Display substrate and display device

Abstract

Disclosed herein are a display substrate and a display device. The display substrate (10) comprises: a base substrate (100); a plurality of pixel units (P) arranged in an array, each pixel unit (P) comprising a plurality of sub-pixels, wherein each sub-pixel comprises a first electrode (121), a light-emitting functional layer (122) and a second electrode (123) that are stacked on the base substrate (100); a light extraction layer (130), which has open areas (133) exposing the second electrodes (123); and an auxiliary electrode layer (140), which at least partially overlaps the orthographic projections of the second electrodes (123) on the base substrate (100), and is electrically connected to the second electrodes (123) by means of the open areas (133).

Description

Display substrate and display device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311437949.3, filed on October 31, 2023, the entire contents of which are incorporated herein by reference.

[0003] This application claims priority to Chinese patent application No. 202322942048.1, filed on October 31, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present disclosure belongs to the field of display technology and relates to a display substrate and a display device. Background Art

[0005] Electroluminescent devices are playing an increasingly important role in the display industry. For example, organic light-emitting diodes (OLEDs) have seen widespread adoption and application in recent years due to their wide color gamut, flexibility, and fast response time. Furthermore, quantum dot light-emitting diodes (QLEDs) have also gained increasing attention in recent years due to their low manufacturing costs and wide color gamut.

[0006] Summary of the Invention

[0007] In a first aspect of the present disclosure, a display substrate is provided, comprising: a base substrate; a plurality of pixel units arranged in an array, each pixel unit comprising a plurality of sub-pixels, each sub-pixel comprising: a first electrode, a light-emitting functional layer and a second electrode stacked on the base substrate; a light extraction layer, arranged on a side of the second electrode away from the base substrate, the light extraction layer having an opening area exposing the second electrode; and an auxiliary electrode layer, arranged on a side of the light extraction layer away from the second electrode, the auxiliary electrode layer at least partially overlapping with the orthographic projection of the second electrode on the base substrate, the auxiliary electrode layer being electrically connected to the second electrode through the opening area; wherein at least a portion of the light emitted by the sub-pixels is incident on the auxiliary electrode layer through the light extraction layer, and then transmitted from the auxiliary electrode layer.

[0008] In conjunction with the first aspect of the present disclosure, in some embodiments, the plurality of sub-pixels include a first sub-pixel, a second sub-pixel, and a third sub-pixel, and the emission wavelength of the first sub-pixel is greater than the emission wavelengths of the second sub-pixel and the third sub-pixel. The orthographic projection of the light extraction layer on the base substrate at least partially overlaps with the orthographic projection of the second sub-pixel on the base substrate; and / or the orthographic projection of the light extraction layer on the base substrate at least partially overlaps with the orthographic projection of the third sub-pixel on the base substrate.

[0009] In combination with the first aspect of the present disclosure, in some embodiments, the orthographic projections of the second sub-pixel and the third sub-pixel on the base substrate are located within the orthographic projection range of the light extraction layer on the base substrate.

[0010] In combination with the first aspect of the present disclosure, in some embodiments, the orthographic projection of the opening area on the base substrate at least partially overlaps with the orthographic projection of the first sub-pixel on the base substrate, and the auxiliary electrode layer covers the opening area and contacts the second electrode exposed in the opening area.

[0011] In combination with the first aspect of the present disclosure, in some embodiments, the orthographic projection of the first sub-pixel on the base substrate is located within the orthographic projection range of the opening area on the base substrate.

[0012] In combination with the first aspect of the present disclosure, in some embodiments, the first sub-pixel is a red sub-pixel, the second sub-pixel is a green sub-pixel, and the third sub-pixel is a blue sub-pixel.

[0013] In combination with the first aspect of the present disclosure, in some embodiments, the light extraction layers corresponding to sub-pixels of different colors have the same thickness, or the light extraction layers corresponding to sub-pixels of different colors have different thicknesses.

[0014] In combination with the first aspect of the present disclosure, in some embodiments, the light extraction layer includes: a first sub-light extraction layer and a second sub-light extraction layer arranged in a stacked manner, the first sub-light extraction layer is closer to the second electrode relative to the second sub-light extraction layer, and the refractive index of the first sub-light extraction layer is greater than the refractive index of the second sub-light extraction layer.

[0015] In combination with the first aspect of the present disclosure, in some embodiments, the thickness of the first sub-light extraction layer is 50 to 100 nanometers, the thickness of the second sub-light extraction layer is 50 to 150 nanometers, and the thickness of the auxiliary electrode layer is 100 to 1000 nanometers.

[0016] In conjunction with the first aspect of the present disclosure, in some embodiments, the first sub-pixel is a red sub-pixel, the second sub-pixel is a green sub-pixel, and the third sub-pixel is a blue sub-pixel. The auxiliary electrode layer includes: a first region corresponding to the first sub-pixel, a second region corresponding to the second sub-pixel, and a third region corresponding to the third sub-pixel. In a direction perpendicular to the substrate, the thickness of the third region is less than the thickness of the second region, and the thickness of the first region is less than or equal to the thickness of the second region.

[0017] In combination with the first aspect of the present disclosure, in some embodiments, along a direction perpendicular to the substrate, the thickness of the first region is 100 to 150 nanometers, the thickness of the second region is 250 to 350 nanometers, and the thickness of the third region is 100 to 150 nanometers.

[0018] In combination with the first aspect of the present disclosure, in some embodiments, the light extraction layer includes: a plurality of light extraction units, with the opening area between adjacent light extraction units, and each of the light extraction units covers one sub-pixel or multiple sub-pixels.

[0019] In combination with the first aspect of the present disclosure, in some embodiments, each of the light extraction units covers one of the pixel units.

[0020] In conjunction with the first aspect of the present disclosure, in some embodiments, the pixel unit includes: a first subpixel, a second subpixel, and a third subpixel, wherein the first subpixel, the second subpixel, and the third subpixel include a first edge and a second edge disposed opposite the first edge, the first edge being a straight line, and the second edge being a curved line. A line connecting the center points of the first subpixel, the second subpixel, and the third subpixel forms a triangle, the second edge of the first subpixel is disposed opposite the second edge of the second subpixel, and the second edge of the third subpixel is disposed toward the first subpixel and the second pixel.

[0021] In combination with the first aspect of the present disclosure, in some embodiments, the planar shapes of the first sub-pixel, the second sub-pixel, and the third sub-pixel are circular, semi-circular, or semi-elliptical.

[0022] In conjunction with the first aspect of the present disclosure, in some embodiments, the planar shape of the light extraction unit is a hexagon, and the hexagon includes: a first side, a second side, a third side, a fourth side, a fifth side, and a sixth side connected in sequence, the first side is arranged opposite to the fourth side, the second side is arranged opposite to the sixth side, and the third side is arranged opposite to the fifth side. The length of the first side is less than the length of the fourth side, and the extension direction of the fourth side is parallel to the arrangement direction of the first sub-pixel and the second sub-pixel. The first edge of the first sub-pixel and the first edge of the second sub-pixel are respectively arranged opposite to the third side and the fifth side, and the first edge of the third sub-pixel is arranged opposite to the first side.

[0023] In conjunction with the first aspect of the present disclosure, in some embodiments, the pixel unit includes: a first sub-pixel, two second sub-pixels, and a third sub-pixel, the area of ​​the second sub-pixel is smaller than the area of ​​the first sub-pixel and the area of ​​the third sub-pixel, and the line connecting the center points of the first sub-pixel, the two second sub-pixels, and the third sub-pixel forms a rhombus. The spacing between adjacent first sub-pixels and the third sub-pixels is a first distance, the spacing between adjacent second sub-pixels is a second distance, the spacing between adjacent first sub-pixels and the second sub-pixels is a third distance, and the spacing between adjacent second sub-pixels and the third sub-pixel is a fourth distance, and the first distance and the second distance are greater than the third distance and the fourth distance. The light extraction unit is a bent strip structure, and among the multiple light extraction units, at least a portion of the light extraction units covers one first sub-pixel, one second sub-pixel, and one third sub-pixel, and at least a portion of the light extraction units covers one first sub-pixel, two second sub-pixels, and one third sub-pixel.

[0024] In combination with the first aspect of the present disclosure, in some embodiments, the display substrate includes a plurality of the light extraction layers and a plurality of the auxiliary electrode layers, and the plurality of the light extraction layers and the plurality of the auxiliary electrode layers are staggered and stacked on the side of the second electrode away from the base substrate.

[0025] In combination with the first aspect of the present disclosure, in some embodiments, the first electrode is a reflective electrode, the second electrode is configured to partially transmit and partially reflect light emitted by the light-emitting functional layer, and the second electrodes of adjacent sub-pixels are connected to each other.

[0026] In combination with the first aspect of the present disclosure, in some embodiments, the second electrode includes a metal material, and the auxiliary electrode layer includes a transparent conductive material.

[0027] In a second aspect of the present disclosure, a display substrate is provided, comprising: a base substrate; a plurality of pixel units arranged in an array, each pixel unit comprising a first sub-pixel, a second sub-pixel and a third sub-pixel, the first sub-pixel being a red sub-pixel, and each sub-pixel comprising: a first electrode, a light-emitting functional layer and a second electrode stacked on the base substrate; a light extraction layer, arranged on a side of the second electrode away from the base substrate, the light extraction layer covering the second sub-pixel and the third sub-pixel, and having an opening area exposing the second electrode of the first sub-pixel; and an auxiliary electrode layer, arranged on a side of the light extraction layer away from the second electrode, the auxiliary electrode layer covering the light extraction layer and the opening area, and electrically connected to the exposed second electrode at the bottom of the opening area; wherein, light emitted by the first sub-pixel is emitted through the auxiliary electrode layer, and light emitted by the second sub-pixel and the third sub-pixel is emitted through the light extraction layer and the auxiliary electrode layer.

[0028] In a third aspect of the present disclosure, a display device is provided, comprising: the display substrate provided by the first aspect or the second aspect.

[0029] The above description is only an overview of the technical solutions provided by some embodiments of the present disclosure. In order to more clearly understand the technical means of the embodiments of the present disclosure, they can be implemented in accordance with the contents of the specification. In order to make the embodiments of the present disclosure more obvious and easy to understand, the specific implementation methods of the embodiments of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0031] FIG1 is a schematic plan view of a display substrate according to some embodiments of the present disclosure;

[0032] FIG2 shows a schematic diagram of a stacked structure of a display substrate according to some embodiments of the present disclosure;

[0033] FIG3 shows a schematic diagram of the layout of a light extraction unit according to some embodiments of the present disclosure;

[0034] FIG4 shows a schematic diagram of the layout of a light extraction unit according to other embodiments of the present disclosure;

[0035] FIG5 shows a schematic diagram of an exemplary pixel arrangement;

[0036] FIG6 shows a plan view of a pixel structure and a light extraction layer according to some embodiments of the present disclosure;

[0037] FIG7 shows another exemplary pixel arrangement schematic diagram;

[0038] FIG8 shows a plan view of a pixel structure and a light extraction layer according to some embodiments of the present disclosure;

[0039] FIG9 shows a schematic diagram of a stacked structure of a display substrate according to some embodiments of the present disclosure;

[0040] FIG10 shows a schematic plan view of the display substrate of FIG9 ;

[0041] FIG11 shows a schematic diagram of a stacked structure of a display substrate according to some embodiments of the present disclosure;

[0042] FIG12 shows a graph showing the test results of a first set of comparative tests according to some embodiments of the present disclosure;

[0043] FIG13 shows a graph showing test results of a second set of comparative tests according to some embodiments of the present disclosure;

[0044] FIG14 shows a graph showing test results of a third set of comparative tests according to some embodiments of the present disclosure;

[0045] FIG15 shows a schematic diagram of a stacked structure of a display substrate according to some embodiments of the present disclosure;

[0046] FIG16 shows a graph showing the test results of a fourth set of comparative tests according to some embodiments of the present disclosure;

[0047] FIG17 shows a schematic diagram of a stacked structure of a display substrate according to some embodiments of the present disclosure; and

[0048] FIG18 shows a schematic structural diagram of a display device according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0049] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0050] It should be noted that the term "and / or" appearing in this article is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. "Multiple" includes two or more than two situations. "Include" or "comprising" and other similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but do not exclude other elements or objects. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0051] The terms "parallel", "perpendicular", and "equal" appearing in this document include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0052] It should be understood that in the exemplary embodiments of the present disclosure, when a layer or element is referred to as being on another layer or substrate, it may be that the layer or element is directly on the other layer or substrate, or there may be an intermediate layer between the layer or element and the other layer or substrate. "Thickness" refers to the thickness in the direction perpendicular to the substrate. "A and B are arranged in the same layer" means that after A and B adopt the same film forming process to form a film layer for forming a specific pattern, a layer structure is formed by using the same mask through a single composition process. "The orthographic projection of B is within the range of the orthographic projection of A" means that the boundary of the orthographic projection of B falls within the boundary of the orthographic projection of A, or the boundary of the orthographic projection of A overlaps with the boundary of the orthographic projection of B.

[0053] In related display substrates, the following technical solutions are generally used to reduce cathode resistance: 1) Select a metal with higher conductivity as the cathode. However, since the selection of the cathode metal also needs to consider the energy level matching of the cathode's adjacent electron transport layer, the actual room for optimization is relatively small. 2) Reduce the cathode resistance by adding metal traces (auxiliary cathodes) in the non-display area. 3) Prepare a transparent auxiliary electrode on the cathode to form a parallel resistor with the cathode, thereby reducing the cathode resistance.

[0054] In related display substrates, the following technical solutions are generally used to reduce cathode resistance: 1) Selecting a metal with higher conductivity as the cathode. However, since the choice of cathode metal also needs to consider the energy level matching of the adjacent electron transport layer, the actual optimization space is limited; 2) Adding metal traces (auxiliary cathodes) in non-pixel areas to reduce cathode resistance. 3) Preparing a transparent auxiliary electrode on the cathode to form a parallel resistor with the original cathode, thereby reducing cathode resistance.

[0055] However, the inventors have discovered that if a transparent auxiliary electrode is formed directly on the cathode through a sputtering process, the principle of the sputtering process is to use a high-energy ion beam to bombard the target material, transfer the kinetic energy of the ions to the target atoms, and splash out from the target surface and deposit on the substrate surface. Due to the high sputtering energy, the cathode and the electroluminescent functional layer will be damaged, resulting in a high leakage current of the electroluminescent device. The high leakage current will cause the brightness of the electroluminescent device to decay faster, affecting the service life of the electroluminescent device. In addition, the transparent auxiliary electrode directly sputtered onto the metal cathode will also cause the luminous efficiency of the electroluminescent device to decrease. For example, when the transparent auxiliary electrode is indium zinc oxide (IZO), the luminous efficiency decreases by more than 10%, thereby increasing the power consumption of the display substrate.

[0056] In view of this, the inventors conducted further research to achieve the goal of reducing the resistance of the second electrode (such as the cathode) to improve brightness uniformity while ensuring the luminous efficiency of the display substrate. Below, the display substrate and display device provided by some embodiments of the present disclosure are described in detail with reference to the accompanying drawings.

[0057] Some embodiments of the present disclosure provide a display substrate, which includes: a base substrate and a plurality of pixel units arranged in an array on the base substrate. Each pixel unit includes a plurality of sub-pixels, and each sub-pixel includes: a first electrode, a light-emitting functional layer and a second electrode stacked on the base substrate. The display substrate also includes: a light extraction layer and an auxiliary electrode layer. The light extraction layer is arranged on the side of the second electrode away from the base substrate, and the light extraction layer has an opening area exposing the second electrode; the auxiliary electrode layer is arranged on the side of the light extraction layer away from the second electrode, and the auxiliary electrode layer and the orthographic projection of the second electrode on the base substrate at least partially overlap, and the auxiliary electrode layer is electrically connected to the second electrode through the above-mentioned opening area to realize the parallel connection of the auxiliary electrode layer and the second electrode. Wherein, the light emitted by at least a part of the sub-pixels is incident on the auxiliary electrode layer through the light extraction layer, and then transmitted from the auxiliary electrode layer.

[0058] By adding an auxiliary electrode layer, connected in parallel with the second electrode, on the side of the second electrode away from the base substrate, the resistance of the second electrode can be effectively reduced. Furthermore, by adding a light extraction layer between the auxiliary electrode layer and the second electrode, at least a portion of the light emitted by the sub-pixels is incident on the auxiliary electrode layer through the light extraction layer and then transmitted through the auxiliary electrode layer. This light extraction layer protects the second electrode, reducing damage to the second electrode caused by the preparation of the auxiliary electrode layer. It also compensates for the loss of luminous efficiency caused by the auxiliary electrode layer, thereby reducing the resistance of the second electrode to improve brightness uniformity while ensuring the luminous efficiency of the display substrate.

[0059] FIG1 shows a schematic plan view of a display substrate according to some embodiments of the present disclosure. As shown in FIG1 , the display substrate 10 may include a display region DR and a non-display region NR. The display region DR is the region of the display substrate 10 used to display an image, and the non-display region NR is the region of the display substrate 10 other than the display region DR. The non-display region NR may be located on at least one side (e.g., one side, or multiple sides) of the display region DR. For example, the non-display region NR may be arranged around the display region DR.

[0060] The display region DR is provided with a plurality of pixel units P arranged in an array in a first direction and a second direction. For example, the plurality of pixel units P may be arranged in M ​​rows and N columns, where M and N are integers greater than or equal to 2. The first direction is a pixel row direction, and the second direction is a pixel column direction. The first direction and the second direction intersect, for example, are perpendicular to each other.

[0061] Each pixel unit P includes multiple sub-pixels, each of which can display a single color, such as a red sub-pixel displaying red, a green sub-pixel displaying green, and a blue sub-pixel displaying blue. The brightness (grayscale) of the sub-pixels of different colors in each pixel unit P can be adjusted. By combining and superimposing colors, multiple colors can be displayed, thereby achieving full-color display on the display substrate 10.

[0062] For example, the plurality of sub-pixels may include a first sub-pixel p1, a second sub-pixel p2, and a third sub-pixel p3, and the different sub-pixels may emit different colors. For example, the first sub-pixel p1 may be a red sub-pixel, and one of the second sub-pixel p2 and the third sub-pixel p3 may be a green sub-pixel and the other may be a blue sub-pixel, such as the second sub-pixel p2 may be a green sub-pixel and the third sub-pixel p3 may be a blue sub-pixel.

[0063] Each sub-pixel may include an electroluminescent device and a pixel driving circuit for driving the electroluminescent device. For example, the electroluminescent device may be an OLED device or a QLED device. For example, a red sub-pixel may include an electroluminescent device for emitting red light, a green sub-pixel may include an electroluminescent device for emitting green light, and a blue sub-pixel may include an electroluminescent device for emitting blue light.

[0064] 1 , the display substrate 10 further includes a plurality of scan lines GL and a plurality of data lines DL. The plurality of scan lines GL and the plurality of data lines DL intersect with each other to define a plurality of pixel areas arranged in an array in the display region DR.

[0065] For example, as shown in Figure 1, the display substrate 10 may also include a scan drive circuit SC and a data drive circuit DC located in the non-display area NR. The scan drive circuit SC may be, for example, a gate drive circuit (such as a GOA drive circuit). The scan drive circuit SC is connected to the pixel drive circuit via a scan line GL to provide various scan signals, and the data drive circuit DC is connected to the pixel drive circuit via a data line DL to provide a data signal. It should be noted that the positional relationship between the scan drive circuit SC and the data drive circuit DC, the scan line GL, and the data line DL in the display substrate 10 shown in Figure 1 is only an example, and the actual arrangement position can be designed as needed. For example, a scan drive circuit SC may be provided in the non-display area on one side of the display substrate 10 as shown in Figure 1, or a scan drive circuit SC may be provided in the non-display areas on both opposite sides of the display substrate 10.

[0066] The pixel driving circuit may include multiple electronic components such as transistors and capacitors. For example, the pixel driving circuit may include three transistors and one capacitor, forming a 3T1C (i.e., one driving transistor, two switching transistors and one capacitor). For another example, the pixel driving circuit may also include more than three transistors and at least one capacitor, such as a 4T1C (i.e., one driving transistor, three switching transistors and one capacitor), a 5T1C (i.e., one driving transistor, four switching transistors and one capacitor), or a 7T1C (i.e., one driving transistor, six switching transistors and one capacitor). Among them, the transistor may be a thin film transistor (TFT), a metal oxide semiconductor (MOS), or other switching devices with the same characteristics.

[0067] It is understood that a transistor may include a control electrode, a first electrode, and a second electrode. The control electrode is the gate of the transistor, the first electrode is one of the source and drain of the transistor, and the second electrode is the other of the source and drain of the transistor. Since the source and drain of a transistor may be structurally symmetrical, their structures may be identical, and the source of the transistor may be referred to as the first electrode, or may also be referred to as the second electrode.

[0068] Figure 2 shows a schematic diagram of the stacked structure of a display substrate according to some embodiments of the present disclosure. As shown in Figure 2, in a direction perpendicular to the surface of the display substrate 10, the display substrate 10 may include: a base substrate 100, a drive circuit layer 101, a pixel definition layer 110, an electroluminescent device 120, a light extraction layer 130, and an auxiliary electrode layer 140.

[0069] For example, the base substrate 100 may be a rigid substrate, such as a glass substrate, a PMMA (Polymethyl methacrylate) substrate, a silicon substrate, etc. In this case, the display substrate 10 may be a rigid display substrate.

[0070] For another example, the base substrate 100 may be a flexible substrate. The flexible substrate may include, for example, a PET (Polyethylene terephthalate) substrate, a PEN (Polyethylene naphthalate diformic acid glycol ester) substrate, or a PI (Polyimide) substrate. In this case, the display substrate 10 may be a flexible display substrate.

[0071] It should be noted that the base substrate 100 may be a single-layer structure or a multi-layer structure. For example, the base substrate 100 may include at least one flexible substrate and at least one buffer layer, and the flexible substrates and the buffer layers are alternately stacked.

[0072] The pixel defining layer 110 has a plurality of pixel openings, each of which is configured to define a light emitting region of an electroluminescent device 120 .

[0073] In a direction away from the base substrate 100, the electroluminescent device 120 may include a first electrode 121, a light-emitting functional layer 122, and a second electrode 123, which are stacked in sequence. One of the first electrode 121 and the second electrode 123 serves as the anode of the electroluminescent device 120, and the other serves as the cathode. The light-emitting functional layer 122 may at least include: a light-emitting layer (EML), which emits display light under the drive of the first electrode 121 and the second electrode 123. In some exemplary embodiments, the light-emitting functional layer 122 may further include any one or more of the following: a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL), which may be arranged according to actual needs and are not limited in this disclosure.

[0074] For example, as shown in Figure 2, the light-emitting functional layer 122 can be divided into: a pixelated layer 122a and a common layer 122b. The pixelated layer 122a is arranged corresponding to each sub-pixel, and the pixelated layers 122a of sub-pixels of different colors are isolated from each other. For example, the pixelated layer 122a may include the above-mentioned light-emitting layer (EML). The common layers 122b of each electroluminescent device 120 are interconnected to form an integrated structure. For example, the common layer 122b can be formed by an evaporation process. For example, the common layer 122b may include the above-mentioned electron transport layer (ETL) and the electron injection layer (EIL).

[0075] Taking the first electrode 121 as an anode and the second electrode 123 as a cathode as an example, the structure of the first electrode 121 can be a composite structure composed of a transparent conductive oxide film / a metal film / a transparent conductive oxide film stacked in sequence. The material of the transparent conductive oxide film can be, for example, any one of ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide), and the material of the metal film can be, for example, any one or more of aluminum (Al), silver (Ag), titanium (Ti), molybdenum (Mo), etc. For another example, the structure of the first electrode 121 can also be a single-layer structure, such as the material of the single-layer structure can be any one of aluminum (Al), silver (Ag), titanium (Ti), and molybdenum (Mo).

[0076] Each pixel opening exposes at least a portion of the first electrode 121 of the corresponding electroluminescent device 120 . At least a portion of the light-emitting functional layer 122 is located within the corresponding pixel opening and is electrically connected to the corresponding first electrode 121 .

[0077] For example, the second electrodes 123 of adjacent electroluminescent devices 120 can be connected to each other, and the entire layer is arranged as shown in Figure 2 to facilitate the access of voltage signals. For example, the second electrode 123 may include a metal material, such as any one of lithium (Li), aluminum (Al), magnesium (Mg), silver (Ag), or alloys of any of the above materials such as magnesium-silver alloy and aluminum-lithium alloy. For example, the first electrode 121 can serve as a reflective electrode, and the second electrode 123 is configured to partially transmit and partially reflect the light emitted by the light-emitting functional layer 122, so that the electroluminescent device 120 can achieve a strong microcavity effect, thereby achieving a better color gamut and luminous efficiency. For example, the thickness of the second electrode 123 can be 5 to 20 nanometers, such as 5 nanometers, 10 nanometers, 15 nanometers or 20 nanometers, so that the second electrode 123 has light-transmitting properties.

[0078] The driving circuit layer 101 is stacked between the base substrate 100 and the pixel definition layer 110 and is configured to form at least a pixel driving circuit for each of the above-mentioned sub-pixels. Of course, in addition to the pixel driving circuit, the driving circuit layer 101 can also be configured to form other functional circuits according to the needs of the actual application scenario. For example, in a display substrate 10 with a fingerprint recognition function, the driving circuit layer 101 can also be configured to form a photosensitive element, which is not limited in this disclosure.

[0079] For example, the driving circuit layer 101 may include at least: an active layer, a first conductive pattern layer, a second conductive pattern layer, a third conductive pattern layer, and an insulating layer separating these functional layers, which are stacked in sequence. These layers may form a plurality of pixel driving circuits.

[0080] It should be noted that the "pattern layer" can be a layer structure containing a specific pattern formed by forming at least one film layer using the same film-forming process, and then performing a patterning process on the at least one film layer. Depending on the specific pattern, the patterning process may include multiple coating, exposure, development or etching processes, and the specific pattern in the formed layer structure may be continuous or discontinuous, and these specific patterns may also be at different heights (or thicknesses). The "conductive pattern layer" here refers to a pattern layer with conductive properties, which is made of conductive material.

[0081] For example, the active layer may include the active pattern (also referred to as the channel region) of each transistor in the pixel driving circuit. The first conductive pattern layer may also be referred to as the first gate metal layer (Gate1 layer), which may include: the gate of each transistor in the pixel driving circuit. In addition, the first conductive pattern layer may also include: the first capacitor plate of the capacitor in the pixel driving circuit. For example, the gate pattern of the transistor may be used as the first capacitor plate at the same time, or a first capacitor plate may be provided in the first conductive pattern layer. The specific structure is provided according to actual needs, and the present disclosure does not impose any restrictions on this. The second conductive pattern layer may also be referred to as the second gate metal layer (Gate2 layer), which includes: the second capacitor plate of the capacitor in the pixel driving circuit. The first capacitor plate and the second capacitor plate are arranged relative to each other to form a capacitor in the pixel driving circuit. The third conductive pattern layer may also be referred to as the first metal routing layer (SD1 layer), which includes: the first electrode and the second electrode, i.e., the source and the drain, of each transistor in the pixel driving circuit.

[0082] In addition, the first conductive pattern layer, the second conductive pattern layer, and the third conductive pattern layer may further include multiple signal lines. For example, the first conductive pattern layer may further include a reset signal line, a scan signal line, and an enable signal line; the second conductive pattern layer may further include an initialization signal line. For details, please refer to the relevant art and will not be described in detail here.

[0083] It should be noted that, in some exemplary embodiments, the driving circuit layer 101 may further include more conductive pattern layers, such as a fourth conductive pattern layer, which may also be referred to as a first metal routing layer (SD2 layer), or even a fifth conductive pattern layer, which may also be referred to as a first metal routing layer (SD3 layer). These layers may be configured according to actual needs, and the present disclosure does not impose any restrictions on this.

[0084] The light extraction layer 130 (Capping Layer, abbreviated as CPL) is provided on the side of the second electrode 123 of the photoluminescent device away from the base substrate 100. On the one hand, it can protect the second electrode 123, and on the other hand, it can extract a portion of the light that is confined to propagate within the microcavity structure of the display substrate 10, thereby increasing the light emitted by the display substrate 10, thereby improving the electro-optical conversion efficiency of the electroluminescent device 120. It is understandable that among the light emitted from the light-emitting side of the electroluminescent device 120, some light with a larger incident angle is easily totally reflected and reflected back into the electroluminescent device 120, unable to exit. By adding the light extraction layer 130 to the outside of the light-emitting side of the electroluminescent device 120 to change the path of the light, the light coupling efficiency of the device can be effectively improved, allowing the light originally confined inside the device to be emitted, thereby showing a higher light extraction efficiency.

[0085] In some exemplary embodiments, the thickness of the light extraction layer 130 corresponding to sub-pixels of different colors can be the same to simplify the process. Alternatively, the thickness of the light extraction layer 130 corresponding to sub-pixels of different colors can be different. By varying the thickness of the light extraction layer 130, the microcavity length corresponding to the sub-pixels of different colors can be specifically adjusted, thereby further improving the luminous efficiency of the electroluminescent device 120.

[0086] The light extraction layer 130 can have a single-layer structure or a multi-layer structure, and can be configured according to actual needs. For example, the light extraction layer 130 may include: a first sub-light extraction layer 131 and a second sub-light extraction layer 132 arranged in a stacked manner, wherein the first sub-light extraction layer 131 is closer to the second electrode 123 than the second sub-light extraction layer 132, and the refractive index of the first sub-light extraction layer 131 is greater than the refractive index of the second sub-light extraction layer 132, thereby further improving the light extraction efficiency of the light extraction layer 130.

[0087] For example, for the visible light band (such as 450-780 nm), the refractive index of the first sub-light extraction layer 131 can be greater than 2.0, and the refractive index of the second sub-light extraction layer 132 can be less than or equal to 1.4, and the absorption coefficients of the first sub-light extraction layer 131 and the second sub-light extraction layer 132 can both be less than or equal to 0.01.

[0088] For example, the first sub-light extraction layer 131 can be made of materials with a higher refractive index such as N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4-4′-diamine (NPB), triphenyldiamine derivative (TPD), N,N'-diphenyl-N,N'-di(4'-(N,N-di(1-naphthyl)-amino)-4-biphenyl)-benzidine (TPTE), 1,3,5-tris(N-3-methylphenyl-N-phenylamino)benzene (TDAB), copper phthalocyanine (CuPc), etc. The second sub-light extraction layer 132 can be made of LiF, N,N′-diphenyl-N,N′-di(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine, N,N′-di(1-naphthyl)-N,N′-diamine. Materials having a relatively low refractive index include phenyl[1,1'-biphenyl]-4,4'-diamine or 4,4'-bis[N-(3-methylphenyl)-N-phenylamino]biphenyl, N4,N4'-diphenyl-N4,N4'-bis(9-phenyl-9H-carbazol-3-yl)diphenyl-4,4'-diamine, and N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine.

[0089] The thickness of the first sub-light extraction layer 131 and the second sub-light extraction layer 132 can be set according to actual needs. For example, the thickness of the first sub-light extraction layer 131 can be 50 to 100 nanometers, such as 50 nanometers, 60 nanometers, 80 nanometers, or 100 nanometers; and the thickness of the second sub-light extraction layer 132 can be 50 to 150 nanometers, such as 50 nanometers, 80 nanometers, 100 nanometers, or 150 nanometers, to further improve light extraction efficiency.

[0090] In order to facilitate the electrical connection between the auxiliary electrode layer 140 and the second electrode 123, the light extraction layer 130 can be patterned, that is, it has an opening area 133 exposing the second electrode 123, so that the auxiliary electrode layer 140 can be electrically connected to the second electrode 123 from the opening area 133, which is equivalent to connecting the auxiliary electrode layer 140 and the second electrode 123 in parallel, effectively reducing the resistance of the second electrode 123.

[0091] There are many ways to set up the light extraction layer 130. This article mainly lists the following exemplary embodiments for illustration. It should be noted that in addition to the listed setting methods, other applicable setting methods can also be used, and this disclosure does not limit this.

[0092] In some exemplary embodiments, a corresponding light extraction layer 130 may be provided for each sub-pixel. That is, the orthographic projection of the light extraction layer 130 on the substrate 100 at least partially overlaps with the orthographic projection of each sub-pixel on the substrate 100. It should be noted that there are various ways to define the orthographic projection range of a sub-pixel on the substrate 100. For example, it can be defined by the pixel opening corresponding to the sub-pixel. For example, the orthographic projection edge of the upper end of the pixel opening (i.e., the end of the pixel opening relatively far from the first electrode 121) on the substrate 100 can be used to define the orthographic projection range of the sub-pixel on the substrate 100. This can be determined according to actual needs and is not limited in this disclosure.

[0093] For example, the light extraction layer 130 may include: a plurality of light extraction units 1301, with the aforementioned opening regions 133 between adjacent light extraction units 1301. In this case, the opening regions 133 may be a mesh-like opening region, i.e., the opening regions 133 between each light extraction unit 1301 are interconnected. The auxiliary electrode layer 140 covers the plurality of light extraction units 1301 and the opening regions 133 between adjacent light extraction units 1301, and contacts the exposed second electrode 123 at the bottom of the opening regions 133 to achieve electrical connection between the auxiliary electrode layer 140 and the second electrode 123.

[0094] For example, as shown in FIG2 , each light extraction unit 1301 may correspond to covering one sub-pixel. For example, the above-mentioned multiple sub-pixels include a first sub-pixel, a second sub-pixel, and a third sub-pixel, and the multiple light extraction units 1301 may include a first light extraction unit, a second light extraction unit, and a third light extraction unit. The orthographic projection of the first sub-pixel on the substrate 100 is located within the orthographic projection range of the first light extraction unit on the substrate 100, the orthographic projection of the second sub-pixel on the substrate 100 is located within the orthographic projection range of the second light extraction unit on the substrate 100, and the orthographic projection of the third sub-pixel on the substrate 100 is located within the orthographic projection range of the third light extraction unit on the substrate 100, thereby improving the light extraction efficiency of the first sub-pixel, the second sub-pixel, and the third sub-pixel through the mutually independent light extraction units 1301.

[0095] It should be noted that the thicknesses of the first light extraction unit, the second light extraction unit, and the third light extraction unit in the direction perpendicular to the base substrate 100 may be the same, or may be different.

[0096] For example, as shown in Figure 2, the light extraction layer 130 may include a first sub-light extraction layer 131 and a second sub-light extraction layer 132, and the light extraction layer 130 is further divided into a first light extraction unit, a second light extraction unit and a third light extraction unit. The auxiliary electrode layer 140 covers the light extraction layer 130 and the opening area 133 of the light extraction layer 130, and is electrically connected to the second electrode 123 exposed at the opening area 133. At this time, the light emitted from the side of the second electrode 123 of the first sub-pixel first passes through the first sub-light extraction layer 131 and the second sub-light extraction layer 132 at the first light extraction unit, and then passes through the auxiliary electrode layer 140 to be emitted; the light emitted from the side of the second electrode 123 of the second sub-pixel first passes through the first sub-light extraction layer 131 and the second sub-light extraction layer 132 at the second light extraction unit, and then passes through the auxiliary electrode layer 140 to be emitted; the light emitted from the side of the second electrode 123 of the third sub-pixel first passes through the first sub-light extraction layer 131 and the second sub-light extraction layer 132 at the third light extraction unit, and then passes through the auxiliary electrode layer 140 to be emitted.

[0097] Taking into account the difficulty of reserving gaps between each pixel in the process implementation and the complexity of the process, three high-precision metal masks are usually required to realize the evaporation of the light extraction layer 130 above the first sub-pixel, the second sub-pixel and the third sub-pixel respectively. In some embodiments, each light extraction unit 1301 can cover multiple sub-pixels. Figure 3 shows a schematic diagram of the layout of the light extraction unit according to some embodiments of the present disclosure, and Figure 4 shows a schematic diagram of the layout of the light extraction unit according to other embodiments of the present disclosure. For example, as shown in Figure 3, each light extraction unit 1301 can cover two sub-pixels. For another example, as shown in Figure 4, each light extraction unit 1301 can cover three sub-pixels.

[0098] It should be noted that, in actual implementation, the number and shape of sub-pixels covered by the light extraction unit 1301 can be set according to the pixel arrangement adopted. The following mainly lists the layout of the light extraction layer 130 corresponding to two pixel arrangements as examples for illustration. In other embodiments, other pixel arrangements can also be adopted, and the arrangement and shape of the light extraction unit 1301 can be adaptively set. This disclosure does not limit this.

[0099] FIG5 shows a schematic diagram of an exemplary pixel arrangement. As shown in FIG5 , each pixel unit P may include: a first sub-pixel p1, a second sub-pixel p2, and a third sub-pixel p3, and the first sub-pixel p1, the second sub-pixel p2, and the third sub-pixel p3 are arranged in a delta arrangement. It should be noted that the sub-pixel shapes shown in FIG5 are for illustration only and are not intended to be limiting. For example, in addition to the circular shape shown in FIG5 , the sub-pixel shape may also adopt other shapes such as an ellipse, square, triangle, pentagon, or hexagon, or a shape similar to an ellipse, square, triangle, pentagon, or hexagon may also be adopted.

[0100] Considering that when the pixel units P are arranged according to the arrangement shown in FIG5 , the gaps between the first sub-pixel p1, the second sub-pixel p2, and the third sub-pixel p3 are relatively small, providing a light extraction unit 1301 for each sub-pixel would be very difficult to manufacture. Therefore, in some exemplary embodiments, to reduce the difficulty of manufacturing the light extraction layer 130, the pixel structure can be modified based on the pixel arrangement shown in FIG5 , thereby increasing the spacing between adjacent sub-pixels by reducing the pixel aperture ratio, thereby facilitating the corresponding arrangement of each light extraction unit 1301. For example, the pixel aperture ratio of each sub-pixel can be reduced to 50% to 80% of the pixel structure shown in FIG5 , such as 50%, 60%, 70%, or 80%.

[0101] Figure 6 shows a schematic plan view of a pixel structure and a light extraction layer according to some embodiments of the present disclosure. As shown in Figure 6, in some exemplary embodiments, the first subpixel p1, the second subpixel p2, and the third subpixel p3 may include a first edge and a second edge opposite the first edge, wherein the first edge is a straight line and the second edge is a curved line. A line connecting the center points of the first subpixel p1, the second subpixel p2, and the third subpixel p3 forms a triangle, wherein the second edge of the first subpixel p1 is opposite the second edge of the second subpixel p2, and the second edge of the third subpixel p3 is toward the first subpixel p1 and the second subpixel p2. For example, the opening area of ​​each subpixel can be reduced by half based on the pixel structure shown in Figure 5. In this case, if the subpixel shape before the improvement was circular, then after the improvement, the planar shape of the first subpixel p1, the second subpixel p2, and the third subpixel p3 can be semicircular. If the subpixel shape before the improvement was elliptical, then after the improvement, the planar shape of the first subpixel p1, the second subpixel p2, and the third subpixel p3 can be semi-elliptical. Of course, if the shape of the sub-pixels before improvement is a square, then after improvement, the first sub-pixel p1 , the second sub-pixel p2 and the third sub-pixel p3 may be squares with reduced areas.

[0102] At this point, to further reduce the difficulty of processing the light extraction layer 130, as shown in Figure 6, each light extraction unit 1301 can cover a pixel unit P. For example, multiple pixel units P and multiple light extraction units 1301 can be provided in a one-to-one correspondence, and the orthographic projection of each sub-pixel contained in each pixel unit P on the base substrate 100 can be located within the orthographic projection range of the corresponding light extraction unit 1301 on the base substrate 100. In this case, the opening area 133 located between adjacent light extraction units 1301 can be a mesh-shaped opening area as shown in Figure 6.

[0103] For example, as shown in FIG6 , the planar shape of the light extraction unit 1301 can be a hexagon, which includes: a first side, a second side, a third side, a fourth side, a fifth side, and a sixth side connected in sequence. The first side is arranged opposite to the fourth side, the second side is arranged opposite to the sixth side, and the third side is arranged opposite to the fifth side; the length of the first side is less than the length of the fourth side, and the extension direction of the fourth side is parallel to the arrangement direction of the first sub-pixel p1 and the second sub-pixel p2; the first edge of the first sub-pixel p1 and the first edge of the second sub-pixel p2 are arranged opposite to the third side and the fifth side, respectively, and the first edge of the third sub-pixel p3 is arranged opposite to the first side. Of course, in addition to the planar shape shown in FIG6 , in other embodiments, the planar shape of the light extraction unit 1301 can also be other shapes such as a triangle, a rhombus, a circle, or an ellipse, etc., and the present disclosure does not limit this.

[0104] For example, according to the pixel arrangement shown in FIG5 , for the same column of pixel units P, the third sub-pixel p3 is on the same side of the line connecting the centers of the first sub-pixel p1 and the second sub-pixel p2. For two adjacent columns of pixel units P, the third sub-pixel p3 is on different sides of the line connecting the centers of the first sub-pixel p1 and the second sub-pixel p2. Accordingly, for the same column of light extraction units 1301 arranged along the pixel column direction, the first sides are oriented in the same direction, while the first sides of the light extraction units 1301 in two adjacent columns are oriented in opposite directions.

[0105] Figure 7 shows another exemplary pixel arrangement. As shown in Figure 7 , each pixel unit P includes: a first sub-pixel p1, two second sub-pixels p2, and a third sub-pixel p3. Within the same pixel unit P, a line connecting the center points of the first sub-pixel p1, the two second sub-pixels p2, and the third sub-pixel p3 forms a diamond shape. The area of ​​the second sub-pixel p2 is smaller than the area of ​​the first sub-pixel p1 and the area of ​​the third sub-pixel p3. The area of ​​the first sub-pixel p1 can be smaller than or equal to the area of ​​the third sub-pixel p3. For example, the first sub-pixel p1 is a red sub-pixel, the second sub-pixel p2 is a green sub-pixel, and the third sub-pixel p3 is a blue sub-pixel. It should be noted that the first sub-pixel p1 and the third sub-pixel p3 can be square as shown in Figure 7 , and the second sub-pixel p2 can be elliptical as shown in Figure 7 . Alternatively, the first sub-pixel p1, the second sub-pixel p2, and the third sub-pixel p3 can also have other shapes, such as triangles, circles, pentagons, or hexagons. These shapes can be arranged as needed and are not limited in this disclosure.

[0106] The spacing between adjacent first sub-pixels p1 and third sub-pixels p3 is a first distance, the spacing between adjacent second sub-pixels p2 is a second distance, the spacing between adjacent first sub-pixels p1 and second sub-pixels p2 is a third distance, and the spacing between adjacent second sub-pixels p2 and third sub-pixels p3 is a fourth distance. The first distance and the second distance are greater than the third distance and the fourth distance.

[0107] Taking into account that according to the pixel arrangement adopted in FIG7 , there are relatively large gaps between some sub-pixels. Therefore, when laying out the light extraction layer 130, the opening areas 133 of adjacent light extraction units 1301 can be set correspondingly at positions where these gaps are relatively large. FIG8 shows a planar schematic diagram of the pixel structure and the light extraction layer 130 according to some embodiments of the present disclosure. For example, as shown in FIG8 , the light extraction unit 1301 can be a bent strip structure, and among the above-mentioned multiple light extraction units 1301, at least a portion of the light extraction units 1301 covers a first sub-pixel p1, a second sub-pixel p2, and a third sub-pixel p3, and at least a portion of the light extraction units 1301 covers a first sub-pixel p1, two second sub-pixels p2, and a third sub-pixel p3. At this time, the above-mentioned opening area 133 between adjacent light extraction units 1301 can be a mesh opening area as shown in FIG8 .

[0108] Furthermore, the inventors have discovered through research that the absorption spectrum of the second electrode 123 shows greater absorption in short-wavelength bands, such as blue light, compared to long-wavelength bands, such as red light. Taking the red sub-pixel, for example, directly placing the auxiliary electrode layer 140 on the second electrode 123 of the red sub-pixel without the light extraction layer 130 can also improve luminous efficiency. This is because, while placing the auxiliary electrode layer 140 on the second electrode 123 increases the reflectivity of the second electrode 123, this increased reflected light can enhance the microcavity effect of the electroluminescent device 120, thereby improving luminous efficiency.

[0109] Thus, in some exemplary embodiments, the emission wavelength of the first sub-pixel is greater than the emission wavelengths of the second and third sub-pixels. Therefore, the orthographic projection of the light extraction layer 130 on the substrate 100 may at least partially overlap with the orthographic projection of the second sub-pixel on the substrate 100; and / or, the orthographic projection of the light extraction layer 130 on the substrate 100 may at least partially overlap with the orthographic projection of the third sub-pixel on the substrate 100, thereby increasing the light extraction efficiency of the second and / or third sub-pixels by providing the light extraction layer 130. For the first sub-pixel, a corresponding light extraction layer 130 may also be provided as shown in FIG2 to more comprehensively protect the second electrode 123 of each sub-pixel. Alternatively, the light extraction layer 130 does not need to be covered above the first sub-pixel, that is, the opening area of ​​the light extraction layer 130 is set at a position directly opposite the first sub-pixel, so that the auxiliary electrode layer 140 is in direct contact with the second electrode 123. On the one hand, it can enhance the microcavity effect to improve the luminous efficiency, and on the other hand, it can also realize the electrical connection between the auxiliary electrode layer 140 and the second electrode 123, reduce the resistance of the second electrode, and also help to reduce the difficulty of the process.

[0110] FIG9 shows a schematic diagram of the stacked structure of the display substrate 10 according to some embodiments of the present disclosure, and FIG10 shows a schematic plan view of the display substrate 10 of FIG9 , wherein FIG9 is a cross-sectional view taken along the AA section line in FIG10 . For example, as shown in FIG9 and FIG10 , the light extraction layer 130 (such as the dot-filled area in FIG10 ) can cover the second sub-pixel p2 and the third sub-pixel p3, while the light extraction layer 130 is not covered above the first sub-pixel p1, that is, the opening area 133 of the light extraction layer 130 is set at the position corresponding to the first sub-pixel. For example, the orthographic projections of the second sub-pixel p2 and the third sub-pixel p3 on the base substrate 100 can be located within the orthographic projection of the light extraction layer 130 on the base substrate 100. For example, the first sub-pixel p1 can be a red sub-pixel, and one of the second sub-pixel p2 and the third sub-pixel p3 can be a green sub-pixel and the other can be a blue sub-pixel.

[0111] For example, the orthographic projection of the opening area 133 of the light extraction layer 130 on the substrate 100 at least partially overlaps with the orthographic projection of the first sub-pixel on the substrate 100. In this case, the light extraction layer 130 has a plurality of independent and spaced-apart opening areas 133, and the auxiliary electrode layer 140 can cover these opening areas 133 and contact the second electrode 123 exposed at the opening areas 133, thereby achieving electrical connection between the two. For example, as shown in Figure 10, the orthographic projection of the first sub-pixel p1 on the substrate 100 can be located within the orthographic projection of the opening area 133 on the substrate 100. For example, the shape and size of the opening area 133 can be set according to the shape and size of the first sub-pixel p1.

[0112] As shown in Figure 9, the light extraction layer 130 may include a first sub-light extraction layer 131 and a second sub-light extraction layer 132. The light emitted from the second electrode 123 side of the second sub-pixel and the third sub-pixel passes through the first sub-light extraction layer 131, the second sub-light extraction layer 132 and the auxiliary electrode layer 140 in sequence, while the light emitted from the second electrode 123 side of the first sub-pixel is emitted through the auxiliary electrode layer 140.

[0113] For example, as shown in Figure 9, the thickness of the light extraction layer 130 covering the second sub-pixel and the light extraction layer 130 covering the third sub-pixel can be set to the same. In this case, the light extraction layer 130 not only covers the second sub-pixel and the third sub-pixel, but also covers the spacing area between the second sub-pixel and the third sub-pixel. For example, the thickness of the first sub-light extraction layer 131 can be 50 to 100 nanometers, such as 50 nanometers, 60 nanometers, 80 nanometers, or 100 nanometers; the thickness of the second sub-light extraction layer 132 can be 50 to 150 nanometers, such as 50 nanometers, 80 nanometers, 100 nanometers, or 150 nanometers, so as to further improve the light extraction efficiency.

[0114] For example, the thickness of the light extraction layer 130 can also be set according to the luminous color of the covered sub-pixel, that is, the thickness of the light extraction layer 130 covering the second sub-pixel is different from the thickness of the light extraction layer 130 covering the third sub-pixel, so as to specifically improve the light extraction efficiency of sub-pixels of different colors. Figure 11 shows a schematic diagram of the stacked structure of the display substrate 10 according to some embodiments of the present disclosure. In Figure 11, taking the first sub-pixel as a red sub-pixel, the second sub-pixel as a green sub-pixel, and the third sub-pixel as a blue sub-pixel as an example, the light extraction layer 130 is not covered above the first sub-pixel, and the thickness of the light extraction layer 130 covering the third sub-pixel can be less than the thickness of the light extraction layer 130 covering the second sub-pixel. For example, the thickness of the first sub-light extraction layer 131 covering the second sub-pixel can be 80 to 100 nanometers, such as 80 nanometers, 90 nanometers or 100 nanometers, and the thickness of the second light extraction layer 130 can be 80 to 100 nanometers, such as 80 nanometers, 90 nanometers or 100 nanometers; and the thickness of the first sub-light extraction layer 131 covering the third sub-pixel can be 60 to 80 nanometers, such as 60 nanometers, 70 nanometers or 80 nanometers, and the thickness of the second sub-light extraction layer 132 can be 80 to 100 nanometers, such as 80 nanometers, 90 nanometers or 100 nanometers.

[0115] As shown in Figures 2 and 9, the auxiliary electrode layer 140 is disposed on a side of the light extraction layer 130 away from the second electrode 123. The auxiliary electrode layer 140 is electrically connected to the second electrode 123 through the opening region 133 to reduce the resistance of the second electrode 123. The orthographic projections of the auxiliary electrode layer 140 and the second electrode 123 on the base substrate 100 overlap.

[0116] In some example embodiments, the auxiliary electrode layer 140 can be a single-layer structure, and the auxiliary electrode layer 140 is stacked on the side of the light extraction layer 130 away from the base substrate 100, covering the first sub-pixel, the second sub-pixel, the third sub-pixel and the spacing area between each sub-pixel, and is electrically connected to the second electrode 123 at the opening area 133 of the light extraction layer 130.

[0117] For example, the auxiliary electrode layer 140 can be made of a transparent conductive material, making the auxiliary electrode layer 140 both conductive and light-transmissive. This reduces the resistance of the second electrode 123 while minimizing the loss in luminous efficiency caused by the auxiliary electrode layer 140. For example, the auxiliary electrode layer 140 can be made of an oxide semiconductor material, such as indium zinc oxide (IZO), indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or aluminum-doped zinc oxide (AZO). For example, the thickness of the auxiliary electrode layer 140 can be 100 to 1000 nanometers, and the transmittance of the auxiliary electrode layer 140 for light with a wavelength of 532 nm is greater than 90%.

[0118] In some example embodiments, the auxiliary electrode layer 140 may also have a multi-layer film structure. The auxiliary electrode layer 140 may include multiple transparent conductive layers stacked and electrically connected to each other, with the multiple transparent conductive layers sequentially arranged in a direction away from the base substrate 100. The auxiliary electrode layer 140 composed of multiple transparent conductive layers can further reduce the resistance of the second electrode 123.

[0119] In addition, the inventors have discovered through research that by adapting the thickness of the auxiliary electrode layer 140 to the thickness of the light extraction layer 130, the auxiliary electrode layer 140 can not only reduce the resistance of the second electrode 123, but also cooperate with the light extraction layer 130 to adjust the path of light and extract more display light, thereby improving the luminous efficiency of the device.

[0120] In order to obtain a suitable thickness range, the inventors conducted a comparative test during the research process, taking the first sub-pixel as a red sub-pixel, the second sub-pixel as a green sub-pixel, the third sub-pixel as a blue sub-pixel, and the auxiliary electrode layer 140 as indium zinc oxide (IZO) as an example. The reference device of the comparative test is a device provided with a light extraction layer 130 such as the first sub-light extraction layer 131 and the second sub-light extraction layer 132, but without an auxiliary electrode layer 140. At this time, the thickness of the first sub-light extraction layer 131 and the second sub-light extraction layer 132 is a thickness that simply considers the light extraction efficiency without considering the light regulation in cooperation with the auxiliary electrode layer 140. First test the luminous efficiency of the reference device, that is, the electro-optical conversion efficiency, and normalize the luminous efficiency of the reference device to 100% for comparison.

[0121] Then, based on the reference device, an auxiliary electrode layer 140 was provided above the first sub-light extraction layer 131 and the second sub-light extraction layer 132. To improve luminous efficiency compared to the reference device, the thicknesses of the first sub-light extraction layer 131, the second sub-light extraction layer 132, and the auxiliary electrode layer 140 were comprehensively adjusted. The results of these comparative tests are described below using the several exemplary embodiments provided above as examples.

[0122] The first set of comparative tests corresponds to the embodiment shown in FIG2 . FIG12 shows the test result of the first set of comparative tests according to some embodiments of the present disclosure, where the horizontal axis represents the thickness of the auxiliary electrode layer 140 in nanometers, and the vertical axis represents the luminous efficiency. For example, the thickness of the light extraction layer 130 of different color sub-pixels in the reference device is equal, the thickness of the first sub-light extraction layer 131 is 80 nanometers, and the thickness of the second sub-light extraction layer 132 is 60 nanometers. The dotted line L0 in FIG12 represents the luminous efficiency of the reference device (100%), the curve LR represents the red light efficiency curve, the curve LG represents the green light efficiency curve, and the curve LB represents the blue light efficiency curve. It can be seen from FIG12 that within a certain range of the thickness of the auxiliary electrode layer 140, as the thickness of the auxiliary electrode layer 140 increases, the red light luminous efficiency shows a trend of first decreasing and then increasing; the green light luminous efficiency shows a trend of increasing and then decreasing, and the blue light luminous efficiency shows a trend of continuously decreasing. Compared with the reference device, by setting the auxiliary electrode layer 140 and adjusting the thickness of the light extraction layer 130 and the thickness of the auxiliary electrode layer 140, the luminous efficiency of the red sub-pixel can be increased by 20%, and the luminous efficiency of the blue sub-pixel and the green sub-pixel can be increased by 2%, which is beneficial to improving the luminous efficiency of the display substrate 10.

[0123] The second set of comparative tests corresponds to the embodiment shown in Figure 9. Figure 13 shows the test results of the second set of comparative tests according to some embodiments of the present disclosure. As shown in Figure 13, it is not necessary to provide a light extraction layer 130 above the red sub-pixel. With the auxiliary electrode layer 140, light extraction can be enhanced, thereby improving luminous efficiency. Within a certain range of auxiliary electrode layer 140 thickness, the red light luminous efficiency shows a continuous decrease with increasing thickness; the green light luminous efficiency shows a trend of increasing and then decreasing, and the blue light luminous efficiency shows a continuous decrease. Compared to the reference device, by providing an auxiliary electrode layer 140 and adjusting the thickness of the light extraction layer 130 covering the green and blue sub-pixels, as well as the thickness of the auxiliary electrode layer 140 above each sub-pixel, the luminous efficiency of the red sub-pixel can be increased by 15-20%, the luminous efficiency of the green sub-pixel by approximately 2%, and the luminous efficiency of the blue sub-pixel by ±2%, thereby improving the luminous efficiency of the display substrate 10.

[0124] The third group of comparative tests corresponds to the embodiment shown in FIG11 . FIG14 shows a graph of the test results of the third group of comparative tests according to some embodiments of the present disclosure. As can be seen from FIG14 , by differentially setting the thickness of the light extraction layer 130 covering the green sub-pixel and the blue sub-pixel, it is beneficial to improve the overall luminous efficiency of the green sub-pixel and the blue sub-pixel. For example, as shown in FIG14 , compared with the reference device, by setting the auxiliary electrode layer 140 and adjusting the thickness of the light extraction layer 130 covering the green sub-pixel and the blue sub-pixel differently, and adjusting the thickness of the auxiliary electrode layer 140, the luminous efficiency of the red sub-pixel can be increased by 15 to 21%, the luminous efficiency of the green sub-pixel can be increased by about 4% to 6%, and the luminous efficiency of the blue sub-pixel can be increased by -1% to 4%, thereby helping to improve the luminous efficiency of the display substrate 10.

[0125] Based on the above research, it was found that as the thickness of the auxiliary electrode layer 140 increases, there are differences in the change trends of the luminous efficiency of sub-pixels of different colors. Therefore, the thickness of the auxiliary electrode layer 140 area corresponding to sub-pixels of different colors can be set differently to further improve the luminous efficiency of each sub-pixel while reducing the resistance of the second electrode 123, thereby improving the luminous efficiency of the display substrate 10.

[0126] Figure 15 shows a schematic diagram of the stacked structure of a display substrate 10 according to some embodiments of the present disclosure. As shown in Figure 15 , in some exemplary embodiments, the first sub-pixel is a red sub-pixel, the second sub-pixel is a green sub-pixel, and the third sub-pixel is a blue sub-pixel. The auxiliary electrode layer 140 may include a first region 1401 corresponding to the first sub-pixel, a second region 1402 corresponding to the second sub-pixel, and a third region 1403 corresponding to the third sub-pixel. The thickness of the third region 1403 is less than that of the second region 1402, and the thickness of the first region 1401 is less than or equal to that of the second region 1402. For example, the thickness of the first region 1401 can be 100 to 150 nanometers, such as 100 nanometers, 110 nanometers, 130 nanometers, 140 nanometers, or 150 nanometers, etc. The thickness of the second region 1402 can be 250 to 350 nanometers, such as 250 nanometers, 300 nanometers, or 350 nanometers, etc. The thickness of the third region 1403 can be 100 to 150 nanometers, such as 100 nanometers, 110 nanometers, 130 nanometers, 140 nanometers, or 150 nanometers, etc. The thicknesses of the first region 1401 and the third region 1403 can be the same or different, depending on actual needs.

[0127] For example, during the preparation process, a transparent conductive film with a thickness of 250 to 350 nanometers can be formed first, and then the transparent conductive film above the red sub-pixel and the transparent conductive film above the blue sub-pixel are etched using an etching process to reduce the thickness of the transparent conductive film above the red sub-pixel and the blue sub-pixel to 100 to 150 nanometers, thereby obtaining the auxiliary electrode layer 140.

[0128] In order to verify the effect of differentially setting the thickness of the auxiliary electrode layer 140, a fourth set of comparative tests was also conducted corresponding to the embodiment shown in FIG15. FIG16 shows the test results of the fourth set of comparative tests according to some embodiments of the present disclosure. As shown in FIG16, compared with the reference device, when the thickness of the first region 1401 is 120 nanometers, the thickness of the second region 1402 is 300 nanometers, and the thickness of the third region 1403 is 100 nanometers, the luminous efficiency of the red sub-pixel R can be increased by 16%, the luminous efficiency of the green sub-pixel G can be increased by about 5%, and the luminous efficiency of the blue sub-pixel B can be increased by 2%, thereby helping to improve the luminous efficiency of the display substrate 10.

[0129] In addition, the number of light extraction layers 130 and auxiliary electrode layers 140 included in the display substrate 10 can be set according to actual needs. For example, in the embodiments corresponding to Figures 2, 9, 11, and 15, the display substrate 10 includes one light extraction layer 130 and one auxiliary electrode layer 140. In other exemplary embodiments, the display substrate 10 may also include multiple light extraction layers 130 and multiple auxiliary electrode layers 140. The multiple light extraction layers 130 and multiple auxiliary electrode layers 140 are alternately stacked on the side of the second electrode 123 away from the base substrate 100, so as to reduce the resistance of the second electrode 123 while improving the luminous efficiency of the light-emitting substrate.

[0130] In some embodiments, to minimize the thickness of the display substrate 10, the thickness of each layer in a solution with multiple light extraction layers 130 and multiple auxiliary electrode layers 140 can be reduced compared to a solution with a single light extraction layer 130 and a single auxiliary electrode layer 140. For example, if the display substrate 10 includes m light extraction layers 130 and m auxiliary electrode layers 140 (m is an integer greater than or equal to 2) arranged in an alternating stack, the thickness of each layer can be reduced to one-mth of that in a solution with a single light extraction layer 130 and a single auxiliary electrode layer 140.

[0131] Figure 17 shows a schematic diagram of the stacked structure of a display substrate 10 according to some embodiments of the present disclosure. For example, as shown in Figure 17, the display substrate 10 may include two light extraction layers 130a and 130b and two auxiliary electrode layers 140a and 140b. The two light extraction layers 130a and 130b and the two auxiliary electrode layers 140a and 140b are arranged in an alternating manner, with the light extraction layer 130 being arranged first and the auxiliary electrode layer 140 being arranged second and third sub-pixels, respectively. The light extraction layers 130a and 130b are arranged corresponding to the second and third sub-pixels, and include a first sub-light extraction layer 131 and a second sub-light extraction layer 132. Both the light extraction layer 130a and the light extraction layer 130b are provided with an opening area 133 above the first sub-pixel, the auxiliary electrode layer 140a covers the light extraction layer 130a, and contacts the exposed second electrode 123 at the opening area 133 to achieve electrical connection, and the auxiliary electrode layer 140b covers the light extraction layer 130b, and contacts the exposed auxiliary electrode layer 140a at the opening area 133 to achieve electrical connection.

[0132] In some exemplary embodiments, the display substrate 10 further includes: an encapsulation layer (not shown in the figure), which is arranged on the side of the auxiliary electrode layer 140 away from the base substrate 100 to encapsulate the electroluminescent device 120 of each sub-pixel and prevent water and oxygen from corroding and damaging the device.

[0133] For example, the encapsulation layer may include a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer stacked in sequence. The first encapsulation layer and the third encapsulation layer may be inorganic encapsulation layers, for example, inorganic materials such as nitrides, oxides, nitrogen oxides, nitrates, carbides, or any combination thereof may be used, and the preparation process may be a chemical vapor deposition (CVD) process. The second encapsulation layer may be an organic encapsulation layer, for example, organic materials such as acrylic, hexamethyldisiloxane, polyacrylates, polycarbonates, polystyrene, etc. may be used, and the preparation process may be an inkjet printing (IJP) process. For example, the refractive index of the first encapsulation layer may be greater than the refractive index of the second sub-light extraction layer 132, and less than the refractive index of the first sub-light extraction layer 131, so as to further improve the luminous efficiency of the display substrate 10. For example, the refractive index of the first encapsulation layer can be 1.5-1.9, such as 1.5, 1.6, 1.7 or 1.9, the refractive index of the second encapsulation layer can be 1.2-1.6, such as 1.2, 1.4 or 1.6, and the refractive index of the third encapsulation layer can be 1.5, 1.6, 1.7 or 1.9.

[0134] Of course, in other embodiments, the display substrate 10 may also include other film layer structures, such as but not limited to a touch layer (not shown in the figure) for providing a touch function, a color filter layer (or polarizer) (not shown in the figure), and a cover layer (not shown in the figure) for protecting the display substrate 10, etc., which can be set according to the needs of the actual application scenario, and the present disclosure does not impose any restrictions on this.

[0135] Figure 18 shows a schematic diagram of the structure of a display device according to some embodiments of the present disclosure. As shown in Figure 18, some embodiments of the present disclosure provide a display device 20, including the display substrate 10 provided in any of the embodiments described above. The display device 20 can be, for example, a monitor, a television, a tablet computer, a laptop computer, a mobile phone, a digital photo frame, a navigation system, or any other product or component with a display function. Of course, the display device 20 provided in the embodiments of the present disclosure is not limited to the types listed above.

[0136] It should be noted that the drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures can refer to general designs. In the absence of conflict, the embodiments of the present disclosure and the features therein can be combined with each other to obtain new embodiments.

[0137] Although some embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the present disclosure.

Claims

1. A display substrate, comprising: substrate substrate; A plurality of pixel units arranged in an array, each pixel unit comprising a plurality of sub-pixels, each sub-pixel comprising: a first electrode, a light-emitting functional layer and a second electrode stacked on the substrate; a light extraction layer, disposed on a side of the second electrode away from the base substrate, the light extraction layer having an opening region exposing the second electrode; and an auxiliary electrode layer, disposed on a side of the light extraction layer away from the second electrode, the auxiliary electrode layer and the orthographic projection of the second electrode on the base substrate at least partially overlap, and the auxiliary electrode layer is electrically connected to the second electrode through the opening area; At least a portion of the light emitted by the sub-pixel is incident on the auxiliary electrode layer through the light extraction layer, and then transmitted from the auxiliary electrode layer.

2. The display substrate according to claim 1, wherein: The plurality of sub-pixels include a first sub-pixel, a second sub-pixel and a third sub-pixel, wherein the light emission wavelength of the first sub-pixel is greater than the light emission wavelengths of the second sub-pixel and the third sub-pixel; The orthographic projection of the light extraction layer on the base substrate at least partially overlaps with the orthographic projection of the second sub-pixel on the base substrate; and / or The orthographic projection of the light extraction layer on the base substrate at least partially overlaps with the orthographic projection of the third sub-pixel on the base substrate.

3. The display substrate according to claim 2, wherein: The orthographic projections of the second sub-pixel and the third sub-pixel on the base substrate are located within the orthographic projection range of the light extraction layer on the base substrate.

4. The display substrate according to claim 2, wherein: The orthographic projection of the opening area on the base substrate at least partially overlaps with the orthographic projection of the first sub-pixel on the base substrate, and the auxiliary electrode layer covers the opening area and contacts the second electrode exposed in the opening area.

5. The display substrate according to claim 4, wherein: The orthographic projection of the first sub-pixel on the base substrate is located within the orthographic projection range of the opening area on the base substrate.

6. The display substrate according to claim 2, characterized in that: The first sub-pixel is a red sub-pixel, the second sub-pixel is a green sub-pixel, and the third sub-pixel is a blue sub-pixel.

7. The display substrate according to any one of claims 1 to 6, wherein: The thickness of the light extraction layer corresponding to the sub-pixels of different colors is the same, or the thickness of the light extraction layer corresponding to the sub-pixels of different colors is different.

8. The display substrate according to any one of claims 1 to 6, wherein: The light extraction layer includes: a first sub-light extraction layer and a second sub-light extraction layer which are stacked, wherein the first sub-light extraction layer is closer to the second electrode than the second sub-light extraction layer, and the refractive index of the first sub-light extraction layer is greater than the refractive index of the second sub-light extraction layer.

9. The display substrate according to claim 8, wherein: The thickness of the first sub-light extraction layer is 50 to 100 nanometers, the thickness of the second sub-light extraction layer is 50 to 150 nanometers, and the thickness of the auxiliary electrode layer is 100 to 1000 nanometers.

10. The display substrate according to claim 2, wherein: The first sub-pixel is a red sub-pixel, the second sub-pixel is a green sub-pixel, and the third sub-pixel is a blue sub-pixel; The auxiliary electrode layer includes: a first area corresponding to the first sub-pixel, a second area corresponding to the second sub-pixel, and a third area corresponding to the third sub-pixel; In a direction perpendicular to the substrate, the thickness of the third region is smaller than the thickness of the second region, and the thickness of the first region is The thickness is less than or equal to the thickness of the second region.

11. The display substrate according to claim 10, wherein: In a direction perpendicular to the substrate, the thickness of the first region is 100-150 nanometers, the thickness of the second region is 250-350 nanometers, and the thickness of the third region is 100-150 nanometers.

12. The display substrate according to any one of claims 1 to 3, wherein: The light extraction layer includes: a plurality of light extraction units, the opening area is provided between adjacent light extraction units, and each of the light extraction units covers one sub-pixel or a plurality of sub-pixels.

13. The display substrate according to claim 12, wherein: Each of the light extraction units covers one of the pixel units.

14. The display substrate according to claim 13, wherein: The pixel unit comprises: a first sub-pixel, a second sub-pixel and a third sub-pixel, wherein the first sub-pixel, the second sub-pixel and the third sub-pixel comprise a first edge and a second edge arranged opposite to the first edge, the first edge is a straight line, and the second edge is a curve; The center points of the first sub-pixel, the second sub-pixel and the third sub-pixel are connected to form a triangle, the second edge of the first sub-pixel is arranged opposite to the second edge of the second sub-pixel, and the second edge of the third sub-pixel is arranged toward the first sub-pixel and the second sub-pixel.

15. The display substrate according to claim 14, wherein: The planar shapes of the first sub-pixel, the second sub-pixel and the third sub-pixel are circular, semi-circular or semi-elliptical.

16. The display substrate according to claim 14, wherein: The planar shape of the light extraction unit is a hexagon, and the hexagon includes: a first side, a second side, a third side, a fourth side, a fifth side and a sixth side connected in sequence, the first side is arranged opposite to the fourth side, the second side is arranged opposite to the sixth side, and the third side is arranged opposite to the fifth side; The length of the first side is smaller than the length of the fourth side, and the extension direction of the fourth side is parallel to the arrangement direction of the first sub-pixel and the second sub-pixel; The first edge of the first sub-pixel and the first edge of the second sub-pixel are respectively arranged opposite to the third side and the fifth side, and the first edge of the third sub-pixel is arranged opposite to the first side.

17. The display substrate according to claim 12, wherein: The pixel unit comprises: a first sub-pixel, two second sub-pixels and a third sub-pixel, the area of ​​the second sub-pixel is smaller than the area of ​​the first sub-pixel and the area of ​​the third sub-pixel, and the center points of the first sub-pixel, the two second sub-pixels and the third sub-pixel are connected in a rhombus shape; The spacing between adjacent first sub-pixels and the third sub-pixels is a first distance, the spacing between adjacent second sub-pixels is a second distance, the spacing between adjacent first sub-pixels and the second sub-pixels is a third distance, the spacing between adjacent second sub-pixels and the third sub-pixels is a fourth distance, and the first distance and the second distance are greater than the third distance and the fourth distance; The light extraction unit is a bent strip structure, and among the multiple light extraction units, at least a portion of the light extraction units covers one first sub-pixel, one second sub-pixel and one third sub-pixel, and at least a portion of the light extraction units covers one first sub-pixel, two second sub-pixels and one third sub-pixel.

18. The display substrate according to any one of claims 1 to 6, wherein: It comprises a plurality of the light extraction layers and a plurality of the auxiliary electrode layers, wherein the plurality of the light extraction layers and the plurality of the auxiliary electrode layers are alternately stacked and arranged on a side of the second electrode away from the base substrate.

19. The display substrate according to any one of claims 1 to 6, wherein: The first electrode is a reflective electrode, the second electrode is configured to partially transmit and partially reflect the light emitted by the light-emitting functional layer, and the second electrodes of adjacent sub-pixels are connected to each other.

20. The display substrate according to any one of claims 1 to 6, wherein: The second electrode comprises a metal material, and the auxiliary electrode layer comprises a transparent conductive material.

21. A display substrate, comprising: substrate substrate; A plurality of pixel units arranged in an array, each pixel unit comprising a first sub-pixel, a second sub-pixel and a third sub-pixel, the first sub-pixel being a red sub-pixel, and each sub-pixel comprising: a first electrode, a light-emitting functional layer and a second electrode stacked on the base substrate; a light extraction layer, disposed on a side of the second electrode away from the base substrate, the light extraction layer covers the second sub-pixel and the third sub-pixel, and has an opening area exposing the second electrode of the first sub-pixel; and an auxiliary electrode layer, disposed on a side of the light extraction layer away from the second electrode, the auxiliary electrode layer covering the light extraction layer and the opening area, and electrically connected to the exposed second electrode at the bottom of the opening area; The light emitted by the first sub-pixel is emitted through the auxiliary electrode layer, and the light emitted by the second sub-pixel and the third sub-pixel is emitted through the light extraction layer and the auxiliary electrode layer.

22. A display device, comprising: The display substrate according to any one of claims 1 to 21.

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