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, disposed on one side of the first conductive layer; a support layer, disposed on a side of the total reflection layer away from the first conductive layer, the edge of the support layer being connected to the first conductive layer; and a second conductive layer, disposed on a side of the support layer away from the first conductive layer, the edge of the second conductive layer being connected to the first conductive layer; wherein the support layer comprises a zinc alloy. 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 support 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 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 supporting layer, disposed on a side of the total reflection layer away from the first conductive layer, wherein an edge of the supporting layer is connected to the first conductive layer; and

[0010] A second conductive layer is provided on a side of the support 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 support layer comprises zinc alloy.

[0012] In some embodiments, the support layer comprises:

[0013] 90% to 99% of metallic zinc and 1% to 10% of at least one of metallic bismuth, metallic aluminum, metallic copper, metallic magnesium, and metallic titanium.

[0014] In some embodiments, the supporting layer uniformly covers a side of the total reflection layer away from the first conductive layer and an exposed peripheral side of the total reflection layer, and the second conductive layer uniformly covers a side of the total reflection layer away from the first conductive layer and an exposed peripheral side of the supporting layer;

[0015] Alternatively, the support layer and the second conductive layer uniformly cover a side of the total reflection layer away from the first conductive layer and an exposed peripheral side of the total reflection layer.

[0016] 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 one of indium tin oxide, indium zinc oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, zinc oxide, and tin oxide;

[0017] And / or, the total reflection layer is a silver layer.

[0018] In a second aspect, an embodiment of the present application provides a method for preparing a composite anode, comprising the following steps:

[0019] Provide light-transmitting conductive oxides and zinc alloys;

[0020] Depositing the light-transmitting conductive oxide to form a first conductive layer;

[0021] Depositing metal on one side of the first conductive layer to form a total reflection layer;

[0022] Disposing the zinc alloy on a side of the total reflection layer away from the first conductive layer;

[0023] Depositing the light-transmitting conductive oxide on a side of the support layer away from the first conductive layer;

[0024] The first conductive layer, the total reflection layer and the zinc alloy layer are developed, exposed and etched, and a support layer covering the total reflection layer is formed on a side of the total reflection layer away from the first conductive layer, and a second conductive layer covering the support layer is formed on a side of the support layer away from the first conductive layer.

[0025] In some embodiments, developing, exposing and etching the first conductive layer, the total reflection layer and the zinc alloy layer includes:

[0026] After developing and exposing the first conductive layer, the total reflection layer and the zinc alloy layer, etching is performed at a first temperature to complete patterning of the composite anode;

[0027] Continue etching at a second temperature to form a support layer covering the total reflection layer and a second conductive layer covering the support layer;

[0028] Wherein, the second temperature is greater than the melting point of the support layer.

[0029] In some embodiments, before continuing etching at the second temperature, the process includes:

[0030] The first temperature etching is adopted first, and the edge of the total reflection layer is reduced by 0.1 μm to 0.2 μm toward the middle.

[0031] In some embodiments, an etching rate of the first conductive layer is not greater than an etching rate of the second conductive layer, and a melting temperature of the first conductive layer is greater than a melting temperature of the supporting layer.

[0032] In a third aspect, the embodiments of the present application provide a display panel and a substrate;

[0033] An insulating layer, disposed on one side of the substrate;

[0034] 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;

[0035] a light-emitting layer, disposed on a side of the composite anode away from the substrate; and

[0036] The cathode is arranged on a side of the light emitting layer away from the substrate.

[0037] 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.

[0038] The composite anode and preparation method provided in the embodiments of the present application are prepared by compounding metal bismuth and metal zinc into a zinc alloy. The anode structure is ITO-zinc alloy-Ag-ITO. Since the zinc alloy has a low melting point, the zinc alloy will melt and flow under the second conductive layer. The molten zinc alloy will evenly cover the inwardly contracted surface of the total reflection layer and then quickly cool and form. The second conductive layer will slowly deform and cover with the support of the zinc alloy, thereby ensuring that the zinc alloy and the second conductive layer stably and evenly cover the exposed side of the total reflection layer, thereby improving the stability of the anode.

[0039] 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

[0040] 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.

[0041] Figure 1 It is a schematic diagram of the anode structure in the prior art;

[0042] Figure 2 It is a schematic diagram of the process of forming the anode structure in the prior art;

[0043] Figure 3 is a schematic diagram of the structure of the composite anode provided in an embodiment of the present application;

[0044] 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;

[0045] Figure 5 The process diagram of the preparation method of the composite anode provided in the embodiment of the present application is as follows Figure 1 ;

[0046] Figure 6 The process diagram of the preparation method of the composite anode provided in the embodiment of the present application is as follows Figure 2 ;

[0047] Figure 7 It is a schematic diagram of the structure of the display panel provided in the embodiment of the present application.

[0048] Among them, the figure numbers are:

[0049] 10. Composite anode; 11. First conductive layer; 12. Total reflection layer; 13. Support layer; 14. Second conductive layer;

[0050] 20. Substrate;

[0051] 30. Insulation layer;

[0052] 40. Luminescent layer;

[0053] 50. Cathode. DETAILED DESCRIPTION

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] OLED, which stands for Organic Light-Emitting Diode (OLED);

[0061] ITO, namely Indium Tin Oxide (ITO);

[0062] Ag means silver.

[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, in the embodiment of the present application, the zinc alloy is covered on the total reflection layer. Due to the low melting point of the zinc alloy, the zinc alloy will melt and flow under the ITO. The molten zinc alloy will evenly cover the inwardly contracted surface of the Ag and then quickly cool and form. The top ITO film layer will slowly deform and cover with the support of the alloy material, thereby ensuring that the alloy material and ITO stably and evenly cover the exposed side of the Ag, thereby 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 Figure 3 , Figure 4 as well as Figure 7As shown, the composite anode 10 includes a first conductive layer 11, a total reflection layer 12, a support 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 support 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 support layer 13 is connected to the first conductive layer 11;

[0072] The second conductive layer 14 is disposed on a side of the support 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 support layer 13 includes a zinc alloy.

[0074] The composite anode 10 provided in the embodiment of the present application is prepared by using a zinc alloy as a support layer, and the composite anode structure is composed of ITO-zinc alloy-Ag-ITO. Since the zinc alloy has a low melting point, the zinc alloy will melt and flow under the second conductive layer 14, and the molten zinc alloy will evenly cover the inwardly contracted surface of the total reflection layer 12 and then quickly cool and form. The second conductive layer 14 will slowly deform and cover with the support of the zinc alloy, thereby ensuring that the zinc alloy 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.

[0075] In some embodiments, the support layer includes 90% to 99% of metallic zinc and 1% to 10% of at least one of metallic bismuth, metallic aluminum, metallic copper, metallic magnesium, and metallic titanium. In applications, zinc alloys are alloys composed of zinc with other elements added, and commonly added alloying elements include aluminum, copper, magnesium, bismuth, titanium, and the like. Zinc alloys have low melting points, good fluidity, easy fusion welding, brazing, and plastic processing, and are corrosion-resistant in the atmosphere. The work functions of metallic bismuth and metallic zinc are 4.5 eV (electron volts) and 4.33 eV (electron volts), respectively, which are close to the work function of Ag, 4.26 eV (electron volts), and can be used as components of anode materials. In a preferred embodiment, the support layer is prepared from metallic zinc and metallic bismuth. An important feature of zinc-bismuth alloys is that they have a low melting point, which allows them to be melted and used at relatively low temperatures, reducing energy consumption and being suitable for applications requiring low melting point properties. With good fluidity and low cost, zinc and bismuth are more economical than some precious metals, so zinc-bismuth alloys are cost competitive.

[0076] In some embodiments, Figure 3 and Figure 4As shown, the support layer 13 uniformly covers the side of the total reflection layer 12 away from the first conductive layer 11 and the exposed peripheral side of the total reflection layer 12, and the second conductive layer 14 uniformly covers the side of the total reflection layer 12 away from the first conductive layer 11 and the exposed peripheral side of the support layer 13. In other embodiments, the support layer 13 and the second conductive layer 14 uniformly cover the side of the total reflection layer 12 away from the first conductive layer 11 and the exposed peripheral side of the total reflection layer 12. In this way, it is ensured that the total reflection layer (i.e., the silver layer) can be uniformly covered and wrapped, thereby preventing leakage and oxidation or damage, and improving the stability of the anode.

[0077] In some embodiments, Figure 3 and Figure 4 As shown, the support layer 13 covers the total reflection layer 12, and the edge of the support 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 support 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 support layer 13 and the first conductive layer 11 together cover and envelop 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 support layer 13, and the edge of the second conductive layer 14 covers the side wall of the support 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 support layer 13 and the total reflection layer 12. On the basis of the support 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 support layer 13 , and between the support 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 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 the composite anode 10. Figure 5 and Figure 6 As shown, the following steps are included:

[0090] S10, providing a light-transmitting conductive oxide and a zinc alloy;

[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 zinc alloy on a side of the total reflection layer 12 away from the first conductive layer 11 to form a zinc alloy layer;

[0094] S50, depositing a light-transmitting conductive oxide on a side of the zinc alloy layer away from the first conductive layer 11;

[0095] S60, developing, exposing and etching the first conductive layer 11, the total reflection layer 12 and the zinc alloy layer, forming a support layer 13 covering the total reflection layer 12 on the side of the total reflection layer 12 away from the first conductive layer 11, and forming a second conductive layer 14 covering the support layer 13 on the side of the support layer 13 away from the first conductive layer 11.

[0096] Compared with the existing anode structure, the preparation method of the composite anode 10 provided in the embodiment of the present application covers a support layer 13 on the total reflection layer 12. Due to the low melting point of zinc alloy, during the patterning process, when the total reflection layer 12 shrinks inwardly inside the sandwich, the upper support 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 support layer 13, thereby ensuring that the support 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.

[0097] In applications, such as Figure 3 and Figure 4As shown, the materials of the composite anode 10 are ITO (~150 angstroms)-zinc alloy (~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 approximately. 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 zinc alloy and silver layers. The silver layer acts as a total reflection layer 12, which 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 upper and lower ITO layers. Improve mechanical stability: The zinc alloy layer and the lower ITO layer provide additional mechanical protection, reducing the risk of the silver layer breaking due to external stress.

[0098] In step S10, the light-transmitting conductive oxide is indium tin oxide, and the zinc alloy includes but is not limited to zinc-bismuth alloy, zinc-aluminum alloy, zinc-magnesium alloy, zinc-titanium alloy, and zinc-copper alloy.

[0099] 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 .

[0100] In steps S40 and S50, a zinc alloy is disposed on the side of the total reflection layer 12 away from the first conductive layer 11, and a light-transmitting conductive oxide is deposited on the side of the zinc alloy layer away from the first conductive layer 11 to facilitate subsequent photolithography processes, thereby obtaining corresponding support layers and second conductive layers.

[0101] In some embodiments, the etching rate of the first conductive layer is not greater than the etching rate of the second conductive layer, and the melting temperature of the first conductive layer is greater than the melting temperature of the support layer. In other words, under the same etching solution, the etching rate of the first conductive layer is less than or equal to the second conductive layer. In this way, the first conductive layer 11 can be made of an inert conductor material other than ITO material, and it only needs to have an etching 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 support 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.

[0102] like Figure 6 As shown, in the embodiment of the present application, step S60 includes:

[0103] S61, after developing and exposing the above layer structure (i.e., the first conductive layer 11, the total reflection layer 12, the support layer 13, and the second conductive layer 14), etching is performed at a first temperature to complete patterning of the composite anode;

[0104] S62, continuing etching at the second temperature to form a support layer 13 covering the total reflection layer 12 and a second conductive layer 14 covering the support layer 13;

[0105] The second temperature is greater than the melting point of the support layer 13 .

[0106] In application, the first temperature is room temperature, ranging from 0°C to 30°C. The support layer 13 is made of zinc alloy, and the melting point of zinc alloy is lower than 300°C, so the second temperature is any value greater than or equal to 300°C. In order to save energy and reduce costs, the second temperature can be controlled at 300°C.

[0107] In some embodiments, before continuing etching at the second temperature, the process includes:

[0108] First, the first temperature is used for etching, and the edge of the total reflection layer 12 shrinks by 0.1 μm to 0.2 μm toward the middle. Under the same etching solution, the total reflection layer 12, i.e., the silver layer, the support layer 13, and the second conductive layer 14, have different etching rates, and the Ag layer is faster. Therefore, after the total reflection layer 12 shrinks by 0.1 μm to 0.2 μm from the circumference to the middle, the support layer 13 begins to collapse with the shrinkage of the Ag layer, thereby covering the Ag layer. Similarly, the second conductive layer 14 collapses with the collapse of the support layer 13, uniformly covering the support layer 13, thereby ensuring uniform coverage and wrapping of the Ag layer. In this way, the support layer 13 can slowly collapse with the shrinkage of the Ag layer, so as not to generate cracks, thereby causing the support layer 13 to be unable to cover and wrap the total reflection layer. Furthermore, the support layer 13 slowly deforms, which also provides effective support for the collapse of the second conductive layer 14. The second conductive layer 14 deforms and collapses with the support layer 13, thereby fully and evenly covering and wrapping the total reflection layer 12. The use of the second temperature etching can also be understood as heating the entire composite anode 10 structure, and the temperature range is 300°C and above.

[0109] 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;

[0110] The insulating layer 30 is disposed on one side of the substrate 20;

[0111] 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;

[0112] The light emitting layer 40 is disposed on a side of the composite anode 10 away from the substrate 20;

[0113] The cathode 50 is disposed on a side of the light emitting layer 40 away from the substrate 20 .

[0114] 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.

[0115] 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.

[0116] 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:

[0117] 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). 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 function of the electron injection layer is to improve the injection efficiency of electrons from the cathode 50 to the electron transport layer. The cathode 50 is used to inject electrons into the OLED and is usually a metal or alloy such as aluminum, magnesium or lithium.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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 method for preparing a composite anode, characterized in that: The following steps are involved: Provide light-transmitting conductive oxides and zinc alloys; 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; Disposing the zinc alloy on a side of the total reflection layer away from the first conductive layer to form a zinc alloy layer; Depositing the light-transmitting conductive oxide on a side of the zinc alloy layer away from the first conductive layer; Developing, exposing and etching the first conductive layer, the total reflection layer and the zinc alloy layer, forming a support layer covering the total reflection layer on a side of the total reflection layer away from the first conductive layer, and forming a second conductive layer covering the support layer on a side of the support layer away from the first conductive layer; The developing, exposing and etching the first conductive layer, the total reflection layer and the zinc alloy layer comprises: After developing and exposing the first conductive layer, the total reflection layer and the zinc alloy layer, etching is performed at a first temperature to complete patterning of the composite anode; Continue etching at a second temperature to form a support layer covering the total reflection layer and a second conductive layer covering the support layer; Wherein, the second temperature is greater than the melting point of the support layer; The etching speed of the first conductive layer is not greater than the etching speed of the second conductive layer, and the melting temperature of the first conductive layer is greater than the melting temperature of the supporting layer.

2. The preparation method according to claim 1, characterized in that Before continuing etching at the second temperature, the method comprises: The first temperature etching is adopted first, and the edge of the total reflection layer is reduced by 0.1 μm to 0.2 μm toward the middle.

3. A composite anode, characterized in that: The composite anode is prepared by the preparation method according to claim 1 or 2, and comprises: a first conductive layer; A total reflection layer, disposed on one side of the first conductive layer; a supporting layer, disposed on a side of the total reflection layer away from the first conductive layer, wherein an edge of the supporting layer is connected to the first conductive layer; and A second conductive layer is provided on a side of the support layer away from the first conductive layer, and an edge of the second conductive layer is connected to the first conductive layer; Wherein, the support layer comprises zinc alloy.

4. The composite anode according to claim 3, characterized in that The support layer comprises: 90% to 99% of metallic zinc and 1% to 10% of at least one of metallic bismuth, metallic aluminum, metallic copper, metallic magnesium, and metallic titanium.

5. The composite anode according to claim 3, characterized in that The supporting layer uniformly covers a side of the total reflection layer away from the first conductive layer and an exposed peripheral side of the total reflection layer, and the second conductive layer uniformly covers a side of the total reflection layer away from the first conductive layer and an exposed peripheral side of the supporting layer; Alternatively, the support layer and the second conductive layer uniformly cover a side of the total reflection layer away from the first conductive layer and an exposed peripheral side of the total reflection layer.

6. The composite anode according to claim 3, 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 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.

7. A display panel, characterized in that: include: substrate; An insulating layer, disposed on one side of the substrate; A composite anode obtained by the preparation method according to claim 1 or 2, or a composite anode according to any one of claims 3 to 6, 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; 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.

8. A display device, characterized in that: include: The display panel as claimed in claim 7; A housing, wherein the display panel is arranged in the housing.

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