Array substrate, preparation method of array substrate and display panel

Abstract

The array substrate, the preparation method of the array substrate and the display panel provided by the application set the first electrode layer on the light-transmitting substrate, the first electrode layer is a light-transmitting structure; the light-emitting layer is arranged on the first electrode layer; the second electrode layer is arranged on the light-emitting layer, the second electrode layer comprises at least one light-transmitting microstructure and a conductive layer, the conductive layer is arranged on the side of the light-transmitting microstructure away from the light-emitting layer, the light-transmitting microstructure and the conductive layer are in contact to form a reflecting surface, and the reflecting surface is used at least for reflecting the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate, so that the light-emitting efficiency of the light emitted by the light-emitting layer in the array substrate and emitted through the light-transmitting substrate is improved.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to an array substrate, a method for fabricating the array substrate, and a display panel. Background Technology

[0002] Organic Light Emitting Diode (OLED) has gradually become the mainstream technology for display devices due to its advantages such as wide viewing angle, uniform image quality, fast response speed, and low power consumption. However, current technologies are generally limited by the luminous efficiency of the emissive layer, as well as differences in the refractive indices of various film layers and film reflections, resulting in low light extraction efficiency for OLEDs, which in turn affects the power consumption and lifespan of the panel. Therefore, improving the light extraction efficiency of display panels has become a technical problem that needs to be solved. Summary of the Invention

[0003] This application provides an array substrate for improving light extraction efficiency, a method for fabricating the array substrate, and a display panel.

[0004] In a first aspect, an array substrate provided in this application includes a light-transmitting substrate and a plurality of light-emitting units, wherein the light-emitting units include:

[0005] A first electrode layer is disposed on the light-transmitting substrate, and the first electrode layer is a light-transmitting structure.

[0006] A light-emitting layer is disposed on the first electrode layer; and

[0007] A second electrode layer is disposed on the light-emitting layer. The second electrode layer includes at least one light-transmitting microstructure and a conductive layer. The conductive layer is disposed on the side of the light-transmitting microstructure away from the light-emitting layer. The light-transmitting microstructure and the conductive layer are in contact to form a reflective surface. The reflective surface is at least used to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate.

[0008] The array substrate provided in this application embodiment has a first electrode layer disposed on a light-transmitting substrate, the first electrode layer being a light-transmitting structure; a light-emitting layer disposed on the first electrode layer; and a second electrode layer disposed on the light-emitting layer, the second electrode layer including at least one light-transmitting microstructure and a conductive layer, the conductive layer being disposed on the side of the light-transmitting microstructure away from the light-emitting layer, the light-transmitting microstructure and the conductive layer being in contact to form a reflective surface, the reflective surface being used at least to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate, thereby improving the light extraction rate of the light emitted by the light-emitting layer in the array substrate after being emitted through the light-transmitting substrate.

[0009] In one optional implementation, the reflective surface is a spherical surface.

[0010] In one optional embodiment, the light-transmitting microstructure is a microsphere structure; or, the light-transmitting microstructure is a hemispherical structure, wherein the spherical surface of the hemispherical structure is in contact with the conductive layer.

[0011] In one optional embodiment, the light-transmitting microstructure is made of a conductive material, and the light-transmitting microstructure is electrically conductive between the light-emitting layer and the conductive layer.

[0012] In one optional embodiment, the light-transmitting microstructure is made of a non-conductive material, and a portion of the conductive layer is disposed in the gap between the light-transmitting microstructures and is electrically connected to the light-emitting layer.

[0013] In one optional embodiment, the conductive layer is made of a reflective material.

[0014] In one optional embodiment, the light-emitting unit further includes a first injection layer, a first transport layer, a second injection layer, a second transport layer, and the first electrode layer, the first injection layer, the first transport layer, the light-emitting layer, the second transport layer, the second injection layer, the light-transmitting microstructure, and the conductive layer are arranged sequentially.

[0015] In one optional embodiment, the array substrate further includes a driving TFT layer and a pixel definition layer. The driving TFT layer is disposed on the light-transmitting substrate, a plurality of light-emitting units are disposed on the driving TFT layer, the pixel definition layer is disposed in the gap between the plurality of light-emitting units, the driving TFT layer is electrically connected to the first electrode layer, and the conductive layers of at least two light-emitting units are interconnected.

[0016] Secondly, an embodiment of this application provides a method for fabricating an array substrate, the method comprising:

[0017] A first electrode layer is formed in multiple predetermined areas of a light-transmitting substrate;

[0018] A light-emitting layer is formed on the first electrode layer;

[0019] At least one light-transmitting microstructure is formed on the light-emitting layer;

[0020] A conductive layer is formed on the light-transmitting microstructure, and the light-transmitting microstructure and the conductive layer are in contact to form a reflective surface. The reflective surface is at least used to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate.

[0021] The method for fabricating an array substrate provided in this application involves forming a first electrode layer in multiple predetermined regions of a light-transmitting substrate; forming a light-emitting layer on the first electrode layer; forming at least one light-transmitting microstructure on the light-emitting layer; forming a conductive layer on the light-transmitting microstructure; and forming a reflective surface between the light-transmitting microstructure and the conductive layer. The reflective surface is used at least to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate, thereby improving the light extraction efficiency of the light emitted by the light-emitting layer in the array substrate.

[0022] Thirdly, an embodiment of this application provides a display panel including the array substrate described above.

[0023] The display panel provided in this application embodiment is designed such that a first electrode layer is disposed on a light-transmitting substrate in an array substrate, and the first electrode layer is a light-transmitting structure; a light-emitting layer is disposed on the first electrode layer; and a second electrode layer is disposed on the light-emitting layer. The second electrode layer includes at least one light-transmitting microstructure and a conductive layer. The conductive layer is disposed on the side of the light-transmitting microstructure away from the light-emitting layer. The light-transmitting microstructure and the conductive layer are in contact to form a reflective surface. The reflective surface is at least used to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate, thereby improving the light extraction rate of the light emitted by the light-emitting layer in the display panel after being emitted through the light-transmitting substrate. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below.

[0025] Figure 1 This is a schematic diagram of the structure of the display panel provided in an embodiment of this application;

[0026] Figure 2 yes Figure 1 A partial schematic diagram of the array substrate;

[0027] Figure 3 for Figure 2 A schematic diagram of the light-emitting unit shown;

[0028] Figure 4 This is a first schematic diagram of the effect of the light-emitting unit on light provided in the embodiments of this application;

[0029] Figure 5 This is a second schematic diagram of the effect of the light-emitting unit on light provided in the embodiments of this application;

[0030] Figure 6 This is a third schematic diagram of the light-emitting unit's effect on light provided in the embodiments of this application;

[0031] Figure 7 This is a flowchart of the method for fabricating an array substrate provided in an embodiment of this application;

[0032] Figure 8 This is a process diagram of one fabrication of an array substrate provided in an embodiment of this application;

[0033] Figure 9 This is another fabrication process diagram of the array substrate provided in the embodiments of this application.

[0034] Explanation of icon numbers:

[0035] Display panel 100; array substrate 11; light-emitting unit 12; TFT unit 13; light-transmitting substrate 14; light-emitting unit 12; pixel definition layer 15; opening area 15a; first electrode layer 16; light-emitting layer 17; second electrode layer 18; light-transmitting microstructure 19; conductive layer 20; reflective surface 25; first injection layer 21; first transport layer 22; second injection layer 23; second transport layer 24; driving TFT layer 26; passivation layer 28; gate 29; insulating layer 30; active layer 31; source electrode 32; drain electrode 33; conductive via 34. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. In addition, the reference to "embodiment" or "implementation method" in this application means that a specific feature, structure or characteristic described in connection with the embodiment or implementation method can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0037] In describing some embodiments, the term "electrical connection" and its derivative expressions may be used. For example, the term "connection" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact with each other. As another example, the term "electrical connection" may be used in describing some embodiments to indicate that two or more components have physical contact or an electrical signal path, such as two components being connected by a signal line, or other electrical components or circuits existing between the two components, but a signal path exists between them through these other electrical components. However, the term "electrical connection" may also refer to two or more components that do not have direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0038] Please see Figure 1This application provides a display panel 100 with improved light extraction efficiency. The display panel 100 includes, but is not limited to, panels with self-emissive units such as OLEDs. The display panel 100 includes an array substrate 11. The array substrate 11 includes, but is not limited to, a pixel unit array substrate 11. The array substrate 11 has a plurality of pixel units arranged in an array. Each pixel unit includes at least one light-emitting unit 12 and a TFT unit 13. The TFT unit 13 is electrically connected to the anode layer of the light-emitting unit 12, providing an anode voltage to the light-emitting unit 12. The light-emitting unit 12 emits light under the voltage driven between the anode layer and the cathode layer.

[0039] Please see Figure 2 The array substrate 11 includes a light-transmitting substrate 14 and a plurality of light-emitting units 12. A pixel definition layer 15 is located between the plurality of light-emitting units 12. Alternatively, the plurality of light-emitting units 12 are located in the opening area 15a of the pixel definition layer 15.

[0040] Please see Figure 2 The light-emitting unit 12 includes a first electrode layer 16, a light-emitting layer 17, and a second electrode layer 18.

[0041] The first electrode layer 16 is disposed on the light-transmitting substrate 14. It can be understood that the first electrode layer 16 may directly contact the light-transmitting substrate 14 or be disposed on a functional layer on the light-transmitting substrate 14.

[0042] The first electrode layer 16 is a light-transmitting structure. Optionally, the material of the first electrode layer 16 may include, but is not limited to, transparent conductive materials such as indium tin oxide (ITO).

[0043] The light-emitting layer 17 is disposed on the first electrode layer 16. The light-emitting layer 17 may directly contact the first electrode layer 16 or be indirectly disposed on the first electrode layer 16. The material of the light-emitting layer 17 includes, but is not limited to, organic light-emitting materials.

[0044] The second electrode layer 18 is disposed on the light-emitting layer 17. The second electrode layer 18 may directly contact the first electrode layer 16, or be indirectly disposed on the first electrode layer 16.

[0045] Please see Figure 2 The second electrode layer 18 includes at least one light-transmitting microstructure 19 and a conductive layer 20. The conductive layer 20 is disposed on the side of the light-transmitting microstructure 19 opposite to the light-emitting layer 17. The light-transmitting microstructure 19 is in contact with the conductive layer 20, and the contact surface between the light-transmitting microstructure 19 and the conductive layer 20 forms a reflective surface 25. The reflective surface 25 is at least used to reflect the light emitted by the light-emitting layer 17 to be emitted through the light-transmitting substrate 14, thereby increasing the light extraction efficiency from the light-transmitting substrate 14 side.

[0046] Optionally, the second electrode layer 18 of some light-emitting units 12 in the array substrate 11 of the display panel 100 is designed to include a light-transmitting microstructure 19 and a conductive layer 20, so as to improve the light extraction efficiency of some light-emitting units 12 in the display panel 100. Alternatively, the second electrode layer 18 of all light-emitting units 12 in the array substrate 11 of the display panel 100 is designed to include a light-transmitting microstructure 19 and a conductive layer 20, so as to improve the light extraction efficiency of all light-emitting units 12 in the display panel 100.

[0047] When the light-emitting layer 17 emits light under the voltage of the first electrode layer 16 and the second electrode layer 18, the light emitted by the light-emitting layer 17 is emitted in all directions. That is, part of the light is directed towards the first electrode layer 16 and exits through the light-transmitting substrate 14, where the light-transmitting substrate 14 is located, which is the light-emitting side of the display panel 100. The other part of the light emitted by the light-emitting layer 17 is directed towards the second electrode layer 18. In general technology, the light directed towards the second electrode layer 18 causes light loss in the light-emitting layer 17, reducing the light extraction efficiency of the display panel 100. Currently, in order to improve the light extraction efficiency of OLED panels, the thickness of the first electrode layer 16 (e.g., the anode layer) is usually reduced to increase the light extraction brightness. However, reducing the thickness of the first electrode layer 16 may impair the hole injection efficiency.

[0048] The array substrate 11 provided in this application embodiment has a first electrode layer 16 disposed on a light-transmitting substrate 14, the first electrode layer 16 being a light-transmitting structure; a light-emitting layer 17 disposed on the first electrode layer 16; and a second electrode layer 18 disposed on the light-emitting layer 17. The second electrode layer 18 includes at least one light-transmitting microstructure 19 and a conductive layer 20. The conductive layer 20 is disposed on the side of the light-transmitting microstructure 19 facing away from the light-emitting layer 17. The light-transmitting microstructure 19 and the conductive layer 20 are in contact to form a reflective surface 25. The reflective surface 25 is at least used to reflect the light emitted by the light-emitting layer 17. The light emitted from the light-emitting layer 17 is emitted through the light-transmitting substrate 14. Thus, a portion of the light emitted from the light-emitting layer 17 is directly emitted through the first electrode layer 16 and the light-transmitting substrate 14, while another portion is reflected by the reflective surface 25 in the second electrode layer 18 and then emitted through the first electrode layer 16 and the light-transmitting substrate 14. In other words, most or all of the light emitted by the light-emitting layer 17 is emitted from the light-transmitting substrate 14 (the light-emitting side of the display panel 100), thereby increasing the light extraction efficiency of the light emitted from the light-emitting layer 17 in the array substrate 11 through the light-transmitting substrate 14, and thus increasing the light extraction efficiency of the display panel 100. In this embodiment, there is no need to reduce the thickness of the first electrode layer 16, avoiding damage to the hole injection efficiency.

[0049] In one optional embodiment, the first electrode layer 16 is an anode layer and the second electrode layer 18 is a cathode layer. In other words, the anode layer of the light-emitting unit 12 transmits the light emitted by the light-emitting layer 17, and the cathode layer of the light-emitting unit 12 reflects the light emitted by the light-emitting layer 17. In this case, the display panel 100 is a bottom-emitting panel.

[0050] In another alternative embodiment, the first electrode layer 16 is a cathode layer and the second electrode layer 18 is an anode layer. In other words, the cathode layer of the light-emitting unit 12 transmits the light emitted by the light-emitting layer 17, and the anode layer of the light-emitting unit 12 reflects the light emitted by the light-emitting layer 17. In this case, the display panel 100 is a top-emitting panel.

[0051] Optional, please refer to Figure 3 The light-emitting unit 12 further includes a first injection layer 21, a first transport layer 22, a second injection layer 23, and a second transport layer 24. The first electrode layer 16, the first injection layer 21, the first transport layer 22, the light-emitting layer 17, the second transport layer 24, the second injection layer 23, the light-transmitting microstructure 19, and the conductive layer 20 are sequentially arranged. When the first electrode layer 16 is an anode layer and the second electrode layer 18 is a cathode layer, the first injection layer 21 is a hole injection layer, the first transport layer 22 is a hole transport layer, the second injection layer 23 is an electron injection layer, and the second transport layer 24 is an electron transport layer. When the second electrode layer 18 is an anode layer and the first electrode layer 16 is a cathode layer, the second injection layer 23 is a hole injection layer, the second transport layer 24 is a hole transport layer, the first injection layer 21 is an electron injection layer, and the first transport layer 22 is an electron transport layer.

[0052] Optionally, the reflective surface 25 is a spherical surface. In other words, a spherical reflective surface is formed between the light-transmitting microstructure 19 in the second electrode layer 18 and the conductive layer 20. This spherical reflective surface includes a sphere and an ellipsoid.

[0053] Optionally, the conductive layer 20 is made of a reflective material. Specifically, the conductive layer 20 is a reflective metal layer. For example, the conductive layer 20 is made of a material with high reflectivity (visible light), such as silver or aluminum. Furthermore, a highly reflective spherical reflective surface is formed between the light-transmitting microstructure 19 in the second electrode layer 18 and the reflective metal layer.

[0054] For example, please see Figure 3 The second electrode layer 18 includes a light-transmitting microstructure 19 and a conductive layer 20 covering the light-transmitting microstructure 19. Thus, the contact surface between the light-transmitting microstructure 19 and the conductive layer 20 forms a plurality of interconnected microsphere reflective surfaces to spherically reflect the light emitted from the light-emitting layer 17. The light emitted from the light-emitting layer 17 towards the second electrode layer 18 is reflected by the microsphere reflective surfaces and then emitted through the light-transmitting substrate 14.

[0055] In one alternative implementation, please refer to Figure 3The light-transmitting microstructure 19 is a microsphere structure. In other words, the second electrode layer 18 includes a layer of transparent microspheres and a conductive layer 20 disposed on the transparent microspheres. Of course, the microsphere structure includes, but is not limited to, spheres, ellipsoids, etc. This application does not specifically limit the diameter range of the microspheres. The smaller the diameter of the microsphere structure, the smaller the thickness of the microsphere structure, which is beneficial to reducing the thickness of the second electrode layer 18. However, if the microsphere structure is too small, the spherical reflective surface formed is not obvious, and the spherical reflection effect of light is weakened.

[0056] In another alternative embodiment, the light-transmitting microstructure 19 is a hemispherical structure, with the spherical surface of the hemispherical structure in contact with the conductive layer 20. The plane of the hemispherical structure faces the light-emitting layer 17.

[0057] In other words, the second electrode layer 18 includes a transparent hemisphere and a conductive layer 20 disposed on the transparent hemisphere. Of course, the transparent hemisphere includes, but is not limited to, a sphere, an ellipsoid, etc. This application does not specifically limit the diameter range of the transparent hemisphere. The smaller the diameter of the transparent hemisphere, the smaller the thickness of the transparent hemisphere layer, which is beneficial for reducing the thickness of the second electrode layer 18. However, if the transparent hemisphere is too small, the resulting spherical reflective surface is not obvious, and the spherical reflection effect on light is weakened.

[0058] Compared to a single solid sphere, this embodiment achieves a spherical reflective surface in the second electrode layer 18 and reduces the thickness of the second electrode layer 18. Furthermore, when preparing the second electrode layer 18, the plane of the transparent hemisphere can be directly placed on the flat film surface without the need to set a spherical fixing position for the solid sphere.

[0059] Taking the translucent microstructure 19 as a whole sphere, the reflection of light by a microsphere reflector is illustrated as an example. The light rays emitted from the light-emitting layer 17 toward the second electrode layer 18 are the incident light. When the incident light enters the translucent microsphere, it undergoes a first refraction and is then reflected by the spherical reflector. After a second refraction on the surface of the translucent microsphere, it is emitted.

[0060] Please see Figure 4 and Figure 5 If the incident light enters the transparent microsphere in a direction perpendicular to the array substrate 11, and the normal of the light reflected by the spherical reflective surface is the radial direction of the transparent microsphere, then the reflected light when it exits the transparent microsphere is also perpendicular to the array substrate 11. In this way, a large amount of light emitted by the light-emitting layer 17 that is perpendicularly incident on the transparent microsphere is emitted in a direction perpendicular to the transparent substrate 14, thereby improving the utilization rate of light and reducing light loss.

[0061] The microsphere reflective layer, which is composed of the translucent microspheres and the conductive layer 20, allows light emitted from the light-emitting layer 17 to be reflected out when it hits the contact surface between the microspheres and the conductive layer 20 (e.g., the reflective metal layer). This increases the light emissivity.

[0062] Please see Figure 6 If the incident light is obliquely incident into the transparent microsphere, the incident light undergoes a first refraction upon entering the transparent microsphere and is then reflected by the spherical reflective surface. After a second refraction on the surface of the transparent microsphere, it is emitted. The direction of the emitted light is nearly parallel to the direction of the incident light. Thus, when the light emitted from the light-emitting layer 17 at various angles is directed toward the second electrode layer 18, most of the light will be emitted along a direction close to the incident light, improving the utilization rate of the light and increasing the number of angles at which the light is emitted.

[0063] In one optional embodiment, the light-transmitting microstructure 19 is made of a conductive material. Thus, the light-transmitting microstructure 19 can electrically connect the light-emitting layer 17 and the conductive layer 20, allowing current to flow from the conductive layer 20 through the light-transmitting microstructure 19 to the light-emitting layer 17. In this embodiment, the light-transmitting microstructure 19 is both light-transmitting and conductive, and it can also form a spherical reflective surface with the conductive layer 20.

[0064] For example, the material of the light-transmitting microstructure 19 includes at least one of carbon nanotubes, graphene, and indium tin oxide.

[0065] In another optional embodiment, the light-transmitting microstructure 19 is made of a non-conductive material. A portion of the conductive layer 20 is disposed in the gap between the light-transmitting microstructures 19 and is electrically connected to the light-emitting layer 17. When the light-transmitting microstructure 19 is a spherical structure, one side of the light-transmitting microstructure 19 is the second injection layer 23, and the other side of the light-transmitting microstructure 19 is the conductive layer 20. The second injection layer 23 and the conductive layer 20 are electrically connected through the gap between adjacent light-transmitting microstructures 19, thereby realizing the electrical connection between the second electrode layer 18 and the second injection layer 23, allowing current to flow to the light-emitting layer 17 and exciting the light-emitting layer 17 to emit light.

[0066] The conductive layer 20 in the cathode layer is a highly reflective metal layer, such as Ag or Al or their alloys; and a microsphere layer is formed below the cathode layer in the pixel unit opening region 15a. The reflective metal layer and the microsphere layer constitute a microbead reflective film, which reflects the light emitted by the light-emitting layer 17 by utilizing the reflective principle of glass microspheres, thereby improving the light utilization rate. The combination of the highly reflective metal layer and the microspheres reflects the light emitted by the light-emitting layer 17 to improve the light extraction efficiency of the light-emitting layer 17; the microsphere layer includes, but is not limited to, uniformly sized spherical transparent conductive structures, and the material of the microspheres may include microsphere carbon nanotubes or graphene microspheres. The size of the microspheres can also be unequal. Compared with indium tin oxide (ITO), carbon nanotubes and graphene have better transparency and conductivity; in addition, the microsphere layer is located below the highly reflective metal layer, and the microsphere layer is in direct contact with the highly reflective metal layer to ensure that the current flows to the light-emitting layer 17.

[0067] Taking the second electrode layer 18 as the cathode layer, the light-transmitting microstructure 19 as graphene spheres, and the conductive layer 20 as Ag metal as an example, graphene is a highly transparent and highly conductive structure, and the Ag metal layer is a highly reflective conductive structure. The combination of the two forms a highly reflective conductive structure used as the cathode layer of the OLED. When the light-emitting layer 17 emits light, in addition to emitting light towards the anode layer, it also emits light towards the cathode layer. In general, the reflection efficiency of the cathode layer is low. However, in this embodiment, the cathode layer is a reflective film layer including a layer of graphene spheres and Ag metal, which improves the reflection efficiency of the cathode layer. It can fully reflect the light incident on the cathode layer to the light-transmitting substrate 14, making full use of the light emitted by the light-emitting layer 17 and improving the light output of the display panel 100; at the same time, the reflective film layer is also the cathode conductive layer 20.

[0068] Optional, please refer to Figure 2 The array substrate 11 further includes a driving TFT layer 26 and a pixel definition layer 15. The driving TFT layer 26 is disposed on the light-transmitting substrate 14. A plurality of light-emitting units 12 are disposed on the driving TFT layer 26. The pixel definition layer 15 is disposed in the gap between the plurality of light-emitting units 12. When the first electrode layer 16 is an anode layer, the driving TFT layer 26 is electrically connected to the first electrode layer 16.

[0069] Optional, please refer to Figure 2The driving TFT layer 26 further includes a plurality of TFT units 13 and a passivation layer 28. The plurality of TFT units 13 are disposed on the light-transmitting substrate 14. Specifically, the light-transmitting substrate 14 has a gate 29, an insulating layer 30 covering the gate 29, an active layer 31 disposed on the insulating layer 30, a source 32 connected to the active layer 31, and a drain 33 connected to the active layer 31, the active layer 31 corresponding to the gate 29. The passivation layer 28 covers the source 32, drain 33, and active layer 31 of the plurality of TFT units 13. A pixel definition layer 15 and a light-emitting unit 12 are disposed on the passivation layer 28. The drain 33 of the TFT unit 13 corresponds to the anode layer (first electrode layer 16) of the light-emitting unit 12. The passivation layer 28 includes a conductive via 34. The conductive via 34 electrically connects the anode layer (first electrode layer 16) of the light-emitting unit 12 to the drain 33 of the TFT unit 13.

[0070] Optionally, the TFT unit 13 is located in the light-shielding area of ​​the pixel unit, and the light-emitting unit 12 is located in the opening area 15a of the pixel unit.

[0071] The anode layers (first electrode layers 16) of two adjacent light-emitting units 12 are spaced apart. Each TFT unit 13 is electrically connected to the anode layer (first electrode layer 16) of one light-emitting unit 12. The TFT unit 13 is used to provide an anode voltage to the anode layer (first electrode layer 16) of each light-emitting unit 12.

[0072] In a first optional embodiment, the array substrate 11 further includes a plurality of cathode driving units (not shown). The cathode layers (second electrode layers 18) of at least two of the light-emitting units 12 are spaced apart, i.e., not directly connected. For independently configured cathode layers (second electrode layers 18), each cathode driving unit is electrically connected to the cathode layer (second electrode layer 18) of one light-emitting unit 12. This is a cathode-driven design. In this configuration, the cathode layer (second electrode layer 18) and anode layer (first electrode layer 16) of each light-emitting unit 12 are driven by independent driving devices.

[0073] In the embodiment of the cathode-driven design, each light-emitting unit 12 has its own driving device for its cathode layer (second electrode layer 18) and anode layer (first electrode layer 16), which can be supplied with current separately for each light-emitting unit 12.

[0074] In the second alternative embodiment, please refer to Figure 2The array substrate 11 further includes at least one cathode driving unit. The pixel definition layer 15, facing away from the light-transmitting substrate 14, also includes electrical connection traces. These electrical connection traces are located outside the aperture region 15a of the pixel unit, reducing the impact of the electrical connection traces on the aperture ratio of the pixel unit. The electrical connection traces electrically connect the cathode layers (second electrode layers 18) of at least two of the light-emitting units 12. The cathode driving unit is electrically connected to the electrical connection traces. One cathode driving unit drives the cathode layers (second electrode layers 18) of multiple light-emitting units 12 through the electrical connection traces, reducing the number of cathode driving units required. Optionally, the cathode layers (second electrode layers 18) of all light-emitting units 12 are connected through electrical connection traces, and all the cathode layers (second electrode layers 18) of the light-emitting units 12 are driven by one cathode driving unit. This is a common cathode driving method. Further, the cathode layers (second electrode layers 18) can extend above the pixel definition layer 15, and the electrical connection traces connect the cathode layers (second electrode layers 18) in each pixel unit to achieve a common cathode effect.

[0075] Furthermore, the conductive layers 20 of at least two of the light-emitting units 12 extend onto the pixel definition layer 15 and are interconnected. Specifically, the light-transmitting microstructures 19 in the cathode layer may be disposed together with the anode layer in the opening region 15a formed by the pixel definition layer 15, and the conductive layers 20 of the cathode layer may extend onto the pixel definition layer 15 and be interconnected.

[0076] In the common cathode driving design implementation, the anode layer (first electrode layer 16) is a separate driving device. The cathode layer (second electrode layer 18) is driven together. In the common cathode method, the anode is inside the pixel opening, while part of the cathode is inside the pixel opening and part is above the pixel definition layer 15, avoiding the opening region 15a, thereby reducing the number of film layers in the opening region 15a.

[0077] Please see Figure 7 Combined with reference Figure 8 and Figure 9 This embodiment also provides a method S100 for fabricating an array substrate 11. The method S100 includes, but is not limited to, the following steps.

[0078] Step S110: Form a first electrode layer 16 in a plurality of preset regions of the light-transmitting substrate 14.

[0079] Specifically, a driving TFT layer 26 is formed on the light-transmitting substrate 14; a pixel definition layer 15 is formed on the driving TFT layer 26; the pixel definition layer 15 is exposed to form an opening region 15a, and a conductive via 34 is formed simultaneously; a preset area corresponds to the opening region 15a in the pixel unit. A first electrode layer 16 is formed in the opening region 15a of the pixel definition layer 15. The first electrode layer 16 covers the conductive via 34 and is electrically connected to the drain of the driving TFT layer 26 through the conductive via 34.

[0080] Step S120: Form a light-emitting layer 17 on the first electrode layer 16.

[0081] Specifically, a hole injection layer is formed (including but not limited to coating) on ​​the first electrode layer 16, a hole transport layer is formed (including but not limited to coating) on ​​the hole injection layer, and a light-emitting layer 17 is formed (including but not limited to coating) on ​​the hole transport layer.

[0082] Step S130: Form at least one layer of light-transmitting microstructure 19 on the light-emitting layer 17.

[0083] Specifically, an electron transport layer is formed (including but not limited to coating) on ​​the light-emitting layer 17, an electron injection layer is formed (including but not limited to coating) on ​​the electron transport layer, and a light-transmitting microstructure 19 is formed (including but not limited to coating) on ​​the electron injection layer, wherein the light-transmitting microstructure 19 includes but is not limited to graphene microspheres.

[0084] Furthermore, photoresist is coated onto the electron injection layer, and exposure and development are performed to form multiple continuous spherical holes. Graphene microspheres are then filled into the spherical holes formed above.

[0085] Step S140: A conductive layer 20 is formed (including but not limited to coating) on ​​the light-transmitting microstructure 19. The light-transmitting microstructure 19 and the conductive layer 20 are in contact to form a reflective surface 25. The reflective surface 25 is at least used to reflect the light emitted by the light-emitting layer 17 to be emitted through the light-transmitting substrate 14.

[0086] Specifically, an Ag metal layer is formed on the graphene sphere, and the Ag metal layer and the graphene sphere are brought into contact to form a reflective film layer. That is, a microsphere reflective structure is formed in the opening region 15a, which reflects the light emitted by the light-emitting layer 17 and improves the light utilization rate; at the same time, it serves as a cathode layer.

[0087] The method for fabricating the array substrate 11 provided in this application embodiment involves forming a first electrode layer 16 in multiple predetermined regions of a light-transmitting substrate 14; forming a light-emitting layer 17 on the first electrode layer 16; forming at least one light-transmitting microstructure 19 on the light-emitting layer 17; forming a conductive layer 20 on the light-transmitting microstructure 19; and forming a reflective surface 25 between the light-transmitting microstructure 19 and the conductive layer 20. The reflective surface 25 is at least used to reflect the light emitted by the light-emitting layer 17 back to the light-transmitting substrate. The light emitted from the light-emitting layer 17 is emitted directly through the first electrode layer 16 and the light-transmitting substrate 14, while the other part of the light is reflected by the reflective surface 25 in the second electrode layer 18 and then emitted from the first electrode layer 16 and the light-transmitting substrate 14. In other words, most or all of the light emitted by the light-emitting layer 17 is emitted from the light-transmitting substrate 14 (the light-emitting side of the display panel 100), thereby increasing the light extraction rate of the light emitted by the light-emitting layer 17 in the array substrate 11 through the light-transmitting substrate 14, that is, increasing the light extraction rate of the display panel 100.

[0088] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application, and such improvements and refinements are also considered to be within the protection scope of this application.

Claims

1. An array substrate, characterized in that, The system includes a light-transmitting substrate, a driving TFT layer, a pixel definition layer, and multiple light-emitting units. The driving TFT layer is disposed on the light-transmitting substrate, the multiple light-emitting units are disposed on the driving TFT layer, and the pixel definition layer is disposed in the gaps between the multiple light-emitting units. Each light-emitting unit includes: The conductive layers of at least two of the light-emitting units are interconnected; A first electrode layer is disposed on the light-transmitting substrate. The first electrode layer is a light-transmitting anode and is electrically connected to the drain of the driving TFT layer. A hole injection layer, a hole transport layer, a light emission layer, an electron transport layer, and an electron injection layer are stacked sequentially; the hole injection layer is disposed on the first electrode layer; the electron injection layer includes a plurality of continuous spherical holes, which are formed by coating photoresist and exposure and development. The second electrode layer is a cathode layer integrally formed on the electron injection layer. The second electrode layer includes at least one transparent microstructure and a conductive layer. The transparent microstructure fills a plurality of continuous spherical holes. The transparent microstructure includes carbon nanotube microspheres or graphene microspheres. The transparent microstructure is electrically conductive between the electron injection layer and the conductive layer, allowing current to flow to the light-emitting layer. The conductive layer is located on the side of the transparent microstructure facing away from the light-emitting layer. The transparent microstructure is a microsphere structure or a hemispherical structure, and the spherical surface of the transparent microstructure is in contact with the conductive layer. The conductive layer is a highly reflective metal layer, and the material of the conductive layer includes Ag, Al, or an alloy. The conductive layer is formed by coating the light-transmitting microstructure. The light-transmitting microstructure and the conductive layer are in contact to form a spherical reflective surface. The spherical reflective surface is used at least to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate. The conductive layers of adjacent light-emitting units are connected to each other above the pixel definition layer to form a common cathode structure. The pixel definition layer also fills the gaps between the light-transmitting microstructures corresponding to different light-emitting units.

2. The array substrate according to claim 1, characterized in that, The material of the light-transmitting microstructure is a conductive material.

3. The array substrate according to claim 1, characterized in that, The conductive layer is made of a reflective material.

4. A method for fabricating an array substrate, characterized in that, The method is used to prepare the array substrate as described in any one of claims 1-3, the method comprising: A first electrode layer is formed in multiple predetermined areas of a light-transmitting substrate. The first electrode layer is a light-transmitting anode and is electrically connected to the drain of the driving TFT layer of the array substrate. A hole injection layer, a hole transport layer, a light emission layer, an electron transport layer, and an electron injection layer are formed in sequence and stacked; the hole injection layer is disposed on the first electrode layer; a plurality of continuous spherical holes are formed by coating the electron injection layer with photoresist and exposing and developing it. At least one layer of transparent microstructure is formed on the light-emitting layer. The transparent microstructure fills a plurality of continuous spherical holes. The transparent microstructure includes carbon nanotube microspheres or graphene microspheres. The transparent microstructure can electrically connect the electron injection layer and the conductive layer, so that current flows to the light-emitting layer. The pixel definition layer also fills the gaps between the light-transmitting microstructures on different electron injection layers; A conductive layer is coated on the light-transmitting microstructure to form a highly reflective metal layer, the material of which includes Ag, Al, or an alloy; the light-transmitting microstructure and the conductive layer are in contact to form a spherical reflective surface, the spherical reflective surface being used at least to reflect the light emitted by the light-emitting layer to be emitted through the light-transmitting substrate; the conductive layers of adjacent light-emitting units are interconnected above the pixel definition layer to form a common cathode structure.

5. A display panel, characterized in that, Includes the array substrate as described in any one of claims 1 to 3.

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