Composite anode, composite anode preparation method, display panel and display device

Abstract

The embodiments of the present application provide a composite anode, a method for preparing a composite anode, a display panel and a display device, wherein the composite anode comprises: a first conductive layer; a total reflection layer, arranged on one side of the first conductive layer; a composite material layer, arranged on the side of the total reflection layer away from the first conductive layer, the edge of the composite material layer being connected to the first conductive layer; and a second conductive layer, arranged on the side of the composite material layer away from the first conductive layer, the edge of the second conductive layer being connected to the first conductive layer; wherein the composite material layer comprises indium tin oxide and carbon nanotubes. The composite anode, the method for preparing a composite anode, the display panel and the display device provided in the embodiments of the present application uniformly cover and wrap the exposed peripheral side of the total reflection layer through the composite material layer and the second conductive layer, thereby preventing the total reflection layer from leaking out and being oxidized and failing, thereby achieving the purpose of improving the stability of the anode.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular relates to a composite anode, a method for preparing the composite anode, a display panel, and a display device. Background Art

[0002] Organic Light-Emitting Diode (OLED) display, also known as organic electric laser display, organic light-emitting semiconductor (Organic Electroluminescence Display, OLED). OLED is a current-type organic light-emitting device, which is a phenomenon of luminescence caused by the injection and recombination of carriers. The luminescence intensity is proportional to the injected current. Under the action of the electric field, the holes generated by the anode and the electrons generated by the cathode of the OLED will move, inject into the hole transport layer and the electron transport layer respectively, and migrate to the light-emitting layer. When the two meet in the light-emitting layer, energy excitons are generated, thereby exciting the light-emitting molecules to finally produce visible light.

[0003] At present, the commonly used material for the anode is the three-layer sandwich structure of ITO-Ag-ITO (Indium Tin Oxide). Since Ag is an active metal and is easily oxidized or corroded, the Ag layer cannot have any exposed parts when patterning is required, and the ITO layer can fully surround the Ag layer. Currently, the etching rate is often controlled to achieve the wrapping of the Ag layer by the ITO layer. However, the wrapping film structure formed by this solution is unstable and uncontrollable, which greatly affects the stability of the anode.

[0004] In summary, the existing anode has the problem of unstable wrapping structure of the ITO layer on the Ag layer. Summary of the invention

[0005] In view of this, the embodiments of the present application provide a composite anode, a method for preparing the composite anode, a display panel and a display device to solve the technical problem of the unstable wrapping structure of the ITO layer of the existing anode for the Ag layer.

[0006] In a first aspect, an embodiment of the present application provides a composite anode, comprising:

[0007] a first conductive layer;

[0008] A total reflection layer, disposed on one side of the first conductive layer;

[0009] a composite material layer, disposed on a side of the total reflection layer away from the first conductive layer, wherein an edge of the composite material layer is connected to the first conductive layer; and

[0010] A second conductive layer is provided on a side of the composite material layer away from the first conductive layer, and an edge of the second conductive layer is connected to the first conductive layer;

[0011] Wherein, the composite material layer includes indium tin oxide and carbon nanotubes.

[0012] In some embodiments, the composite material layer covers the total reflection layer, and the edge of the composite material layer covers the side wall of the total reflection layer and is connected to the first conductive layer;

[0013] And / or, the second conductive layer covers the composite material layer, and the edge of the second conductive layer covers the side wall of the composite material layer and is connected to the first conductive layer.

[0014] In some embodiments, the composite material layer is made of reticulated carbon nanotubes and indium tin oxide nanoparticles.

[0015] In some embodiments, the first conductive layer and the second conductive layer are light-transmitting conductive oxide layers, and the light-transmitting conductive oxide layers include at least one of indium tin oxide, indium zinc oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, zinc oxide, and tin oxide;

[0016] And / or, the total reflection layer is a silver layer.

[0017] In a second aspect, an embodiment of the present application provides a method for preparing a composite anode, comprising the following steps:

[0018] Providing light-transmitting conductive oxides and composite materials;

[0019] Depositing the light-transmitting conductive oxide to form a first conductive layer;

[0020] Depositing metal on one side of the first conductive layer to form a total reflection layer;

[0021] Arranging the composite material on a side of the total reflection layer away from the first conductive layer to form a composite material layer;

[0022] The light-transmitting conductive oxide is deposited on a side of the composite material layer away from the first conductive layer to form a second conductive layer.

[0023] In some embodiments, the composite material is made of reticulated carbon nanotubes and indium tin oxide nanoparticles by high temperature sintering or hydrothermal method.

[0024] In some embodiments, the composite material is disposed on a side of the total reflection layer away from the first conductive layer to form a composite material layer, comprising:

[0025] Patterning the composite material on a side of the total reflection layer away from the first conductive layer by inkjet printing to form the composite material layer;

[0026] Alternatively, the composite material is first plated on a side of the total reflection layer away from the first conductive layer, and then exposed, developed, and etched for patterning to form the composite material layer.

[0027] In some embodiments, the composite material layer uniformly covers the exposed peripheral side of the total reflection layer, and the second conductive layer uniformly covers the exposed peripheral side of the composite material layer;

[0028] Alternatively, the composite material layer and the second conductive layer uniformly cover the exposed peripheral side of the total reflection layer.

[0029] In a third aspect, the embodiments of the present application provide a display panel and a substrate;

[0030] An insulating layer, disposed on one side of the substrate;

[0031] The composite anode as described in the first aspect or the composite anode obtained by the preparation method as described in the second aspect, wherein the composite anode is arranged on one side of the substrate and on the same side as the insulating layer, the composite anode is partially embedded in the insulating layer, and both ends of the composite anode are located on the side of the insulating layer away from the substrate;

[0032] a light-emitting layer, disposed on a side of the composite anode away from the substrate; and

[0033] The cathode is arranged on a side of the light emitting layer away from the substrate.

[0034] In a fourth aspect, an embodiment of the present application provides a display device, such as the display panel and the housing as described in the third aspect, wherein the display panel is disposed in the housing.

[0035] The composite anode provided in the embodiment of the present application is prepared by compounding carbon nanotubes with indium tin oxide to form a mesh carbon nanotube / ITO (CNT / ITO) composite nanomaterial, and the anode structure is ITO-CNT / ITO-Ag-ITO. Since the structure of the mesh composite material is more stable, the exposed side of the total reflection layer is evenly covered and wrapped by the composite material layer and the second conductive layer, thereby preventing the total reflection layer from leaking out and being oxidized and failing, thereby achieving the purpose of improving the stability of the anode.

[0036] Compared with the existing anode structure, the preparation method of the composite anode provided in the embodiment of the present application covers a composite material layer on the total reflection layer. Since the structure of the mesh composite material is more stable, during the patterning process, when the total reflection layer shrinks inwardly inside the sandwich, the upper composite material layer will evenly cover the shrinking surface, while avoiding the fracture of the collapsed second conductive layer above. The uppermost second conductive layer will slowly deform and cover with the support of the composite material layer, thereby ensuring that the composite material layer and the second conductive layer stably and evenly cover the exposed side of the total reflection layer, thereby improving the stability of the anode.

[0037] The display panel and display device provided in the embodiments of the present application have all the above beneficial effects because they include the above-mentioned composite anode. Moreover, because of the highly stable composite anode, the service life of the display panel and the display device, as well as the brand reputation will be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of the anode structure in the prior art;

[0040] Figure 2 It is a schematic diagram of the process of forming the anode structure in the prior art;

[0041] Figure 3 is a schematic diagram of the structure of the composite anode provided in an embodiment of the present application;

[0042] Figure 4 is a schematic diagram of the process of forming the structure of the composite anode provided in an embodiment of the present application;

[0043] Figure 5 is a schematic diagram of the microstructure of carbon nanotubes in the composite anode provided in an embodiment of the present application;

[0044] Figure 6 is a schematic diagram of the microstructure of the composite material in the composite anode provided in the embodiment of the present application;

[0045] Figure 7 It is a schematic diagram of the structure of the display panel provided in the embodiment of the present application.

[0046] Among them, the figure numbers are:

[0047] 10. composite anode; 11. first conductive layer; 12. total reflection layer; 13. composite material layer; 14. second conductive layer;

[0048] 20. Substrate;

[0049] 30. Insulation layer;

[0050] 40. Luminescent layer;

[0051] 50. Cathode. DETAILED DESCRIPTION

[0052] In the following description, specific details such as specific system structures, technologies, etc. are proposed for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the embodiments of the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from hindering the description of the embodiments of the present application.

[0053] It should also be understood that the term “and / or” used in the description of the embodiments of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0054] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0055] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0056] In addition, in the description of the embodiments of the present application and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0057] References to "some embodiments" or "some embodiments" etc. described in the specification of the embodiments of the present application mean that one or more embodiments of the embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the statements "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in the different parts of this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. "Multiple" refers to two or more.

[0058] OLED, which stands for Organic Light-Emitting Diode (OLED);

[0059] ITO, namely Indium Tin Oxide (ITO);

[0060] Ag, which means silver;

[0061] CNT, Carbon Nanotubes (CNT or CNts);

[0062] CNT / ITO, that is, carbon nanotube / indium tin oxide composite material.

[0063] OLED devices are composed of substrates, cathodes, anodes, hole injection layers, electron injection layers, hole transport layers, electron transport layers, electron blocking layers, hole blocking layers, and light-emitting layers. The substrate is the basis of the entire device, and all functional layers need to be evaporated onto the substrate of the device; glass is usually used as the substrate of the device, but if you need to make a bendable flexible OLED device, you need to use other materials such as plastic as the substrate of the OLED device.

[0064] The anode is connected to the positive pole of the device's external driving voltage. The holes in the anode will move to the light-emitting layer in the device under the drive of the external driving voltage. Its work function is required to be as high as possible in order to improve the hole injection efficiency. OLED devices require that one side of the electrode must be light-transmitting. Taking the top-emitting OLED as an example, the anode is located below the light-emitting layer. The light emitted by the light-emitting layer will be emitted to the surrounding side. The light below needs to be reflected by the anode, so a total reflection layer is required. The upper layer requires a light-transmitting electrode. Therefore, the anode usually uses ITO, a light-transmitting material with a high work function. ITO has a transmittance of more than 80% in the wavelength range of 400nm to 1000nm, and also has a high transmittance in the near-ultraviolet region. The Ag layer needs to be protected by other relatively inert electrodes. The common lower layer uses an ITO layer. The anode structure in the prior art is as follows Figure 1 and Figure 2 shown.

[0065] In the general process preparation, the three-layer structure of the anode includes a first conductive layer 11, a total reflection layer 12 and a second conductive layer 14, wherein the method of sequential coating and one-time etching is adopted, that is, Figure 2 As shown, after the three film layers are coated in sequence and the exposure and development processes are completed, during the etching process, the etching rate of the etching solution on the second conductive layer 14 and the total reflection layer 12 is generally controlled so that the etching rate of the total reflection layer 12 is greater than that of the second conductive layer 14. At this time, the total reflection layer 12 will shrink. After the shrinkage reaches a certain level, the upper second conductive layer 14 will break without the support of the total reflection layer 12. At this time, the upper second conductive layer 14 will fall on the exposed surface of the total reflection layer 12 after the film breaks and accumulate, thereby covering the exposed surface of the total reflection layer 12, thereby protecting the total reflection layer 12. In this way, the film fracture of the second conductive layer 14 is a brittle fracture of the film. Due to the large brittleness of the ITO layer itself, large pores and cracks will be generated at the fracture point, and the film layer stacking below is uneven, the film layer continuity of the wrapped surface is poor, and the wrapping of the total reflection layer 12 is also poor. Therefore, under this process, the film thickness around the total reflection layer 12 will be uneven and the film quality will be poor, which has a greater impact on the stability of the anode.

[0066] After research, it was found that the structure of carbon nanotubes is the same as the layer structure of graphite, and has good electrical conductivity. The resistance of carbon nanotubes has nothing to do with their length and diameter, and electrons do not generate heat to heat the carbon nanotubes when they pass through them. The transmission of electrons in carbon nanotubes is like the transmission of light signals in optical fiber cables, with little energy loss, so they have high electrical conductivity.

[0067] Therefore, the embodiment of the present application prepares a composite material with a mesh structure by compounding carbon nanotubes and indium tin oxide. The material has a high conductivity. Since the work function of carbon nanotubes is about 4.95 eV (electron volts) and the work function of ITO is about 5 eV (electron volts) eV, the work function of the composite material meets the anode requirements. The composite material layer 13 formed by the composite material cooperates with the second conductive layer 14 to uniformly cover and wrap the total reflection layer 12, avoiding the peripheral side of the total reflection layer 12 from being exposed to the outside, thereby effectively preventing the total reflection layer 12 from being oxidized and thus failing, and greatly improving the stability of the anode.

[0068] It should be noted that the thickness direction of the composite anode 10 and the display panel mentioned in the embodiment of the present application is the Y direction in the figure, and the X direction is the length / width direction of the composite anode 10 and the display panel. The above is only for the convenience of understanding the technical solution of the embodiment of the present application, and should not be understood as limiting the scope of the embodiment of the present application.

[0069] In a first aspect, an embodiment of the present application provides a composite anode 10, such as Figures 3 to 6 As shown, the composite anode 10 includes a first conductive layer 11, a total reflection layer 12, a composite material layer 13 and a second conductive layer 14;

[0070] The total reflection layer 12 is disposed on one side of the first conductive layer 11;

[0071] The composite material layer 13 is disposed on a side of the total reflection layer 12 away from the first conductive layer 11, and an edge of the composite material layer 13 is connected to the first conductive layer 11;

[0072] The second conductive layer 14 is disposed on a side of the composite material layer 13 away from the first conductive layer 11, and an edge of the second conductive layer 14 is connected to the first conductive layer 11;

[0073] The composite material layer 13 includes indium tin oxide and carbon nanotubes.

[0074] The composite anode 10 provided in the embodiment of the present application is a composite material obtained by compounding carbon nanotubes with ITO to form a mesh composite material, so that a composite material layer 13 that uniformly covers and wraps the total reflection layer 12 can be formed on the total reflection layer 12, thereby improving the stability of the anode. In addition, since the composite material has high conductivity, high mechanical strength, good light transmittance and low cost, it is conducive to commercial production.

[0075] In some embodiments, Figure 5 and Figure 6As shown, the composite material layer 13 is made of mesh carbon nanotubes and indium tin oxide nanoparticles. The structure of carbon nanotubes is the same as the lamellar structure of graphite, and has good electrical conductivity. The resistance of carbon nanotubes is independent of their length and diameter, and electrons passing through carbon nanotubes do not generate heat to heat the carbon nanotubes. The transmission of electrons in carbon nanotubes is like the transmission of light signals in optical fiber cables, with little energy loss, so it has high electrical conductivity. In applications, such as Figure 6 As shown, ITO nanoparticles and CNTs are sintered at high temperature or hydrothermally so that the ITO nanoparticles can be attached to the gaps between CNTs, effectively enhancing the mechanical strength and conductivity of the composite material.

[0076] Among them, the high conductivity of CNTs can significantly improve the conductivity of the overall material. The high strength of CNTs can increase the tensile strength and toughness of the composite material. The light transmittance of ITO nanoparticles allows the composite material to still maintain a high light transmittance. Compared with pure ITO, the use of CNTs can reduce costs because ITO is more expensive.

[0077] In some embodiments, Figure 3 and Figure 4 As shown, the composite material layer 13 covers the total reflection layer 12, and the edge of the composite material layer 13 covers the side wall of the total reflection layer 12 and is connected to the first conductive layer 11. In other words, the end of the composite material layer 13 along the length or width direction of the composite anode 10 is located on the first conductive layer 11 and is connected to the first conductive layer 11, that is, the composite material layer 13 and the first conductive layer 11 together cover and encapsulate the total reflection layer 12 to prevent the peripheral side of the total reflection layer 12 from being exposed to the outside, thereby effectively preventing the active metal in the total reflection layer 12 from being oxidized, and finally achieving the purpose of improving the stability of the anode.

[0078] In some embodiments, Figure 3 and Figure 4 As shown, the second conductive layer 14 covers the composite material layer 13, and the edge of the second conductive layer 14 covers the side wall of the composite material layer 13 and is connected to the first conductive layer 11. In other words, the end of the second conductive layer 14 along the length or width direction of the composite anode 10 is located on the first conductive layer 11 and is connected to the first conductive layer 11. The second conductive layer 14 cooperates with the first conductive layer 11 to uniformly cover and wrap the composite material layer 13 and the total reflection layer 12. On the basis of the composite material layer 13, the sealing of the covering and wrapping is further improved, thereby further protecting the total reflection layer 12, and achieving the effect of fully improving the stability of the anode.

[0079] In other embodiments, other functional layers may be provided between the first conductive layer 11 and the total reflection layer 12, between the total reflection layer 12 and the composite material layer 13, and between the composite material layer 13 and the second conductive layer 14, which is not limited in the embodiments of the present application.

[0080] In some embodiments, the first conductive layer 11 and the second conductive layer 14 are light-transmitting conductive oxide layers, and the light-transmitting conductive oxide layers include at least one of indium tin oxide, indium zinc oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, zinc oxide, and tin oxide. In some embodiments, the first conductive layer 11 is an indium tin oxide layer, and the second conductive layer 14 is also an indium tin oxide layer. ITO has good optical transmittance, allowing light to pass through, which is crucial for displays that need to view images from the front. In OLED display technology, ITO is often used as an anode material because its low work function helps inject holes from the anode into the organic layer.

[0081] In some embodiments, the total reflection layer 12 is a silver layer. In some embodiments, in an OLED display panel, the anode generally needs to have two main characteristics: light transmittance and good electrical conductivity. In the embodiment of the present application, the anode includes a total reflection layer 12 to optimize the light extraction efficiency. The benefits of using silver (Ag) as the total reflection layer 12 are mainly reflected in the following aspects:

[0082] High reflectivity: Silver has a very high reflectivity, especially in the visible spectrum, which allows it to effectively reflect unextracted light back to the light-emitting layer 40. By reflecting unextracted light, the chances of light exiting can be increased, thereby improving the overall brightness and efficiency of the display panel.

[0083] High conductivity: Silver is a metal with extremely high conductivity, which means it can efficiently transmit electric current. The presence of the silver layer can reduce the resistance of the entire anode, reduce energy loss, and thus improve the efficiency of OLED.

[0084] Total reflection effect: By introducing a total reflection layer 12 in the anode, the propagation path of light inside the OLED can be changed, reducing the loss of light caused by multiple reflections between the substrate 20 and other layers. The total reflection layer 12 helps to guide more light to the exit direction, thereby improving the light extraction efficiency.

[0085] Low Absorption: Silver has low light absorption properties relative to other metals. This reduces the likelihood that light will be absorbed as it passes through the anode, further increasing the amount of light that can be extracted.

[0086] Color purity: Silver's high reflectivity helps maintain color purity because it reduces dispersion and absorption during light transmission. This is very important for display technology that pursues high color accuracy and contrast.

[0087] Chemical stability: Silver has good chemical stability, which helps to extend the service life of OLED display panels.

[0088] Layer Thickness Adjustment: The thickness of the silver layer can be adjusted according to specific design requirements to optimize the balance between reflectivity and conductivity.

[0089] The present application also provides a method for preparing a composite anode 10, comprising the following steps:

[0090] S10, providing light-transmitting conductive oxides and composite materials;

[0091] S20, depositing a light-transmitting conductive oxide to form a first conductive layer 11;

[0092] S30, depositing metal on one side of the first conductive layer 11 to form a total reflection layer 12;

[0093] S40, disposing a composite material on a side of the total reflection layer 12 away from the first conductive layer 11 to form a composite material layer 13;

[0094] S50 , depositing a light-transmitting conductive oxide on a side of the composite material layer 13 away from the first conductive layer 11 to form a second conductive layer 14 .

[0095] Compared with the existing anode structure, the preparation method of the composite anode 10 provided in the embodiment of the present application covers a composite material layer 13 on the total reflection layer 12. Since the structure of the mesh composite material is more stable, during the patterning process, when the total reflection layer 12 shrinks inwardly inside the sandwich, the upper composite material layer 13 will evenly cover the shrinking surface, while avoiding the fracture of the collapsed part of the second conductive layer 14 above. The uppermost second conductive layer 14 will slowly deform and cover with the support of the composite material layer 13, thereby ensuring that the composite material layer 13 and the second conductive layer 14 stably and evenly cover the exposed side of the total reflection layer 12, thereby improving the stability of the anode.

[0096] In applications, such as Figure 3 and Figure 4As shown, the materials of the composite anode 10 are ITO (~100 angstroms)-CNT / ITO (~100 angstroms)-Ag (~1000 angstroms)-ITO (~200 angstroms) from top to bottom. ITO and Ag coating (PVD deposition) are performed from bottom to top respectively. The thickness units of the layer structure are in brackets, and ~ means about. The advantages of the composite anode 10 structure include that the resistance of the anode can be significantly reduced and the current transmission efficiency can be improved by introducing CNTs and silver layers. The silver layer, as a total reflection layer 12, can redirect the unextracted light back to the light-emitting layer 40, thereby increasing the probability of light emission. Optimize the propagation path of light and reduce the loss of multiple reflections of light inside the OLED. Although the silver layer is thick, the overall optical transmittance can be maintained by designing a multi-layer structure, especially the CNT / ITO layer and the upper and lower ITO layers. Improve mechanical stability: The CNT / ITO layer and the lower ITO layer provide additional mechanical protection, reducing the risk of the silver layer breaking due to external stress. Chemical stability: The CNT / ITO layer can reduce the contact of the silver layer with oxygen and moisture in the air, thus preventing the silver layer from oxidizing.

[0097] In step S10, the light-transmitting conductive oxide is indium tin oxide, and the composite material is made of mesh carbon nanotubes and indium tin oxide nanoparticles by high-temperature sintering or hydrothermal method. The composite material synthesized by mesh carbon nanotubes and ITO nanoparticles by a specific preparation method (such as high-temperature sintering or hydrothermal method) is usually called CNT / ITO composite material. This material combines the high conductivity and mechanical strength of CNT with the good light transmittance and conductivity of ITO. Among them, the high-temperature sintering method: CNTs and ITO nanoparticles are mixed and sintered at high temperature to form a strong connection between the two materials. Advantages: The conductivity and mechanical stability of the composite material can be improved. Hydrothermal method: The composite material is synthesized in a high-pressure and high-temperature aqueous solution. This method is conducive to the formation of a uniformly dispersed composite structure. A more uniform dispersion effect can be obtained while retaining the light transmittance of the material.

[0098] In steps S20 and S30 , a light-transmitting conductive oxide is deposited to obtain a first conductive layer 11 , that is, indium tin oxide is deposited. Then, a metal is deposited on one side of the first conductive layer 11 . In some embodiments, the metal is silver (Ag) to form a total reflection layer 12 .

[0099] In step S40, a composite material is disposed on a side of the total reflection layer 12 away from the first conductive layer 11 to form a composite material layer 13, including:

[0100] The composite material is patterned on the side of the total reflection layer 12 away from the first conductive layer 11 by inkjet printing to form a composite material layer 13. Among them, the second conductive layer 14 on the top is still deposited by PVD, and then patterned by ordinary exposure, development, etching and other photolithography processes. In this scheme, since the CNT properties are relatively stable and the etching is difficult, patterning is used during direct coating, and no etching is performed subsequently. In this way, it can be ensured that the second conductive layer 14 and the composite material layer 13 uniformly cover and wrap the total reflection layer 12.

[0101] In other embodiments, the composite material is first plated on the side of the total reflection layer 12 away from the first conductive layer 11, and then exposed, developed, and etched to form the composite material layer 13. In this way, etching can be performed once, which is conducive to simplifying the process steps. In application, the composite material needs to be connected to Ag and ITO for etching, so it is necessary to reduce the CNT content and increase the concentration of the etching solution, or use other etching methods, such as plasma bombardment scheme to modify the position to be disconnected, and then use the etching solution for etching. In this way, it can be ensured that when the Ag layer is etched, the composite material layer 13 collapses evenly, and no large pores and cracks are generated, which ensures the coverage and wrapping of the Ag layer (total reflection layer 12) and improves its stability.

[0102] In some embodiments, the first conductive layer 11 can be made of an inert conductive material other than ITO material, and it only needs to be etched at a rate less than or equal to the second conductive layer 14 under the above-mentioned etching solution. It is recommended to use a rate less than that of ITO, so that the second conductive layer 14 can collapse to the lower layer so that it can be carried out on the bottom plane of Ag, and the collapsed height of the second conductive layer 14 is equal to the height of the total reflection layer 12, ensuring the coverage thickness of the composite material layer 13 and the second conductive layer 14 on the total reflection layer 12 and reducing the occurrence of faults between the film layers caused by too high a height.

[0103] In some embodiments, Figure 3 and Figure 4 As shown, the composite material layer 13 is evenly covered on the exposed peripheral side of the total reflection layer 12, and the second conductive layer 14 is evenly covered on the exposed peripheral side of the composite material layer 13. The composite material layer 13 is first used to preliminarily cover and wrap the total reflection layer 12, and then the second conductive layer 14 is used to cover and wrap the composite material layer 13, so that the total reflection layer 12 can be protected to the greatest extent to avoid being affected by the outside world, thereby achieving the effect of improving the stability of the anode.

[0104] In other embodiments, the composite material layer 13 and the second conductive layer 14 are uniformly covered on the exposed peripheral side of the total reflection layer 12. In other words, the exposed peripheral side of the total reflection layer 12 can be covered and wrapped by the cooperation of the composite material layer 13 and the second conductive layer 14, and it is not limited to that the total reflection layer 12 must be fully covered by one of the composite material layer 13 and the second conductive layer 14.

[0105] The present application also provides a display panel. Figure 7 As shown, the display panel includes a substrate 20, an insulating layer 30, a composite anode 10, a light-emitting layer 40 and a cathode 50, which are sequentially stacked along the thickness direction of the display panel;

[0106] The insulating layer 30 is disposed on one side of the substrate 20;

[0107] The composite anode 10 is disposed on one side of the substrate 20, the composite anode 10 and the insulating layer 30 are located on the same side of the substrate 20, the composite anode 10 is partially embedded in the insulating layer 30, and both ends of the composite anode 10 are located on the side of the insulating layer 30 away from the substrate 20, wherein the composite anode 10 is the composite anode 10 provided in the first aspect or the composite anode 10 prepared by the preparation method described in the second aspect;

[0108] The light emitting layer 40 is disposed on a side of the composite anode 10 away from the substrate 20;

[0109] The cathode 50 is disposed on a side of the light emitting layer 40 away from the substrate 20 .

[0110] The display panel provided in the embodiment of the present application, because it includes the above-mentioned composite anode 10, has all the beneficial effects described in the first aspect and the second aspect, that is, the preparation method provided by the second aspect can evenly cover and wrap the mesh composite material on the total reflection layer 12 to avoid the total reflection layer 12 being exposed to the outside, which effectively improves the stability compared with the existing anode.

[0111] In application, the two ends of the composite anode 10 refer to Figure 7 The two ends of the composite anode 10 along the length or width direction of the display panel, that is, the circumference of the composite anode 10 in practical applications, are located on the insulating layer 30. The light-emitting layer 40 and the insulating layer 30 cover and wrap the composite anode 10. Specifically, in the manufacturing process of the display panel, the light-emitting layer 40 is first deposited on the side of the composite anode 10 away from the substrate 20, and then the edge of the light-emitting layer 40 is wrapped and covered with the composite anode 10 by photolithography technology (spin coating photoresist, exposure, development, etching, peeling). Similarly, the cathode 50 is also designed in the same way, covering and wrapping the light-emitting layer 40; thereby ensuring the structural stability of the display panel and improving the display effect.

[0112] In application, the display panel further includes a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, an electron blocking layer and a hole blocking layer, wherein the positional relationship of the above layer structures is: substrate 20-insulating layer 30-composite anode 10-hole injection layer-hole transport layer-electron blocking layer-luminescent layer 40-hole blocking layer-electron transport layer-electron injection layer-cathode 50. The functions of each layer are as follows:

[0113] The function of the substrate 20 is to provide a basic platform to support the entire OLED structure. It is usually glass or plastic film. The function of the insulating layer 30 is to isolate the substrate 20 from the subsequent layers to ensure that the charge passes correctly through the active layer of the OLED instead of the substrate 20. In some embodiments, the insulating layer 30 may not be set. The function of the composite anode 10 is to inject holes into the OLED. It is usually a light-transmitting conductive material, such as ITO (indium tin oxide). In the embodiment of the present application, a mesh material composed of CNT and ITO is used. The function of the hole injection layer is to improve the injection efficiency of holes from the anode to the hole transport layer. The function of the hole transport layer is to transport holes from the hole injection layer to the light-emitting layer 40. The function of the electron blocking layer is to prevent electrons from flowing back from the electron transport layer to the hole transport layer and reduce non-radiative recombination. The function of the light-emitting layer 40 is that holes and electrons recombine in this layer to form excitons, and photons are emitted when the excitons decay. The function of the hole blocking layer is to prevent holes from entering the electron transport layer and reduce non-radiative recombination. The function of the electron transport layer is to transport electrons from the electron injection layer to the light-emitting layer 40. The electron injection layer is used to improve the efficiency of electron injection from the cathode 50 to the electron transport layer. The cathode 50 is used to inject electrons into the OLED. It is usually a metal or alloy, such as aluminum, magnesium or lithium.

[0114] An embodiment of the present application further provides a display device, comprising the display panel of the third aspect and a housing (not shown in the figure), wherein the display panel is disposed in the housing.

[0115] The display device provided in the embodiment of the present application has a highly stable composite anode 10, so the service life and brand reputation of the display device are significantly improved.

[0116] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0117] The above-described embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application are described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the embodiments of the present application, and should all be included in the protection scope of the embodiments of the present application.

Claims

1. A composite anode, characterized in that: include: a first conductive layer; A total reflection layer, disposed on one side of the first conductive layer; A composite material layer, disposed on a side of the total reflection layer away from the first conductive layer, wherein an edge of the composite material layer is connected to the first conductive layer; as well as A second conductive layer is provided on a side of the composite material layer away from the first conductive layer, and an edge of the second conductive layer is connected to the first conductive layer; Wherein, the composite material layer comprises indium tin oxide and carbon nanotubes; The composite material layer covers the total reflection layer, and the edge of the composite material layer covers the side wall of the total reflection layer and is connected to the first conductive layer; The second conductive layer covers the composite material layer, and the edge of the second conductive layer covers the side wall of the composite material layer and is connected to the first conductive layer; The composite material layer uniformly covers the circumference of the total reflection layer, and the second conductive layer uniformly covers the circumference of the composite material layer; The etching speed of the first conductive layer is lower than the etching speed of the second conductive layer, so that the collapsed height of the second conductive layer is equal to the height of the total reflection layer.

2. The composite anode according to claim 1, characterized in that The composite material layer is prepared from mesh carbon nanotubes and indium tin oxide nanoparticles.

3. The composite anode according to claim 1, characterized in that The first conductive layer and the second conductive layer are light-transmitting conductive oxide layers, and the light-transmitting conductive oxide layers include at least one of indium tin oxide, indium zinc oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, zinc oxide, and tin oxide; And / or, the total reflection layer is a silver layer.

4. A method for preparing a composite anode, characterized in that: For preparing the composite anode according to any one of claims 1 to 3, the preparation method comprises the following steps: Providing light-transmitting conductive oxides and composite materials; Depositing the light-transmitting conductive oxide to form a first conductive layer; Depositing metal on one side of the first conductive layer to form a total reflection layer; Arranging the composite material on a side of the total reflection layer away from the first conductive layer to form a composite material layer; The light-transmitting conductive oxide is deposited on a side of the composite material layer away from the first conductive layer to form a second conductive layer.

5. The preparation method according to claim 4, characterized in that: The composite material is made of mesh carbon nanotubes and indium tin oxide nanoparticles through high-temperature sintering or a hydrothermal method.

6. The preparation method according to claim 4, characterized in that: The composite material is arranged on a side of the total reflection layer away from the first conductive layer to form a composite material layer, comprising: Patterning the composite material on a side of the total reflection layer away from the first conductive layer by inkjet printing to form the composite material layer; Alternatively, the composite material is first plated on a side of the total reflection layer away from the first conductive layer, and then exposed, developed, and etched for patterning to form the composite material layer.

7. The preparation method according to claim 4, characterized in that: The composite material layer uniformly covers the exposed peripheral side of the total reflection layer, and the second conductive layer uniformly covers the exposed peripheral side of the composite material layer; Alternatively, the composite material layer and the second conductive layer uniformly cover the exposed peripheral side of the total reflection layer.

8. A display panel, characterized in that: include: substrate; An insulating layer, disposed on one side of the substrate; The composite anode according to any one of claims 1 to 3, or the composite anode obtained by the preparation method according to any one of claims 4 to 7, wherein the composite anode is arranged on one side of the substrate and on the same side as the insulating layer, the composite anode is partially embedded in the insulating layer, and the two ends of the composite anode are located on the side of the insulating layer away from the substrate; a light-emitting layer, disposed on a side of the composite anode away from the substrate; and The cathode is arranged on a side of the light emitting layer away from the substrate.

9. A display device, characterized in that: include: The display panel as claimed in claim 8; A housing, wherein the display panel is arranged in the housing.

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