Display panel, electronic device, and method for manufacturing display panel

Abstract

The embodiments of the present disclosure provide a display panel, an electronic device, and a method for preparing a display panel, wherein the display panel includes: an anode and a first auxiliary electrode whose positions are defined by a pixel defining layer, the orthographic projection of the first auxiliary electrode on a first plane surrounds the orthographic projection of the anode on the first plane, and the first plane is parallel to the plane where the first electrode layer is located; a second auxiliary electrode and a third auxiliary electrode are provided on the first auxiliary electrode, the third auxiliary electrode is connected to the first auxiliary electrode, the second auxiliary electrode is embedded in the third auxiliary electrode, the second auxiliary electrode is a second conductive material having a surface roughness greater than the first roughness, and the third auxiliary electrode is a third conductive material having a surface roughness less than the first roughness; the second auxiliary electrode is embedded in the luminescent material layer provided on the third auxiliary electrode, and the second auxiliary electrode is embedded in the second electrode layer; the first auxiliary electrode and the second electrode layer are connected to a first voltage signal.

Description

Technical Field

[0001] The present disclosure relates to the field of display, and in particular to a display panel, an electronic device, and a method for manufacturing a display panel. Background Art

[0002] Top-emitting OLEDs require a transparent or translucent cathode, but in large-size products, the high resistance of the transparent electrode or the low thickness uniformity of the translucent electrode will cause a voltage drop (i.e., IRDrop) between the middle and peripheral areas of the display panel. Normally, the display image will appear dark in the middle and bright at the edges, which will affect the product image quality and reduce product performance. Summary of the Invention

[0003] In view of this, the embodiments of the present disclosure propose a display panel, an electronic device, and a method for preparing a display panel to solve the following problems in the prior art: there is a voltage drop between the middle area and the peripheral area of ​​a large-size display panel. Under normal circumstances, the display image will appear dark in the middle and bright at the edges, which in turn affects the product image quality and reduces product performance.

[0004] On the one hand, an embodiment of the present disclosure proposes a display panel, comprising: a pixel driving structure layer and a pixel light-emitting structure layer, wherein the pixel light-emitting structure layer is arranged on the pixel driving structure layer; the pixel light-emitting structure layer comprises: a first electrode layer, a pixel defining layer, a light-emitting material layer, and a second electrode layer; the first electrode layer comprises: an anode and a first auxiliary electrode, wherein the anode and the first auxiliary electrode are positioned by the pixel defining layer, and the positive projection of the first auxiliary electrode on the first plane surrounds the positive projection of the anode on the first plane, wherein the first plane is parallel to the plane where the first electrode layer is located; a second auxiliary electrode and a third auxiliary electrode are arranged on the first auxiliary electrode, and the third auxiliary electrode The first auxiliary electrode is connected to the first auxiliary electrode, and the second auxiliary electrode is embedded in the third auxiliary electrode, wherein the second auxiliary electrode is a second conductive material with a surface roughness greater than the first roughness, and the third auxiliary electrode is a third conductive material with a surface roughness less than the first roughness; the light-emitting material layer is arranged on the first electrode layer and the pixel defining layer, and the second electrode layer is arranged on the light-emitting material layer, wherein the second auxiliary electrode is embedded in the light-emitting material layer arranged on the third auxiliary electrode, and the second auxiliary electrode is embedded in the second electrode layer; the first auxiliary electrode is connected to a first voltage signal, and the first voltage signal is used to provide voltage to the second electrode layer.

[0005] In some embodiments, the first roughness ranges from 0.1 um to 10 um.

[0006] In some embodiments, the conductivity of the third auxiliary electrode is greater than the conductivity of the second auxiliary electrode, and the conductivity of the first auxiliary electrode is greater than the conductivity of the third auxiliary electrode.

[0007] In some embodiments, the second auxiliary electrode has a filamentous structure.

[0008] In some embodiments, the material of the second auxiliary electrode includes at least one of the following: carbon nanotubes and silver nanotubes.

[0009] In some embodiments, the material of the third auxiliary electrode includes at least one of the following: polyethylene dioxythiophene (PEDOT) and copper phthalocyanine (CuPc).

[0010] In some embodiments, the pixel definition layer includes: a first pixel definition sublayer and a second pixel definition sublayer, the first pixel definition sublayer is connected to the pixel driving structure layer, the second pixel definition sublayer is connected to the first pixel definition sublayer, and the coverage range of the orthographic projection of the second pixel definition sublayer on the first plane is greater than the coverage range of the orthographic projection of the first pixel definition sublayer on the first plane.

[0011] In some embodiments, a disconnected structure is formed between the light emitting material layer disposed on the anode and the third auxiliary electrode and the light emitting material layer disposed on the pixel defining layer.

[0012] On the other hand, an embodiment of the present disclosure provides an electronic device, including: the display panel provided by any embodiment of the present disclosure.

[0013] On the other hand, an embodiment of the present disclosure proposes a method for preparing a display panel, which is used to prepare the display panel provided by any embodiment of the present disclosure, including: preparing a first electrode layer on a pixel driving structure layer to obtain a first display substrate, wherein the first electrode layer includes: an anode and a first auxiliary electrode; preparing a pixel defining layer on the first display substrate to obtain a second display substrate; preparing a second auxiliary electrode layer and a third auxiliary electrode layer on the second display substrate to obtain a third display substrate; preparing a light-emitting material layer on the third display substrate to obtain a fourth display substrate; and preparing a second electrode layer on the fourth display substrate to obtain a display panel.

[0014] In the embodiment of the present disclosure, a second auxiliary electrode and a third auxiliary electrode are arranged on the first auxiliary electrode. The first auxiliary electrode is connected to the power supply voltage signal of the second electrode layer. The first auxiliary electrode is also connected to the second electrode layer through the second auxiliary electrode and the third auxiliary electrode. The surface roughness of the second auxiliary electrode is relatively high, and it can be embedded in the subsequently formed light-emitting material layer and the second electrode layer, providing better conductivity. The third auxiliary electrode can assist in establishing a good connection between the rough second auxiliary electrode and the first auxiliary electrode, thereby ensuring that the auxiliary electrodes including the three structures as a whole can better conduct electricity, so that the brightness displayed at various positions of the display panel is consistent, solving the problem of poor display caused by voltage drop between the edge and middle parts of the large-size display panel, and improving the product performance of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 3T1C circuit structure diagram provided for related technologies;

[0017] Figure 2 A schematic diagram of a partial cross-sectional structure of a display panel provided in the first embodiment of the present disclosure;

[0018] Figure 3 A schematic diagram of resistance decreasing as the number of spraying times increases according to the first embodiment of the present disclosure;

[0019] Figure 4 SEM photograph of the carbon nanotubes provided in the first embodiment of the present disclosure;

[0020] Figure 5 SEM photograph of the silver nanotubes provided in the first embodiment of the present disclosure;

[0021] Figure 6 A front schematic diagram of a display panel provided in the first embodiment of the present disclosure;

[0022] Figure 7 A schematic cross-sectional view of a display panel according to a first embodiment of the present disclosure;

[0023] Figure 8 A schematic diagram of a partial cross-sectional structure of a display panel provided in a second embodiment of the present disclosure;

[0024] Figure 9A schematic cross-sectional view of a prepared pixel driving structure layer provided in the third embodiment of the present disclosure;

[0025] Figure 10 A schematic cross-sectional view of a first display substrate provided in a third embodiment of the present disclosure;

[0026] Figure 11 A schematic cross-sectional view of a second display substrate provided in a third embodiment of the present disclosure;

[0027] Figure 12 A schematic cross-sectional view of a third display substrate during the preparation process provided in the third embodiment of the present disclosure;

[0028] Figure 13 This is a schematic cross-sectional view of a third display substrate provided in the third embodiment of the present disclosure.

[0029] Reference numerals:

[0030] 1-pixel driving structure layer, 2-pixel light-emitting structure layer, 3-first electrode layer, 4-pixel defining layer, 5-luminescent material layer, 6-second electrode layer, 7-second auxiliary electrode, 8-third auxiliary electrode;

[0031] 31- anode, 32- first auxiliary electrode;

[0032] 41 - a first pixel defining sublayer, 42 - a second pixel defining sublayer. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0034] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by persons of ordinary skill in the field to which this disclosure belongs. The words "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0035] In order to keep the following description of the embodiments of the present disclosure clear and concise, the present disclosure omits detailed descriptions of known functions and known components.

[0036] On large-size products, due to the high resistance of the transparent electrode or the low thickness uniformity of the semi-transparent electrode, there will be a voltage drop (i.e., IR Drop) between the center and peripheral areas of the display panel. Usually, the display image will appear dark in the middle and bright at the edges, which will affect the product image quality and reduce product performance. In addition, in cases such as Figure 1 In the 3T1C circuit structure diagram shown, for the nmos DTFT, the OLED cathode voltage drop will affect the S voltage of the DTFT and will also have a significant impact on the current control of the DTFT.

[0037] Based on the above considerations, the first embodiment of the present disclosure provides a display panel, the partial cross-sectional structure of which is shown as follows: Figure 2 Shown, including:

[0038] A pixel driving structure layer 1 and a pixel light emitting structure layer 2, wherein the pixel light emitting structure layer 2 is arranged on the pixel driving structure layer 1;

[0039] The pixel light emitting structure layer 2 includes: a first electrode layer 3, a pixel defining layer 4, a light emitting material layer 5, and a second electrode layer 6;

[0040] The first electrode layer 3 includes: an anode 31 and a first auxiliary electrode 32. The positions of the anode and the first auxiliary electrode are defined by a pixel defining layer 4. The orthographic projection of the first auxiliary electrode on the first plane surrounds the orthographic projection of the anode on the first plane. The first plane is parallel to the plane where the first electrode layer is located.

[0041] A second auxiliary electrode 7 and a third auxiliary electrode 8 are provided on the first auxiliary electrode. The third auxiliary electrode is connected to the first auxiliary electrode and the second auxiliary electrode is embedded in the third auxiliary electrode. The second auxiliary electrode is made of a second conductive material having a surface roughness greater than that of the first auxiliary electrode, and the third auxiliary electrode is made of a third conductive material having a surface roughness less than that of the first auxiliary electrode.

[0042] The light-emitting material layer 5 is provided on the first electrode layer 3 and the pixel defining layer 4, and the second electrode layer 6 is provided on the light-emitting material layer 5, wherein the second auxiliary electrode is embedded in the light-emitting material layer provided on the third auxiliary electrode, and the second auxiliary electrode is embedded in the second electrode layer;

[0043] The first auxiliary electrode is connected to a first voltage signal, and the first voltage signal is used to provide a voltage for the second electrode layer.

[0044] In the embodiment of the present disclosure, a second auxiliary electrode and a third auxiliary electrode are arranged on the first auxiliary electrode. The first auxiliary electrode is connected to the power supply voltage signal of the second electrode layer. The first auxiliary electrode is also connected to the second electrode layer through the second auxiliary electrode and the third auxiliary electrode. The surface roughness of the second auxiliary electrode is relatively high, and it can be embedded in the subsequently formed light-emitting material layer and the second electrode layer, providing better conductivity. The third auxiliary electrode can assist in establishing a good connection between the rough second auxiliary electrode and the first auxiliary electrode, thereby ensuring that the auxiliary electrodes including the three structures as a whole can better conduct electricity, so that the brightness displayed at various positions of the display panel is consistent, solving the problem of poor display caused by voltage drop between the edge and middle parts of the large-size display panel, and improving the product performance of the display panel.

[0045] As long as the third auxiliary electrode can play its role in reducing the contact resistance between the second auxiliary electrode and the first auxiliary electrode (and / or the second electrode layer), when specifically set, the thickness of the third auxiliary electrode is generally preferably set to be smaller than the thickness of the second auxiliary electrode. Of course, the thickness of the third auxiliary electrode can also be the same as the thickness of the second auxiliary electrode. Since the second auxiliary electrode has a higher surface roughness, the third auxiliary electrode is not completely flat. After the light-emitting material layer is prepared, the material of the light-emitting material layer will also be embedded in the second auxiliary electrode and the third auxiliary electrode.

[0046] In a preferred embodiment, the conductivity of the third auxiliary electrode may be greater than that of the second auxiliary electrode, and the conductivity of the first auxiliary electrode may be greater than that of the third auxiliary electrode, thereby ensuring a better conductive effect.

[0047] For the first auxiliary electrode, the same material and film thickness as the OLED anode (i.e., the anode of the first electrode layer) can be selected, such as ITO (8nm) / Ag (100nm) / ITO (8nm). Of course, other materials can also be selected, such as Cu, Al, etc., or composite film layers such as Al / ITO, etc. The film thickness can be 5nm-5000nm.

[0048] For the second auxiliary electrode, the second auxiliary electrode can be made of a high-roughness material, that is, the roughness is greater than the first roughness. The value range of the first roughness can be 0.1um-10um. Figure 2 As shown, the second auxiliary electrode has a filamentous structure, which forms a film with a relatively large surface roughness. Correspondingly, the surface roughness of the first and third auxiliary electrodes should be at least less than 0.1 μm, thus having a smoother surface than the second auxiliary electrode.

[0049] The material of the second auxiliary electrode can be carbon nanotubes (CNTs). The resistance of a single layer of CNT is shown in Table 1 below (resistance of a single layer of CNT prepared by different processes). If the resistance needs to be reduced, the thickness of the CNT film can be increased. Figure 3 A schematic diagram showing the decrease in resistance as the number of spraying times increases is shown.

[0050] Table 1

[0051]

[0052] The SEM (scanning electron microscope) photos of the above carbon nanotubes can be referred to Figure 4 Usually, the overlapping of CNTs will cause the surface roughness of CNTs to increase. Due to the increase in the surface roughness of CNTs, the light-emitting material layer (i.e., the EL organic film layer of OLED) cannot completely cover the CNTs, which will cause the CNTs to be conductive with the OLED cathode (i.e., the second electrode layer). Some structures of the second auxiliary electrode are embedded in the second electrode layer, thereby producing the effect of an auxiliary electrode of the second electrode layer.

[0053] When selecting CNT materials, they can be selected based on predetermined parameters (m and n below). For single-walled carbon nanotubes (SWCNTs) with n=m, the conduction band and valence band overlap, and the tube is a metallic tube with a zero band gap; for nm=3q (q is an integer), the SWCNT is a semi-metallic tube with a very small band gap; and for n–m=3q±1 (q is a positive integer), the electronic state density in the SWCNT exhibits a significant band gap near the Fermi level, and is referred to as a semiconductor tube. Here, n and m are a pair of integers, often referred to as the chiral index of the SWCNT. At room temperature, both metallic and semi-metallic SWCNTs exhibit metallic properties. In this patent, the CNT acts as a conductor, so the material needs to be metallic CNT.

[0054] The material used to form the second auxiliary electrode film layer can be a water-based CNT mixture dispersed in a liquid and modified with a surfactant to reduce CNT resistance. The CNTs have a diameter of 0.5nm-3nm. Spin coating, spray coating, or other methods can be used to form the CNT film (i.e., the second auxiliary electrode). The film formation speed and density are controlled by adjusting the surfactant and CNT concentrations. The linear density of the CNTs is greater than 30 / μm. High temperatures of 300°C-400°C are required to remove the surfactant, as residual surfactant can affect electrical properties. The film uniformity and stability are controlled by monitoring the CNT concentration and material compensation. The resulting film has good adhesion and a transmittance of 87%-90% when the CNT thickness is 10nm.

[0055] The material of the second auxiliary electrode may also be silver nanotubes (AgNW). The resistance of AgNW is shown in Table 2 below (resistance of AgNW with different thicknesses).

[0056] Table 2

[0057]

[0058] The SEM images of AgNW are shown in Figure 2. Figure 5 As shown in FIG, since the diameter of the AgNW is relatively thick, the EL organic film layer cannot completely cover it, so the AgNW will be connected to the cathode of the OLED, thereby generating an auxiliary electrode effect of the second electrode layer.

[0059] The third auxiliary electrode is used to reduce the contact resistance between the high-roughness material and the first auxiliary electrode and the OLED cathode. The material may be polyethylene dioxythiophene (PEDOT), copper phthalocyanine (CuPc) or other materials with good conductivity.

[0060] Figure 6 Shown Figure 2 Front view of the display panel with a mid-section structure. Figure 2 In the embodiment, each anode is surrounded by a first auxiliary electrode, and the first auxiliary electrodes surrounding the respective anodes are connected. Figure 6 This is only a possible structural diagram. The first auxiliary electrodes surrounding each anode can also be independent of each other and not connected to each other. The anode area composed of multiple anodes can also be surrounded by only one first auxiliary electrode. It will not be repeated here.

[0061] There is no improvement on the pixel driving structure layer, which may include PLN (flat layer), ILD (inorganic dielectric layer), GI1 (insulating layer), GI2 (insulating layer), Buffer (buffer layer) and Fan Out (fan-out line), Active (semiconductor layer), Data (data signal) and other film layers, which are all conventional TFT film layers. Subtract (substrate / base) may be Glass (glass) or PI (polyimide). The display panel including the specific pixel driving structure layer may be as follows: Figure 7 shown.

[0062] The second embodiment of the present disclosure provides a display panel, the partial cross-sectional structure of which is shown as follows: Figure 8 Shown, including:

[0063] A pixel driving structure layer 1 and a pixel light emitting structure layer 2, wherein the pixel light emitting structure layer 2 is arranged on the pixel driving structure layer 1;

[0064] The pixel light emitting structure layer 2 includes: a first electrode layer 3, a pixel defining layer 4, a light emitting material layer 5, and a second electrode layer 6;

[0065] The pixel definition layer 4 includes: a first pixel definition sublayer 41 and a second pixel definition sublayer 42, wherein the first pixel definition sublayer is connected to the pixel driving structure layer, and the second pixel definition sublayer is connected to the first pixel definition sublayer, and the coverage of the orthographic projection of the second pixel definition sublayer on the first plane is larger than the coverage of the orthographic projection of the first pixel definition sublayer on the first plane;

[0066] The first electrode layer 3 includes: an anode 31 and a first auxiliary electrode 32. The positions of the anode and the first auxiliary electrode are defined by a pixel defining layer 4. The orthographic projection of the first auxiliary electrode on the first plane surrounds the orthographic projection of the anode on the first plane. The first plane is parallel to the plane where the first electrode layer is located.

[0067] A second auxiliary electrode 7 and a third auxiliary electrode 8 are provided on the first auxiliary electrode. The third auxiliary electrode is connected to the first auxiliary electrode and the second auxiliary electrode is embedded in the third auxiliary electrode. The second auxiliary electrode is made of a second conductive material having a surface roughness greater than that of the first auxiliary electrode, and the third auxiliary electrode is made of a third conductive material having a surface roughness less than that of the first auxiliary electrode.

[0068] The light-emitting material layer 5 is provided on the first electrode layer 3 and the pixel defining layer 4, and the second electrode layer 6 is provided on the light-emitting material layer 5, wherein the second auxiliary electrode is embedded in the light-emitting material layer provided on the third auxiliary electrode, and the second auxiliary electrode is embedded in the second electrode layer;

[0069] The first auxiliary electrode is connected to a first voltage signal, and the first voltage signal is used to provide a voltage for the second electrode layer.

[0070] Compared with the first embodiment, the embodiment of the present disclosure defines the pixel definition layer (PDL). The PDL includes two substructures PDL1 (i.e., the first pixel definition sublayer 41) and PDL2 (i.e., the second pixel definition sublayer 42). PDL1 and PDL2 form a Rib structure (i.e., a double-layer trapezoidal structure that is narrow at the top and wide at the bottom and empty in the middle). The PDL can isolate the film layer with higher mobility in the EL organic film layer, thereby improving the display quality (such as color gamut) of the display product. Since the isolation ability of the PDL structure is strong, it is necessary to control the thickness of PDL1 and PDL2, and the thickness usually needs to be controlled within 5nm-500nm. The material of PDL1 and PDL2 can be organic material, such as polyurethane, or inorganic material, such as SiO, SiN, Al2O3, etc. By controlling the preparation process, a Rib structure or an undercut structure (the pixel definition layer structure in the first embodiment) is formed to form a partition of the EL organic film layer. The Rib structure solves the problem of high conductivity of CGL (charge generation layer) in Tandem (series) devices that easily causes crosstalk.

[0071] Depend on Figure 8 It can be seen that in order to ensure that there is no crosstalk problem in the display, the embodiment of the present disclosure provides a disconnection structure between the light-emitting material layer arranged on the anode and the third auxiliary electrode and the light-emitting material layer arranged on the pixel defining layer, that is, the light-emitting material layer is discontinuous between the pixel area and the non-pixel area.

[0072] In the embodiment of the present disclosure, a second auxiliary electrode and a third auxiliary electrode are arranged on the first auxiliary electrode. The first auxiliary electrode is connected to the power supply voltage signal of the second electrode layer. The first auxiliary electrode is also connected to the second electrode layer through the second auxiliary electrode and the third auxiliary electrode. The surface roughness of the second auxiliary electrode is relatively high, and it can be embedded in the subsequently formed light-emitting material layer and the second electrode layer, providing better conductivity. The third auxiliary electrode can assist in establishing a good connection between the rough second auxiliary electrode and the first auxiliary electrode, thereby ensuring that the auxiliary electrodes including the three structures as a whole can better conduct electricity, so that the brightness displayed at each position of the display panel is consistent, solving the problem of poor display caused by voltage drop between the edge and middle parts of the large-size display panel, and because the pixel junction layer is a double-layer trapezoidal structure, the display panel will not have crosstalk problems, thereby improving the product performance of the display panel.

[0073] The PDL structure provided in the first embodiment of the present disclosure is a trapezoidal PDL structure, which can be applied to Single RGBOLED display products without the need to isolate the film layer. The PDL structure in the second embodiment is a double-layer trapezoidal PDL structure, which can be applied to Tandem devices. Regardless of the device, it is suitable for the auxiliary electrode of the three-layer structure of the embodiment of the present disclosure.

[0074] A third embodiment of the present disclosure provides a method for preparing a display panel, which is used to prepare the display panel of the above embodiment (taking the preparation of the display panel of the second embodiment as an example), and the preparation process includes the following steps (1) to (4):

[0075] (1) A first electrode layer is prepared on the pixel driving structure layer to obtain a first display substrate, wherein the first electrode layer includes: an anode and a first auxiliary electrode.

[0076] Figure 9 The cross-sectional diagram of the prepared pixel driving structure layer is shown in FIG. Figure 9 Prepare the first electrode layer based on Figure 10 The first display substrate shown has the anode and the first auxiliary electrode prepared.

[0077] (2) Preparing a pixel defining layer on the first display substrate to obtain a second display substrate.

[0078] The pixel definition layer of the embodiment of the present disclosure includes two layers. The prepared second display substrate can be Figure 11 shown.

[0079] (3) A second auxiliary electrode layer and a third auxiliary electrode layer are formed on the second display substrate to obtain a third display substrate.

[0080] The preparation method of the second auxiliary electrode layer includes at least one of the following: spin coating, scraping, spraying; the preparation method of the third auxiliary electrode includes at least one of the following: printing, evaporation.

[0081] The third auxiliary electrode can be prepared before or after the second auxiliary electrode. Since the second auxiliary electrode is a film layer with a filamentous structure, the third auxiliary electrode can be connected to the first auxiliary electrode regardless of the preparation order.

[0082] Figure 12 Schematic diagram of the preparation of the second auxiliary electrode. Figure 13 This is a schematic diagram of the completed preparation of the third auxiliary electrode. After the preparation is completed, the third display substrate is obtained.

[0083] (4) preparing a light-emitting material layer on the third display substrate to obtain a fourth display substrate, and preparing a second electrode layer on the fourth display substrate to obtain Figure 8 display panel.

[0084] In order to achieve large-size screen design on the top-emitting OLED structure, the embodiment of the present disclosure adopts a highly transparent transparent electrode (cathode, i.e., the second electrode layer). At the same time, in order to prevent IR Drop, a graphic auxiliary electrode in the form of wiring under the substrate is used. It should be noted that the auxiliary electrode of the embodiment of the present disclosure includes three structures: one is the second auxiliary electrode, which is a conductive film layer with a rough surface (such as carbon nanotubes CNT, silver nanowires, etc.), which can be connected to the cathode through the EL organic film layer (i.e., the light-emitting material layer); the contact resistance between the second auxiliary electrode and the metal film layer (i.e., the first auxiliary electrode) is large. In order to reduce the contact resistance, the embodiment of the present disclosure prepares a contact resistance reducing film layer on the metal film layer, i.e., the third auxiliary electrode; the other structure is a metal film layer (i.e., the first auxiliary electrode) of a high conductivity film, such as Ag, Al, etc., which can improve the conductivity of the auxiliary electrode.

[0085] An embodiment of the present disclosure further provides an electronic device, which includes the display panel in any of the above embodiments. The structure of the display panel is not described in detail here.

[0086] The embodiment of the present disclosure achieves the technical effect of connecting the OLED cathode to the first auxiliary electrode of the backplane by means of the technical means of adding a second auxiliary electrode with high roughness (such as CNT, AgNW) in the first auxiliary electrode, thereby solving the technical problem of IR drop caused by the large resistance of the OLED cathode; and the embodiment of the present disclosure reduces the contact resistance between the high-roughness film layer and the OLED cathode and auxiliary electrode by preparing a transition film layer above the high-roughness film layer, thereby achieving the technical effect of reducing the connection resistance between the OLED cathode and the auxiliary electrode, thereby solving the technical problem of severe IR drop caused by the large resistance of the OLED cathode.

[0087] Furthermore, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on the present disclosure with equivalent elements, modifications, omissions, combinations (e.g., solutions that intersect various embodiments), adaptations, or changes. The elements in the claims are to be interpreted broadly based on the language employed in the claims and are not limited to the examples described in this specification or during the prosecution of this application, which examples are to be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered as examples only, with the true scope and spirit being indicated by the following claims and the full scope of their equivalents.

[0088] The above description is intended to be illustrative and not restrictive. For example, the above examples (or one or more schemes thereof) can be used in combination with each other. For example, a person of ordinary skill in the art may use other embodiments when reading the above description. In addition, in the above-mentioned specific embodiments, various features can be grouped together to simplify the present disclosure. This should not be interpreted as an intention that a disclosed feature that is not required to be protected is necessary for any claim. On the contrary, the subject matter of the present disclosure may be less than all the features of a specific disclosed embodiment. Thus, the following claims are incorporated into the specific embodiments as examples or embodiments, wherein each claim is independently a separate embodiment, and it is considered that these embodiments can be combined with each other in various combinations or arrangements. The scope of the present disclosure should be determined with reference to the appended claims and the full scope of equivalents to which these claims are entitled.

[0089] The above describes in detail multiple embodiments of the present disclosure, but the present disclosure is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications to the embodiments based on the concepts of the present disclosure, and these variations and modifications should all fall within the scope of protection claimed by the present disclosure.

Claims

1. A display panel, characterized in that: include: A pixel driving structure layer and a pixel light emitting structure layer, wherein the pixel light emitting structure layer is arranged on the pixel driving structure layer; The pixel light emitting structure layer includes: a first electrode layer, a pixel defining layer, a light emitting material layer, and a second electrode layer; The first electrode layer includes: an anode and a first auxiliary electrode, wherein the positions of the anode and the first auxiliary electrode are defined by the pixel defining layer, and the orthographic projection of the first auxiliary electrode on a first plane surrounds the orthographic projection of the anode on the first plane, wherein the first plane is parallel to the plane where the first electrode layer is located; A second auxiliary electrode and a third auxiliary electrode are provided on the first auxiliary electrode, the third auxiliary electrode is connected to the first auxiliary electrode, and the second auxiliary electrode is embedded in the third auxiliary electrode, wherein the second auxiliary electrode is made of a second conductive material having a surface roughness greater than the first roughness, and the third auxiliary electrode is made of a third conductive material having a surface roughness less than the first roughness; The light-emitting material layer is provided on the first electrode layer and the pixel defining layer, and the second electrode layer is provided on the light-emitting material layer, wherein the second auxiliary electrode is embedded in the light-emitting material layer provided on the third auxiliary electrode, and the second auxiliary electrode is embedded in the second electrode layer; The first auxiliary electrode is connected to a first voltage signal, and the first voltage signal is used to provide a voltage for the second electrode layer.

2. The display panel according to claim 1, wherein The first roughness ranges from 0.1 um to 10 um.

3. The display panel according to claim 1, wherein The conductivity of the third auxiliary electrode is greater than that of the second auxiliary electrode, and the conductivity of the first auxiliary electrode is greater than that of the third auxiliary electrode.

4. The display panel according to claim 1, wherein: The second auxiliary electrode has a filament structure.

5. The display panel according to claim 4, wherein: The material of the second auxiliary electrode includes at least one of the following: carbon nanotubes and silver nanotubes.

6. The display panel according to claim 5, wherein: The material of the third auxiliary electrode includes at least one of the following: polyethylene dioxythiophene and copper phthalocyanine.

7. The display panel according to any one of claims 1 to 6, wherein: The pixel definition layer includes: A first pixel defining sublayer and a second pixel defining sublayer, the first pixel defining sublayer is connected to the pixel driving structure layer, the second pixel defining sublayer is connected to the first pixel defining sublayer, and the coverage of the orthographic projection of the second pixel defining sublayer on the first plane is greater than the coverage of the orthographic projection of the first pixel defining sublayer on the first plane.

8. The display panel according to any one of claims 1 to 6, wherein: A disconnect structure is formed between the light emitting material layer disposed on the anode and the third auxiliary electrode and the light emitting material layer disposed on the pixel defining layer.

9. An electronic device, characterized in that: include: The display panel according to any one of claims 1 to 8.

10. A method for preparing a display panel, for preparing the display panel according to any one of claims 1 to 8, characterized in that: include: Preparing a first electrode layer on the pixel driving structure layer to obtain a first display substrate, wherein the first electrode layer includes: an anode and a first auxiliary electrode; preparing a pixel defining layer on the first display substrate to obtain a second display substrate; forming a second auxiliary electrode layer and a third auxiliary electrode layer on the second display substrate to obtain a third display substrate; preparing a light-emitting material layer on the third display substrate to obtain a fourth display substrate; A second electrode layer is prepared on the fourth display substrate to obtain a display panel.

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