Substrate and display device

Abstract

The present disclosure provides a display substrate, the display substrate including a pixel definition layer 304 disposed on a base 101, the pixel definition layer 304 having a pixel opening, the pixel opening exposing at least a portion of a surface of a first electrode 301, and at least a portion of a second electrode 303 covering the pixel opening, the pixel definition layer 304 having a first side surface close to the first electrode 301, the first side surface including n first step portions 1 sequentially arranged along a light emission direction of the light emitting functional layer 302, the first step portions 1 including first step side portions 11, and an inclination angle a of the first step side portion 11 of the i-th first step portion 1 i is the inclination angle a of the first step side surface 11 of the first step 1 of the jth step j The first step 1 of the i-th stage is located closer to the base 101 of the first step 1 of the j-th stage, and i, j, and n are all natural numbers, and n is greater than 1 and is equal to or greater than 0.

Description

[Technical Field]

[0001] The present disclosure relates to, but is not limited to, the field of display technology, and specifically to display substrates and display devices. [Background technology]

[0002] Micro organic light emitting diode (Micro OLED) displays have gradually become a hotspot in display technology, and are mainly applied in the fields of near-eye displays, virtual reality, augmented reality, etc. Micro organic light emitting diodes can be applied to near-eye display devices such as AR / VR head-mounted display devices.

[0003] Micro organic light-emitting diodes (MOLEDs) are a new type of silicon-based OLED display device that features small size, high resolution, and is fabricated using mature complementary metal oxide semiconductor (CMOS) processes, enabling active pixel addressing and lightweight design. Summary of the Invention [Means for solving the problem]

[0004] The following is a summary of the subject matter described herein, which does not limit the scope of protection of the claims.

[0005] In one aspect, the present disclosure provides a display substrate, With the base, a light emitting element provided on the base, the light emitting element including a first electrode, a light emitting functional layer, and a second electrode sequentially stacked along a direction away from the base; a pixel definition layer disposed on the base, the pixel definition layer having a pixel opening, the pixel opening exposing at least a portion of the surface of the first electrode, and at least a portion of the second electrode covering the pixel opening; the pixel definition layer includes a first side face close to the first electrode, the first side face includes n first steps sequentially arranged along a light emission direction of the light emitting functional layer, the first steps include a first step side face, an inclination angle of the first step side face of the i-th first step is larger than an inclination angle of the first step side face of the j-th first step, and the i-th first step is located on a side of the j-th first step close to the base, i, j, and n are all natural numbers, and n is greater than 1 and 0 <i<j≦nである。

[0006] In some examples, the first side includes three first steps arranged sequentially along the light emission direction of the light-emitting functional layer, and the inclination angle of the first step side of the first step of the first step of the first step is greater than the inclination angle of the first step side of the first step of the second step, and the inclination angle of the first step side of the first step of the second step is greater than the inclination angle of the first step side of the first step of the third step.

[0007] In some examples, the inclination angle of the first step side of the first step of the first step is 65 degrees to 75 degrees, the inclination angle of the first step side of the first step of the second step is 50 degrees to 60 degrees, and the inclination angle of the first step side of the first step of the third step is 40 degrees to 45 degrees.

[0008] In some examples, the step thickness of the i step is greater than the step thickness of the j step.

[0009] In some examples, the step length of the i-th step is greater than the step length of the j-th step.

[0010] In some examples, the pixel definition layer further includes a second side surface away from the first electrode, the second side surface including one second step, the second step including a second step side surface, and a slope angle of the second step side surface of the second step being greater than a slope angle of the first step side surface of the i-th step.

[0011] In some examples, the inclination angle of the second step side surface of the second step is 80 degrees to 90 degrees.

[0012] In some examples, the pixel definition layer further includes a second side surface away from the first electrode, the second side surface including m second steps sequentially arranged along the light emission direction of the light-emitting functional layer, the second steps including a second step side surface, a slope angle of the second step side surface of the zth second step being larger than a slope angle of the second step side surface of the kth second step, and the zth second step being located closer to the base of the kth second step.

[0013] In some examples, the second of the m steps and the first of the n steps are mirror images of each other about a centerline of the pixel defining layer in a direction perpendicular to the base.

[0014] In some examples, the number of second steps in the m steps is less than the number of first steps in the n steps.

[0015] In some examples, the orthogonal projections of at least a portion of the second step side of the second step and the first electrode at the base do not overlap, and the spacing between the edge of the second step side facing away from the first side and the edge of the first electrode facing away from the first side is greater than 150A.

[0016] In some examples, the second electrode includes a first portion covering the first side surface and a second portion covering the second step, the first portion is connected to the second portion, a surface of the first portion includes at least one first curved surface, and a surface of the second portion includes at least one second curved surface, and a change in curvature of the first curved surface is smaller than a change in curvature of the second curved surface.

[0017] In some examples, the angle of inclination of the second portion is between 35 degrees and 45 degrees.

[0018] In some examples, the second side further includes a third step, the third step being located between the second step and the base, the third step including a third step side, and the inclination angle of the third step side of the third step being smaller than the inclination angle of the second step side of the second step.

[0019] In some examples, the length of the third step is greater than the sum of the total length of the n first steps on the first side surface and the length of the second step.

[0020] In some examples, the second side further includes r third steps arranged sequentially along the light emission direction of the light-emitting functional layer, the r third steps being located between the second steps and the base, the third steps including a third step side, the inclination angle of the third step side of the oth third step being smaller than the inclination angle of the third step side of the pth third step, and the oth third step being located on the side of the pth third step closer to the base.

[0021] In some examples, the surface of the second electrode is uneven, and the distance between the highest point on the surface of the second electrode and the lowest point on the surface of the second electrode is less than 800 Å.

[0022] In some examples, the length of the first step side surface of the first step is 10% to 15% of the thickness of the first electrode.

[0023] In some examples, the light-emitting functional layer includes a first film layer portion located closer to the base and a second film layer portion located away from the base, and the first film layer portion forms at least one convex portion at a first step of the n steps.

[0024] The present disclosure also provides a display device including the above-described display substrate.

[0025] Other aspects will be understood after reading and understanding the drawings and detailed description. [Brief explanation of the drawings]

[0026] [Figure 1]FIG. 1 is a structural schematic diagram of a display device. [Figure 2] 1 is a structural schematic diagram 1 of a display substrate according to an embodiment of the present invention. [Figure 3] 1 is a schematic plan view of a display region of a display substrate according to an embodiment of the present invention; [Figure 4] 1 is a schematic cross-sectional view of a display region of a display substrate according to an embodiment of the present invention; [Figure 5] 1 is a schematic diagram of a display substrate according to an embodiment of the present disclosure. [Figure 6] FIG. 2 is a schematic diagram 2 of a display substrate according to an embodiment of the present disclosure. [Figure 7] 2 is a schematic cross-sectional view of a light-emitting structure layer in a display substrate according to an embodiment of the present invention; FIG. [Figure 8] FIG. 2 is a partially enlarged view of a display substrate according to an embodiment of the present invention. [Figure 9] 1 is an enlarged view of a pixel definition layer in a display substrate according to an embodiment of the present invention; [Figure 10] 2 is an enlarged view 2 of the pixel definition layer of the display substrate according to the embodiment of the present application. [Figure 11] 3 is an enlarged view 3 of the pixel definition layer in the display substrate according to the embodiment of the present application. [Figure 12] 4 is an enlarged view 4 of the pixel definition layer in the display substrate according to the embodiment of the present application. [Figure 13] FIG. 2 is an enlarged view of a second electrode on a display substrate according to an embodiment of the present invention. [Figure 14] FIG. 2 is a structural schematic diagram 2 of a display substrate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The drawings are intended to facilitate understanding of the technical solutions of the present disclosure, constitute a part of the specification, and are used to explain the technical solutions of the present disclosure together with the embodiments of the present application, but are not intended to limit the technical solutions of the present disclosure.

[0028] To clarify the objectives, technical solutions, and advantages of the present disclosure, the following detailed description of the embodiments of the present disclosure will be given with reference to the accompanying drawings. It should be noted that the embodiments can be implemented in many different forms. As those skilled in the art can easily understand, the manner and content of the present disclosure can be transformed into various forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the following embodiments. Where there is no conflict, the embodiments and features of the embodiments of the present disclosure can be combined with each other.

[0029] In the drawings, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to this size, and the shape and size of each part in the drawings do not reflect the true scale. Note that the drawings schematically show desirable examples, and one embodiment of the present disclosure is not limited to the shapes, numerical values, etc. shown in the drawings.

[0030] In this specification, ordinal numbers such as "first," "second," and "third" are used to avoid confusion of components and are not intended to limit the number of components.

[0031] For convenience, the positions of components in this specification are described with reference to the drawings using terms indicating orientation or positional relationships, such as "middle," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer." However, this is intended to simplify and explain the specification, and is not intended to indicate or suggest that the described devices or elements have a specific orientation or must be configured and operated in a specific orientation. Therefore, it is not intended to limit the present disclosure. The positional relationships of components may be appropriately changed depending on the direction in which each component is described. Therefore, the terms described in the specification may not be limited and may be appropriately changed as the case may be.

[0032] In this specification, unless otherwise clearly specified and limited, the terms "attach," "couple," and "connect" should be understood in a broad sense. For example, they may be fixedly connected, detachably connected, or integrally connected. They may be mechanically connected or electrically connected. They may be directly connected, indirectly connected via a linker, or internally connected between two elements. Those skilled in the art can understand the specific meanings of the above terms in the present disclosure according to the specific circumstances.

[0033] In this specification, a transistor refers to an element including at least three terminals: a gate electrode, a drain electrode, and a source electrode. A transistor has a channel region between a drain electrode (drain electrode terminal, drain region, or drain electrode) and a source electrode (source electrode terminal, source region, or source electrode), and a current can flow through the drain electrode, channel region, and source electrode. In this specification, the channel region refers to a region through which a current mainly flows.

[0034] In this specification, the first electrode may be a drain electrode and the second electrode may be a source electrode, or the first electrode may be a source electrode and the second electrode may be a drain electrode. The functions of "source electrode" and "drain electrode" may be interchangeable, such as when using transistors with opposite polarity or when the current direction during operation in a circuit changes. Therefore, in this specification, "source electrode" and "drain electrode" may be interchangeable.

[0035] In this specification, "electrically connected" includes cases where components are connected via an element having a certain electrical function. The "element having a certain electrical function" is not particularly limited as long as it can transmit and receive electrical signals between the connected components. Examples of "elements having a certain electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements with various functions.

[0036] In this specification, "parallel" refers to a state in which the angle formed by two straight lines is between -10° and 10°, and includes a state in which the angle is between -5° and 5°. "Perpendicular" refers to a state in which the angle formed by two straight lines is between 80° and 100°, and includes a state in which the angle is between 85° and 95°.

[0037] In this specification, the terms "film" and "layer" are interchangeable. For example, a "conductive layer" may be changed to a "conductive thin film." Similarly, an "insulating film" may be changed to an "insulating layer."

[0038] In this disclosure, "about" refers to a case where the boundary is not precisely defined, but rather allows for a numerical value within the tolerances of process and measurement.

[0039] Micro OLED display substrates can be used in near-field display devices, and the mounting position of the display substrate is crucial to the user's experience. Current display substrates are used in AR / VR devices. Conventional stacked device CGL blocking methods often involve "grooving downward" or "protruding upward" in the inter-pixel space, creating a step. This extends the CGL path, increasing CGL resistance to a certain extent and reducing inter-pixel leakage. Meanwhile, silicon-based OLED display devices fail to fundamentally block the CGL leakage path during manufacturing. This method is affected by the step, which leads to significant changes in the shape of the second electrode. This change in the shape of the second electrode affects the uniformity of the electric field distribution between the negative and first electrodes, ultimately adversely affecting vertical leakage across the display substrate. The process implementation of this structure also has many constraints, affecting process stability and uniformity. The stability of this blocking structure has a significant impact on the product.

[0040] The following describes some examples of this embodiment.

[0041] FIG. 1 is a structural schematic diagram of a display device. As shown in FIG. 1, the display device may include a timing controller, a data signal driver, a scan signal driver, and a pixel array. The pixel array may include a plurality of scan signal lines (S1 to Sm), a plurality of data signal lines (D1 to Dn), and a plurality of sub-pixels Pxij. In an exemplary embodiment, the timing controller may supply gray scale values ​​and control signals according to the specifications of the data signal driver to the data signal driver, and may supply clock signals, scan start signals, and the like according to the specifications of the scan signal driver to the scan signal driver. The data signal driver may generate data voltages to be supplied to the data signal lines D1, D2, D3, ..., Dn using the gray scale values ​​and control signals received from the timing controller. For example, the data signal driver may sample gray scale values ​​using a clock signal and apply data voltages corresponding to the gray scale values ​​to the data signal lines D1 to Dn in units of sub-pixel rows, where n may be a natural number. The scan signal driver may receive a clock signal, a scan start signal, etc. from a timing controller to generate scan signals to be supplied to the scan signal lines S1, S2, S3, ..., Sm. For example, the scan signal driver may sequentially supply scan signals having an on-level pulse to the scan signal lines S1 to Sm. For example, the scan signal driver may be configured in the form of a shift register and may generate scan signals by sequentially transmitting the scan start signal, supplied in the form of an on-level pulse, to a subsequent circuit under the control of a clock signal, where m may be a natural number. The subpixel array may include multiple subpixels Pxij. Each subpixel Pxij may be connected to a corresponding data signal line and a corresponding scan signal line, where i and j may be natural numbers. The subpixel Pxij may refer to a subpixel whose transistor is connected to the ith scan signal line and the jth data signal line.

[0042] 2 is a structural schematic diagram 1 of a display substrate according to an embodiment of the present application. In an exemplary embodiment, as shown in FIG. 2, the display substrate according to an embodiment of the present application may include a display area 100, a binding area 200 located on one side of the display area 100, and a bezel area 300 located on the other side of the display area 100.

[0043] 2, the display area 100 may be a flat area and includes a plurality of pixel units P that form a pixel array. The plurality of pixel units P may be configured to display moving or still images, and the display area 100 may be referred to as an active area (AA). In some examples, the display substrate may employ a flexible substrate, so that the display substrate may be deformable, for example, by being curled, bent, folded, or rolled up.

[0044] In some examples, the binding region 200 may include a fan-out region, a bend region, a driver chip region, and a binding pin region, which are sequentially arranged in a direction away from the display region 100. The fan-out region is connected to the display region 100 and includes at least data fan-out lines, and the multiple data fan-out lines are configured to be connected to data signal lines in the display region 100 in a fan-out wiring manner. The bend region is connected to the fan-out region and may include a composite insulating layer having a groove formed therein, and is configured to bend the driver chip region and the binding pin region to the back surface of the display region 100. An integrated circuit (IC) may be provided in the driver chip region, and the integrated circuit may be configured to be connected to the multiple data fan-out lines. The binding pin region may include binding pads, and the binding pads may be configured to be bound and connected to an external flexible printed circuit (FPC).

[0045] 3 is a schematic planar diagram of a display area on a display substrate according to an embodiment of the present disclosure. As shown in FIG. 3, the display area may include a plurality of pixel units P arranged in a matrix, at least one of which may include a first sub-pixel P1 emitting a first color light, a second sub-pixel P2 emitting a second color light, and a third sub-pixel P3 emitting a third color light. Each of the first sub-pixel P1, the second sub-pixel P2, and the third sub-pixel P3 includes a pixel driving circuit and a light-emitting element. The pixel driving circuits of the sub-pixels are connected to the scanning signal lines and the data signal lines, respectively. The pixel driving circuits are configured to receive data voltages transmitted by the data signal lines under the control of the scanning signal lines and output corresponding currents to the display light-emitting elements. Each display light-emitting element in a sub-pixel is connected to its corresponding pixel driving circuit, and the display light-emitting element is configured to emit light of a corresponding brightness in response to the current output by the pixel driving circuit of the corresponding sub-pixel.

[0046] In an exemplary embodiment, the first subpixel P1 may be a red subpixel emitting a red (R) light ray, the second subpixel P2 may be a blue subpixel emitting a blue (B) light ray, and the third subpixel P3 may be a green subpixel emitting a green (G) light ray. In an exemplary embodiment, the shape of the subpixels may be one or more of a triangle, square, rectangle, rhombus, trapezoid, parallelogram, pentagon, hexagon, or other polygon, and may be arranged in a horizontally aligned, vertically aligned, X-shaped, cross-shaped, square-shaped, diamond-shaped, delta-shaped, or other manner, and the present disclosure is not limited thereto.

[0047] In an exemplary embodiment, the pixel unit may include four sub-pixels, which is not limited here.

[0048] FIG. 4 is a cross-sectional view of a display region of a display substrate according to an embodiment of the present disclosure, illustrating a structure for achieving full color using a white light and color film method. As shown in FIG. 4 , the display substrate may include a base 101, a driving circuit layer 102 disposed on the base 101, a light-emitting structure layer 103 disposed on the driving circuit layer 102 facing away from the base 101, a first encapsulation layer 104 disposed on the light-emitting structure layer 103 facing away from the base 101, a color film structure layer 105 disposed on the first encapsulation layer 104 facing away from the base 101, a second encapsulation layer 106 disposed on the color film structure layer 105 facing away from the base 101, and a cover plate layer 107 disposed on the second encapsulation layer 106 facing away from the base 101. In some possible embodiments, the silicon-based OLED display device may include other film layers, such as a touch structure layer. The present disclosure is not limited thereto.

[0049] In an exemplary embodiment, the base 101 may be a bulk silicon base or a silicon-on-insulator (SOI) base. The driving circuit layer 102 may be fabricated on the base 101 by a silicon semiconductor process (e.g., a CMOS process). The driving circuit layer 102 may include a plurality of circuit units, each of which includes at least a pixel driving circuit, each of which is connected to a scanning signal line and a data signal line. The pixel driving circuit may include a plurality of transistors and a storage capacitor, and FIG. 4 shows only one transistor as an example. The transistor includes a control electrode G, a first electrode S, and a second electrode D, which are respectively connected to corresponding connection electrodes through vias filled with tungsten metal (i.e., tungsten vias, or W-vias), and may also be connected to other electrical structures (e.g., wiring, etc.) through the connection electrodes.

[0050] In some examples, the pixel driving circuit may have a 3T1C, 4T1C, 5T1C, 5T2C, 6T1C, 7T1C, or 8T1C structure. In the above circuit structures, T refers to a thin film transistor, C refers to a capacitor, and the number before T indicates the number of thin film transistors in the circuit, and the number before C indicates the number of capacitors in the circuit. In some examples, the multiple transistors in the pixel driving circuit may be P-type transistors or N-type transistors. Using the same type of transistors in the pixel driving circuit can simplify the process flow, reduce the process difficulty of the display substrate, and improve product yield. In other examples, the multiple transistors in the pixel driving circuit may include P-type transistors and N-type transistors.

[0051] In an exemplary embodiment, the light-emitting structure layer 103 may include a plurality of light-emitting elements, each of which may include a first electrode, a light-emitting functional layer, and a second electrode stacked sequentially at least along a direction away from the base. The first electrode may be connected to the second electrode D of the transistor via a connecting electrode, the light-emitting functional layer connected to the first electrode, the second electrode connected to the light-emitting functional layer, and the second electrode connected to a second electrode voltage line. The light-emitting functional layer is driven by the first electrode and the second electrode to emit light. In an exemplary embodiment, the light-emitting functional layer may include an emitting layer (abbreviated as EML) and one or more of 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), an electron injection layer (EIL), and a charge generation layer (CGL). In an exemplary embodiment, for a light-emitting element that emits white light, the light-emitting functional layers of all subpixels may be a common layer connected to each other.

[0052] In an exemplary embodiment, the light-emitting structure layer 103 may further include a pixel definition layer, in which a pixel opening is provided, and the pixel opening may expose a portion of the surface of the first electrode. The light-emitting functional layer is disposed within the pixel opening and connected to the first electrode. At least a portion of the second electrode covers the pixel opening. The first electrode may be an anode, and the second electrode may be a cathode.

[0053] In an exemplary embodiment, the first encapsulation layer 104 and the second encapsulation layer 106 may adopt a thin film encapsulation (TFE) method to ensure that external water vapor does not penetrate into the light-emitting structure layer, and both the first encapsulation layer 104 and the second encapsulation layer 106 may adopt organic or inorganic materials, and the inorganic material may be silicon oxide or silicon nitride, etc.

[0054] In an exemplary embodiment, the color film structure layer 105 may include a black matrix (BM) and a color filter (CF), the positions of the color filters may correspond to the positions of the light-emitting elements, the black matrix may be located between adjacent color filters, and the color filters are configured to filter the white light emitted from the light-emitting elements into red (R) light, green (G) light, and blue (B) light to form red sub-pixels, green sub-pixels, and blue sub-pixels.

[0055] In an exemplary embodiment, the cover plate layer 107 may employ glass, or may employ a plastic-based colorless polyimide or the like having flexible properties.

[0056] 5 is a schematic diagram 1 of a display substrate according to an embodiment of the present disclosure. In some examples, as shown in FIG. 5, the display substrate may further include a flexible printed circuit (FPC) 108, which may be bound and connected to the binding pin area of ​​the binding area 200, thereby connecting a plurality of signal lead lines (e.g., drive control lines, power lines, etc.) on the display substrate to an external control device via a plurality of binding pins and the flexible printed circuit 108.

[0057] 6 is a schematic diagram 2 of a display substrate according to an embodiment of the present disclosure. In some examples, as shown in FIG. 6, the orthogonal projection of the cover plate 107 on the base 101 is located within the base 101, and the area of ​​the orthogonal projection of the cover plate 107 on the base 101 is smaller than the area of ​​the base 101. For example, the cover plate 107 and the base 101 may both be rectangular, and the edges of the cover plate 107 may all be recessed inward relative to the edges of the base 101. The cover plate 107 covers the first electrode 301, the light-emitting functional layer 303, and the color film structure layer 105, and the edges of the cover plate 107 extend beyond the edges of the first electrode 301, the light-emitting functional layer 303, and the color film structure layer 105, so that the edges of the cover plate 107 can be positioned and fixed.

[0058] 6 , the orthogonal projection of the color film structure layer 105 on the base 101 is located within the cover plate 107, and the area of ​​the orthogonal projection of the color film structure layer 105 on the base 101 is smaller than the area of ​​the cover plate 107, for example, the color film structure layer 105 and the cover plate 107 may both be rectangular, and the edges of the color film structure layer 105 are both retracted inward relative to the edges of the cover plate 107. The color film structure layer 105 covers the first electrode 301 and the light-emitting functional layer 303.

[0059] 6 , the orthogonal projection of the light-emitting functional layer 303 on the base 101 is located within the color film structure layer 105, and the area of ​​the orthogonal projection of the light-emitting functional layer 303 on the base 101 is smaller than the area of ​​the color film structure layer 105; for example, the light-emitting functional layer 303 and the color film structure layer 105 may both be rectangular, and the edges of the light-emitting functional layer 303 are all contracted inward relative to the edges of the color film structure layer 105. The light-emitting functional layer 303 covers the first electrode 301, and the edges of the light-emitting functional layer 303 extend beyond the edges of the first electrode 301.

[0060] In some examples, as shown in FIG. 6 , the orthogonal projection of the first electrode 301 on the base 101 is located within the light-emitting functional layer 303, and the area of ​​the orthogonal projection of the first electrode 301 on the base 101 is smaller than the area of ​​the light-emitting functional layer 303; for example, the first electrode 301 and the light-emitting functional layer 303 may both be rectangular, and the edges of the first electrode 301 may all shrink inward relative to the edges of the light-emitting functional layer 303.

[0061] FIG. 7 is a schematic cross-sectional view of the light-emitting structure layer of a display substrate in an embodiment of the present disclosure. FIG. 7 shows the structure of two light-emitting elements. In an exemplary embodiment, the display substrate in an embodiment of the present disclosure may include more light-emitting elements. Although FIG. 7 shows two adjacent light-emitting elements, the embodiment of the present disclosure is not limited thereto. For example, other assemblies such as wiring may be disposed between the two light-emitting elements. In FIG. 7, the cross sections of the two light-emitting elements may not be taken along the same direction of the display substrate.

[0062] 7 , the light-emitting element may include a first electrode 301, a light-emitting functional layer 302, and a second electrode 303, which are stacked sequentially at least along a direction away from the base 101, the light-emitting functional layer 302 being connected to the first electrode 301, and the second electrode 303 being connected to the light-emitting functional layer 302, and the light-emitting functional layer 302 being driven by the first electrode 301 and the second electrode 302 to emit light. A portion of the pixel definition layer 304 is disposed on the first electrode 301, and a pixel opening is disposed in the pixel definition layer 304. The pixel opening may expose a portion of the surface of the first electrode 301, and a portion of the light-emitting functional layer 302 is disposed within the pixel opening and connected to the first electrode 301. The orthogonal projections of the second electrode 203 and the pixel opening at the base overlap, and at least a portion of the second electrode 203 covers the pixel opening.

[0063] In some examples, as shown in FIG. 7, a groove body is formed between the first electrodes 301 of adjacent light-emitting elements. The middle portion 3041 of the pixel definition layer 304 is located in the groove body between adjacent first electrodes 301, the edge portion 3042 of the pixel definition layer 304 covers the side surface and a part of the surface of the first electrode 301, and the edge portion 3042 of the pixel definition layer 304 is formed in a stepped manner with the middle portion 3041 of the pixel definition layer 304. The thickness of the middle portion 3041 of the pixel definition layer 304 is smaller than the thickness of the first electrode 301.

[0064] In some examples, as shown in FIG. 7, the edge portion 3042 of the pixel definition layer 304 includes a first side surface 10 on the side close to the first electrode 301, and the first side surface 10 is a side wall of the pixel aperture in the pixel definition layer 304. Since the angle formed by the first side surface 10 and the surface on the side away from the base 101 of the first electrode 301 is an obtuse angle, the light-emitting area of the sub-pixel can be increased. In some embodiments, the first side surface may form a right angle with the surface on the side away from the base of the first electrode.

[0065] FIG. 8 is a partially enlarged view of the display substrate according to an embodiment of the present application. In some examples, as shown in FIGS. 7 and 8, the first side surface 10 sequentially includes n first steps 1 along the light-emitting direction of the light-emitting functional layer 302. The first step 1 includes a first step side surface 11 and a first step upper surface 12. The extending direction of the first step side surface 11 is different from the extending direction of the first step upper surface 12. The extending direction of the first step side surface 11 forms an obtuse angle with the surface on the side away from the base 101 of the first electrode 301, and the extending direction of the first step upper surface 12 is substantially parallel to the surface on the side away from the base 101 of the first electrode 301. The inclination angle ai of the first step side surface 11 of the first step of the i-th stage is larger than the inclination angle aj of the first step side surface of the first step of the j-th stage. The first step 1 of the i-th stage is located on the side close to the base of the first step 1 of the j-th stage, and the orthographic projections of the first step 1 of the i-th stage and the first step 1 of the j-th stage on the base 101 do not overlap. i, j, and n are all natural numbers, n is greater than 1, and 0 < i < j ≤ n. The inclination angle of the first step side surface 11 means the angle formed by the first step side surface 11 and the plane where the base is located.

[0066] In the display substrate of the embodiment of the present application, the first step difference of n steps on the first side can extend the length of some of the film layers (e.g., charge generating layers) in the light-emitting functional layer, increase the resistance of some of the film layers in the light-emitting functional layer, and reduce the flow of carriers between pixels, or separate some of the film layers in the light-emitting functional layer to block the flow of carriers between pixels and avoid the occurrence of leakage current between pixels.

[0067] In the display substrate of the embodiment of the present application, the inclination angle ai of the first step of the ith step is greater than the inclination angle aj of the first step side of the first step of the jth step, so that the first side 10 gradually becomes gentler along the light emission direction of the light-emitting functional layer 302. The step formed by the large inclination angle ai extends the length of some film layers in the light-emitting functional layer or blocks some film layers in the light-emitting functional layer. The first step of the jth step reduces the step of the first side, preventing a drastic change in the shape of the second electrode (cathode) due to an excessively large step. The second electrode (cathode) can be extended gradually at the first step 1 of the jth step, ensuring uniformity of the electric field distribution between the first electrode (anode) and the second electrode (cathode), improving display efficiency and yield.

[0068] 7, some film layers in the light-emitting functional layer 302 may be common layers connected to each other. The light-emitting functional layer 302 includes a first film layer portion 3021 located closer to the base 101 and a second film layer portion 3022 located farther from the base 101, and both the first film layer portion 3021 and the second film layer portion 3022 may have a continuous structure. The first film layer portion 3021 includes a film layer with high carrier mobility (e.g., a charge generation layer), covers a first side surface of the pixel definition layer 304, and extends along the shape of the n-step first step 1. The first film layer portion 3021 forms at least one protrusion in the n-step first step 1, and the protrusion extends the length of the first film layer portion 3021, thereby increasing the resistance of the first film layer portion 3021 and reducing the flow of carriers between pixels. Alternatively, in order to prevent carrier flow between pixels, the first film layer portions 3021 are separated by at least one step in the n-step first step 1.

[0069] In some embodiments, the first film layer portion may be cut at the first step of the i-th stage, and the second film layer portion and the second electrode (cathode) may be a continuous structure, thereby making the shape of the second electrode (cathode) at the first step of the j-th stage gentler, and the embodiments of the present application are not described here.

[0070] In some examples, the first step side surface of the first step 1 may be a flat surface. Alternatively, the first step side surface of the first step 1 may not be a flat surface, for example, the first step side surface of the first step may be an arcuate surface. When the first step side surface is an arcuate surface, the inclination angle of the first step side surface is the angle between the connecting line between both end points of the first step side surface and the plane on which the base is located.

[0071] In some examples, the first step upper surface of the first step may be flat, or the first step upper surface of the first step may not be flat, for example, the first step side surface of the first step may be an arcuate surface.

[0072] In some examples, the length of the first step side surface 11 of the first step is 10 to 15% of the thickness of the first electrode 301. The length of the first step side surface 11 is the distance between both end points of the first step side surface 11.

[0073] 9 is an enlarged view 1 of a pixel definition layer in a display substrate according to an embodiment of the present disclosure. In some examples, as shown in FIG. 9, the first side of the pixel definition layer includes a first step 1a of a first stage, a first step 1b of a second stage, and a first step 1c of a third stage, which are sequentially arranged along the light emission direction of the light-emitting functional layer. The first step 1a of the first stage, the first step 1b of the second stage, and the first step 1c of the third stage are not orthogonally projected at their bases. The inclination angle a1 of the first step side of the first step 1a of the first stage is greater than the inclination angle a2 of the first step side of the first step 1b of the second stage, and the inclination angle a2 of the first step side of the first step 1b of the second stage is greater than the inclination angle a3 of the first step side of the first step 1c of the third stage. The inclination angle a1 of the first step side surface of the first step 1a of the first step may be 65 degrees to 75 degrees, the inclination angle a2 of the first step side surface of the first step 1b of the second step may be 50 degrees to 60 degrees, and the inclination angle a3 of the first step side surface of the first step 1c of the third step may be 40 degrees to 45 degrees.

[0074] In some examples, as shown in FIG. 9, the first step 1 of the ith stage and the first step 1 of the jth stage may be adjacent, and another first step 1 may be provided between the first step 1 of the ith stage and the first step 1 of the jth stage, for example, n may be 3, j may be 3, and i may be 1, and the first step 1 of the second stage is provided between the first step 1 of the first stage and the first step 1 of the third stage.

[0075] In some examples, the thickness of the first step 1 of the ith step is greater than the thickness of the first step 1 of the jth step. The thickness of the first step 1 is the length of the first step 1 in a direction perpendicular to the plane on which the base is located. If the top surface of the first step 1 is an arcuate surface, the thickness of the first step 1 is the minimum length of the first step 1 in a direction perpendicular to the plane on which the base is located.

[0076] In the display substrate of the embodiment of the present application, the thickness of the first step 1 of the i-th stage is greater than the thickness of the first step 1 of the j-th stage, so that the first side 10 gradually becomes gentler along the light emission direction of the light-emitting functional layer 302, the first step 1 of the i-th stage can extend or block the length of some of the film layers in the light-emitting functional layer, the step of the first step 1 of the j-th stage can be gentler, and the second electrode (cathode) can be gently extended by the first step 1 of the j-th stage.

[0077] FIG. 10 is an enlarged view 2 of a pixel definition layer in a display substrate according to an embodiment of the present application. In some examples, as shown in FIG. 10, the thickness h1 of the first step 1a of the first stage is greater than the thickness h2 of the first step 1b of the second stage, and the thickness h2 of the first step 1b of the second stage is greater than the thickness h3 of the first step 1c of the third stage. For example, the thickness h1 of the first step 1a of the first stage may be 55 nm to 80 nm. The thickness h2 of the first step 1b of the second stage may be 30 nm to 50 nm. The thickness h3 of the first step 1c of the third stage may be 15 nm to 25 nm.

[0078] The above-mentioned structure of the first side of the display substrate in the embodiment of the present application is advantageous for the etching process manufacturing of the first side of the pixel definition layer 304, so that some film layers in the light-emitting functional layer can be extended or blocked at the first step 1 of the i-th stage, and the second electrode (cathode) can be gently extended at the first step 1 of the j-th stage.

[0079] In some examples, the length of the first step 1 of the ith step is greater than the length of the first step 1 of the jth step. The length of the first step 1 is the distance between the two end points of the first step 1 in a direction parallel to the base.

[0080] 10, the length L1 of the first step 1a of the first step is greater than the length L2 of the first step 1b of the second step, and the length L2 of the first step 1b of the second step is greater than the length L3 of the first step 1c of the third step. For example, the length L1 of the first step 1a of the first step is 40 nm to 80 nm, the length L2 of the first step 1b of the second step is 90 nm to 110 nm, and the length L3 of the first step 1c of the third step is 120 nm to 200 nm.

[0081] The above-mentioned structure of the first side of the display substrate in the embodiment of the present application is advantageous for the etching process manufacturing of the first side of the pixel definition layer 304, so that some film layers in the light-emitting functional layer can be extended or blocked at the first step 1 of the i-th stage, and the second electrode (cathode) can be gently extended at the first step 1 of the j-th stage.

[0082] 7 , the pixel definition layer 304 further includes a second side surface 20 located away from the first electrode 301, the second side surface 20 being located away from the pixel opening. The angle between the second side surface 20 and the surface of the base 101 may be an obtuse angle, thereby ensuring the continuity of the second electrode (cathode) and preventing the second electrode (cathode) from being interrupted at the second side surface 20.

[0083] 8 and 9, the second side surface 20 includes one second step 2, and the second step 2 includes a second step side surface 21, and the extending direction of the second step side surface 21 is different from the extending direction of the first step side surface 11 and the first step top surface 12. The inclination angle b of the second step side surface 21 is larger than the inclination angle ai of the first step side surface of the i-th first step. The inclination angle b of the second step side surface 21 may be 80 degrees to 90 degrees.

[0084] In some examples, the second step side surface of the second step 2 may be a flat surface. Alternatively, the second step side surface of the second step 2 may not be a flat surface, for example, the second step side surface of the second step 2 may be an arcuate surface. When the second step side surface of the second step 2 is an arcuate surface, the inclination angle of the second step side surface of the second step 2 is the angle formed by the connecting line between both end points of the second step side surface and the plane on which the base is located.

[0085] In the display substrate of the embodiment of the present application, the large inclination angle b of the second step side 21 can sufficiently extend some of the film layers in the light-emitting functional layer 303, such as the hole injection layer and the charge generation layer, or block some of the film layers in the light-emitting functional layer 303, so that the second electrode on the second step 2 of the second side 20 has little effect on the display effect, and the change in the shape of the second electrode on the second step 2 has little effect on the display effect.

[0086] In some examples, as shown in FIG. 10, the thickness h4 of the second step 2 is greater than the sum of the thickness h1 of the first step 1a of the first step, the thickness h2 of the first step 1b of the second step, and the thickness h3 of the first step 1c of the third step, i.e., h4 is greater than h1+h2+h3.

[0087] In some examples, as shown in FIG. 8, the distance from the end point of the second step 2 closer to the base 101 to the surface of the base 101 is smaller than the distance from the first electrode 301 to the surface of the base 101, and the distance from the end point of the second step 2 away from the base 101 to the surface of the base 101 is greater than the distance from the first electrode 301 to the surface of the base 101, i.e., the end point of the second step 2 closer to the base 101 is higher than the surface of the first electrode 301.

[0088] In some examples, as shown in FIG. 8 , the orthogonal projections of at least a portion of the second step side 21 of the second step 2 and the first electrode 301 on the base 101 do not overlap, and the distance L6 between the edge of the second step side 21 away from the first side and the edge of the first electrode away from the first side is greater than 150A, ensuring that the second step 2 can completely cover the first electrode 301 and preventing defects such as corrosion due to the first electrode 301 not being covered by the second step 2.

[0089] 11 is an enlarged view 3 of a pixel definition layer in a display substrate according to an embodiment of the present application. In some examples, as shown in FIG. 11, the second side surface 20 may include m second steps arranged sequentially along the light emission direction of the light-emitting functional layer 302, where the inclination angle of the second step side surface of the zth second step is greater than the inclination angle of the second step side surface of the kth second step, the zth second step is located closer to the base of the kth second step, and the orthogonal projections of the zth second step and the kth second step on the base 101 do not overlap. z, k, and m are all natural numbers, and m is greater than 1 and less than 0. <z<k≦m。

[0090] 11 , the second side of the pixel definition layer 304 includes a first second step 2a, a second second step 2b, and a third second step 2c, which are sequentially arranged along the light emission direction of the light-emitting functional layer. The orthogonal projections of the first second step 2a, the second second step 2b, and the third second step 2c at their bases do not overlap. The inclination angle b1 of the second step side of the first second step 2a is greater than the inclination angle b2 of the second step side of the second step 2b, which is greater than the inclination angle b3 of the second step side of the third second step 2c.

[0091] In the display substrate of the embodiment of the present application, the inclination angle of the second step of the zth step is larger than the inclination angle of the second step of the kth step, so that the second side surface 20 gradually becomes gentler along the light emission direction of the light-emitting functional layer 302, and the second step of the kth step reduces the step of the second side surface, avoiding a drastic change in the shape of the second electrode (cathode) due to the step being too large, and allowing the second electrode (cathode) to extend gently at the second step 2 of the kth step.

[0092] In some examples, as shown in FIG. 11 , the m-step second step on the second side may have the same step number as the n-step first step on the first side, i.e., m is n, and the m-step second step on the second side and the n-step first step on the first side may be mirror images of each other with respect to the center line of the pixel definition layer in a direction perpendicular to the base.

[0093] In some examples, the m second steps on the second side may not have the same number of steps as the n first steps on the first side, i.e., m is not equal to n, e.g., m is greater than n, or m is less than n.

[0094] 8, the second side surface 20 may include one third step 3, which is located between the second step 2 and the base, and which includes a third step side surface 31 and a third step upper surface 32, the extension direction of the third step side surface 31 being different from the extension direction of the third step upper surface 32, forming an obtuse angle between the extension direction of the third step side surface 31 and the surface of the base 101, and the extension direction of the third step upper surface 32 being approximately parallel to the plane on which the base 101 is located. The inclination angle c of the third step side surface 31 is smaller than the inclination angle b of the second step side surface of the second step.

[0095] In the display substrate of the embodiment of the present application, the inclination angle c of the third step side surface 31 can reduce the step of the second side surface 20, thereby mitigating the change in the shape of the second electrode on the third step 3.

[0096] In some examples, the third step side surface of the third step 3 may be flat. Alternatively, the third step side surface of the third step 3 may not be flat, for example, the third step side surface of the third step 3 may be an arcuate surface. When the third step side surface of the third step 3 is an arcuate surface, the inclination angle of the third step side surface of the third step 3 is the angle between the connecting line between both end points of the third step side surface and the plane on which the base is located.

[0097] In some examples, the third step 3 may have a flat upper surface, or may not have a flat upper surface, for example, may have an arcuate upper surface.

[0098] As shown in Figure 8, the distance from the third step upper surface 32 of the third step 3 to the surface of the base 101 is smaller than the distance from the first electrode 301 to the surface of the base 101, and the thickness of the third step 3 is smaller than the thickness of the first electrode 301.

[0099] 10, the thickness h5 of the third step 3 is smaller than the thickness h4 of the second step 2. When the third step upper surface 32 of the third step 3 is an arcuate surface, the thickness h5 of the third step 3 is the thickness of the highest point of the third step upper surface 32.

[0100] The above structure of the second side of the display substrate in the embodiment of the present application is advantageous for the etching process manufacturing of the second side of the pixel defining layer 304, so that the second electrode (cathode) can be gently extended at the third step 3.

[0101] In some examples, the length of the third step 3 is greater than the sum of the total length of the n first steps and the length of the second steps. For example, as shown in Fig. 10, the length L5 of the third step 3 is greater than the sum of the length L1 of the first step 1a of the first step, the length L2 of the first step 1b of the second step, the length L3 of the first step 1c of the third step, and the length L4 of the second step 2. The length of the third step 3 is the distance between both end points of the third step 3 in a direction parallel to the base.

[0102] The above structure of the third step 3 of the display substrate in the embodiment of the present application is advantageous for the etching process manufacturing of the third step 3 of the pixel definition layer 304, so that the second electrode (cathode) can be gently extended at the third step 3.

[0103] 12 is an enlarged view 4 of a pixel definition layer in a display substrate according to an embodiment of the present application. In some examples, as shown in FIG. 12, the second side surface 20 may include r third step portions 3 arranged sequentially along the light emission direction of the light-emitting functional layer 302, where the inclination angle co of the third step portion 3 of the oth step is smaller than the inclination angle cp of the third step portion 3 of the pth step, the third step portion 3 of the oth step is located closer to the base of the third step portion 3 of the pth step, and the orthogonal projections of the third step portion 3 of the oth step and the third step portion 3 of the pth step on the base 101 do not overlap. r, o, and p are all natural numbers, where r is greater than 1 and 0. <o<p≦r。

[0104] In the display substrate of the embodiment of the present application, the inclination angle co of the third step side of the third step 3 of the oth step is smaller than the inclination angle cp of the third step side of the third step 3 of the pth step, thereby avoiding a drastic change in the shape of the second electrode (cathode) due to the step of the second side being too large, and allowing the second electrode (cathode) to extend gradually.

[0105] In some examples, the r third steps 3 on the second side may have the same number of steps as the n first steps 1 on the first side, ie, r is equal to n.

[0106] In some examples, the third step 3 of the r steps on the second side may not have the same number of steps as the first step 1 of the n steps on the first side, i.e., r is not equal to n, e.g., r is greater than n, or r is less than n.

[0107] FIG. 13 is an enlarged view of a second electrode on a display substrate according to an embodiment of the present disclosure. In some examples, as shown in FIG. 13, the second electrode 303 includes a first portion 41 covering a first side of the pixel definition layer 304, a second portion 42 covering a second step on a second side of the pixel definition layer 304, and a third portion 43 covering a third step on the second side of the pixel definition layer 304, with the first portion 41, the second portion 42, and the third portion 43 being sequentially connected. The surface of the first portion 41 includes at least one first curved surface 51, and the orthogonal projections of the first curved surface 51 and the first step on the first side may overlap. The surface of the second portion 42 includes at least one second curved surface 52, and the orthogonal projections of the second curved surface 52 and the second step on the second side may overlap. The surface of the third portion 43 includes at least one third curved surface 53, and the orthogonal projections of the third curved surface 53 and the third step on the second side may overlap. The change in curvature of the first curved surface 51 of the first portion 41 is smaller than the change in curvature of the second curved surface 52 of the second portion 42, and the change in curvature of the third curved surface 53 of the third portion 43 is smaller than the change in curvature of the second curved surface 52 of the second portion 42.

[0108] In the display substrate of the embodiment of the present application, the change in curvature of the first curved surface 51 of the first part 41 is smaller than the change in curvature of the second curved surface 52 of the second part 42, thereby ensuring that the first part 41 does not break.

[0109] 13, the inclination angle d of the second portion 42 of the second electrode 303 may be 35 to 45 degrees so that the second portion 42 of the second electrode 303 is not broken due to a sudden change in shape. The inclination angle of the second portion 42 is the angle between the connecting line between both end points of the second portion 42 and the plane on which the base is located.

[0110] In some examples, as shown in FIG. 13, the distance L6 between the highest point on the surface of the second electrode 303 and the lowest point on the surface of the second electrode 303 is less than 800A, thereby preventing the second electrode 303 from breaking due to too large a step.

[0111] In some examples, the second electrode 303 may have a two-layer structure, for example, the second electrode 303 may include a metallic silver layer or a magnesium-silver alloy layer closer to the first electrode and an indium tin oxide layer or an indium zinc oxide layer farther from the first electrode. Alternatively, the second electrode 303 may have a single-layer structure, for example, the second electrode 303 may be a single metallic silver layer or a single magnesium-silver alloy layer.

[0112] FIG. 14 is a structural schematic diagram 2 of a display substrate according to an embodiment of the present application. In some examples, as shown in FIG. 14, the display substrate according to an embodiment of the present application further includes a virtual display area 400, at least a portion of which is located between the display area 100 and the bezel area 300. The virtual display area 400 may include a base, a virtual drive circuit layer provided on the base, and a virtual light-emitting structure layer provided on the side of the virtual drive circuit layer away from the base. No moving images or still images are displayed in the virtual display area 400.

[0113] In some examples, at least a portion of the pixel definition layer of the display region 100 is located at an edge of the display region 100 closer to the virtual display region 400, and the pixel definition layer includes a third side surface closer to the display region 100, and the third side surface includes q fourth step portions arranged sequentially along the light emission direction of the display region 100, and the fourth step portions include a fourth step side surface and a fourth step top surface, and the extension direction of the fourth step side surface differs from the extension direction of the fourth step top surface. The inclination angle of the fourth step side surface of the sth fourth step portion is greater than the inclination angle of the fourth step side surface of the uth fourth step portion, and the sth fourth step portion is located closer to the base of the uth fourth step portion, and orthogonal projections of the sth fourth step portion and the uth fourth step portion at the base do not overlap. s, u, and q are all natural numbers, and q is greater than 1 and less than 0. <s<u≦q。

[0114] In some examples, the fourth step of the q steps on the third side of the pixel definition layer may be identical in structure to the first step of the n steps on the first side of the pixel definition layer, examples of which are not described herein.

[0115] The above-described structure of the third side of the display substrate in the embodiment of the present application makes the third side gradually gentler along the light emission direction of the display area 100, and the step formed by the fourth step of the s-th step extends or blocks the length of some film layers in the light-emitting functional layer. The fourth step of the u-th step reduces the step of the third side, preventing a drastic change in the shape of the second electrode (cathode) due to an excessively large step.

[0116] In some examples, the pixel definition layer further includes a fourth side closer to the virtual display area 400, and the fourth side may include one fifth step, and the fifth step includes a fifth step side, and the inclination angle of the fifth step side is greater than the inclination angle of the fourth step side of the sth step.

[0117] In some examples, the fifth step on the fourth side of the pixel definition layer may be identical in structure to the second step on the second side of the pixel definition layer, examples of which are not described herein.

[0118] In some examples, the fourth side may include one sixth step, the sixth step being located between the fifth step and the base, the sixth step including a sixth step side and a sixth step side, and the inclination angle of the sixth step side being smaller than the inclination angle of the fifth step side of the fifth step.

[0119] In some examples, the sixth step on the fourth side of the pixel definition layer may be identical in structure to the third step on the second side of the pixel definition layer, examples of which are not described herein.

[0120] In the display substrate of the embodiment of the present application, the sixth step can reduce the step on the fourth side surface, thereby mitigating the change in shape of the second electrode on the sixth step.

[0121] The present disclosure further provides a display device including the display substrate of the above-described embodiment, which may be any product or component having a display function, such as a mobile phone, a tablet terminal, a television, a display, a laptop computer, a digital photo frame, or a navigation system.

[0122] The drawings in this disclosure only relate to the structure of the present disclosure, and other configurations can refer to conventional designs. The embodiments of the present disclosure, i.e., the features in the embodiments, can be combined with each other to obtain new embodiments, unless they conflict.

[0123] It should be understood that those skilled in the art can make modifications or equivalent substitutions to the technical solutions of the present disclosure without departing from the spirit and scope of the technical solutions of the present disclosure, and all should be included in the scope of the claims of the present disclosure. [Explanation of symbols]

[0124] 101 Base 301 1st electrode 302 Light-emitting functional layer 303 2nd electrode 304 Pixel Definition Layer 1 First step 2. Second step 3 Third step 11 First step side 21 Second step side 31 Third step side

Claims

1. A display substrate, With the base, a light emitting element provided on the base, the light emitting element including a first electrode, a light emitting functional layer, and a second electrode sequentially stacked along a direction away from the base; a pixel definition layer provided on the base, the pixel definition layer having a pixel opening, the pixel opening exposing at least a portion of the surface of the first electrode, and at least a portion of the second electrode covering the pixel opening; the pixel definition layer includes a first side surface close to the first electrode, the first side surface including n first steps sequentially arranged along a light emission direction of the light emitting functional layer, the first steps including a first step side surface, an inclination angle of the first step side surface of the i-th first step is greater than an inclination angle of the first step side surface of the j-th first step, and the i-th first step is located on a side of the j-th first step that is close to the base, A display substrate, wherein i, j, and n are all natural numbers, n is greater than 1, and 0<i<j≦n.

2. 2. The display substrate of claim 1, wherein the first side includes three first steps arranged sequentially along the light emission direction of the light-emitting functional layer, and the inclination angle of the first step side of the first step of the first step of the first step is larger than the inclination angle of the first step side of the first step of the second step, and the inclination angle of the first step side of the first step of the second step is larger than the inclination angle of the first step side of the first step of the third step.

3. 3. The display substrate of claim 2, wherein a slope angle of a first step side of the first step of the first step is 65 degrees to 75 degrees, a slope angle of a first step side of the first step of the second step is 50 degrees to 60 degrees, and a slope angle of a first step side of the first step of the third step is 40 degrees to 45 degrees.

4. The display substrate of claim 1 , wherein the thickness of the first step of the i-th level is greater than the thickness of the first step of the j-th level.

5. The display substrate of claim 1 , wherein a length of the first step of the i-th stage is greater than a length of the first step of the j-th stage.

6. 2. The display substrate of claim 1, wherein the pixel definition layer further includes a second side surface away from the first electrode, the second side surface including one second step, the second step including a second step side surface, and a slope angle of the second step side surface of the second step being greater than a slope angle of the first step side surface of the i-th step.

7. 7. The display substrate of claim 6, wherein the second step has a side surface with an inclination angle of 80 degrees to 90 degrees.

8. 2. The display substrate of claim 1, wherein the pixel definition layer further includes a second side surface away from the first electrode, the second side surface including m second steps sequentially arranged along the light emission direction of the light-emitting functional layer, the second steps including a second step side surface, a slope angle of the second step side surface of the zth second step being larger than a slope angle of the second step side surface of the kth second step, and the zth second step being located closer to the base than the kth second step.

9. The display substrate of claim 8 , wherein the m-th second step and the n-th first step are arranged as mirror images of each other with respect to a center line of the pixel definition layer in a direction perpendicular to the base.

10. The display substrate of claim 8 , wherein the number of the m second steps is smaller than the number of the n first steps.

11. 7. The display substrate of claim 6, wherein at least a portion of the second step side surface of the second step does not overlap with the first electrode when projected orthogonally at the base, and a distance between an edge of the second step side surface away from the first side surface and an edge of the first electrode away from the first side surface is greater than 150 Å.

12. 7. The display substrate of claim 6, wherein the second electrode includes a first portion covering the first side surface and a second portion covering the second step, the first portion is connected to the second portion, a surface of the first portion includes at least one first curved surface, and a surface of the second portion includes at least one second curved surface, and a change in curvature of the first curved surface is smaller than a change in curvature of the second curved surface.

13. The display substrate of claim 12, wherein the second portion has an inclination angle of 35 degrees to 45 degrees.

14. 7. The display substrate of claim 6, wherein the second side further includes a third step, the third step being located between the second step and the base, the third step including a third step side, and a tilt angle of the third step side of the third step being smaller than a tilt angle of the second step side of the second step.

15. The display substrate of claim 14 , wherein the length of the third step is greater than the sum of the total length of the n first step differences on the first side surface and the length of the second step difference.

16. 7. The display substrate of claim 6, wherein the second side further includes r-step third steps arranged sequentially along the light emission direction of the light-emitting functional layer, the r-step third step being located between the second step and the base, the third step including a third-step side surface, the inclination angle of the third-step side surface of the o-th step third step being smaller than the inclination angle of the third-step side surface of the p-th step third step, and the o-th step third step being located on a side of the p-th step third step closer to the base.

17. 2. The display substrate of claim 1, wherein the second electrode has an uneven surface, and the distance between the highest point on the surface of the second electrode and the lowest point on the surface of the second electrode is less than 800 Å.

18. 2. The display substrate of claim 1, wherein a length of the first step side of the first step is 10% to 15% of a thickness of the first electrode.

19. 2. The display substrate of claim 1, wherein the light-emitting functional layer includes a first film layer portion located closer to the base and a second film layer portion located away from the base, and the first film layer portion forms at least one convex portion at a first step of the n steps.

20. A display device comprising the display substrate according to any one of claims 1 to 19.

Images