Display panel and fabrication method therefor, and display apparatus

Abstract

Disclosed in the present invention are a display panel and a fabrication method therefor, and a display apparatus. The display panel comprises a light-emitting device, wherein the light-emitting device comprises: at least two functional layers, which are disposed on one side of a first electrode layer, each functional layer comprising a crosslinking layer and a first-color light-emitting layer that are stacked in the direction away from the first electrode layer; and a second electrode layer, which is disposed on the side of the functional layers that faces away from the first electrode layer. The crosslinking layer can crosslink with the first-color light-emitting layer to form a crosslinked structure, and the crosslinked structure in the device can reduce the electron mobility and balance the carrier concentration, thereby improving the full-color performance of the display panel. In addition, in the embodiments of the present invention, the crosslinking layer and the first-color light-emitting layer are provided as two separate layers, that is, the crosslinking layer and the first-color light-emitting layer can be prepared separately. The film layer thickness of the separately prepared first-color light-emitting layer is easier to control, and thus a first-color light-emitting layer having a smaller thickness can be obtained, thereby improving the usage performance of the display panel.

Description

Display panel, display panel manufacturing method and display device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510238227.8, filed on February 28, 2025, entitled “Display Panel, Method for Manufacturing Display Panel and Display Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention belongs to the field of electronic product technology, and particularly relates to a display panel, a method for manufacturing the display panel, and a display device. Background Technology

[0004] Quantum dot light-emitting diodes (LEDs) have attracted attention due to their superior characteristics, such as high purity of emission spectrum, tunable emission wavelength, and high photothermal stability.

[0005] However, due to the structural limitations of existing display panels, their performance cannot meet the requirements.

[0006] Therefore, there is an urgent need for a new display panel, a display panel manufacturing method, and a display device. Summary of the Invention

[0007] This invention provides a display panel, a method for manufacturing the display panel, and a display device. The light-emitting device formed by the thinner first color light-emitting layer has a longer lifespan, thereby improving the performance of the display panel.

[0008] An embodiment of the first aspect of this application provides a display panel including a light-emitting device, the light-emitting device including: a first electrode layer; at least two functional layers disposed on one side of the first electrode layer, the functional layers including a crosslinking layer and a first color light-emitting layer stacked in a direction away from the first electrode layer; and a second electrode layer disposed on the side of the functional layers opposite to the first electrode layer.

[0009] An embodiment of the second aspect of this application provides a display panel, comprising: a first electrode layer; at least two functional layers disposed on one side of the first electrode layer, the functional layers including a crosslinking layer and a first color emitting layer stacked in a direction away from the first electrode layer, and a second color emitting layer disposed on one side of the first color emitting layer in a direction parallel to the plane of the first electrode layer, the second color emitting layer including a crosslinking material and a second color emitting material; and a second electrode layer disposed on the side of the functional layers opposite to the first electrode layer.

[0010] An embodiment of the third aspect of this application provides a method for manufacturing a display panel, comprising the following steps: providing a first electrode layer; forming a functional layer on one side of the first electrode layer, wherein the side of the functional layer opposite to the first electrode layer includes a crosslinking layer; forming a first color luminescent material on the side of the crosslinking layer opposite to the first electrode layer; patterning the first color luminescent material to form a first color luminescent layer; and forming a second electrode layer on the side of the first color luminescent layer opposite to the first electrode layer.

[0011] An embodiment of the fourth aspect of this application provides a display device, including the display panel described in any of the above embodiments or including a display panel obtained by the display panel preparation method in any of the above embodiments.

[0012] Compared with related technologies, the display panel provided in this invention includes a first electrode layer, at least two functional layers, and a second electrode layer. The functional layers include at least a crosslinking layer and a first color emitting layer. The crosslinking layer can crosslink with the first color emitting layer to form a crosslinked structure. This crosslinked structure in the device can reduce electron mobility and balance carrier concentration, thereby improving the full-color performance of the display panel. Furthermore, in this invention, the crosslinking layer and the first color emitting layer are separate layers, each independently configured. Therefore, the crosslinking layer and the first color emitting layer can be fabricated separately. The thickness of the separately fabricated first color emitting layer is easier to control, resulting in a thinner first color emitting layer. Through the inventors' research and experiments, it has been found that the light-emitting device formed by the thinner first color emitting layer has a longer lifespan, thus improving the performance of the display panel. Attached Figure Description

[0013] Figure 1 is a schematic diagram of the structure of a display panel according to an embodiment of the present invention;

[0014] Figure 2 is a partial schematic diagram of point A in Figure 1 provided by an embodiment of the present invention;

[0015] Figure 3 is a cross-sectional view of section BB in Figure 2 provided by an embodiment of the present invention;

[0016] Figure 4 is a cross-sectional view of the CC section in Figure 2 provided by an embodiment of the present invention;

[0017] Figure 5 is a cross-sectional view of the CC section in Figure 2 provided by another embodiment of the present invention;

[0018] Figure 6 is a flowchart of a display panel manufacturing method according to an embodiment of the present invention;

[0019] Figures 7 to 10 are schematic diagrams of the structure obtained by the display panel manufacturing method according to an embodiment of the present invention. Detailed Implementation

[0020] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0022] To better understand the present invention, a detailed description of the display panel, display panel manufacturing method, and display device according to embodiments of the present invention is provided below with reference to Figures 1 to 10.

[0023] Please refer to Figures 1 to 3. An embodiment of the present invention provides a display panel including a light-emitting device 10. The light-emitting device 10 includes: a first electrode layer 1; at least two functional layers G disposed on one side of the first electrode layer 1, the functional layers G including a crosslinking layer 2 and a first color light-emitting layer 31 stacked in a direction away from the first electrode layer 1; and a second electrode layer 4 disposed on the side of the functional layers G opposite to the first electrode layer 1.

[0024] The display panel provided in this embodiment of the invention includes a first electrode layer 1, at least two functional layers G, and a second electrode layer 4. The functional layers G include at least a crosslinking layer 2 and a first color emitting layer 31. The crosslinking layer 2 can crosslink with the first color emitting layer 31 to form a crosslinked structure. This crosslinked structure in the device can reduce electron mobility, balance carrier concentration, and improve the full-color performance of the display panel. Furthermore, in this embodiment of the invention, the crosslinking layer 2 and the first color emitting layer 31 are separate layers, each independently configured. Therefore, the crosslinking layer 2 and the first color emitting layer 31 can be prepared separately. The thickness of the separately prepared first color emitting layer 31 is easier to control, resulting in a thinner first color emitting layer 31. Through the inventors' research and experiments, it has been found that the light-emitting device 10 formed by the thinner first color emitting layer 31 has a longer lifespan, thereby improving the performance of the display panel.

[0025] On the other hand, the cross-linked structure formed by the cross-linked layer 2 and the first color emitting layer 31 can also make the cross-linked layer 2 and the first color emitting layer 31 adhere more firmly, avoiding the film cracking and overall film detachment that may occur during the use of flexible devices, thereby improving the problem of easy device failure.

[0026] Through research and experiments, the inventors discovered that the lifespan of the light-emitting device 10 is extremely sensitive to the thickness of the light-emitting layer. When the thickness of the first color light-emitting layer 31 is relatively thin, the lifespan of the light-emitting device 10 reaches its optimal value; when the thickness of the first color light-emitting layer 31 is relatively thick, the lifespan of the light-emitting device 10 is shorter. The light-emitting device 10 may include a first electrode layer 1, at least two functional layers G, and a second electrode layer 4.

[0027] Due to the limitations of the structure and manufacturing precision of the display panel in the prior art, the thickness of the light-emitting layer is relatively large and cannot meet the requirements. In order to improve the lifespan of the light-emitting device 10, this embodiment sets the cross-linking layer 2 and the first color light-emitting layer 31 to cross-link, and the cross-linking layer 2 and the first color light-emitting layer 31 are divided into two layers, each set separately, so as to form a thinner first color light-emitting layer 31 and improve the lifespan of the light-emitting device 10.

[0028] Optionally, the material of the first electrode layer 1 is generally a material with a high work function to improve hole injection efficiency. It can be gold (Au), platinum (Pt), titanium (Ti), silver (Ag), indium tin oxide (ITO), zinc tin oxide (IZO), or a transparent conductive polymer (such as polyaniline). For example, the first electrode layer 1 can be made of ITO-Ag-ITO composite material, without any particular limitation.

[0029] Optionally, the material of the second electrode layer 4 can be one of the following metals: silver (Ag), aluminum (Al), lithium (Li), magnesium (Mg), ytterbium (Yb), calcium (Ca), or indium (In). It can also be an alloy of the aforementioned metals, such as magnesium-silver alloy (Mg / Ag) or lithium-aluminum alloy (Li / Al). This embodiment does not limit this.

[0030] Optionally, the first color emitting layer 31 includes a first color emitting material, that is, the first color emitting layer 31 is a first color quantum dot emitting layer.

[0031] Optionally, the first color emitting layer 31 includes a first quantum dot and ligands. The quantum dot is composed of zinc, cadmium, selenium and sulfur atoms and is a particle with a diameter of less than 10 nm. The ligands represent atoms, molecules and ions that can form bonds with the central atom (metal or metalloid).

[0032] Optionally, the crosslinking layer 2 includes crosslinking groups, and the crosslinking groups and the ligands in the first color emitting layer 31 are crosslinked by light irradiation. That is, under light irradiation, the crosslinking groups and the ligands in the first color emitting layer 31 undergo a crosslinking reaction to achieve crosslinking.

[0033] Optionally, the mobility of the cross-linked layer 2 material is greater than or equal to 10⁻⁴ cm² / Vs. Mobility refers to the average drift velocity of charge carriers under a unit electric field strength. Its unit is centimeters. 2 / (volt-second), usually represented by the Greek letter μ. Mobility represents the magnitude of the charge carrier's conductivity. It, together with the charge carrier (electron or hole) concentration, determines the conductivity of a semiconductor. By limiting the mobility of the cross-linked layer 2 material to be greater than or equal to 10-4 cm2 / Vs, the hole transport capability is avoided, ensuring that the device performance is not damaged.

[0034] For example, the mobility of the material in the crosslinked layer 2 can be equal to any one of 1.1×10-4 cm² / Vs, 1.2×10-4 cm² / Vs, 1.3×10-4 cm² / Vs, 1.4×10-4 cm² / Vs, or 1.5×10-4 cm² / Vs.

[0035] Please refer to Figure 3. In some optional embodiments, the side of the first color emitting layer 31 near the first electrode layer 1 and the side of the crosslinking layer 2 away from the first electrode layer 1 are in contact, that is, at least the ligands included in the side of the first color emitting layer 31 near the first electrode layer 1 and the crosslinking groups in the corresponding contacting crosslinking layer 2 are crosslinked.

[0036] Optionally, the thickness ratio of the crosslinking layer 2 to the first color emitting layer 31 is greater than or equal to 1:8 and less than or equal to 5:1. That is, the thickness of the crosslinking layer 2 can be greater than or less than or equal to the thickness of the first color emitting layer 31. The specific ratio can be determined according to the actual process and the performance requirements of the first color emitting layer 31, and there is no special limitation. As long as the thickness of the first color emitting layer 31 is small enough to improve the lifespan of the light-emitting device 10, it is acceptable. For example, the thickness ratio of the crosslinking layer 2 to the first color emitting layer 31 can be any one of 1:8, 1:7, 1:6, 1:5.5, 1:4, 1:3, 1:2.5, 1:1.5, 1:1, 2:1.5, 3.5:1, 4:1, and 5:1.

[0037] Due to limitations in the preparation process and materials of the crosslinked layer 2 and the first color emitting layer 31, and to ensure preparation accuracy, the thickness ratio of the crosslinked layer 2 to the first color emitting layer 31 may be greater than or equal to 1:8 and less than or equal to 1:1. For example, the thickness ratio of the crosslinked layer 2 to the first color emitting layer 31 may be any one of 1:8, 1:6, 1:4, 1:2, and 1:1.

[0038] In some optional embodiments, the thickness of the crosslinking layer 2 is greater than or equal to 1 nm and less than or equal to 100 nm. It can be prepared using a coating process. The specific thickness needs to be selected based on process precision and requirements. The thickness of the crosslinking layer 2 should not be too large, as this will affect the overall thickness of the light-emitting device 10; nor should it be too small, as this will impose high process requirements, increase preparation difficulty, and result in low yield. Optionally, the thickness of the crosslinking layer 2 can be any of 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0039] Optionally, the thickness of the first color emitting layer 31 is greater than or equal to 8 nm and less than or equal to 18 nm. Specifically, a thicker first color emitting material 31' can be formed first through a coating process, and then a portion of the first color emitting material 31' can be removed through a patterning process such as photolithography to form a thinner first color emitting layer 31, thereby improving the lifetime of the light-emitting device 10. Optionally, the thickness of the first color emitting layer 31 can be any of 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, or 18 nm.

[0040] Through research and experiments, the inventors discovered that when the thickness of the first color emitting layer 31 is the same, but the thickness of the corresponding crosslinking layer 2 is different, the difference in the lifespan of the corresponding light-emitting device 10 is small. For example, when the thickness of the first color emitting layer 31 is 15 nm, the lifespan of the light-emitting device 10 is 84 hours when the thickness of the crosslinking layer 2 is 20 nm, and the lifespan of the light-emitting device 10 is 82 hours when the thickness of the crosslinking layer 2 is 10 nm. That is, the thickness of the crosslinking layer 2 has little impact on the lifespan of the light-emitting device 10.

[0041] When the thickness of the first color emitting layer 31 is 15 nm and the thickness of the crosslinking layer 2 is 5 nm, the lifetime of the light-emitting device 10 is 202 hours. In contrast, in the prior art, when the thickness of the film layer with a quantum emitting layer and crosslinking layer is 15 nm, the lifetime of the light-emitting device 10 is 118 hours, and when the film layer thickness is 25 nm, the light-emitting device 10 has virtually no lifetime. Therefore, the structural form of the first color emitting layer 31 and the crosslinking layer 2 provided in this embodiment can significantly increase the lifetime of the light-emitting device 10.

[0042] In some optional embodiments, the first color emitting layer 31 includes a monolayer quantum dot molecular layer that is in contact with the crosslinking layer 2. That is, the first color emitting layer 31 may include only one monolayer quantum dot molecular layer that is in contact with the crosslinking layer 2 and forms crosslinks, thereby minimizing the thickness of the first color emitting layer 31 while achieving crosslinking with the crosslinking layer 2.

[0043] Optionally, the monolayer quantum dot molecular layer includes a monolayer of quantum dots and ligands. The quantum dots are used to realize the light emission display of each color of the display panel, while the ligands are used to crosslink with the crosslinking groups of the crosslinking layer 2.

[0044] When etching the first color luminescent material 31', the portion of the first color luminescent material 31' that is cross-linked with the cross-linking layer 2 is more firmly connected to the cross-linking layer 2. This portion of the first color luminescent material 31' will not be removed, while the first color luminescent material 31' located on it will be removed. That is, it may include retaining a thinner portion of the first color luminescent material 31', such as a single layer of quantum dot molecules, to form the first color luminescent layer 31.

[0045] Please refer to Figure 3. Optionally, along the direction away from the first electrode layer 1, the functional layer G also includes a hole injection layer 5, a hole transport layer 6 disposed between the crosslinking layer 2 and the first electrode layer 1, and an electron transport layer 7 disposed on the side of the first color emitting layer 31 away from the first electrode layer 1.

[0046] Hole transport layer 6 is responsible for transporting holes, while electron transport layer 7 is responsible for transporting electrons. The first color luminescent material 31' emits photons by receiving these charge carriers and recombination.

[0047] Optionally, the hole transport layer 6 includes a thermosensitive group, and the hole transport layer 6 and the crosslinking group do not react. A thermosensitive group is a chemical group whose properties can change with temperature. Specifically, when the temperature changes, the thermosensitive group undergoes a change in molecular structure, resulting in changes in its physical or chemical properties, such as fluorescence intensity and emission wavelength. In this embodiment, the thermosensitive group and the crosslinking group in the hole transport layer 6 do not react to avoid mutual interference.

[0048] Alternatively, the hole transport layer 6 may include photosensitive groups, which are chemical groups capable of undergoing chemical reactions under illumination. These groups, when irradiated with light of a specific wavelength, can absorb light energy and initiate chemical reactions, thereby altering their physical or chemical properties. In this embodiment, the photosensitive groups and crosslinking groups of the hole transport layer 6 undergo a crosslinking reaction under illumination, thereby achieving crosslinking and enhancing luminous efficiency.

[0049] Please refer to Figure 4. In some optional embodiments, the functional layer G also includes a second color light-emitting layer 32 and a third color light-emitting layer 33 disposed on one side of the first electrode layer 1. Along the direction parallel to the plane where the first electrode layer 1 is located, the second color light-emitting layer 32, the third color light-emitting layer 33 and the first color light-emitting layer 31 are adjacent to each other in the same layer.

[0050] Optionally, the second color emitting layer 32 includes a second color quantum dot material, and the third color emitting layer 33 includes a third color quantum dot material.

[0051] In this embodiment, the functional layer G may include three quantum light-emitting layers that emit different colors: a first color light-emitting layer 31, a second color light-emitting layer 32, and a third color light-emitting layer 33. Depending on the actual material properties, the second color light-emitting layer 32 and the third color light-emitting layer 33 may be provided with a cross-linking layer 2, or they may not be provided with a cross-linking layer 2, and there is no special limitation.

[0052] Along the direction parallel to the plane where the first electrode layer 1 is located, the second color light-emitting layer 32, the third color light-emitting layer 33 and the first color light-emitting layer 31 are adjacent to each other in the same layer. That is, along the direction perpendicular to the plane where the first electrode layer 1 is located, the first color light-emitting layer 31, the second color light-emitting layer 32 and the third color light-emitting layer 33 do not overlap, so as to avoid mutual interference with light emission.

[0053] Optionally, the first color emitting layer 31 includes a green quantum emitting layer. Through research and experimentation, the inventors discovered that green light-emitting devices are highly sensitive to the thickness of the first color emitting layer 31; the light-emitting device 10 achieves a better lifespan only when the first color emitting layer 31 is thinner. Therefore, in this embodiment, the first color emitting layer 31 includes a green quantum emitting layer to improve the lifespan of the light-emitting device 10.

[0054] Optionally, the first color emitting layer 31 includes a green quantum emitting layer, the second color emitting layer 32 includes a blue quantum emitting layer, and the third color emitting layer 33 includes a red quantum emitting layer.

[0055] Optionally, in the thickness direction of the display panel, the crosslinking layer 2, the second color emitting layer 32, and the third color emitting layer 33 do not overlap. That is, in this embodiment, the crosslinking layer 2 is only provided between the first electrode layer 1 and the first color emitting layer 31, and the crosslinking layer 2 is not provided between the first electrode layer 1 and the second color emitting layer 32, or between the first electrode layer 1 and the third color emitting layer 33, because the material properties of the second color emitting layer 32, the third color emitting layer 33, and the first color emitting layer 31 are different.

[0056] Of course, depending on actual needs, a crosslinking layer 2 can also be provided between the first electrode layer 1 and the second color emitting layer 32, and / or between the first electrode layer 1 and the third color emitting layer 33. As shown in Figure 5, a crosslinking layer 2 is also provided between the first electrode layer 1 and the second color emitting layer 32.

[0057] Referring to Figure 4, in some optional embodiments, the thickness of the second color light-emitting layer 32 is greater than or equal to the thickness of the third color light-emitting layer 33, and the thickness of the third color light-emitting layer 33 is greater than or equal to the thickness of the first color light-emitting layer 31.

[0058] Because the first color emitting layer 31, the second color emitting layer 32, and the third color emitting layer 33 are made of different materials, their luminescent characteristics differ, and therefore their corresponding thicknesses also differ. The thickness of the second color emitting layer 32 can be greater than or equal to the thickness of the third color emitting layer 33, depending on the specific manufacturing process and materials used. Similarly, the thickness of the third color emitting layer 33 can be greater than or equal to the thickness of the first color emitting layer 31. In other words, the thicknesses of the first color emitting layer 31, the second color emitting layer 32, and the third color emitting layer 33 can be equal or unequal.

[0059] Optionally, the thickness of the second color emitting layer 32 is greater than or equal to 10 nm and less than or equal to 80 nm. For example, the thickness of the second color emitting layer 32 can be any of 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, or 80 nm.

[0060] Optionally, the thickness of the third color emitting layer 33 is greater than or equal to 10 nm and less than or equal to 50 nm. For example, the thickness of the third color emitting layer 33 can be any of 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm.

[0061] Please refer to Figures 1 to 4. This embodiment of the invention also provides a display panel, including: a first electrode layer 1; at least two functional layers G disposed on one side of the first electrode layer 1, the functional layers G including a crosslinking layer 2 and a first color emitting layer 31 stacked in a direction away from the first electrode layer 1, and a second color emitting layer 32 disposed on one side of the first color emitting layer 31 in a direction parallel to the plane where the first electrode layer 1 is located, the second color emitting layer 32 including a crosslinking material and a second color emitting material; and a second electrode layer 4 disposed on the side of the functional layers G away from the first electrode layer 1.

[0062] The display panel provided in this embodiment of the invention includes a first electrode layer 1, at least two functional layers G, and a second electrode layer 4. The functional layers G include at least a crosslinking layer 2, a first color emitting layer 31, and a second color emitting layer 32. In this embodiment, the crosslinking layer 2 can crosslink with the first color emitting layer 31 to form a crosslinked structure. This crosslinked structure in the device can reduce electron mobility, balance carrier concentration, and improve the full-color performance of the display panel. Furthermore, in this embodiment of the invention, the crosslinking layer 2 and the first color emitting layer 31 are separate layers, each independently configured. Therefore, the crosslinking layer 2 and the first color emitting layer 31 can be fabricated separately. The thickness of the separately fabricated first color emitting layer 31 is easier to control, resulting in a thinner first color emitting layer 31. Furthermore, the second color emitting layer 32 includes a crosslinking material and a second color emitting material. That is, the crosslinking material and the second color emitting material in the second color emitting layer 32 are prepared simultaneously. The second color emitting layer 32 includes a mixture of crosslinking material and second color emitting material, without the need to set an additional crosslinking layer 2. This can also improve the luminous performance of the second color emitting layer 32, thereby improving the performance of the display panel.

[0063] In this embodiment, the crosslinking material can be dispersed in the second color emitting layer 32. The crosslinking material can form a light-connected structure with other materials in the second color emitting layer 32, such as ligands, under illumination, thereby improving device performance.

[0064] Optionally, the first color emitting layer 31 includes a first color quantum dot material, and the second color emitting layer 32 includes a second color quantum dot material, that is, both the first color emitting layer 31 and the second color emitting layer 32 are quantum dot emitting layers.

[0065] In some optional embodiments, the functional layer G further includes a third color emitting layer 33 disposed on one side of the first color emitting layer 31 along a direction parallel to the plane of the first electrode layer 1. The third color emitting layer 33 includes a cross-linked material and a third color quantum dot material.

[0066] It is understandable that the third color luminescent layer 33 is also formed by mixing cross-linked materials and third color quantum dot materials, and the luminescence performance is improved by cross-linking the ligand phases in the cross-linked materials and the third color quantum dot materials.

[0067] Alternatively, the third color emitting layer 33 may include a third color quantum dot material, meaning that the third color emitting layer 33 may not have a corresponding crosslinking layer 2 or crosslinking material, in order to simplify the process and reduce costs.

[0068] Optionally, the first color emitting layer 31 includes a green quantum emitting layer, the second color emitting layer 32 includes a blue quantum emitting layer, and the third color emitting layer 33 includes a red quantum emitting layer.

[0069] Optionally, the thickness ratio of the crosslinking layer 2 to the first color emitting layer 31 is greater than or equal to 1:8 and less than or equal to 5:1. That is, the thickness of the crosslinking layer 2 can be greater than or less than or equal to the thickness of the first color emitting layer 31. The specific ratio can be determined according to the actual process and the performance requirements of the first color emitting layer 31, and there is no special limitation. As long as the thickness of the first color emitting layer 31 is small enough to improve the lifespan of the light-emitting device 10, it is acceptable. For example, the thickness ratio of the crosslinking layer 2 to the first color emitting layer 31 can be any one of 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, and 5:1.

[0070] Due to limitations in the preparation process and materials of the crosslinked layer 2 and the first color emitting layer 31, and to ensure preparation accuracy, the thickness ratio of the crosslinked layer 2 to the first color emitting layer 31 may be greater than or equal to 1:8 and less than or equal to 1:1. For example, the thickness ratio of the crosslinked layer 2 to the first color emitting layer 31 may be any one of 1:8, 1:6, 1:4, 1:2, and 1:1.

[0071] In some optional embodiments, the thickness of the crosslinking layer 2 is greater than or equal to 1 nm and less than or equal to 100 nm. It can be prepared using a coating process. The specific thickness needs to be selected based on process precision and requirements. The thickness of the crosslinking layer 2 should not be too large, as this will affect the overall thickness of the light-emitting device 10; nor should it be too small, as this will impose high process requirements, increase preparation difficulty, and result in low yield. Optionally, the thickness of the crosslinking layer 2 can be any of 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0072] Optionally, the thickness of the first color emitting layer 31 is greater than or equal to 8 nm and less than or equal to 18 nm. Specifically, this can be achieved by first forming a thicker first color emitting material 31' through a coating process, and then removing part of the first color emitting material 31' through a patterning process such as photolithography, to form a thinner first color emitting layer 31, thereby improving the lifetime of the light-emitting device 10. Optionally, the thickness of the first color emitting layer 31 can be any of 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, or 18 nm.

[0073] In some optional embodiments, the first color emitting layer 31 includes a monolayer quantum dot molecular layer that is in contact with the crosslinking layer 2. That is, the first color emitting layer 31 may include only one monolayer quantum dot molecular layer that is in contact with the crosslinking layer 2 and forms crosslinks, thereby minimizing the thickness of the first color emitting layer 31 while achieving crosslinking with the crosslinking layer 2.

[0074] Optionally, the monolayer quantum dot molecular layer includes a monolayer of quantum dots and ligands. The quantum dots are used to realize the light emission display of each color of the display panel, while the ligands are used to crosslink with the crosslinking groups of the crosslinking layer 2.

[0075] When etching the first color luminescent material 31', the portion of the first color luminescent material 31' that is cross-linked with the cross-linking layer 2 is more firmly connected to the cross-linking layer 2. This portion of the first color luminescent material 31' will not be removed, while the first color luminescent material 31' located on it will be removed. That is, it may include retaining a thinner portion of the first color luminescent material 31', such as a single layer of quantum dot molecules, to form the first color luminescent layer 31.

[0076] Please refer to Figure 6. This embodiment of the invention also provides a method for manufacturing a display panel, including the following steps:

[0077] S110: Provides the first electrode layer 1, as shown in Figure 7;

[0078] S120: A functional layer G is formed on one side of the first electrode layer 1. The side of the functional layer G facing away from the first electrode layer 1 includes a crosslinking layer 2, as shown in Figure 8.

[0079] S130: A first color luminescent material 31' is formed on the side of the crosslinked layer 2 away from the first electrode layer 1, as shown in Figure 9;

[0080] S140: The first color luminescent material 31' is patterned to form the first color luminescent layer 31, as shown in Figure 10;

[0081] S150: A second electrode layer 4 is formed on the side of the first color emitting layer 31 away from the first electrode layer 1, as shown in Figure 3.

[0082] In the display panel manufacturing method provided in the embodiments of the present invention, a cross-linking layer 2 is first formed on one side of the first electrode layer 1, and then a first color light-emitting material 31' is formed on the side of the cross-linking layer 2 away from the first electrode layer 1. The first color light-emitting material 31' is then patterned to reduce its thickness, thereby forming a thinner first color light-emitting layer 31. Through the inventors' research and experiments, it has been found that the light-emitting device 10 formed by the thinner first color light-emitting layer 31 has a longer lifespan, which can improve the performance of the display panel.

[0083] In step S110, the material of the first electrode layer 1 is generally a material with a high work function to improve hole injection efficiency. It can be gold (Au), platinum (Pt), titanium (Ti), silver (Ag), indium tin oxide (ITO), zinc tin oxide (IZO), or a transparent conductive polymer (such as polyaniline). For example, the first electrode layer 1 can be made of an ITO-Ag-ITO composite material, without any particular limitation.

[0084] In step S120, the crosslinking layer 2 includes crosslinking groups. The crosslinking groups and the ligands in the first color emitting layer 31 are crosslinked by light irradiation. That is, under light irradiation, the crosslinking groups and the ligands in the first color emitting layer 31 undergo a crosslinking reaction to achieve crosslinking.

[0085] Optionally, the mobility of the cross-linked layer 2 material is greater than or equal to 10⁻⁴ cm² / Vs. Mobility refers to the average drift velocity of charge carriers under a unit electric field strength. Its unit is centimeters. 2 / (volt-second), usually represented by the Greek letter μ. Mobility represents the magnitude of the charge carrier's conductivity. It, together with the charge carrier (electron or hole) concentration, determines the conductivity of a semiconductor. By limiting the mobility of the cross-linked layer 2 material to be greater than or equal to 10-4 cm2 / Vs, the hole transport capability is avoided, ensuring that the device performance is not damaged.

[0086] For example, the mobility of the material in the crosslinked layer 2 can be equal to any one of 1.1×10-4 cm² / Vs, 1.2×10-4 cm² / Vs, 1.3×10-4 cm² / Vs, 1.4×10-4 cm² / Vs, or 1.5×10-4 cm² / Vs.

[0087] In step S130, optionally, the first color emitting layer 31 includes a first quantum dot and a ligand. The quantum dot is composed of zinc, cadmium, selenium and sulfur atoms and is a particle with a diameter of less than 10 nm. The ligand represents an atom, molecule and ion that can form a bond with the central atom (metal or metalloid).

[0088] When etching the first color luminescent material 31', the portion of the first color luminescent material 31' that is cross-linked with the cross-linking layer 2 is more firmly connected to the cross-linking layer 2. This portion of the first color luminescent material 31' will not be removed, while the first color luminescent material 31' located on it will be removed. That is, it may include retaining a thinner portion of the first color luminescent material 31', such as a single layer of quantum dot molecules, to form the first color luminescent layer 31.

[0089] In step S140, a first color emitting layer 31 of the required thickness can be formed by photolithography processes such as exposure, development and annealing.

[0090] In step S150, the material of the second electrode layer 4 can be one of the following metals: silver (Ag), aluminum (Al), lithium (Li), magnesium (Mg), ytterbium (Yb), calcium (Ca), or indium (In). It can also be an alloy of the aforementioned metals, such as magnesium-silver alloy (Mg / Ag) or lithium-aluminum alloy (Li / Al). This embodiment does not limit this.

[0091] In some optional embodiments, the step of forming the first color luminescent material 31' on the side of the crosslinked layer 2 opposite to the first electrode layer 1 includes: forming the first color quantum dot material on the side of the crosslinked layer 2 opposite to the first electrode layer 1 by a coating process. Specifically, a spin coating process can be used, which is a process of uniformly coating a liquid material onto the surface of a substrate. The basic principle of spin coating is to distribute the liquid material onto a rotating substrate, using centrifugal force to uniformly distribute the material on the surface, and the excess liquid is thrown off during the rotation, ultimately leaving a uniform thin film. The thickness of the formed first color quantum dot material can be adjusted by adjusting the concentration of the material and the selected speed.

[0092] Optionally, the thickness of the first color luminescent material 31' is greater than or equal to 25nm and less than or equal to 50nm. For example, the thickness of the first color luminescent material 31' can be any of 25nm, 30nm, 35nm, 40nm, 45nm, or 50nm, and can be adjusted according to the process.

[0093] In some optional embodiments, the step of patterning the first color luminescent material 31' to form the first color luminescent layer 31 includes: patterning the first color luminescent material 31' to form the first color luminescent layer 31 by photolithography, wherein the thickness of the first color luminescent layer 31 is less than the thickness of the first color luminescent material 31', that is, thinning the first color luminescent material 31' by photolithography, removing part of the first color luminescent material 31', so that the thickness of the first color luminescent layer 31 meets the requirements.

[0094] Optionally, between the step of providing the first electrode layer 1 and the step of forming the crosslinked layer 2 of the functional layer G on one side of the first electrode layer 1, the method further includes: sequentially forming a hole injection layer 5 and a hole transport layer 6 on one side of the first electrode layer 1 along a direction away from the first electrode layer 1.

[0095] Between the step of patterning the first color luminescent material 31' to form the first color luminescent layer 31 and the step of forming the second electrode layer 4 on the side of the first color luminescent layer 31 away from the first electrode layer 1, the method further includes: forming an electron transport layer 7 on the side of the first color luminescent layer 31 away from the first electrode layer 1.

[0096] Hole transport layer 6 is responsible for transporting holes, while electron transport layer 7 is responsible for transporting electrons. The first color luminescent material 31' emits photons by receiving these charge carriers and recombination.

[0097] Optionally, the hole transport layer 6 includes a thermosensitive group, and the hole transport layer 6 and the crosslinking group do not react. A thermosensitive group is a chemical group whose properties can change with temperature. Specifically, when the temperature changes, the thermosensitive group undergoes a change in molecular structure, resulting in changes in its physical or chemical properties, such as fluorescence intensity and emission wavelength. In this embodiment, the thermosensitive group and the crosslinking group in the hole transport layer 6 do not react to avoid mutual interference.

[0098] Alternatively, the hole transport layer 6 may include photosensitive groups, which are chemical groups capable of undergoing chemical reactions under illumination. These groups, when irradiated with light of a specific wavelength, can absorb light energy and initiate chemical reactions, thereby altering their physical or chemical properties. In this embodiment, the photosensitive groups and crosslinking groups of the hole transport layer 6 undergo a crosslinking reaction under illumination, thereby achieving crosslinking and enhancing luminous efficiency.

[0099] In some optional embodiments, between the steps of sequentially forming a hole injection layer 5 and a hole transport layer 6 on one side of the first electrode layer 1 along a direction away from the first electrode layer 1 and forming a crosslinking layer 2 of the functional layer G on one side of the first electrode layer 1, the method further includes: forming a third color emitting layer 33 on one side of the first electrode layer 1; between the steps of patterning the first color emitting material 31' to form the first color emitting layer 31 and forming an electron transport layer 7 on the side of the first color emitting layer 31 away from the first electrode layer 1, the method further includes: forming a second color emitting layer 32 on one side of the first electrode layer 1.

[0100] In this embodiment, the functional layer G includes three quantum light-emitting layers that can emit different colors: a first color light-emitting layer 31, a second color light-emitting layer 32, and a third color light-emitting layer 33. Depending on the actual material properties, the second color light-emitting layer 32 and the third color light-emitting layer 33 may or may not have a cross-linking layer 2, and there are no special limitations.

[0101] Along the direction parallel to the plane where the first electrode layer 1 is located, the second color light-emitting layer 32, the third color light-emitting layer 33 and the first color light-emitting layer 31 are adjacent to each other in the same layer. That is, along the direction perpendicular to the plane where the first electrode layer 1 is located, the first color light-emitting layer 31, the second color light-emitting layer 32 and the third color light-emitting layer 33 do not overlap, so as to avoid mutual interference with light emission.

[0102] Optionally, the first color emitting layer 31 includes a green quantum emitting layer. Through research and experiments by the inventors, it has been found that the green light-emitting device 10 is very sensitive to the thickness of the first color emitting layer 31. When the first color emitting layer 31 is thinner, the green light-emitting device 10 can have a better lifespan. Therefore, in this embodiment, the first color emitting layer 31 includes a green quantum emitting layer to improve the lifespan of the green light-emitting device 10.

[0103] Optionally, the first color emitting layer 31 includes a green quantum emitting layer, the second color emitting layer 32 includes a blue quantum emitting layer, and the third color emitting layer 33 includes a red quantum emitting layer.

[0104] This invention also provides a display device, including the display panel of any of the above embodiments or the display panel obtained by the display panel preparation method of any of the above embodiments.

[0105] The display device provided in this embodiment of the invention has the technical effects of the display panel in any of the above embodiments. The explanations of the same or corresponding structures and terms in the above embodiments will not be repeated here.

[0106] The display device provided in the embodiments of the present invention can be an organic light-emitting diode (OLED) display device, a quantum dot light-emitting diode (QLED) device, or a micro flat panel display device (Micro-OLED or Micro-LED), etc.

[0107] The display device provided in this embodiment of the invention can be applied to mobile phones or any electronic product with display function, including but not limited to the following categories: televisions, laptops, desktop monitors, tablets, digital cameras, smart bracelets, smart glasses, in-vehicle displays, medical devices, industrial control equipment, touch interactive terminals, etc. This embodiment of the invention does not impose any special limitations on these.

[0108] The above are merely specific embodiments of the present invention. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

[0109] It should also be noted that the exemplary embodiments mentioned in this invention describe methods or systems based on a series of steps or apparatus. However, this invention is not limited to the order of the steps described above; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

Claims

1. A display panel, comprising a light-emitting device, the light-emitting device comprising: First electrode layer; At least two functional layers are disposed on one side of the first electrode layer, and the functional layers include a crosslinking layer and a first color emitting layer stacked in a direction away from the first electrode layer; The second electrode layer is disposed on the side of the functional layer opposite to the first electrode layer.

2. The display panel according to claim 1, wherein, The first color emitting layer comprises a first color quantum dot material.

3. The display panel according to claim 1, wherein, The side of the first color emitting layer closest to the first electrode layer and the side of the crosslinking layer away from the first electrode layer are in contact. The thickness ratio of the cross-linked layer to the first color emitting layer is greater than or equal to 1:8 and less than or equal to 5:

1.

4. The display panel according to claim 3, wherein, The thickness ratio of the cross-linked layer to the first color emitting layer is greater than or equal to 1:8 and less than or equal to 1:

1.

5. The display panel according to claim 2, wherein, The thickness of the crosslinked layer is greater than or equal to 1 nm and less than or equal to 100 nm; The thickness of the first color emitting layer is greater than or equal to 8 nm and less than or equal to 18 nm.

6. The display panel according to claim 2 or 3, wherein, The first color emitting layer includes a monolayer quantum dot molecular layer, and the monolayer quantum dot molecular layer is in contact with the cross-linked layer; The monolayer quantum dot molecular layer comprises a monolayer of quantum dots and ligands.

7. The display panel according to claim 1, wherein, Along the direction away from the first electrode layer, the functional layer further includes a hole injection layer and a hole transport layer disposed between the crosslinking layer and the first electrode layer, and an electron transport layer disposed on the side of the first color emitting layer opposite to the first electrode layer.

8. The display panel according to claim 7, wherein, The cross-linking layer includes cross-linking groups, and the cross-linking groups and the ligands in the first color emitting layer are cross-linked under light irradiation; The migration rate of the material in the cross-linked layer is greater than or equal to 10⁻⁴ cm² / Vs; The hole transport layer includes a thermosensitive group, and the hole transport layer and the crosslinking group do not react; or, the hole transport layer includes a photosensitive group, and the hole transport layer and the crosslinking group crosslink under light irradiation.

9. The display panel according to claim 1, wherein, The functional layer further includes a second color emitting layer and a third color emitting layer disposed on one side of the first electrode layer. Along a direction parallel to the plane where the first electrode layer is located, the second color emitting layer, the third color emitting layer and the first color emitting layer are disposed in the same layer. The second color emitting layer comprises a second color quantum dot material, and the third color emitting layer comprises a third color quantum dot material.

10. The display panel according to claim 9, wherein, The first color-emitting layer includes a green quantum light-emitting layer; The first color emitting layer includes a green quantum emitting layer, the second color emitting layer includes a blue quantum emitting layer, and the third color emitting layer includes a red quantum emitting layer; In the thickness direction of the display panel, the crosslinking layer, the second color emitting layer, and the third color emitting layer do not overlap. The thickness of the second color emitting layer is greater than or equal to the thickness of the third color emitting layer, and the thickness of the third color emitting layer is greater than or equal to the thickness of the first color emitting layer; The thickness of the second color emitting layer is greater than or equal to 10 nm and less than or equal to 80 nm; The thickness of the third color emitting layer is greater than or equal to 10 nm and less than or equal to 50 nm.

11. A display panel, comprising: First electrode layer; At least two functional layers are disposed on one side of the first electrode layer. The functional layer includes a crosslinking layer and a first color emitting layer stacked in a direction away from the first electrode layer, and a second color emitting layer disposed on one side of the first color emitting layer in a direction parallel to the plane where the first electrode layer is located. The second color emitting layer includes a crosslinking material and a second color emitting material. The second electrode layer is disposed on the side of the functional layer opposite to the first electrode layer.

12. The display panel according to claim 11, wherein, The functional layer further includes a third color emitting layer disposed on one side of the first color emitting layer along a direction parallel to the plane of the first electrode layer; the third color emitting layer includes a cross-linked material and a third color quantum dot material; or, The third color emitting layer comprises a third color quantum dot material; The first color emitting layer includes a first color quantum dot material, and the second color emitting layer includes a second color quantum dot material; The first color emitting layer includes a green quantum emitting layer, the second color emitting layer includes a blue quantum emitting layer, and the third color emitting layer includes a red quantum emitting layer.

13. The display panel according to claim 11, wherein, The thickness ratio of the cross-linked layer to the first color-emitting layer is greater than or equal to 1:8 and less than or equal to 5:

1.

14. The display panel according to claim 11, wherein, The thickness of the crosslinked layer is greater than or equal to 1 nm and less than or equal to 100 nm; and / or, The thickness of the first color emitting layer is greater than or equal to 8 nm and less than or equal to 18 nm; wherein the first color emitting layer includes a monolayer quantum dot molecular layer, and the monolayer quantum dot molecular layer is in contact with the cross-linking layer.

15. A method for manufacturing a display panel, comprising the following steps: Provide a first electrode layer; A functional layer is formed on one side of the first electrode layer, and the side of the functional layer opposite to the first electrode layer includes a cross-linking layer. A first color luminescent material is formed on the side of the crosslinked layer opposite to the first electrode layer; The first color luminescent material is patterned to form a first color luminescent layer; A second electrode layer is formed on the side of the first color emitting layer that is opposite to the first electrode layer.

16. The method for manufacturing a display panel according to claim 15, wherein, The step of forming a first color luminescent material on the side of the crosslinked layer opposite to the first electrode layer includes: A first-color quantum dot material is formed on the side of the cross-linked layer away from the first electrode layer by a coating process; The thickness of the first color luminescent material is greater than or equal to 25 nm and less than or equal to 50 nm.

17. The method for manufacturing a display panel according to claim 15, wherein, The step of patterning the first color luminescent material to form the first color luminescent layer includes: The first color luminescent material is patterned using a photolithography process to form a first color luminescent layer, the thickness of which is less than the thickness of the first color luminescent material.

18. The method for manufacturing a display panel according to claim 15, wherein, Between the step of providing the first electrode layer and the step of forming a crosslinked layer of a functional layer on one side of the first electrode layer, the method further includes: Along a direction away from the first electrode layer, a hole injection layer and a hole transport layer are sequentially formed on one side of the first electrode layer; Between the step of patterning the first color emitting material to form a first color emitting layer and the step of forming a second electrode layer on the side of the first color emitting layer opposite to the first electrode layer, the method further includes: An electron transport layer is formed on the side of the first color emitting layer that is away from the first electrode layer.

19. The method for manufacturing a display panel according to claim 18, wherein, Between the steps of sequentially forming a hole injection layer and a hole transport layer on one side of the first electrode layer in a direction away from the first electrode layer and the step of forming a crosslinking layer of a functional layer on one side of the first electrode layer, the method further includes: A third color emitting layer is formed on one side of the first electrode layer; Between the step of patterning the first color emitting material to form a first color emitting layer and the step of forming an electron transport layer on the side of the first color emitting layer opposite to the first electrode layer, the method further includes: A second color emitting layer is formed on one side of the first electrode layer.

20. A display device comprising a display panel as described in any one of claims 1 to 14, or comprising a display panel obtained by any one of the display panel manufacturing methods of claims 15 to 19.

Images