represented by the following formula (IA-15);

[0309]

[0310] wherein, * is the first connection site.

[0311] Here, for the description of the first connection site, reference may be made to the description of the first connection site in formula (IA-1), which will not be elaborated here.

[0312] It can be understood that the acetyl ketone group can undergo a decomposition reaction (such as a bond-breaking reaction or a cleavage reaction) under the action of a second preset condition, causing the crosslinked functional material to decompose, and the position where the decomposition occurs is in the middle of the second segment.

[0313] In some embodiments, when the second group is a methanethiol group, the second group is a structure represented by the following general formula (IA-16).

[0314]

[0315] wherein, * is the first connection site.

[0316] Here, for the description of the first connection site, reference may be made to the description of the first connection site in formula (IA-1), which will not be elaborated here.

[0317] Understandably, the thiophenol group can undergo a decomposition reaction (such as a bond-breaking reaction or a cleavage reaction) under the action of a second preset condition, causing the cross-linked functional material to decompose, and the position where the decomposition occurs is in the middle of the second segment.

[0318] In some embodiments, the cross-linked material is selected from any one of the structures represented by the following general formula (I) and general formula (II).

[0319]

[0320] G is selected from any one of the structures represented by the following general formula (IB).

[0321]

[0322] Wherein, J is a first group; # is a second connection site.

[0323] A is a second group; in the case where the second group includes a first connection site, the first connection site is connected to the second connection site. L1, L2, and L3 are the same or different, and are independently selected from any one of C1-C40 substituted or unsubstituted amide groups, C1-C40 substituted or unsubstituted ester groups, C1-C40 substituted or unsubstituted saturated or unsaturated straight-chain or branched-chain alkyl groups, C3-C40 substituted or unsubstituted cycloalkyl groups, 3- to 40-membered substituted or unsubstituted heterocyclic groups, C6-C40 substituted or unsubstituted aryl groups, and 5- to 40-membered substituted or unsubstituted heteroaryl groups. E1 and E2 are the same or different, and are independently selected from carbon, oxygen, sulfur, selenium, sulfur, phosphorus, C1-C40 substituted or unsubstituted saturated or unsaturated straight-chain or branched-chain alkyl groups, C3-C40 substituted or unsubstituted cycloalkyl groups, 3- to 40-membered substituted or unsubstituted heterocyclic groups, C6-C40 substituted or unsubstituted aryl groups, and 5- to 40-membered substituted or unsubstituted heteroaryl groups. x, y, and w are the same or different, and are independently selected from any one of 1, 2, 3, 4, 5, and 6. z is selected from any one of 2, 3, 4, 5, and 6.

[0324] Here, E1 and E2 in the general formula (IB) can be understood as a molecular backbone (such as an atom or a molecular chain), and w first groups J are respectively connected to the molecular backbone E2 through w L3s, and the w L3s can be the same or different.

[0325] The general formula (I) is the case where the cross-linked material contains one second group A. In the general formula (I), containing x Gs means that x molecular backbones E2 are respectively connected to the second group A through x L2s, and the x L2s can be the same or different.

[0326] General formula (II) is the case where a crosslinked material contains multiple (i.e., z) second groups A, and the z second groups A are respectively connected to E1 through z L1s. In general formula (II), when y Gs are connected to the second group A, it means that y molecular skeletons E2 are respectively connected to the second group A through y L2s, and the y L2s can be the same or different. Here, among the z second groups A, the number (i.e., y) of E2s connected to each second group A can be the same or different.

[0327] The descriptions of the amide group of Cx, the ester group of Cx, etc. here can refer to the above descriptions of the straight-chain alkyl group of Cx; the descriptions of the heteroaryl group of Z yuan, the heterocyclic group of Z yuan, etc. here can refer to the above descriptions of the heteroaryl group of Z yuan; they will not be elaborated here.

[0328] It should be noted that when L1, L2, or L3 is selected from any one of the substituted amide groups of C1-C40, the substituted ester groups of C1-C40, the substituted saturated or unsaturated straight-chain or branched alkyl groups of C1-C40, the substituted cycloalkyl groups of C3-C40, the substituted heterocyclic groups of 3 to 40 members, the substituted aryl groups of C6-C40, and the substituted heteroaryl groups of 5 to 40 members, and / or when E is selected from any one of the substituted saturated or unsaturated straight-chain or branched alkyl groups of C1-C40, the substituted cycloalkyl groups of C3-C40, the substituted heterocyclic groups of 3 to 40 members, the substituted aryl groups of C6-C40, and the substituted heteroaryl groups of 5 to 40 members, there are no restrictions here on the type and number of substituents.

[0329] It can be understood that when the crosslinked material is selected from any one of the structures shown in general formula (I) and general formula (II), the crosslinked material includes multiple first groups and at least one second group. In this way, by using the first group, the crosslinked material can react with the functional material to achieve the purpose of crosslinking; by using the second group, the crosslinked functional material can undergo a decomposition reaction, and the position where the crosslinked functional material decomposes is in the middle of the second chain segment.

[0330] Moreover, when w is not 1, multiple first groups J are connected to the same E2, and the multiple first groups J can be connected to multiple functional material molecules. In this way, when the second group A undergoes a decomposition reaction, the multiple functional material molecules connected to the same E2 still maintain the connection relationship, so that when the crosslinked functional material decomposes, the degree of de-crosslinking is relatively low. In this way, the performance of the functional layer (such as the carrier transport, carrier injection function, or carrier blocking function) can be regulated to achieve the regulation of the carrier transport, injection, or blocking performance of the light-emitting device.

[0331] Exemplarily, when the crosslinked material is one of the structures shown in general formula (I), x is 2, and both 2 w values are 1, the structural formula of the crosslinked material can be illustrated by the following formula.

[0332]

[0333] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (I), x is 3, and all three w's are 1, the structural formula of the crosslinked material can be illustrated by the following formula.

[0334]

[0335] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (I), x is 2, and the two w's are 1 and 2 respectively, the structural formula of the crosslinked material can be illustrated by the following formula.

[0336]

[0337] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (I), x is 4, and all four w's are 1, the structural formula of the crosslinked material can be illustrated by the following formula.

[0338]

[0339] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (I), x is 3, and the three w's are 1, 1, and 2 respectively, the structural formula of the crosslinked material can be illustrated by the following formula.

[0340]

[0341] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (I), x is 2, and the two w's are 1 and 3 respectively, the structural formula of the crosslinked material can be illustrated by the following formula.

[0342]

[0343] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (II), z is 2, both two y's are 2, and all four w's are 1, the structural formula of the crosslinked material can be illustrated by the following formula.

[0344]

[0345] Exemplarily, when the crosslinked material is one of the structures represented by the general formula (II), z is 2, both two y's are 3, and the six w's are 1, 1, 2, 1, 1, 1 respectively, the structural formula of the crosslinked material can be illustrated by the following formula.

[0346]

[0347] It should be noted that the structural formulas listed above are examples of the connection modes between the first group A and the second group J in the crosslinked material, rather than limitations on the connection modes between the first group A and the second group J in the crosslinked material.

[0348] In some embodiments, L1, L2, and L3 are the same or different, and are each independently selected from any one of the structures represented by the following general formulas (IC-1) to (IC-3);

[0349]

[0350] Wherein, R5 and R6 are the same or different, and are each independently selected from any one of a C1-C40 substituted or unsubstituted saturated or unsaturated straight-chain or branched-chain alkyl group, a C1-C40 substituted or unsubstituted nitrile group, a C3-C40 substituted or unsubstituted cycloalkyl group, a 3- to 40-membered substituted or unsubstituted heterocyclic group, a C6-C40 substituted or unsubstituted aryl group, and a 5- to 40-membered substituted or unsubstituted heteroaryl group; moreover, among R5 and R6, at least one is a C1-C6 substituted or unsubstituted saturated straight-chain or branched-chain alkyl group.

[0351] The descriptions of the branched-chain alkyl group of Cx, the cycloalkyl group of Cx, etc. here can refer to the descriptions of the straight-chain alkyl group of Cx above; the descriptions of the heteroaryl group of Z yuan, the heterocyclic group of Z yuan, etc. here can refer to the descriptions of the heteroaryl group of Z yuan above; they will not be elaborated here.

[0352] It should be noted that when R5 and R6 are selected from any one of a C1-C40 substituted saturated or unsaturated straight-chain or branched-chain alkyl group, a C3-C40 substituted cycloalkyl group, a 3- to 40-membered substituted heterocyclic group, a C6-C40 substituted aryl group, and a 5- to 40-membered substituted heteroaryl group, there are no restrictions on the type and number of substituents here.

[0353] Exemplarily, R5 and R6 are the same or different, and are each independently selected from any one of methyl, ethyl, propyl, butyl, pentyl, hexyl, phenyl, and nitrile group.

[0354] Exemplarily, at least one of R5 and R6 is selected from any one of the following formulas (IC-a-1) to (IC-a-9).

[0355]

[0356] Wherein, ** represents the connection site with the adjacent group.

[0357] Understandably, when L1, L2 or L3 is one of the structures shown in the general formula (IC-1), the structures on both sides of L1, L2 or L3 can be connected through an amide reaction; when L1, L2 or L3 is one of the structures shown in the general formula (IC-2), the structures on both sides of L1, L2 or L3 can be connected through an esterification reaction; when L1, L2 or L3 is one of the structures shown in the general formula (IC-3), the structures on both sides of L1, L2 or L3 can be connected through a click reaction between azide and alkyne; thus, the synthesis feasibility of the crosslinked material can be improved.

[0358] Moreover, when at least one of R5 and R6 is a substituted or unsubstituted saturated straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms, the synthesis of the crosslinked material can be made easier, and the synthesis feasibility of the crosslinked material can be improved.

[0359] In some embodiments, E1 and E2 are the same or different and are each independently selected from any one of the structures shown in the following general formulas (ID-1) to (ID-6).

[0360]

[0361]

[0362] Wherein, L is L1, L2 or L3. p, r and s are the same or different and are each independently selected from any one of 1, 2, 3, 4, 5 and 6.

[0363] It should be understood that when E1 or E2 is selected from any one of the structures shown in the general formulas (ID-1) and (ID-4), E1 or E2 is a linear molecular backbone; when E1 or E2 is selected from any one of the structures shown in the general formulas (ID-2), (ID-3), (ID-5) and (ID-6), E1 or E2 is a branched molecular backbone. Among them, (ID-2) and (ID-5) are two-branched molecular backbones, and (ID-3) and (ID-6) are three-branched molecular backbones.

[0364] When E1 or E2 is selected from any one of the structures shown in the general formulas (ID-1) to (ID-3), E1 or E2 is an alkane chain-type molecular backbone; when E1 or E2 is selected from any one of the structures shown in the general formulas (ID-4) to (ID-6), E1 or E2 is a PEO chain-type molecular backbone.

[0365] Understandably, when E1 or E2 is an alkane chain molecular backbone or a PEO chain molecular backbone, it is possible to facilitate the preparation of the crosslinked material. Moreover, when E1 is a branched-chain molecular backbone, multiple second groups can be connected to one E1; when E2 is a branched-chain molecular backbone, multiple first groups can be connected to one E2, and the number of first groups and / or second groups included in the crosslinked material can be regulated.

[0366] In some embodiments, E1 and E2 are the same or different and are each independently selected from a PEG chain or a polyether chain. Here, there are no limitations on the structure and the number of repeating units of the PEG chain or the polyether chain.

[0367] On the other hand, some embodiments of the present disclosure provide a method for preparing a functional layer. As Figure 11 shown, the method for preparing the functional layer includes N1 to N3.

[0368] N1: Provide a functional layer forming material; the functional layer forming material includes: a functional material and a crosslinked material; the ratio of the mass of the crosslinked material to the mass of the functional material is greater than 0 and less than or equal to 15%.

[0369] N2: Under a first preset condition, cause the crosslinked material and the functional material to react to generate a crosslinked functional material; in the crosslinked functional material, the segment corresponding to the functional material is the first segment, and the segment corresponding to the crosslinked material is the second segment.

[0370] N3: Under a second preset condition, cause the crosslinked functional material to undergo a decomposition reaction to form a functional layer; in the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment or in the middle of the second segment.

[0371] The beneficial effects achievable by the method for preparing a functional layer provided by some embodiments of the present disclosure are the same as those achievable by the functional layer forming material provided by the above technical solution, and will not be elaborated here.

[0372] In some embodiments, the first preset condition is an exposure condition. While forming the functional layer, a quantum dot light-emitting layer is also formed.

[0373] The method for preparing the functional layer specifically includes: forming a first initial functional layer, the material of the first initial functional layer including the functional layer forming material. Exposing the first initial functional layer, the exposed part of the first initial functional layer forms a second initial functional layer, the material of the second initial functional layer including the crosslinked functional material. Developing the unexposed part of the first initial functional layer. And under the second preset condition, causing the crosslinked functional material in the second initial functional layer to undergo a decomposition reaction.

[0374] Method for preparing a quantum dot light-emitting layer, comprising: forming an initial quantum dot light-emitting layer; exposing the initial quantum dot light-emitting layer; and developing the initial quantum dot light-emitting layer.

[0375] Wherein, developing the unexposed part of the first initial functional layer and developing the initial quantum dot light-emitting layer are carried out after exposing the first initial functional layer and before causing the crosslinking functional material in the second initial functional layer to undergo a decomposition reaction under a second preset condition.

[0376] It can be understood that through the above settings, the functional layer can serve as an auxiliary sacrificial layer for the quantum dot light-emitting layer, and removing the part of the material for forming the quantum dot light-emitting layer (such as the quantum dot light-emitting material) located in the regions other than the target opening region can solve the color mixing problem caused by the residual layer formed by the quantum dot light-emitting material.

[0377] Hereinafter, taking the functional layer as a hole transport layer as an example, the preparation methods of the functional layer and the quantum dot light-emitting layer will be described.

[0378] Exemplarily, as Figure 12 shown, the methods for forming the hole transport layer and the quantum dot light-emitting layer include H1 to H6.

[0379] H1: Coating and forming a first initial hole transport layer 15iA on the side of the front film layer 13B away from the substrate 11. The material of the first initial hole transport layer 15iA includes: a hole transport material and a crosslinking material. The front film layer 13B is, for example, an anode or a hole injection layer.

[0380] Here, for the exemplary description of the hole transport material and the crosslinking material, please refer to the foregoing content and will not be elaborated herein.

[0381] H2: Coating and forming an initial quantum dot light-emitting layer 14i on the side of the first initial hole transport layer 15iA away from the substrate 11. The material of the initial quantum dot light-emitting layer 14i includes, for example, a quantum dot light-emitting material and a photosensitive material. Exposing the target region W7.

[0382] Exemplarily, the quantum dot light-emitting material includes a quantum dot body and a ligand material coordinated to the quantum dot body.

[0383] In some examples, in H2, exposing the target region W7 causes the quantum dot light-emitting material and the photosensitive material in the target region W7 to react to generate a crosslinked quantum dot light-emitting material, and at the same time causes the hole transport material and the crosslinking material in the target region W7 to react to generate a crosslinked hole transport material (i.e., a crosslinking functional material), forming a second initial hole transport layer 15iB.

[0384] In some other examples, H1 further includes: exposing the target region W7 so that the hole transport material and the crosslinking material in the target region W7 react to generate a crosslinked hole transport material (i.e., a crosslinked functional material), forming a second initial hole transport layer 15iB. In this case, in H2, the target region W7 is exposed so that the quantum dot light-emitting material and the photosensitive material in the target region W7 react to generate a crosslinked quantum dot light-emitting material.

[0385] Among them, in the crosslinked hole transport material, the segment corresponding to the hole transport material is the first segment, and the segment corresponding to the crosslinking material is the second segment.

[0386] Exemplarily, in the exposure process, a mask plate or a mask layer can be used to expose the target region W7.

[0387] In this case, before step H3, removing the mask plate or removing the mask layer is further included.

[0388] H3: Using a seventh solvent to dissolve a part of the initial quantum dot light-emitting layer 14i located in the eighth region W8, and removing the part of the initial quantum dot light-emitting layer 14i located in the eighth region W8. Among them, the eighth region W8 is the remaining region except the target region W7.

[0389] Exemplarily, there will be residues of the part of the quantum dot light-emitting material and the photosensitive material close to the substrate 11, and a temporary residue layer 37 will remain in the eighth region W8.

[0390] H4: Using an eighth solvent to dissolve a part of the first initial hole transport layer 15iA located in the eighth region W8, removing the part of the first initial hole transport layer 15iA located in the eighth region W8 and on the side far from the substrate 11, and retaining the part of the first initial hole transport layer 15iA located in the eighth region W8 and on the side close to the substrate 11, forming an initial residue pattern 38. And obtaining the quantum dot light-emitting layer 14 located in the target region W7.

[0391] In some examples, the light-emitting substrate 10 further includes a pixel defining layer 12, and the initial residue pattern 38 is formed on the side of the pixel defining layer 12 far from the substrate 11 at the same time.

[0392] It should be understood that when removing the part of the first initial hole transport layer 15iA located in the eighth region W8 and on the side far from the substrate 11, the temporary residue layer 37 is also removed, which can effectively prevent the residue of the quantum dot light-emitting material in the eighth region W8.

[0393] H5: Forming other film layer structures located in the eighth region W8.

[0394] Exemplarily, for the method of forming other film layer structures located in the eighth region W8, reference can be made to steps M5 to M12 in the method for preparing a light-emitting substrate in the foregoing part.

[0395] H6: Under a second preset condition, cause the crosslinked hole-transporting material of the second initial hole-transporting layer 15iB to undergo a decomposition reaction to form a hole-transporting layer; in the decomposition reaction, the position where the crosslinked hole-transporting material decomposes is at the connection between the first segment and the second segment, or in the middle of the second segment.

[0396] In some examples, other film layer structures located in the eighth region W8 include the initial hole-transporting layers of other light-emitting devices (such as the second initial hole-transporting layer 152 and the third initial hole-transporting layer 153, as Figure 3 shown), and the materials of these initial hole-transporting layers are crosslinked hole-transporting materials. In this case, under the second preset condition, in addition to the crosslinked hole-transporting material of the second initial hole-transporting layer 15iB, the crosslinked hole-transporting materials located in the eighth region W8 will also undergo a decomposition reaction to form a hole-transporting layer located in the eighth region W8.

[0397] On the other hand, as Figure 10 shown, some embodiments of the present disclosure provide a light-emitting device 20. The light-emitting device 20 includes an anode 16, a cathode 17, and a functional layer located between the anode 16 and the cathode 17. The material for forming the functional layer includes the material for forming the functional layer as described in any of the foregoing embodiments.

[0398] Exemplarily, in order to ensure that the light-emitting device 20 can emit light effectively, the anode 16 can be made of a material with a high work function, such as a material with a work function greater than 6 eV; the cathode 17 can be made of a material with a low work function, such as a material with a work function less than a set value, and the value range of this set value can be 2.0 eV to 3.0 eV. In this way, holes in the anode and electrons in the cathode can effectively migrate to the light-emitting layer (such as the quantum dot light-emitting layer 14) under the drive of an electric field, and thus recombine to emit light.

[0399] In some examples, the material of the anode 16 can be a transparent conductive metal oxide material. For example, the material of the anode 16 can be indium tin oxide (ITO) or indium zinc oxide (IZO).

[0400] In some examples, the material of the cathode 17 can be a metal material. For example, the material of the cathode 12 can be magnesium, silver, aluminum, or a magnesium-silver alloy, etc.

[0401] The beneficial effects achievable by a light-emitting device provided by some embodiments of the present disclosure are the same as those achievable by a material for forming a functional layer provided by the above technical solution, and will not be elaborated herein.

[0402] In some examples, the light-emitting device 20 is a quantum dot light-emitting device, including a quantum dot light-emitting layer 14.

[0403] During operation, a voltage is applied to the anode 16 and the cathode 17 respectively to generate an electric field therebetween, which can drive holes from the anode 16 and electrons from the cathode 17 to recombine in the quantum dot light-emitting layer 14, thereby emitting light.

[0404] Exemplarily, the material for forming the quantum dot light-emitting layer 14 includes a quantum dot light-emitting material and a photosensitive material; wherein, the quantum dot light-emitting material includes a quantum dot body and a ligand material coordinated to the quantum dot body. The photosensitive material is configured to: under light radiation conditions, undergo a cross-linking reaction with the ligand material to generate a cross-linked quantum dot light-emitting material.

[0405] In some examples, the quantum dot body may include any one or more of: II-VI group quantum dots, III-V group quantum dots, IV-VI group quantum dots, IV group quantum dots, I-III-VI group quantum dots, I-II-IV-VI group quantum dots, core-shell structure quantum dots, and ABX3 type perovskite quantum dots, and any combination thereof.

[0406] The II-VI group quantum dots may be selected from: binary compounds such as CdS, CdSe, CdTe, ZnS, ZnO, ZnSe, ZnTe, HgSe, HgTe, and HgS; ternary compounds such as Hg x Cd 1-x Te, Hg x Cd 1-x S, Hg x Cd 1-x Se, Hg x Zn 1-x Te, Cd x Zn 1-x Se, Cd x Zn 1-x S, and ZnTeSe, where 0 < x < 1, but not limited thereto.

[0407] The III-V group quantum dots may be selected from: InP, InAs, InSb, GaAs, GaP, GaN, GaSb, GaNk, InN, AlP, AlN, AlAs, InGaAs, InGaN, or a mixture thereof; but not limited thereto.

[0408] The group-IV to VI quantum dots can be selected from: PbS, PbSe, PbTe, or a mixture thereof; however, it is not limited thereto.

[0409] The core-shell structured quantum dots refer to that one material is the core material and the other is the shell material. For example, the quantum dot CdS@ZnS means that the core material of the quantum dot is CdS and the shell material is ZnS. The core-shell structured quantum dots can be selected from: one or more of CdS@ZnS, CdSe@CdS, InP@ZnS, CdTe@CdSe, CdSe@ZnTe, CdSe@ZnS, PdS@ZnS, ZnTe@CdSe, ZnSe@CdS, and Cd 1-x Zn x xZnS, where 0 < x < 1, however, it is not limited thereto.

[0410] In the ABX3-type perovskite quantum dots, A can be CH3NH3 + (methylamine), NH2CH=NH2 (formamidine), and Cs + one or more of them, B can be Pb 2+ and Sn 2+ one or two of them, X can be Cl - , Br - and I - one or more of them. The ABX3-type perovskite quantum dots can include CH3NH3PbBr3, CH3NH3PbCl3, CH3NH3PbI3, CsPbBr3, CsPbCl3, and CsPbI3, however, it is not limited thereto.

[0411] When multiple quantum dots are combined, the quantum dot body can be one of CsPbCl3 / ZnS, CsPbBr3 / ZnS, CsPhI3 / ZnS, CdS / ZnSeS / ZnS, CdSe / ZnSeS / ZnS, ZnSe / ZnSeS / ZnS, and ZnSeTe / ZnSeS / ZnS.

[0412] In some other examples, the quantum dot body can be other nanoscale materials, such as nanorods, nanosheets, etc. The components of other nanoscale materials can include at least one of materials such as CuInS2, CuInSe2, AgInS2, etc., however, it is not limited thereto.

[0413] Exemplarily, the shape of the quantum dot body can be any geometric shape such as spherical, ellipsoidal, polyhedral, rod-shaped, cross-shaped, annular, etc.

[0414] In some examples, the ligand material can be selected from any one or a combination of organic acids, organic amines, organic phosphines, and organic thiols. For example, the ligand material can be oleic acid, oleylamine, or dodecanethiol, etc.

[0415] In some embodiments, as Figure 10 shown, to improve the luminous efficiency of the light-emitting device 20, the light-emitting device 20 further includes a hole transport functional layer, which is located on the side of the quantum dot light-emitting layer 14 close to the anode 16 and is in contact with the quantum dot light-emitting layer 14. The hole transport functional layer includes, for example, at least one of a hole injection layer 18 (Hole Inject Layer, HIL), a hole transport layer 15 (Hole Transport Layer, HTL), and an electron blocking layer 51 (Electron Blocking Layer, EBL) arranged in a stacked manner.

[0416] In some examples, when the hole transport functional layer includes the hole injection layer 18, the hole transport layer 15, and the electron blocking layer 51, the hole injection layer 18, the hole transport layer 15, and the electron blocking layer 51 are arranged in sequence along the direction away from the anode 16, and the electron blocking layer 51 is in contact with the quantum dot light-emitting layer 14. In other examples, when the hole transport functional layer includes the hole injection layer 18 and the hole transport layer 15, the hole injection layer 18 and the hole transport layer 15 are arranged in sequence along the direction away from the anode 16, and the hole transport layer 15 is in contact with the quantum dot light-emitting layer 14. At this time, the hole injection layer 18 is the front film layer when forming the hole transport layer 15.

[0417] In some embodiments, as Figure 10 shown, to improve the luminous efficiency of the light-emitting device 20, the light-emitting device 20 further includes an electron transport functional layer, which is located on the side of the quantum dot light-emitting layer 14 close to the cathode 12 and is in contact with the quantum dot light-emitting layer 14. The electron transport functional layer includes, for example, at least one of an electron injection layer 53 (Electron Inject Layer, EIL), an electron transport layer 19 (Electron Transport Layer, ETL), and a hole blocking layer 52 (Hole Blocking Layer, EBL) arranged in a stacked manner. When the electron transport functional layer includes the electron injection layer 53, the electron transport layer 19, and the hole blocking layer 52, the electron injection layer 53, the electron transport layer 19, and the hole blocking layer 52 are arranged in sequence along the direction away from the cathode 12, and the hole blocking layer 52 is in contact with the quantum dot light-emitting layer 14.

[0418] By providing these film layers such as the hole injection layer 18, the hole transport layer 15, the electron blocking layer 51, the electron injection layer 53, the electron transport layer 19, and the hole blocking layer 52, it is equivalent to providing a transition step between the anode 16 and the quantum dot light-emitting layer 14 and between the cathode 12 and the quantum dot light-emitting layer 14, reducing the height of the potential barrier that the carriers need to overcome, and making the luminous efficiency higher.

[0419] Exemplarily, the hole transport functional layer is configured to transport holes, and / or block electrons and excitons generated within the quantum dot light-emitting layer 14. For example, the hole injection layer 18 may be configured to reduce the hole injection barrier and improve the hole injection efficiency. The hole transport layer 15 may be configured to transport holes. The electron blocking layer 51 may be configured to transport holes, block electrons, and block excitons generated within the quantum dot light-emitting layer 14.

[0420] Exemplarily, the electron transport functional layer is configured to transport electrons, and / or block holes and excitons generated within the quantum dot light-emitting layer 14.

[0421] In some embodiments, as Figure 4 shown, in the case where the plurality of light-emitting devices 20 includes a red light-emitting device R, a green light-emitting device G, and a blue light-emitting device B, the cathode 17 of the plurality of light-emitting devices 20 is a structure with a whole-layer connection, that is, the cathode 12 may be a common electrode shared by the plurality of light-emitting devices 20. The hole injection layer 18 of the plurality of light-emitting devices 20 may also be a structure with a whole-layer connection, that is, the hole injection layer 18 may be a common film layer shared by the plurality of light-emitting devices 20. The hole transport layer 15, the electron blocking layer 51, the electron injection layer 53, the electron transport layer 19, and the hole blocking layer 52 may also be common film layers shared by the plurality of light-emitting devices 20, which will not be elaborated here.

[0422] Exemplarily, as Figure 4 shown, when the cathode 12 is a common electrode shared by the plurality of light-emitting devices 20, the cathode 12 is simultaneously formed on the side of the pixel defining layer 12 away from the substrate 11.

[0423] In some embodiments, the functional layer includes one or more of the quantum dot light-emitting layer 14, the hole transport layer 15, the hole injection layer 18, the electron blocking layer 51, the electron transport layer 19, the electron injection layer 53, and the hole blocking layer 52.

[0424] In some examples, the functional layer includes one or more of the electron transport layer 19, the electron injection layer 53, and the hole blocking layer 52. That is, the functional layer is located between the cathode 17 and the quantum dot light-emitting layer 14.

[0425] It can be understood that when the functional layer is located between the cathode 17 and the quantum dot light-emitting layer 14, the functional layer can serve as an auxiliary sacrificial layer for the quantum dot light-emitting layer, and removing a part of the formation material of the quantum dot light-emitting layer 14 located in the remaining areas other than the area where the target opening is located can solve the color mixing problem caused by the residual layer formed by the quantum dot light-emitting material.

[0426] In some embodiments, as Figure 10 shown, the functional layer is located between the anode 16 and the quantum dot light-emitting layer 14.

[0427] It should be understood that when the functional layer is located between the anode 16 and the quantum dot light-emitting layer 14, the functional layer is any one of a hole injection layer 18, a hole transport layer 15, and an electron blocking layer 51, for example, the hole transport layer 15. In this way, the functional layer can serve as an auxiliary sacrificial layer for the quantum dot light-emitting layer, and removing a part of the material forming the quantum dot light-emitting layer 14 located in the regions other than the region where the target opening is located can solve the color mixing problem caused by the residual layer formed by the quantum dot light-emitting material.

[0428] As described above, it is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure, thinking of changes or substitutions, should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A functional layer forming material, characterized in that, Comprising: Functional material and crosslinking material; wherein, the ratio of the mass of the crosslinking material to the mass of the functional material is greater than 0 and less than or equal to 15%; the crosslinking material is configured to react with the functional material under a first preset condition to generate a crosslinked functional material; In the crosslinked functional material, the segment corresponding to the functional material is the first segment, and the segment corresponding to the crosslinking material is the second segment; under a second preset condition, the crosslinked functional material can undergo a decomposition reaction; in the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment, or in the middle of the second segment.

2. The functional layer forming material according to claim 1, wherein The crosslinked functional material includes a plurality of the first segments and a plurality of the second segments; In the case where the position where the crosslinked functional material decomposes in the decomposition reaction is at the connection between the first segment and the second segment, after the decomposition reaction, a part of the first segments and a part of the second segments remain connected; In the case where the position where the crosslinked functional material decomposes in the decomposition reaction is in the middle of the second segment, after the decomposition reaction, a part of the second segments do not decompose.

3. The functional layer forming material according to claim 1, wherein The crosslinking material includes: A plurality of first groups located at the ends of the crosslinking material and capable of reacting with the functional material under the first preset condition; and, At least one second group located in the middle of the crosslinking material and capable of decomposing under the second preset condition.

4. The functional layer forming material according to claim 3, characterized in that, The first group is a first photosensitive group, and the first preset condition includes irradiating with a first light.

5. The functional layer forming material according to claim 4, wherein, The plurality of first groups are the same or different and are each independently selected from any one of benzophenone group, azide group, diazo group, and bisaziridine group.

6. The functional layer forming material according to claim 1, characterized in that The crosslinking material and the functional material undergo a hydrocarbon insertion reaction or an addition reaction to generate the crosslinked functional material.

7. The functional layer forming material according to any one of claims 3 to 6, characterized in that, The second group is a second photosensitive group, and the second preset condition includes irradiating with a second light; In the case where the first group is a first photosensitive group, the second light is different from the first light.

8. The functional layer forming material according to claim 7, wherein The second group has the structure shown in the following formula (IA-1); wherein, * is the first connection site.

9. The functional layer forming material according to any one of claims 3 to 6, characterized in that, The second group is a first thermosensitive group, and the second preset condition includes applying a heating means.

10. The functional layer forming material according to claim 9, characterized in that, In the case where the crosslinking material includes one second group, the second group is any one of azo group, peroxide group, persulfide group, acetyl ketone group, and methanethiol group; In the case where the crosslinking material includes a plurality of second groups, the plurality of second groups are the same or different and are each independently selected from any one of azo group, peroxide group, persulfide group, acetyl ketone group, and methanethiol group.

11. The functional layer forming material according to claim 10, characterized in that, In the case where the second group is an azo group, the second group has the structure shown in the following general formula (IA-2); wherein, * is the first connection site; R1, R2, R3 and R4 are the same or different and are each independently selected from any one of hydrogen, a substituted or unsubstituted saturated or unsaturated straight-chain or branched alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted ester group having 1 to 40 carbon atoms, a substituted or unsubstituted nitrile group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 members, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 members, or may be linked to an adjacent group to form a substituted or unsubstituted ring having 3 to 40 members.

12. The functional layer forming material according to claim 11, wherein R1 and R4 are the same and are each selected from any one of the structures represented by the following formulas (IA-2-1) to (IA-2-7); wherein, a, b and c are the same or different and are each independently selected from any one of 0, 1, 2 and 3.

13. The functional layer forming material according to claim 11, wherein R2 and R3 are the same and are each selected from any one of the structures represented by the following formulas (IA-2-8) to (IA-2-16); wherein, d and e are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5 and 6.

14. The functional layer forming material according to claim 10, wherein When the second group is a peroxide group, the second group is selected from any one of the structures represented by the following formulas (IA-3) to (IA-8); wherein, * is the first connection site; f, g, h and i are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5 and 6.

15. The functional layer forming material according to claim 10, characterized in that, When the second group is a persulfide group, the second group is selected from any one of the structures represented by the following formulas (IA-9) to (IA-14); wherein, * is the first connection site; j, k, m and n are the same or different and are each independently selected from any one of 0, 1, 2, 3, 4, 5 and 6.

16. The functional layer forming material according to claim 10, characterized in that, When the second group is an acetyl ketone group, the second group has the structure represented by the following formula (IA-15); wherein, * is the first connection site.

17. The functional layer forming material according to claim 10, wherein When the second group is a thiophenol group, the second group has the structure represented by the following general formula (IA-16); wherein, * is the first connection site.

18. The functional layer forming material according to any one of claims 3 to 6, characterized in that, The crosslinked material is selected from any one of the structures represented by the following general formulas (I) and (II); G is selected from any one of the structures represented by the following general formula (IIB); wherein, J is the first group; # is the second connection site; A is the second group; when the second group includes the first connection site, the first connection site is connected to the second connection site; L1, L2 and L3 are the same or different and are each independently selected from any one of a substituted or unsubstituted amide group having 1 to 40 carbon atoms, a substituted or unsubstituted ester group having 1 to 40 carbon atoms, a substituted or unsubstituted saturated or unsaturated straight-chain or branched alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 members, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 members; E1 and E2 are the same or different, and are each independently selected from any one of carbon, oxygen, sulfur, selenium, sulfur, phosphorus, a substituted or unsubstituted saturated or unsaturated straight-chain or branched-chain alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms; x, y, and w are the same or different, and are each independently selected from any one of 1, 2, 3, 4, 5, and 6; z is selected from any one of 2, 3, 4, 5, and 6.

19. The functional layer forming material according to claim 18, characterized in that, L1, L2, and L3 are the same or different, and are each independently selected from any one of the structures represented by the following general formulas (IC-1) to (IC-3); wherein, R5 and R6 are the same or different, and are each independently selected from a saturated or unsaturated substituted or unsubstituted straight-chain or branched-chain alkyl group having 1 to 40 carbon atoms, a substituted or unsubstituted nitrile group having 1 to 40 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 40 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 ring atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 40 ring atoms; moreover, among R5 and R6, at least one is a saturated substituted or unsubstituted straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms.

20. The functional layer forming material according to claim 18, characterized in that, E1 and E2 are the same or different, and are each independently selected from any one of the structures represented by the following general formulas (ID-1) to (ID-6); wherein, L is L1, L2, or L3; p, r, and s are the same or different, and are each independently selected from any one of 1, 2, 3, 4, 5, and 6.

21. A method for preparing a functional layer, characterized in that, Comprising: Providing a functional layer forming material; The functional layer forming material comprises: a functional material and a crosslinking material; the ratio of the mass of the crosslinking material to the mass of the functional material is greater than 0 and less than or equal to 15%; Under a first preset condition, reacting the crosslinking material with the functional material to generate a crosslinked functional material; in the crosslinked functional material, the segment corresponding to the functional material is the first segment, and the segment corresponding to the crosslinking material is the second segment; Under a second preset condition, subjecting the crosslinked functional material to a decomposition reaction to form a functional layer; in the decomposition reaction, the position where the crosslinked functional material decomposes is at the connection between the first segment and the second segment, or in the middle of the second segment.

22. A light-emitting device, characterized in that, Comprising an anode, a cathode, and a functional layer located between the anode and the cathode; the forming material of the functional layer comprises the functional layer forming material according to any one of claims 1 to 20.

23. The light-emitting device according to claim 22, wherein, The functional layer comprises one or more of a quantum dot light-emitting layer, a hole transport layer, a hole injection layer, an electron blocking layer, an electron transport layer, an electron injection layer, and a hole blocking layer.

24. The light-emitting device according to claim 23, wherein The functional layer is located between the anode and the quantum dot light-emitting layer.

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