Display substrate and electronic device

Abstract

A display substrate and electronic device. The display substrate includes a base substrate, a dielectric layer located on the base substrate, a pixel defining layer, a first electrode layer, and a second electrode layer. The first electrode layer includes a first electrode and a second electrode spaced apart. The portion of the dielectric layer corresponding to the space between the first and second electrodes includes a first groove, which exposes the first groove. The portion of the second electrode layer corresponding to the first groove includes a recessed structure. The pixel defining layer covers the first groove and forms a second groove. The display substrate has a cross section perpendicular to the base substrate, and the recessed structure includes a first recessed point and a second recessed point located in the cross section. Within the cross section and in a direction parallel to the base substrate, the distance L1 between the first side surface of the second groove near the first electrode and the edge of the first electrode is greater than the distance L2 between the first recessed point and the first side surface of the second groove. This display substrate helps improve yield.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a display substrate and an electronic device. Background Art

[0002] Micro OLED displays involve the combination of organic light-emitting diode (OLED) technology and silicon-based CMOS technology. They are related to the cross-integration of the optoelectronics industry and the microelectronics industry, promoting the development of a new generation of micro-display technology and also advancing the research and development of organic electronics on silicon and even molecular electronics on silicon.

[0003] Micro OLED displays have excellent display characteristics, such as high resolution, high brightness, rich colors, low driving voltage, fast response speed, and low power consumption, and have broad development prospects. Summary of the Invention

[0004] At least one embodiment of the present disclosure provides a display substrate, comprising a base substrate, a dielectric layer located on the base substrate, and a first electrode layer, a pixel defining layer, an organic functional layer, and a second electrode layer stacked sequentially on a side of the dielectric layer away from the base substrate. The base substrate comprises a first sub-pixel region and a second sub-pixel region adjacent to each other. The first electrode layer comprises a first electrode located in the first sub-pixel region and a second electrode located in the second sub-pixel region. A gap exists between the first electrode and the second electrode. A portion of the dielectric layer corresponding to the gap comprises a first groove, the gap exposing the first groove. The second electrode layer comprises a recessed structure corresponding to the first groove. The pixel defining layer covers the first groove and forms a second groove. The display substrate has a cross section perpendicular to the base substrate. The recessed structure comprises a first recessed point and a second recessed point located in the cross section. The orthographic projections of the first recessed point and the second recessed point on the base substrate are both located within the orthographic projection of the second recess on the base substrate. Within the cross section and in a first direction parallel to the surface of the base substrate, a distance L1 between a first side surface of the second groove proximate to the first electrode and a first electrode edge of the first electrode proximate to the first groove is greater than a distance L2 between the first recessed point and the first side surface of the second groove.

[0005] In some examples, the pixel defining layer includes a first opening area and a second opening area and a pixel defining portion located between the first opening area and the second opening area, the first opening area exposes at least a portion of the first electrode, the second opening area exposes at least a portion of the second electrode, and the pixel defining portion covers the first groove and a portion of the first electrode and the second electrode; the first electrode includes a first surface away from the substrate substrate, and in the cross section and in the first direction, the length of the portion of the pixel defining portion located on the first surface of the first electrode is L3, and L3 is less than L1.

[0006] In some examples, the first electrode also includes a second surface away from the base substrate, the second surface of the first electrode is closer to the base substrate than the first surface, and within the cross section and in the first direction, the length of the portion of the pixel defining portion located on the second surface of the first electrode is L4, and L2 is less than L4.

[0007] In some examples, L3 is smaller than L4.

[0008] In some examples, the first electrode includes a stacked first sub-electrode and a second sub-electrode, the second sub-electrode being located on a side of the first sub-electrode away from the dielectric layer; the second sub-electrode covers a side surface of the first sub-electrode and contacts the dielectric layer to form the second surface of the first electrode.

[0009] In some examples, within the cross section and in the first direction, the length of the pixel defining portion located on the first side surface of the second groove close to the first electrode is y1, and the maximum length of the second groove is L5; y1 is greater than L5.

[0010] In some examples, the distance between the first concave point and the second concave point in the first direction is less than y1.

[0011] In some examples, the pixel defining layer includes a first surface away from the base substrate, the first surface of the pixel defining layer includes a first slope corresponding to the edge of the first electrode and a second slope connected to the first side surface, and the shapes of the first slope and the second slope in the cross section both include curved surfaces; the first surface of the pixel defining layer also includes a connecting surface located between the first slope and the second slope, and at least a portion of the connecting surface is a plane.

[0012] In some examples, a ratio of a length of the connecting surface in the cross section to L1 is greater than 1 / 3.

[0013] In some examples, the second electrode layer includes a raised portion that at least partially overlaps with the first electrode in a direction perpendicular to the substrate; the raised portion has a first raised point in the cross section, and a raised height of the first raised point is greater than an average thickness of the second electrode layer.

[0014] In some examples, the first depression point and the second depression point are at different distances from the substrate; the depression structure further includes a second protruding point located in the cross section, the second protruding point is located between the first depression point and the second depression point, and the distance from the second protruding point to the substrate is greater than the distance from the first depression point and the second depression point to the substrate; the larger value of the height difference between the second protruding point and the first depression point and the second depression point is △h.

[0015] In some examples, Δh is greater than the height difference between the first concave point and the second concave point.

[0016] In some examples, Δh is greater than an average thickness of the second electrode layer.

[0017] In some examples, Δh is greater than a protrusion height of the first protrusion point.

[0018] In some examples, the second groove includes a third raised point located within the cross section, the third raised point being located between the first depressed point and the second depressed point.

[0019] In some examples, the curvature of the third raised point is smaller than the curvature of the first raised point.

[0020] In some examples, in the cross section, a ratio of a maximum dimension of the second groove in a second direction perpendicular to the first direction to a maximum dimension of the second groove in the first direction is less than or equal to 0.5.

[0021] In some examples, within the cross section and in the first direction, the length of the first electrode is f1, and the ratio of f1 to L1 is in the range of 8-20.

[0022] In some examples, the distance between the first concave point and the second concave point in the first direction is y2; and the ratio of L1 to y2 is greater than 1 / 2.

[0023] At least one embodiment of the present disclosure further provides an electronic device, comprising the display substrate provided by any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below only relate to some embodiments of the present disclosure and are not limitations of the present disclosure.

[0025] Figure 1 A schematic plan view of a display substrate provided for some embodiments of the present disclosure;

[0026] Figure 2 One of the cross-sectional views of a display substrate provided in some embodiments of the present disclosure;

[0027] Figure 3 A second cross-sectional view of a display substrate provided in some embodiments of the present disclosure;

[0028] Figure 4 A schematic plan view of a first electrode layer and a pixel defining layer provided in some embodiments of the present disclosure;

[0029] Figure 5A A schematic diagram illustrating the formation principle of a mask for a pixel electrode layer provided in some embodiments of the present disclosure;

[0030] Figure 5B A schematic plan view of a pixel definition layer provided in some embodiments of the present disclosure;

[0031] Figure 6 A third cross-sectional view of a display substrate provided in some embodiments of the present disclosure;

[0032] Figure 7 A fourth cross-sectional view of a display substrate provided in some embodiments of the present disclosure;

[0033] Figure 8 A fifth cross-sectional view of a display substrate provided for some embodiments of the present disclosure; and

[0034] Figure 9 A schematic diagram of an electronic device provided in accordance with some embodiments of the present disclosure. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. With reference to the non-limiting exemplary embodiments shown in the accompanying drawings and described in detail in the following description, the exemplary embodiments of the present disclosure and their various features and advantageous details are more fully described. It should be noted that the features shown in the figures are not necessarily drawn to scale. The present disclosure omits the description of known materials, components and process technologies so as not to obscure the exemplary embodiments of the present disclosure. The examples given are only intended to facilitate understanding the implementation of the exemplary embodiments of the present disclosure, and to further enable those skilled in the art to implement the exemplary embodiments. Therefore, these examples should not be understood as limiting the scope of the embodiments of the present disclosure.

[0036] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0037] Micro OLED displays typically have a size of less than 100 microns, such as less than 50 microns, and involve the combination of organic light-emitting diode (OLED) technology and CMOS technology, with the OLED array being fabricated on a silicon-based substrate including CMOS circuits.

[0038] Typically, OLED devices are formed by evaporating different organic functional layers (such as electron / hole injection layers) using a fine metal mask (Fine Metal Mask, FMM). For example, the organic functional layer is patterned using FFM to form corresponding patterns in different pixel areas. However, the precision of FMM is limited, and high image resolution (i.e., pixels per inch, Pixels Per Inch, abbreviated as PPI) cannot be achieved, which limits the resolution of OLED devices. Therefore, full-color display can be achieved by combining white light OLED with a color film layer. However, in this process, the organic functional layer is usually formed into a continuous structure covering multiple sub-pixel areas, which is prone to leakage in the lateral direction, resulting in cross-color between sub-pixels and reducing the color gamut of the display device. For example, organic functional sublayers such as the carrier injection layer (such as the electron injection layer (EIL), the hole injection layer (HIL)), the light-emitting layer, and the carrier injection layer (CGL) in OLED devices usually include metal elements, such as metal ions or heavily doped materials containing metal elements. Under the action of voltage, mobile charges will be generated, thereby causing leakage between sub-pixels in the lateral direction, and thus causing cross-color problems.

[0039] For example, the substrate structure can be designed so that the organic functional layer is recessed between sub-pixels, so that the leakage structure in the organic functional layer (such as the carrier injection layer, etc.) is naturally disconnected at the recess, thereby effectively avoiding cross-color between sub-pixels caused by lateral leakage of the organic functional layer, thereby increasing the color gamut of the display substrate and improving the display quality.

[0040] The inventors discovered that the depression of the organic functional layer causes the upper electrode layer (for example, the cathode) of the light-emitting element formed above the organic functional layer to also be depressed accordingly, thereby shortening the distance between the upper electrode layer (for example, the anode) of the organic functional layer and increasing the risk of short circuit; in addition, the upper electrode layer is prone to form a needle-puncture shape at the depression, which makes it easy for tip discharge to occur, further increasing the risk of short circuit between the upper and lower electrode layers.

[0041] At least one embodiment of the present disclosure provides a display substrate, including a base substrate, a dielectric layer located on the base substrate, and a first electrode layer, an organic functional layer, and a second electrode layer located on a side of the dielectric layer away from the base substrate and stacked in sequence, wherein the first electrode layer includes a first electrode located in the first sub-pixel region and a second electrode located in the second sub-pixel region; there is a gap between the first electrode and the second electrode, the dielectric layer is provided with a first groove corresponding to the gap, the gap exposes the first groove, and the second electrode layer includes a recessed structure corresponding to the first groove; the gap also exposes a first exposed portion of the dielectric layer located between the first electrode and the first groove.

[0042] At least one embodiment of the present disclosure provides a display substrate, in which a first groove is provided in the dielectric layer below at the corresponding sub-pixel interval, so that the organic functional layer is recessed between the sub-pixels, so that the leakage structure in the organic functional layer is naturally disconnected at the recess, thereby effectively avoiding cross-color between sub-pixels caused by lateral leakage of the organic functional layer, improving the color gamut of the display substrate, and improving the display quality; at the same time, by providing the first exposed portion, the distance between the edge of the first electrode and the edge of the first groove is increased, thereby increasing the distance between the recessed structures of the first electrode and the second electrode layer, reducing the risk of short circuit between the first electrode and the second electrode layer, and improving the product yield.

[0043] Figure 1 This is a schematic plan view of a display substrate provided by an embodiment of the present disclosure. Figure 1As shown, the display substrate 20 includes a plurality of gate lines 11 and a plurality of data lines 12, and the plurality of gate lines 11 and the plurality of data lines 12 cross each other to define a plurality of sub-pixel areas distributed in an array in the display area, and each sub-pixel area is provided with a sub-pixel, and each sub-pixel includes a light-emitting element and a driving circuit for driving the light-emitting element. The driving circuit is, for example, a conventional pixel circuit. For example, the driving circuit includes a conventional 2T1C (i.e., two transistors and one capacitor) pixel circuit, a 4T2C, 5T1C, 7T1C, and other nTmC (n, m are positive integers) pixel circuits, and in different embodiments, the driving circuit may further include a compensation circuit, which includes an internal compensation circuit or an external compensation circuit, and the compensation circuit may include transistors, capacitors, etc. For example, as needed, the driving circuit may further include a reset circuit, a light-emitting control circuit, a detection circuit, etc.

[0044] For example, the display substrate may further include a data drive circuit 6 and a gate drive circuit 7, which are connected to the drive circuit of the light-emitting element via data lines 12 and gate lines 11, respectively, to provide electrical signals. The data drive circuit is used to provide data signals, and the gate drive circuit is used to provide scan signals, and may further be used to provide various control signals, power signals, and the like.

[0045] It should be noted that Figure 1 The connection relationship between the gate driver circuit and the data driver circuit and the sub-pixel is only schematically shown, which does not represent their actual positional relationship and does not limit the present disclosure. For example, the display substrate uses a silicon substrate as the base substrate 101, and the driver circuit (pixel circuit), the gate driver circuit 6 and the data driver circuit 7 can all be integrated on the silicon substrate. In this case, since silicon-based circuits can achieve higher precision, the gate driver circuit 6 and the data driver circuit 7 can, for example, be formed in an area corresponding to the display area of the display substrate.

[0046] Figure 2 Shown Figure 1 An example of a cross-sectional view of the substrate along the section line AA' is shown.

[0047] For clarity, Figure 2 Only the first sub-pixel 100a and the second sub-pixel 100b in the adjacent first sub-pixel region and the second sub-pixel region are shown, and for each sub-pixel, only the light-emitting element and the transistor directly connected to the light-emitting element in the pixel driving circuit are shown. For example, the transistor can be a driving transistor configured to control the magnitude of the current driving the light-emitting element to emit light. For example, the transistor can also be a light-emitting control transistor for controlling whether the current driving the light-emitting element to emit light flows. The embodiments of the present disclosure are not limited to this.

[0048] like Figure 2 As shown, the display substrate 20 includes a base substrate 101, a dielectric layer 102 located on the base substrate 101, and a first electrode layer 211, a pixel defining layer 230, an organic functional layer 213, and a second electrode layer 212 located on a side of the dielectric layer away from the base substrate 101 and stacked in sequence. The first electrode layer 211 includes a plurality of electrodes spaced apart from each other to serve as a plurality of pixel electrodes of a plurality of light-emitting elements of the display substrate. Figure 2 As shown, the plurality of pixel electrodes include a first electrode 221 located in the first sub-pixel region and a second electrode 222 located in the second sub-pixel region; a gap G exists between the first electrode 221 and the second electrode 222 .

[0049] The first electrode 221, the second electrode layer 212 and the portion of the organic functional layer 213 located between the first electrode 221 and the second electrode layer 212 constitute the light-emitting element of the first sub-pixel, and the second electrode 222, the second electrode layer 212 and the portion of the organic functional layer 213 located between the second electrode 222 and the second electrode layer 212 constitute the light-emitting element of the second sub-pixel.

[0050] The dielectric layer 102 is provided with a first groove 120 corresponding to the interval G, and the interval G exposes the first groove 120, that is, the first groove 120 is provided between the first electrode edge 221c of the first electrode 221 facing the second electrode 221 and the second electrode edge 222c of the second electrode 222 facing the first electrode.

[0051] Due to the presence of the first groove 120, the organic functional layer 213 and the second electrode layer 212 formed thereon also have a corresponding recessed structure at the position corresponding to the first groove 120, so that the organic functional layer 213 is recessed between the first sub-pixel and the second sub-pixel, so that the leakage structure in the organic functional layer is naturally disconnected at the recessed position, thereby effectively avoiding cross-color between the first sub-pixel and the second sub-pixel caused by lateral leakage of the organic functional layer, thereby improving the color gamut of the display substrate and the display quality.

[0052] Figure 3 Shown Figure 1 An example of an electron microscope image of a substrate along the cross-section line AA' is shown. Figure 3 Only a partial schematic diagram of the first groove 120 and its surroundings is shown.

[0053] like Figure 2-3As shown, the second electrode layer 212 includes a recessed structure 130 corresponding to the first groove 120. For example, the recessed structure 130 is W-shaped in the cross section, having a first recessed point V1 and a second recessed point V2. The first recessed point V1 is close to the first electrode 221, and the second recessed point V2 is close to the second recessed point V2. For example, the second electrode layer 212 is closer to the substrate at the first recessed point V1 than at the periphery of the first recessed point V1 (for example, within 10 nanometers, 30 nanometers, or 50 nanometers around the first recessed point V1). The second electrode layer is closer to the substrate at the second recessed point V2 than at the periphery of the second recessed point V2 (for example, within 10 nanometers, 30 nanometers, or 50 nanometers around the second recessed point V2).

[0054] Figure 4 FIG2 shows a schematic plan view of a first electrode layer 211 and a pixel defining layer 230 provided in at least one embodiment of the present disclosure. Figure 4 The position of the section line AA' is also shown accordingly.

[0055] Combined with reference Figure 2-4 The pixel definition layer 230 includes a plurality of opening areas 232, which correspond one to one with the plurality of pixel electrodes in the first electrode layer 211. Each opening area exposes at least a portion of a corresponding pixel electrode, thereby defining a light-emitting area of each light-emitting element. Figure 2-4 As shown, the plurality of opening regions 232 include a first opening region 232 a and a second opening region 232 b . The first opening region 232 a exposes at least a portion of the first electrode 221 , and the second opening region 232 b exposes at least a portion of the second electrode 222 .

[0056] The organic functional layer 213 contacts each pixel electrode through each opening. For example, the first opening region 232a and the second opening region 232b of the pixel defining layer 230 expose at least a portion of the first electrode 221 and the second electrode 222, respectively.

[0057] The pixel electrode layer 230 also includes a pixel defining portion 231 located between the first opening area 232a and the second opening area 232b. The pixel defining portion 231 covers the first groove 120 and respectively covers a portion of the first electrode 221 and the second electrode 222, thereby respectively insulating the ends of the first electrode 221 and the second electrode 222 close to the recessed structure 130 from the second electrode layer 212, thereby reducing the risk of short circuit between the first electrode layer 211 and the second electrode layer 212.

[0058] like Figure 2-3As shown, the pixel defining portion covers the first groove 120 and forms a second groove 220. The second groove 220 is formed by inheriting the morphology of the underlying first groove 120. In the cross section and in a first direction D1 parallel to the substrate surface, the second groove 220 has two opposing sidewalls, namely a first side surface 220a and a second side surface 220b. The first side surface 220a is close to the first electrode 221 and the second side surface 220b is close to the second electrode 222.

[0059] For example, the pixel defining layer 230 is made of an inorganic insulating material, such as silicon nitride, oxide, or oxynitride. Inorganic insulating materials are harder than organic materials and easier to shape, making them more suitable for high-precision display substrates, such as silicon-based display substrates.

[0060] For example, the material of the pixel definition layer 230 is the same as or similar to the material of the dielectric layer 102 .

[0061] For example, since the material of the pixel definition layer 230 is the same as or similar to the material of the dielectric layer 102, Figure 3 The boundary between the pixel definition layer 230 and the dielectric layer 102 cannot be clearly shown in the electron microscope image.

[0062] For example, the orthographic projections of the first depressed point V1 and the second depressed point V2 on the substrate are both located within the orthographic projection of the second groove 220 on the substrate, that is, between the first side surface 220a and the second side surface 220b. In the cross section, along a first direction D1 parallel to the substrate surface, the distance between the first depressed point V1 and the second depressed point V2 is d6 (also referred to as y2). The first sub-pixel and the second sub-pixel are adjacent in the first direction D1.

[0063] The distance between the first and second recessed points V1 and V2 and the first electrode layer 211 needs to be controlled. If the distance is too large, the organic functional layer 213 cannot be sufficiently recessed between the sub-pixels to allow the leakage-prone sub-functional layers to be naturally disconnected. If the distance is too small, the risk of short circuit between the first and second electrode layers 211 and 212 is likely to increase. Due to the tip discharge effect, the short circuit risk at the first and second recessed points V1 and V2 is relatively high.

[0064] For example, the first concave point V1 and the second concave point V2 are at different distances from the base substrate 101; for example, Figure 2 and 3 As shown, the distance between the second recess point V2 and the base substrate 101 is smaller. For example, the angle of the second electrode layer 212 at the second recess point V2 is sharper than that at the first recess point V1.

[0065] This arrangement can increase the slope of the bottom of the recessed structure 130 , thereby helping to further increase the step difference of the leakage structure in the organic functional layer 213 , making it more susceptible to fracture.

[0066] The concave structure 130 and the second groove 220 are formed due to the existence of the first groove 120. The morphology of the concave structure 130 and the second groove 220 is related to the aspect ratio of the first groove 120. The second groove 220 basically inherits the morphology of the first groove 120. For example, the aspect ratio of the first groove 120 is less than or equal to 0.5. Figure 2 As shown, the bottom side of the cross-section of the first groove 120 is an arc shape that bulges upwards. However, the embodiment of the present disclosure is not limited to this. In other embodiments, the cross-section of the first groove 120 can also be a rectangle, a trapezoid, a triangle, etc. Figure 2 In the cross section shown, the ratio of the maximum dimension of the first groove 120 in the direction perpendicular to the substrate to the maximum dimension in the first direction D1 is less than or equal to 0.5. Figure 2 In the cross section shown, a ratio of a maximum dimension of the second groove 220 in a direction perpendicular to the substrate to a maximum dimension d4 in the first direction D1 is less than or equal to 0.5.

[0067] For example, Figure 2-3 As shown, the ratio of the maximum dimension d4 of the second groove 220 in the first direction D1 to the length of the interval G in the first direction is in the range of 1 / 2-2 / 3.

[0068] For example, in a direction perpendicular to the substrate, the distance between the first recessed point V1 and the substrate is different from the distance between the second recessed point V2 and the substrate. Figure 2 As shown, the second recess point V2 is closer to the base substrate 101 .

[0069] For example, the thickness of the second electrode layer 212 at the first depression point V1 and the second depression point V2 are different, which is also caused by the different depression degrees of the second electrode layer 212 at the first depression point V1 and the second depression point V2.

[0070] The gap G also exposes a first exposed portion 121 of the dielectric layer 102 located between a first electrode edge 221c of the first electrode 221 near the first groove 120 and a first groove edge 120a of the first groove 120 facing the first electrode 221, as well as a second exposed portion 122 of the second electrode 222 located between a second electrode edge 222c of the second electrode 222 near the first groove 120 and a second groove edge 120b of the first groove 120 facing the second electrode 222. Both the first exposed portion 121 and the second exposed portion 122 are portions of the dielectric layer 102 not covered by the first electrode layer 211.

[0071] By setting the first exposed portion 121 and the second exposed portion 122, the distance between the edge of the first electrode 221 / the edge of the second electrode 222 and the edge of the first groove 120 is respectively increased, thereby increasing the distance between the first electrode 221 and the first depression point V1 of the second electrode layer 212 and the distance between the second electrode 222 and the second depression point V2, thereby reducing the risk of short circuit between the first electrode layer and the second electrode layer.

[0072] like Figure 2-3 As shown, the first electrode 221 includes a first surface 221a away from the base substrate, and the first surface 221a is the upper surface of the first electrode 221. For example, the first surface 221a is parallel to the plate surface of the base substrate, that is, parallel to the first direction D1.

[0073] In the cross section and in the first direction D1 parallel to the surface of the substrate, the length of the portion of the pixel defining portion 231 located on the first surface 221a of the first electrode 221 (i.e., the portion overlapping with the first surface 221a in the direction perpendicular to the substrate) is d1 (also called L3).

[0074] For example, the first direction D1 is the direction from the first sub-pixel to the second sub-pixel, that is, the first sub-pixel and the second sub-pixel are adjacent to each other in the first direction. Figure 4 As shown, the first direction D1 may be a direction from the geometric center O1 of the orthographic projection of the opening area of the first sub-pixel on the substrate to the geometric center O2 of the orthographic projection of the opening area of the second sub-pixel on the substrate. However, the present disclosure does not limit the first direction D1.

[0075] like Figure 2-3 As shown, the first electrode 211 further includes a second surface 221 b away from the base substrate. For example, the second surface 221 b is parallel to the first direction D1 and parallel to the first surface 221 a.

[0076] The second surface 221b is closer to the base substrate 101 than the first surface 221a. Figure 2As shown, the first surface 221a and the second surface 221b are connected by a third surface, and the third surface is an inclined surface. Figure 3 In the embodiment, since the third surface is omitted due to its small size in the first direction D1, the first surface 221a and the second surface 221b can be approximately regarded as continuous surfaces.

[0077] For example, Figure 2-3 As shown, the first electrode layer 211 includes a stacked first sub-electrode layer and a second sub-electrode layer, with the second sub-electrode layer located on the side of the first sub-electrode layer away from the substrate. The first electrode 221 and the second electrode 222 respectively include a stacked first sub-electrode 211a and a second sub-electrode 211b, with the second sub-electrode 211b located on the side of the first sub-electrode 211a away from the dielectric layer 102. For example, the second sub-electrode 211b covers the side surface of the first sub-electrode 211a and contacts the dielectric layer 102 to form the second surface 221b of the first electrode 221. As a result, the first surface 221a and the second surface 221b of the first electrode 221 form a stepped structure, reducing the step difference of the pixel defining portion 231 located above the first electrode 221. When the pixel defining layer is made of an inorganic insulating material, it is relatively brittle. This stepped structure can prevent the pixel defining layer from breaking due to a large step difference.

[0078] For example, the average thickness of the portion of the pixel defining portion 231 contacting the second surface 211 b of the first electrode 211 is greater than the average thickness of the first electrode 211 at the second surface 211 b .

[0079] For example, the material of the first sub-electrode layer may include titanium (Ti), and the material of the second sub-electrode layer may include silver (Ag). The material of the first sub-electrode layer has high conductivity, which can reduce the contact resistance with the circuit on the substrate; the material of the second sub-electrode layer has high reflectivity, which can improve the light extraction efficiency of the top-emitting light-emitting element.

[0080] In other examples, the first electrode layer may also include a third sub-electrode layer located on the side of the second sub-electrode layer away from the first sub-electrode layer. The material of the third sub-electrode layer is, for example, a transparent conductive material, such as ITO, IZO, IGZO, AZO and other conductive materials with high work function. Direct contact with the organic functional layer 213 can improve the hole injection rate.

[0081] For example, the material of the second electrode layer may be a material with a low work function to serve as a cathode, such as a semi-transmissive metal or metal alloy material, such as an Ag / Mg alloy material.

[0082] For example, Figure 2-3As shown, the second electrode layer 212 includes a first protrusion 241 , and the first protrusion 241 at least partially overlaps with the first electrode 221 in a direction perpendicular to the substrate.

[0083] For example, the first protrusion 241 corresponds to between the first surface 221 a and the second surface 221 b of the first electrode 221 . For example, the first protrusion 241 is caused by the step between the first surface 221 a and the second surface 221 b of the first electrode 221 or by the pixel defining portion 231 .

[0084] For example, in a direction perpendicular to the base substrate, the first protrusion 241 at least partially overlaps with the first surface 221 a and the second surface 221 b .

[0085] For example, in a direction perpendicular to the base substrate, the first protrusion 241 at least partially overlaps with the pixel defining portion 231 .

[0086] The first protrusion 241 has a first protrusion point P1 in the cross section. For example, the first protrusion 241 is farther from the substrate at the first protrusion point P1 than at its periphery (e.g., within 10 nanometers, 30 nanometers, or 50 nanometers of the first protrusion point P1). For example, the orthographic projection of the first protrusion point P1 on the substrate falls within the orthographic projection of the pixel defining portion 231 on the substrate.

[0087] For example, the protrusion height h1 of the first protrusion point P1 is greater than the average thickness of the second electrode layer 212. For example, the protrusion height h1 is based on a plane of the second electrode layer 212 parallel to the first direction D1 (ie, parallel to the substrate surface).

[0088] For example, Figure 2-3 As shown, the second electrode layer 212 includes a second protrusion (not shown), and the second protrusion at least partially overlaps the second electrode 222 in a direction perpendicular to the substrate.

[0089] For example, the orthographic projection of the pixel electrode portion 231 on the base substrate is located between the orthographic projection of the first convex portion 241 on the base substrate and the orthographic projection of the second convex portion on the base substrate.

[0090] For example, the second protrusion also includes a protrusion point, and the orthographic projection of the protrusion point of the second protrusion on the base substrate falls within the orthographic projection of the pixel defining portion 231 on the base substrate.

[0091] For example, Figure 2-3As shown, the recessed structure 130 also includes a second protrusion point P2 located in the cross section, and the second protrusion point P2 is located between the first recessed point V1 and the second recessed point V2. The distance between the second protrusion point P2 and the substrate is greater than the distance between the first recessed point V1 and the second recessed point V2 and the substrate.

[0092] For example, the second electrode layer 212 is farther from the substrate at the second protruding point P2 than at the periphery of the second protruding point P2 (eg, within 10 nm, 30 nm, or 50 nm around the second protruding point P2).

[0093] For example, the larger value Δh of the height difference between the second protruding point P2 and the first concave point V1 and the second concave point V2 is the protruding height of the second protruding point P2; Figure 3 As shown, since the second recessed point V2 is closer to the base substrate than the first recessed point V1, the protrusion height Δh of the second protrusion point P2 is the height difference between the second protrusion point P2 and the second recessed point V2.

[0094] For example, Δh is greater than the height difference between the first concave point and the second concave point.

[0095] For example, Δh is greater than the average thickness of the second electrode layer 212 .

[0096] For example, Figure 2 As shown, Δh is less than the protrusion height h1 of the first protrusion point P. However, this is not intended to limit the embodiments of the present disclosure. For example, Figure 3 As shown, Δh is greater than the protrusion height of the first protrusion point.

[0097] For example, Figure 2 As shown, the bottom edge of the cross-sectional shape of the second groove 220 is an upwardly convex arc, including a third convex point P3 located in the cross-sectional shape, and the third convex point P3 is located between the first concave point V1 and the second concave point V2, that is, the orthographic projection of the third convex point P3 on the substrate is located between the orthographic projection of the first concave point V1 on the substrate and the orthographic projection of the second concave point V2 on the substrate.

[0098] For example, Figure 2 As shown, the curvature of the third protruding point P3 is smaller than the curvature of the first protruding point P1, and the curvature of the third protruding point P3 is smaller than the curvature of the second protruding point P2.

[0099] like Figure 2-3As shown, within the cross section and in the first direction D1, the length of the portion of the pixel defining portion 231 located on the second surface 221b of the first electrode (i.e., the portion overlapping with the second surface in a direction perpendicular to the base substrate) is d2 (also referred to as L4).

[0100] like Figure 2-3 As shown, in the cross section and in the first direction D1, the distance between the first side surface 220a of the second groove 220 (ie, the sidewall of the second groove) and the first electrode edge 221c of the first electrode 221 is d3 (also referred to as L1).

[0101] In the cross section, the distance d3 is greater than the distance d5 (also referred to as L2 ) between the first recess point V1 and the first side surface 220 a of the second groove 220 (ie, the side surface of the pixel defining layer).

[0102] With this arrangement, the short circuit phenomenon between the first electrode 221 and the second electrode layer 212 at the closest location between the first electrode 221 and the second electrode layer 212 and the puncture phenomenon of the second electrode layer 212 can be alleviated or even avoided.

[0103] For example, Figure 2-3 As shown, the pixel defining portion 231 includes a first surface (ie, an upper surface) away from the substrate. Figure 3 2 , a curve schematically illustrates the first surface 231s of the pixel defining portion 231. The first surface 231s of the pixel defining portion includes a first inclined surface z1 corresponding to the first electrode edge 221c of the first electrode 221 and a second inclined surface z2 connected to the first side surface 220a.

[0104] In a direction perpendicular to the base substrate, the first inclined surface z1 at least partially overlaps with the first electrode edge 221 c ; the second inclined surface z2 at least partially overlaps with the first groove edge 120 a .

[0105] For example, Figure 2-3 As shown, the first inclined surface z1 and the second inclined surface z2 both include curved surfaces; for example, the shapes of the first inclined surface z1 and the second inclined surface z2 in the cross section both include arcs.

[0106] The first inclined surface z1 is caused by the step between the first sub-electrode 211a and the second sub-electrode 211b in the first electrode 221, and the second inclined surface z2 is caused by the first groove edge 120a of the first groove 120. For example, because etching is not perfectly isotropic, the pixel defining layer may form a curved surface shape instead of a perfect right angle when covering the step shape below.

[0107] For example, Figure 2-3As shown, the first surface 231s of the pixel defining portion 231 further includes a connecting surface 231c located between the first inclined surface z1 and the second inclined surface z2. For example, at least a portion of the connecting surface 231c is a plane.

[0108] Because the distance d3 between the first side surface 220a of the second groove 220 and the first electrode edge 221c of the first electrode 221 is sufficiently long, the first inclined surface z1 and the second inclined surface z2 are not directly connected, so that a transitional planar portion appears between the first inclined surface z1 and the second inclined surface z2 on the first surface 231a. For example, the connecting surface 231c is entirely planar.

[0109] For example, Figure 2 As shown, in the cross section, the length y3 of the connecting surface 231 c is greater than the average thickness of the pixel defining layer 230 .

[0110] For example, Figure 2 As shown, in the cross section, the ratio of the length y3 of the connecting surface 231c to L3 is greater than 1 / 3.

[0111] For example, Figure 2-3 As shown, d5 is smaller than d2. For example, d5 is greater than the average thickness of the pixel defining layer 230.

[0112] For example, Figure 2-3 As shown, the distance d3 is also greater than the length d1 of the portion of the pixel defining portion 231 located on the first surface 221a of the first electrode 221. However, the present disclosure is not limited thereto. In other embodiments, the distance d3 may also be less than or equal to d1.

[0113] For example, Figure 2-3 As shown, the length d2 of the portion of the pixel defining portion 231 located on the second surface 221 b of the first electrode is greater than the distance d5 between the first recessed point V1 and the first side surface 220 a of the second groove 220 .

[0114] Since the first electrode shrinks inward to form the first exposed portion, the distance between the first electrode and the second electrode layer is increased, reducing the risk of short circuit between the two. Therefore, the length d1 of the portion of the pixel defining portion 231 covering the first surface 221a of the first electrode 221 can be appropriately reduced, which can help increase the size of the opening area and improve the aperture ratio.

[0115] refer to Figure 2 and Figure 3 The length d1 of the portion of the pixel defining portion 231 located on the first surface 221 a of the first electrode 221 is smaller than the length d2 of the portion of the pixel defining portion 231 located on the second surface 221 b of the first electrode.

[0116] For example, Figure 2 and Figure 3 As shown, the length d1 of the portion of the pixel defining portion 231 located on the first surface 221 a of the first electrode 221 is smaller than the distance d3 .

[0117] For example, d1 is also smaller than the average thickness of the pixel defining layer 230 .

[0118] For example, Figure 3 As shown, in the cross section and in the first direction, the length of the first electrode 221a is f1, and the ratio of f1 to the distance d3 (also referred to as L1) ranges from 8 to 20.

[0119] For example, the ratio of d3 to y2 is greater than 1 / 2.

[0120] If the distance d3 is too small, it is not conducive to increasing the distance between the first electrode 221 and the second electrode layer 212 and reducing the risk of short circuit; if the distance d3 is too large, it is not conducive to improving the aperture ratio.

[0121] For example, the distance d3 ranges from 0.1 micrometer to 0.2 micrometer, such as 0.12 micrometer or 0.15 micrometer.

[0122] For example, Figure 2 and Figure 3 As shown, the length d1 of the portion of the pixel defining portion 231 located on the first surface 221 a of the first electrode 221 is greater than the distance d5 between the first recessed point V1 and the first side surface 220 a of the second groove 220 in the first direction D1 .

[0123] For example, Figure 3 As shown, in the cross section, the length y1 of the pixel defining portion 231 located on the first side surface 220a of the second groove 220 close to the first electrode 221 in the first direction D1 is greater than the maximum dimension d4 (also referred to as L5) of the second groove 220 in the first direction D1.

[0124] For example, in the cross section, the length y1 of the pixel defining portion 231 located on the first side surface 220a of the second groove 220 close to the first electrode 221 in the first direction D1 is also greater than the distance d6 between the first recess point V1 and the second recess point V2 in the first direction.

[0125] Providing a longer side of the pixel defining portion 231 close to the first electrode 221 can improve the insulation performance of the pixel defining portion 231 and reduce the risk of short circuit between the first electrode 221 and the second electrode layer 212. However, this is not intended to limit the present disclosure.

[0126] For example, Figure 3 As shown, in the cross section and in the first direction D1, the distance d3' (also referred to as L1') between the second side surface 220b of the second groove 220 and the second electrode 222 is greater than the distance d5' (also referred to as L2') between the second depression point V1 and the second side surface 220b of the second groove 220.

[0127] The inventors discovered that the mask used to create the pixel definition layer (PDL) 230 exhibits periodic variations during the manufacturing process due to process reasons. This periodic variation results in periodic variations in the size of the openings 232 in the resulting PDL. This periodic variation ultimately causes horizontal or vertical stripes to appear on the display device, resulting in uneven display.

[0128] Figure 5A The formation principle of the mask plate of the pixel definition layer is shown. Figure 5B A schematic plan view of a pixel definition layer formed using the mask is shown. Figure 5B Only the opening region 232 in the pixel definition layer is schematically shown.

[0129] For example, when making the mask plate, the entire surface must first be coated with a layer of metal film (such as a chromium film), and then the metal film is laser ablated to form a mesh pattern. When ablation is performed, it is necessary to ablate in sections, and during the second ablation, in order to prevent missing a certain section, the mask plate is returned to a distance (for example, 6-8um) and then ablated to form a repeated ablation area. There are slight differences between the repeated ablation area and the single ablation area. For example, the mesh size of the repeated ablation area is larger than that of the single ablation area; the opening area of the pixel definition layer formed in this way correspondingly shows slight regular differences, so that the final display product has regular horizontal or vertical stripes when displayed, which affects the product display effect. This uneven display phenomenon is particularly evident on high-resolution display products.

[0130] like Figure 5A As shown, for example, the ablation direction is a second direction D2 perpendicular to the first direction D1. In the second direction D2, the primary ablation area and the repeated ablation area appear alternately and in a periodic pattern. Accordingly, as shown in FIG. Figure 5B As shown, the size of the opening area of the pixel defining layer formed by the mask plate changes regularly and periodically in the second direction D2; for example, the T1 section of the pixel defining layer corresponds to the single ablation area, and the T2 section corresponds to the repeated ablation area.

[0131] The inventors have also found that the severity of the display unevenness is related to the size of the opening area. The larger the opening area, the less obvious the display unevenness and the smaller the impact. Figure 2As shown, in the cross section, the smaller the length x1 of the opening area 232 of the first sub-pixel along the first direction D1 is, the more serious the influence of the periodic difference in the size of the opening area 232 on the display uniformity is.

[0132] For example, the length of the opening area 232 along the first direction D1 may have different values in the thickness direction of the pixel definition layer. Since the effective light-emitting area of the sub-pixel is determined by the minimum length of the opening area 232 along the first direction D1, the length x1 of the opening area 232 along the first direction D1 is defined as the minimum value. Figure 2 As shown, the size of the opening area 232 at the end close to the substrate is different from that at the end away from the substrate, and x1 is the size of the end of the opening area 232 away from the substrate, that is, the minimum size.

[0133] At least one embodiment of the present disclosure provides a display substrate, in which the length d1 of the portion of the pixel defining portion 231 located on the first surface 221a of the first electrode 221 is narrowed, thereby increasing the length x1 of the opening area 232. This not only helps to improve the aperture ratio of the display substrate, but also reduces the impact of periodic differences in the size of the opening area 232 on display uniformity, thereby improving the display uniformity of the display substrate.

[0134] Figure 6 Shown Figure 1 The figures show some other examples of electron microscope images of a substrate along the cross-section line AA'. Figure 2 and Figure 6 The length d1 of the portion of the pixel defining portion 231 located on the first surface 221a of the first electrode 221 (i.e., the portion overlapping with the first surface 221a in a direction perpendicular to the substrate) is smaller than the length d2 of the portion of the pixel defining portion 231 located on the second surface 221b of the first electrode (i.e., the portion overlapping with the second surface 221b in a direction perpendicular to the substrate).

[0135] For example, Figure 2 and Figure 6 As shown, the length d1 of the portion of the pixel defining portion 231 located on the first surface 221 a of the first electrode 221 is also smaller than the distance d3 between the first side surface 220 a of the second groove 220 and the first electrode edge 221 c of the first electrode 221 .

[0136] For example, d1 is also smaller than the average thickness of the pixel defining layer 230 .

[0137] For example, Figure 2 and Figure 6As shown, the length d1 of the portion of the pixel defining portion 231 located on the first surface 221 a of the first electrode 221 is also smaller than the distance d5 between the first recessed point V1 and the first side surface 220 a of the second groove 220 in the first direction D1 .

[0138] For example, in Figure 2 In the cross section shown, a length y1 of a portion of the pixel defining portion 231 close to the first electrode 221 in the first direction D1 is greater than a distance d6 between the first recess point V1 and the second recess point V2 in the first direction.

[0139] Providing a longer side of the pixel defining portion 231 close to the first electrode 221 can improve the insulation performance of the pixel defining portion 231 and reduce the risk of short circuit between the first electrode 221 and the second electrode layer 212. However, this is not intended to limit the present disclosure.

[0140] For example, Figure 6 As shown, in the cross section, a length y1 of a portion of the pixel defining portion 231 close to the first electrode 221 in the first direction D1 is smaller than a maximum dimension d4 of the second groove 220 in the first direction D1.

[0141] For example, Figure 6 As shown, in the cross section, the length y1 of the pixel defining portion 231 located on the first side surface 220a of the second groove 220 close to the first electrode 221 in the first direction D1 is smaller than the distance d6 between the first recess point V1 and the second recess point V2 in the first direction D1.

[0142] For example, in the cross section, the length y1 of the pixel defining portion 231 located on the first side surface 220a of the second groove 220 close to the first electrode 221 in the first direction D1 is also smaller than the distance d6 between the first recess point V1 and the second recess point V2 in the first direction.

[0143] When the pixel density is constant, the smaller y1 is, the smaller the interval between the opening areas 232 of adjacent sub-pixels is, and the larger the opening area 232 of the sub-pixel is. This not only helps to improve the aperture ratio of the display substrate, but also reduces the impact of the periodic difference in the size of the opening area 232 on the display uniformity, thereby improving the display uniformity of the display substrate.

[0144] For example, Figure 2 and Figure 6As shown, the second electrode 222 includes a first surface 222a that is away from the substrate and parallel to the substrate surface. In the cross section and in the first direction D1, the length of the portion of the pixel defining portion 231 located on the first surface 222a of the second electrode 222 is d1', and the length d1' of the portion of the pixel defining portion 231 located on the first surface 222a of the second electrode 222 is not equal to the length d1 of the portion of the pixel defining portion 231 located on the first surface 221a of the first electrode 221. For example, Figure 2 As shown, d1 is smaller than d1'.

[0145] Through the above-mentioned setting, the size x1 of the opening area 231 of the first sub-pixel along the first direction D1 is different from the size x2 of the opening area 231 of the second sub-pixel along the first direction D1, so that the first sub-pixel and the second sub-pixel located in the same pixel defining layer period (for example, both located in the T1 segment or T2 segment of the pixel defining layer) have opening areas of different sizes, which interferes with the regularity of the opening areas of the sub-pixels in the same period, avoids the generation of horizontal or vertical stripes, and thus improves the uniformity of the display.

[0146] For example, Figure 6 As shown, the second electrode layer 212 includes a first protrusion 241 between the first surface 221a and the second surface 221b corresponding to the first electrode 221. For example, the first protrusion 241 is caused by the step difference between the first surface 221a and the second surface 221b of the first electrode 221 or by the pixel defining portion 231.

[0147] For example, in a direction perpendicular to the base substrate, the first protrusion 241 at least partially overlaps with the first surface and the second surface respectively.

[0148] The first protrusion 241 has a first protrusion point P1 in the cross section. For example, the protrusion 241 is farther from the substrate at the first protrusion point P1 than at the periphery of the first protrusion point P1 (for example, within 10 nm, 30 nm, or 50 nm of the first protrusion point P1).

[0149] For example, the protrusion height h1 of the first protrusion point P1 is greater than the average thickness of the second electrode layer 212. For example, the protrusion height h1 is based on a plane of the second electrode layer 212 parallel to the first direction D1 (ie, parallel to the substrate surface).

[0150] For example, Figure 2-3As shown, the recessed structure 130 further includes a second protruding point P2 located within the cross section. The second protruding point P2 is located between the first recessed point V1 and the second recessed point V2. The distance between the second protruding point P2 and the substrate is greater than the distance between the first recessed point V1 and the second recessed point V2. For example, the second electrode layer 212 is further away from the substrate at the second protruding point P2 than at the periphery of the second protruding point P2 (e.g., within 10 nanometers, 30 nanometers, or 50 nanometers of the second protruding point P2).

[0151] For example, the larger value Δh of the height difference between the second protruding point P2 and the first concave point and the second concave point is the protruding height of the second protruding point P2; Figure 3 As shown, since the second recessed point V2 is closer to the base substrate than the first recessed point V1, the protrusion height Δh of the second protrusion point P2 is the height difference between the second protrusion point P2 and the second recessed point V2.

[0152] For example, Δh is greater than the height difference between the first concave point and the second concave point.

[0153] For example, Δh is greater than the average thickness of the second electrode layer 212 .

[0154] For example, Figure 6 As shown, Δh is greater than the protrusion height h1 of the first protrusion point P1.

[0155] For example, Figure 6 The second electrode layer 212 is shown as Figure 3 The second electrode layer 212 is shown to be flatter. Figure 6 The protrusion height h1 of the first protrusion point P1 is less than Figure 3 The first protrusion point P1 has a protrusion height h1.

[0156] Figure 7 Schematic diagram of a display substrate provided by some other embodiments of the present disclosure. For the sake of clarity, the circuit structure below the first electrode layer is omitted in the figure. Figure 7 As shown, the pixel defining portion 231 includes a first surface 231a away from the base substrate 101. Figure 7 The orthographic projection of the cross section is a first curve n1, which is the upper contour of the pixel defining portion 231 in the cross section. A first tangent line S1 of the first curve n1 at an end point near the first electrode 221 intersects the first direction D1.

[0157] Because the shape of the pixel defining portion 231 near the first / second electrode easily affects the size of the sub-pixel's opening area, at least one embodiment of the present disclosure forms a raised structure at the end of the pixel defining portion 231 near the first and / or second electrodes, making it easier to fine-tune the size of the opening area, thereby disrupting the periodicity of the opening area and improving display uniformity.

[0158] For example, Figure 7 As shown, the first curve n1 intersects the first direction D1 at a second tangent line S2 close to the second electrode 222. For example, the first tangent line S1 intersects the second tangent line S2.

[0159] For example, Figure 7 As shown, the first tangent line S1 forms a first angle β1 with the first direction, and the second tangent line S2 forms a second angle β2 with the first direction. The first angle β1 is not equal to the second angle β2.

[0160] Through the above configuration, the pixel defining portion 231 has different morphologies at the two ends close to the first electrode and the second electrode, so that opening areas of different sizes can be obtained at both ends of the pixel defining portion 231, which helps to improve display uniformity.

[0161] For example, the intersection of the first tangent line S1 and the base substrate is located on the side of the first electrode 221 close to the second electrode 222, and the intersection of the second tangent line S2 and the base substrate is located on the side of the second electrode 222 close to the first electrode 221; that is, the pixel defining portion 231 is tilted upward (that is, away from the base substrate) at the two ends close to the first electrode and the second electrode.

[0162] For example, the structure of the aforementioned opening region can be formed by first performing a dry etching process and then a wet etching process during the patterning process of the pixel definition layer material. Due to the higher precision of the dry etching process, the opening region can be positioned and a rough outline of the opening region can be formed, and then the wet etching process can be performed to form the final opening region morphology. Since the wet etching process is not as precise as the dry etching process and has randomness, performing wet etching after the dry etching process can make random and subtle adjustments to the morphology of the opening region, breaking the above-mentioned regularity of the opening region and improving display uniformity. For example, the dry etching process takes longer than the wet etching process.

[0163] For example, since wet etching is isotropic and lateral undercutting is likely to occur during etching, the end portion of the pixel defining portion is likely to form a Figure 7 In the upwardly tilted structure shown, the cross-sectional shape of the opening area is approximately a regular trapezoid, that is, the size of the opening area 232 away from the substrate is smaller than the size of the opening area close to the substrate.

[0164] For example, Figure 7 As shown, the opening area 232 of the first sub-pixel has a first side t1 and a second side t2 opposite to each other in the first direction D1 in the cross section, the first side t1 forms an angle β3 with the first surface 221a of the first electrode 221, and the second side t2 forms an angle β4 with the first surface 221a of the first electrode 221, and β3 and β4 are not equal.

[0165] Figure 8 Schematic diagrams of display substrates provided in some further embodiments of the present disclosure. Figure 8 The display substrate is shown with Figure 2 The main difference between the display substrate shown is that the cross-section of the first groove 120 is a regular trapezoid.

[0166] For example, Figure 8 As shown, the regular trapezoid has a first base angle close to the first electrode 221 and a second base angle close to the second electrode 222. For example, the first base angle and the second base angle are not equal.

[0167] For example, in Figure 8 In the cross section shown, the end of the pixel defining portion 231 close to the first electrode 221 has a third base angle, and the angle bisector k2 of the third base angle is not parallel to the angle bisector k1 of the first base angle.

[0168] It should be noted that, in the absence of conflict, features in the same embodiment and different embodiments of the present disclosure may be combined with each other.

[0169] For example, the base substrate 101 may be silicon, such as single crystal silicon or high-purity silicon; the dielectric layer 102 may be silicon oxide, nitride, or oxynitride formed on silicon. The base substrate 101 and the dielectric layer 102 constitute a driving substrate 201. The sub-pixel driving circuit may be integrated into the driving substrate 201 and electrically connected to the pixel electrodes (e.g., the first electrode 221 and the second electrode 222) through contact holes in the dielectric layer 102, thereby driving the light-emitting element to emit light.

[0170] For example, the active layer (ie, semiconductor layer), the first electrode and the second electrode of the transistor are formed in the driving substrate 201 by a doping process, the insulating layer is formed by a silicon oxidation process, and the plurality of conductive layers 105, 106 are formed by a sputtering process. Figure 2 The active layer 322 in the substrate 101 is located inside the substrate 101 or is a part of the substrate 101.

[0171] For example, the pixel driving circuit includes a complementary metal oxide semiconductor circuit (CMOS circuit). For example, the gate driving circuit 6 and the data driving circuit 7 can also be integrated into the driving substrate 201 through the above-mentioned semiconductor process. The gate driving circuit and the data driving circuit can adopt conventional circuit structures in the art, and the embodiments of the present disclosure are not limited thereto.

[0172] like Figure 2 As shown, the first electrode 221 and the second electrode 222 are formed on the surface of the driving substrate 201 and are electrically connected to the first electrode 323 of the first transistor 203 through the contact hole 103 filled with a conductive material (such as tungsten) and the multiple conductive layers. Figure 2 In the figure, two conductive layers 105 and 106 are exemplarily shown above the transistor, but the embodiment of the present disclosure does not limit the number of conductive layers.

[0173] For example, Figure 2 As shown, the topmost conductive layer 106 in the driving substrate 201 is reflective, for example, a stacked structure of titanium / titanium nitride / aluminum. For example, the conductive layer 106 includes a plurality of sub-layers arranged at intervals, which are respectively arranged in a one-to-one correspondence with the plurality of pixel electrodes (such as the first electrode 221 and the second electrode 222) in the first electrode layer 211. In the top emission structure, the conductive layer 106 can be set as a reflective layer to reflect the light emitted by the light-emitting element and improve the light extraction efficiency. For example, the orthographic projection of each pixel electrode in the first electrode layer 211 on the base substrate 101 falls within the orthographic projection of the portion of the conductive layer 106 corresponding to the pixel electrode on the base substrate 101.

[0174] Thanks to mature CMOS integrated circuit technology, silicon-based processes can achieve high precision (e.g., PPI can reach 6500 or even more than 10,000). For example, the length of the gap G between the first electrode 221 and the second electrode 222 in the first direction is less than 1 micron, for example, 700 nanometers to 900 nanometers.

[0175] For example, the light-emitting element may be an organic light-emitting diode (OLED) or a quantum dot light-emitting diode (QLED), etc. The embodiment of the present disclosure does not limit the type of the light-emitting element. For example, the light-emitting layer of the OLED may be a small molecule organic material or a polymer organic material.

[0176] The organic functional layer 213 includes a plurality of sub-functional layers stacked on top of each other in a direction perpendicular to the base substrate 101 , and at least one of the plurality of sub-functional layers is disconnected at a corresponding first groove 120 .

[0177] For example, the multiple sub-functional layers include at least one carrier injection layer and at least one light-emitting layer. The carrier injection layer can be an electron injection layer (EIL) or a hole injection layer (HIL). The electron injection layer is located on the side of the light-emitting layer close to the cathode, and is used to reduce the barrier for injecting electrons from the cathode, so that electrons can be effectively injected from the cathode into the light-emitting layer. The hole injection layer is located on the side of the light-emitting layer close to the anode, and is used to reduce the barrier for injecting holes from the anode, so that holes can be effectively injected from the anode into the light-emitting layer. Therefore, when selecting the material for the electron / hole injection layer, it is necessary to consider the matching of the material energy level and the electrode material. For example, the material for the electron injection layer can be LiQ (8-hydroxyquinoline lithium), AlQ3 (8-hydroxyquinoline aluminum), etc.; the material for the hole injection layer can be CuPc (polyester carbonate), TiOPc, m-MTDATA, 2-TNATA, etc.

[0178] For example, the organic functional layer 213 may further include an electron / hole transport layer, an electron / hole blocking layer, a charge generation layer, etc. as needed.

[0179] For example, to improve the luminous efficiency and the color gamut of the light-emitting device, multiple light-emitting layers stacked on each other may be used to emit white light. That is, the organic functional layer 213 includes multiple light-emitting layers, and the multiple light-emitting layers are stacked in a direction perpendicular to the base substrate 101. For example, the organic functional layer 213 includes two light-emitting layers (yellow and blue) or three light-emitting layers (red, green, and blue) stacked on each other.

[0180] For example, at least two of the multiple light-emitting layers are connected in series via a charge generation layer (CGL) to form a tandem structure, wherein the charge generation layer includes an N-type charge generation layer and a P-type charge generation layer for balancing the transport of carriers. The N-type charge generation layer can be formed by an organic layer doped with an alkali metal such as lithium (Li), sodium (Na), potassium (K) or cesium (Cs) or an alkaline earth metal such as magnesium (Mg), strontium (Sr), barium (Ba) or radium (Ra) (but not limited to any of them); the P-type charge generation layer can be formed by doping an organic matrix material having hole transport capability with a dopant to obtain an organic layer. The tandem structure helps to improve the luminous efficiency and brightness of the device.

[0181] For example, because the charge generation layer includes metallic elements, leakage between sub-pixels can easily occur, leading to color crosstalk. The display substrate provided by at least one embodiment of the present disclosure includes recessed structures 130 between corresponding sub-pixels in the organic functional layer 213. This allows the charge generation layer to be naturally disconnected at the recessed structures 130 due to the large step difference. This effectively prevents color crosstalk between sub-pixels caused by lateral leakage of the organic functional layer, thereby increasing the color gamut of the display substrate and improving display quality.

[0182] Continue to refer to Figure 2 , Figure 2 A first transistor 203 and a second transistor 204 are shown, electrically connected to the light-emitting elements of the first and second sub-pixels, respectively. The embodiments of the present disclosure do not limit the specific types of the first and second transistors 203 and 204. The following is an exemplary description of the first transistor 203, which also applies to the second transistor 204 and is therefore not repeated here.

[0183] For example, the first transistor 203 includes a gate 321, a gate insulating layer 325, an active layer 322, a first electrode 323, and a second electrode 324. The embodiments of the present disclosure do not limit the type, material, and structure of the first transistor 203. For example, it can be a top-gate type, a bottom-gate type, etc. The active layer of the first transistor 203 can be an inorganic semiconductor material such as microcrystalline silicon, amorphous silicon, polycrystalline silicon (low-temperature polycrystalline silicon or high-temperature polycrystalline silicon), an oxide semiconductor (such as IGZO), or an organic material such as PBTTT, PDBT-co-TT, PDQT, PDVT-10, dinaphtho-dithiophene (DNTT), or pentacene. For example, the first transistor 203 can be N-type or P-type.

[0184] It should be noted that the transistors used in the embodiments of the present disclosure can all be thin film transistors, field effect transistors or other switching devices with the same characteristics. Some embodiments of the present disclosure are described by taking a field effect transistor (such as a MOS field effect transistor) formed in a silicon substrate as an example. In this example, the silicon substrate is doped (p-type doping or n-type doping) to form an active layer of the transistor, that is, the active layer of the transistor is located in the silicon substrate, or the active layer of the transistor is part of the silicon substrate. The source and drain of the transistor used here can be symmetrical in structure, so the source and drain can be structurally indistinguishable. In the embodiments of the present disclosure, in order to distinguish the two poles of the transistor other than the gate, for example, one of the poles can be directly described as the first pole and the other pole as the second pole.

[0185] For example, Figure 3 and Figure 6 As shown, the display substrate 20 may further include a light extraction layer 214 located on a side of the second electrode layer 212 away from the base substrate. For example, the refractive index of the light extraction layer 214 is greater than that of the second conductive layer 212, thereby improving light extraction efficiency.

[0186] For example, Figure 3 and Figure 6As shown, the display substrate 20 may further include an encapsulation layer 215 located on a side of the light extraction layer 214 away from the base substrate. For example, the encapsulation layer 215 is configured to seal the light-emitting element to prevent external moisture and oxygen from penetrating into the light-emitting element and pixel circuit and causing damage to the device. For example, the encapsulation layer 215 includes an organic film or a structure comprising alternating layers of organic and inorganic films. For example, a water-absorbing layer may be provided between the encapsulation layer 215 and the light-emitting element to absorb residual water vapor or sol from the early production process of the light-emitting element.

[0187] For example, Figure 3 As shown, the display substrate 20 may further include a color filter layer 216 located on a side of the encapsulation layer 215 away from the base substrate. For example, the light emitting element of the display substrate is configured to emit white light and is combined with the color filter layer to achieve full color display.

[0188] For example, the display substrate 20 is an organic light emitting diode (OLED) display substrate or a micro OLED (Micro OLED) display substrate.

[0189] The embodiment of the present disclosure further provides an electronic device, including the display substrate 20 . Figure 9 FIG2 is a schematic diagram of an electronic device 40 according to at least one embodiment of the present disclosure. For example, the electronic device 40 is a product or component with any display function, such as a digital photo frame, a smart bracelet, a smart watch, a mobile phone, a tablet computer, a display, a laptop computer, or a navigator.

[0190] The foregoing description is merely an exemplary embodiment of the present disclosure and is not intended to limit the scope of protection of the present disclosure. The scope of protection of the present disclosure is determined by the appended claims.

Claims

1. A display substrate, comprising: The base substrate includes a first sub-pixel region and a second sub-pixel region adjacent to each other. a dielectric layer located on the substrate, and A first electrode layer, a pixel defining layer, an organic functional layer, and a second electrode layer are sequentially stacked on the side of the dielectric layer away from the base substrate, wherein the first electrode layer includes a first electrode located in the first sub-pixel region and a second electrode located in the second sub-pixel region. There is a gap between the first electrode and the second electrode, a portion of the dielectric layer corresponding to the gap includes a first groove, the gap exposes the first groove, and a portion of the second electrode layer corresponding to the first groove includes a recessed structure; The pixel defining layer covers the first groove and forms a second groove; the display substrate has a cross section perpendicular to the base substrate, the recessed structure includes a first recessed point and a second recessed point located on the cross section, and the orthographic projections of the first recessed point and the second recessed point on the base substrate are both located within the orthographic projection of the second groove on the base substrate; In the cross section and in a first direction parallel to the surface of the substrate, a distance L1 between a first side surface of the second groove close to the first electrode and a first electrode edge of the first electrode close to the first groove is greater than a distance L2 between the first depression point and the first side surface of the second groove.

2. The display substrate according to claim 1, wherein: The pixel defining layer includes a first opening area and a second opening area, and a pixel defining portion located between the first opening area and the second opening area, the first opening area exposes at least a portion of the first electrode, the second opening area exposes at least a portion of the second electrode, and the pixel defining portion covers the first groove and a portion of the first electrode and the second electrode; The first electrode includes a first surface away from the base substrate. In the cross section and in the first direction, a length of a portion of the pixel defining portion located on the first surface of the first electrode is L3, and L3 is smaller than L1.

3. The display substrate according to claim 2, wherein: The first electrode further includes a second surface away from the base substrate, and the second surface of the first electrode is closer to the base substrate than the first surface. In the cross section and in the first direction, a length of a portion of the pixel defining portion located on the second surface of the first electrode is L4, and L2 is smaller than L4.

4. The display substrate according to claim 3, wherein: L3 is smaller than L4.

5. The display substrate according to claim 3, wherein: The first electrode includes a stacked first sub-electrode and a second sub-electrode, and the second sub-electrode is located on a side of the first sub-electrode away from the dielectric layer; The second sub-electrode covers the side surface of the first sub-electrode and contacts the dielectric layer to form the second surface of the first electrode.

6. The display substrate according to claim 2, wherein: In the cross section and in the first direction, the length of a portion of the pixel defining portion located on a side of the first side surface of the second groove close to the first electrode is y1, and the maximum length of the second groove is L5; y1 is greater than L5.

7. The display substrate according to claim 6, wherein: The distance between the first concave point and the second concave point in the first direction is less than y1.

8. The display substrate according to claim 1, wherein: The pixel defining layer includes a first surface away from the base substrate, the first surface of the pixel defining layer includes a first inclined surface corresponding to an edge of the first electrode and a second inclined surface connected to the first side surface, and the shapes of the first inclined surface and the second inclined surface in the cross section both include curved surfaces; The first surface of the pixel defining layer further includes a connecting surface located between the first inclined surface and the second inclined surface, and at least a portion of the connecting surface is a plane.

9. The display substrate according to claim 8, wherein: The ratio of the length of the connecting surface in the cross section to L1 is greater than 1 / 3.

10. The display substrate according to any one of claims 1 to 9, wherein: The second electrode layer includes a protrusion, and the protrusion at least partially overlaps with the first electrode in a direction perpendicular to the base substrate; The convex portion has a first convex point in the cross section, and a convex height of the first convex point is greater than an average thickness of the second electrode layer.

11. The display substrate according to claim 10, wherein: The first recessed point and the second recessed point are at different distances from the substrate; The recessed structure further includes a second protruding point located in the cross section, the second protruding point being located between the first recessed point and the second recessed point, and a distance from the second protruding point to the substrate being greater than a distance from the first recessed point and the second recessed point to the substrate; The larger value of the height difference between the second protruding point and the first concave point and the second concave point is Δh.

12. The display substrate according to claim 11, wherein: Δh is greater than the height difference between the first concave point and the second concave point.

13. The display substrate according to claim 11, wherein: Δh is greater than the average thickness of the second electrode layer.

14. The display substrate according to claim 11, wherein: Δh is greater than the protrusion height of the first protrusion point.

15. The display substrate according to claim 11, wherein The second groove includes a third protruding point located in the cross section, and the third protruding point is located between the first concave point and the second concave point.

16. The display substrate according to claim 15, wherein: The curvature of the third protruding point is smaller than the curvature of the first protruding point.

17. The display substrate according to claim 1, wherein: In the cross section, a ratio of a maximum dimension of the second groove in a second direction perpendicular to the first direction to a maximum dimension of the second groove in the first direction is less than or equal to 0.

5.

18. The display substrate according to claim 1, wherein: In the cross section and in the first direction, the length of the first electrode is f1, and the ratio of f1 to L1 is in the range of 8-20.

19. The display substrate according to claim 1, wherein: The distance between the first concave point and the second concave point in the first direction is y2; The ratio of L1 to y2 is greater than 1 / 2.

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

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