Display substrate, preparation method thereof and display device

Abstract

A display substrate and a preparation method thereof, and a display device, relating to but not limited to the technical field of display, the display substrate comprising a substrate, and a pixel definition layer (23), an isolation structure (24) and a support structure (25) arranged on one side of the substrate, the support structure (25) being configured to support a mask, the isolation structure (24) is configured to block at least part of the organic light emitting layer; the supporting structure (25) comprises a first supporting layer (251) and a second supporting layer (252) which are arranged in a stacked mode. The vertical distance between the surface, close to one side of the substrate, of the isolation structure (24) and the surface of the substrate is L1, the vertical distance between the surface, close to one side of the substrate, of the second supporting layer (252) and the surface of the substrate is L2, and L1 is smaller than L2.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to, but are not limited to, the field of display technology, and specifically relate to a display substrate and a method for preparing the same, and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) and Quantum-dot Light Emitting Diode (QLED) are active light-emitting display devices with the advantages of self-luminescence, wide viewing angle, high contrast, low power consumption, extremely high response speed, thinness, bendability and low cost. With the continuous development of display technology, flexible display devices (Flexible Display) using OLED or QLED as light-emitting devices and thin film transistors (TFT) for signal control have become the mainstream products in the current display field.

[0003] Active-matrix organic light-emitting diode (AMOLED) display power consumption has become the core competitiveness of products, and Tandem technology has become a key technology for reducing power consumption. Tandem light-emitting devices are devices that have two light-emitting layers instead of one. This solution can significantly improve device efficiency, reduce current, and thus reduce power consumption.

[0004] A charge generation layer (CGL) is added to the AMOLED display substrate to improve the vertical charge conduction capability. The charge generation layer (CGL) increases the lateral charge conduction, which brings crosstalk problems. For example, when a pixel (such as a G pixel) has a display signal, the transmitted charge will be transmitted to the adjacent pixel, lighting up the nearby R / G / B pixels that are not luminous, resulting in color shift and affecting the display effect. Summary of the invention

[0005] The following is a summary of the subject matter of the detailed description of the present disclosure. This summary is not intended to limit the scope of the claims.

[0006] The embodiment of the present disclosure provides a display substrate, comprising a substrate and a pixel definition layer, an isolation structure and a support structure arranged on one side of the substrate, wherein the support structure is configured to support a mask, and the isolation structure is configured to block at least a portion of an organic light-emitting layer;

[0007] The support structure comprises a first support layer and a second support layer which are stacked, the first support layer is located on a side of the second support layer close to the substrate, the first support layer and the pixel definition layer have substantially the same thickness, and a vertical distance from a surface of the second support layer away from the substrate to the surface of the substrate is greater than a vertical distance from a surface of the isolation structure away from the substrate to the surface of the substrate;

[0008] A vertical distance between a surface of the isolation structure close to the substrate and the substrate surface is L1, a vertical distance between a surface of the second supporting layer close to the substrate and the substrate surface is L2, and L1 is smaller than L2.

[0009] In an exemplary embodiment, the first supporting layer is integrally connected to the second supporting layer.

[0010] In an exemplary embodiment, the support structure and the pixel definition layer are located in the same film layer and are made of the same material.

[0011] In an exemplary embodiment, the first supporting layer and the second supporting layer are located in different film layers.

[0012] In an exemplary embodiment, the first supporting layer and the pixel definition layer are located in the same film layer and are made of the same material.

[0013] In an exemplary embodiment, the second supporting layer and the isolation structure are located in the same film layer and are made of the same material.

[0014] In an exemplary embodiment, in a cross section perpendicular to the substrate, the second supporting layer and the isolation structure both have a shape that is larger at a side away from the substrate and smaller at a side close to the substrate.

[0015] In an exemplary embodiment, the difference between L2 and L1 is 0.8 micrometers to 1 micrometer.

[0016] In an exemplary embodiment, a dielectric layer is further included. The dielectric layer is disposed between the isolation structure and the substrate, and the dielectric layer is in contact with the isolation structure.

[0017] In an exemplary embodiment, the dielectric layer and the first supporting layer are both positive optical adhesives, and the isolation structure and the second supporting layer are both negative optical adhesives.

[0018] In an exemplary embodiment, the dielectric layer is integrally connected to the first supporting layer.

[0019] In an exemplary embodiment, the dielectric layer is integrally connected to the pixel definition layer.

[0020] In an exemplary embodiment, the organic light emitting layer includes at least a charge generation layer, and the isolation structure is configured to block at least a portion of the charge generation layer.

[0021] In an exemplary embodiment, a plurality of light emitting devices are further included, a first interval is provided between at least some of the adjacent light emitting devices, and a portion of the isolation structure is provided at the first interval.

[0022] In an exemplary embodiment, a plurality of light emitting devices are further included, a second interval is provided between at least some of the adjacent light emitting devices, and the isolation structure and a portion of the support structure are both provided at the second interval.

[0023] In an exemplary embodiment, in the second interval, a minimum distance between an edge of the bottom wall of the isolation structure and an edge of the bottom wall of the adjacent support structure is 1.5 micrometers to 3 micrometers.

[0024] In an exemplary embodiment, in the second interval, a minimum distance between an edge of a bottom wall of the isolation structure and an edge of a bottom wall of a pixel definition layer adjacent thereto is 2 micrometers to 2.5 micrometers.

[0025] In an exemplary embodiment, in a cross section perpendicular to the substrate, the isolation structure is in an inverted trapezoidal shape, and a slope angle of a sidewall of the isolation structure is 60 degrees to 80 degrees.

[0026] In an exemplary embodiment, the isolation structure has a thickness of 1.2 micrometers to 2 micrometers.

[0027] The embodiment of the present disclosure further provides a display device, comprising any of the display substrates described above.

[0028] The present disclosure also provides a method for preparing a display substrate, comprising:

[0029] forming a pixel definition layer, a support structure, and an isolation structure on a substrate;

[0030] The support structure is configured to support a mask, and the isolation structure is configured to block at least a portion of the organic light-emitting layer; the support structure includes a first support layer and a second support layer stacked in layers, the first support layer is located on a side of the second support layer close to the substrate, and the first support layer and the pixel definition layer have substantially the same thickness;

[0031] A vertical distance between a surface of the isolation structure close to the substrate and the substrate surface is smaller than a vertical distance between a surface of the second supporting layer close to the substrate and the substrate surface.

[0032] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0034] Figure 1 is a structural schematic diagram of a display device;

[0035] Figure 2 It is a schematic diagram of a planar structure of a display substrate;

[0036] Figure 3 A schematic diagram of a cross-sectional structure of a display substrate;

[0037] Figure 4 A schematic diagram of a cross-sectional structure of a display substrate in the related art;

[0038] Figure 5 A schematic cross-sectional structure diagram of a display substrate according to an exemplary embodiment of the present disclosure;

[0039] Figure 6 for Figure 5 A magnified view of the pixel definition layer and isolation structure;

[0040] Figure 7a This is a schematic diagram showing an embodiment of the present disclosure after an insulating film is formed on a substrate;

[0041] Figure 7b This is a schematic diagram showing a substrate after forming a pixel definition layer and a support structure according to an embodiment of the present disclosure;

[0042] Figure 8 is a schematic cross-sectional structure diagram of another display substrate according to an exemplary embodiment of the present disclosure;

[0043] Fig. 9 The figure is a schematic cross-sectional structure diagram of another display substrate according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail in conjunction with the accompanying drawings below. Note that the embodiments can be implemented in multiple different forms. A person of ordinary skill in the art can easily understand the fact that the methods and contents can be transformed into various forms without departing from the purpose and scope of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the contents described in the following embodiments. In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments can be arbitrarily combined with each other.

[0045] In the drawings, the size of each component, the thickness of a layer, or the area is sometimes exaggerated for the sake of clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to this size, and the shape and size of each component in the drawings do not reflect the true proportion. In addition, the drawings schematically show ideal examples, and one embodiment of the present disclosure is not limited to the shapes or values ​​shown in the drawings.

[0046] In the present specification, ordinal numbers such as “first”, “second” and “third” are provided to avoid confusion among constituent elements, and are not intended to limit the number.

[0047] In this specification, for the sake of convenience, the words and phrases indicating the orientation or positional relationship, such as "middle", "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., are used to illustrate the positional relationship of the constituent elements with reference to the drawings. This is only for the convenience of describing this specification and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. The positional relationship of the constituent elements is appropriately changed according to the direction in which each constituent element is described. Therefore, it is not limited to the words and phrases described in the specification, and can be appropriately replaced according to the situation.

[0048] In this specification, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate, or the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0049] In this specification, a transistor refers to an element including at least three terminals: a gate electrode, a drain electrode, and a source electrode. The 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 current can flow through the drain electrode, the channel region, and the source electrode. Note that in this specification, the channel region refers to a region where current mainly flows.

[0050] 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. In the case of using transistors with opposite polarities or when the direction of current changes during circuit operation, the functions of the "source electrode" and the "drain electrode" are sometimes interchanged. Therefore, in this specification, the "source electrode" and the "drain electrode" may be interchanged.

[0051] In this specification, "electrical connection" includes the case where components are connected together through an element having some electrical function. There is no particular limitation on the "element having some electrical function" as long as it can transmit and receive electrical signals between the connected components. Examples of "element having some electrical function" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements having various functions.

[0052] In this specification, "parallel" means a state where the angle formed by two straight lines is greater than -10° and less than 10°, and therefore, also includes a state where the angle is greater than -5° and less than 5°. In addition, "perpendicular" means a state where the angle formed by two straight lines is greater than 80° and less than 100°, and therefore, also includes a state where the angle is greater than 85° and less than 95°.

[0053] In this specification, "film" and "layer" may be interchanged. For example, "conductive layer" may be replaced by "conductive film". Similarly, "insulating film" may be replaced by "insulating layer".

[0054] The term "about" in the present disclosure refers to a numerical value that is not strictly limited to allow for process and measurement errors.

[0055] The inventors of the present disclosure have found that Figure 4 As shown, the related art shows a substrate, including a substrate 101', a driving circuit layer 102' arranged on one side of the substrate 101', a first electrode 12 arranged on the side of the driving circuit layer 102' away from the substrate 101', an organic light-emitting layer (not shown in the figure), a pixel definition layer 13, an isolation structure 14 and a support structure 15. A pixel opening is provided in the pixel definition layer 13, and the pixel opening exposes at least part of the surface of the first electrode 12. The organic light-emitting layer is arranged in the pixel opening and connected to the first electrode 12. The isolation structure 14 and the support structure 15 are both located on one side of the pixel definition layer 13 in the first direction D1. The isolation structure 14 is configured to block a part of the film layer (such as the charge generation layer) in the organic light-emitting layer, so that the organic light-emitting layers of adjacent sub-pixels are disconnected from each other, avoid lateral conduction of charges, and solve the problem of charge crosstalk. The support structure 15 is configured to support a mask, which can be used to form subsequent film layers, such as evaporating an organic light-emitting layer. Among them, the first direction D1 is parallel to the substrate 101.

[0056] like Figure 4As shown, the isolation structure 14 generally adopts a laminated structure of an inorganic layer 141 and a negative optical adhesive layer 142 (negative PS adhesive layer). The negative optical adhesive layer 142 is located on the side of the inorganic layer 141 away from the substrate. The negative optical adhesive layer 142 is in an inverted trapezoidal shape in a cross section perpendicular to the substrate direction to achieve blocking of the organic light-emitting layer; the inorganic layer 141 is generally prepared by the same material and the same process as the pixel definition layer 13, and the thickness of the inorganic layer 141 is approximately the same as the thickness of the pixel definition layer 13. The support structure 15 can be made of inorganic material. Among them, the thickness of the isolation structure 14 is generally 1.2 microns to 1.4 microns, and the thickness of the support structure 15 is generally 1.6 microns to 1.8 microns.

[0057] The preparation process of the related art display substrate includes: first preparing and forming an inorganic thin film; then, using a patterning process, the inorganic thin film is formed into a pixel definition layer 13, an inorganic layer 141 and a support structure 15, the thickness of the pixel definition layer 13 and the inorganic layer 141 are substantially the same, and both are less than the thickness of the support structure 15, for example, the thickness of the pixel definition layer 13 and the inorganic layer 141 are both 0.8 microns to 1.0 microns, and the thickness of the support structure 15 is 1.6 microns to 1.8 microns; then, an inverted trapezoidal negative optical adhesive layer 142 is formed on the inorganic layer 141. The negative optical adhesive layer 142 and the inorganic layer 141 form an isolation structure 14, and the thickness of the isolation structure 14 is 1.2 microns to 1.4 microns.

[0058] Since the thickness of the support structure 15 is close to that of the isolation structure 14, when the support structure 15 supports the mask, as the evaporation material accumulates on the mask, the weight of the mask increases, causing the mask to sag more, and the mask will rub against the film layer on the substrate (such as the isolation structure 14), causing the film layer formed subsequently to stack at the friction point, and then causing the power signal line formed subsequently (such as the VSS signal line) to break at the stacking point, resulting in the problem that the pixel does not emit light or is difficult to emit light (increased cross-voltage). In addition, the negative optical adhesive layer 142 in the isolation structure 14 increases this risk. The pixel ratio of the negative optical adhesive layer 142 is extremely high, which will greatly reduce the quality of the display substrate.

[0059] Figure 1 FIG. 1 is a schematic diagram of the structure of a display device. Figure 1As shown, the display device may include a timing controller, a data driver, a scan driver, a light emitting driver and a pixel array, the timing controller is respectively connected to the data driver, the scan driver and the light emitting driver, the data driver is respectively connected to a plurality of data signal lines (D1 to Dn), the scan driver is respectively connected to a plurality of scan signal lines (S1 to Sm), and the light emitting driver is respectively connected to a plurality of light emitting signal lines (E1 to Eo). The pixel array may include a plurality of sub-pixels Pxij, i and j may be natural numbers, at least one sub-pixel Pxij may include a circuit unit and a light emitting unit, the circuit unit may include at least a pixel driving circuit, the pixel driving circuit is respectively connected to the scan signal line, the light emitting signal line and the data signal line, the light emitting unit may include a light emitting device, and the light emitting device is connected to the pixel driving circuit of the circuit unit. In an exemplary embodiment, the timing controller may provide a grayscale value and a control signal suitable for the specification of the data driver to the data driver, may provide a clock signal suitable for the specification of the scan driver, a scan start signal, etc. to the scan driver, and may provide a clock signal suitable for the specification of the light emitting driver, an emission stop signal, etc. to the light emitting driver. The data driver can generate data voltages to be provided to data signal lines D1, D2, D3, ... and Dn using grayscale values ​​and control signals received from the timing controller. For example, the data driver can sample grayscale values ​​using a clock signal, and apply data voltages corresponding to grayscale values ​​to data signal lines D1 to Dn in units of pixel rows, where n can be a natural number. The scan driver can generate scan signals to be provided to scan signal lines S1, S2, S3, ... and Sm by receiving clock signals, scan start signals, etc. from the timing controller. For example, the scan driver can sequentially provide scan signals with conduction level pulses to scan signal lines S1 to Sm. For example, the scan driver can be constructed in the form of a shift register, and can sequentially transmit scan start signals provided in the form of conduction level pulses to the next level circuit under the control of the clock signal to generate scan signals, where m can be a natural number. The light-emitting driver can generate emission signals to be provided to light-emitting signal lines E1, E2, E3, ... and Eo by receiving clock signals, emission stop signals, etc. from the timing controller. For example, the light emitting driver may sequentially provide an emission signal having a cut-off level pulse to the light emitting signal lines E1 to Eo. For example, the light emitting driver may be configured in the form of a shift register, and may generate an emission signal in a manner of sequentially transmitting an emission stop signal provided in the form of a cut-off level pulse to a next stage circuit under the control of a clock signal, and o may be a natural number. In an exemplary embodiment, a pixel array may be provided on a display substrate.

[0060] Figure 2FIG. 1 is a schematic diagram of a planar structure of a display substrate. In an exemplary embodiment, the display substrate may include a display area and a frame area located around the display area. Figure 2 As shown, the display area of ​​the display substrate may include a plurality of pixel units P arranged in a matrix, and at least one pixel unit P 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 sub-pixel may include a circuit unit and a light-emitting unit, and the circuit unit may include at least a pixel driving circuit, and the pixel driving circuit is respectively connected to the scanning signal line, the data signal line, and the light-emitting signal line, and the pixel driving circuit is configured to receive the data voltage transmitted by the data signal line under the control of the scanning signal line and the light-emitting signal line, and output a corresponding current to the light-emitting device. The light-emitting unit may include at least a light-emitting device, and the light-emitting device is respectively connected to the pixel driving circuit of the sub-pixel, and the light-emitting device is configured to emit light of corresponding brightness in response to the current output by the pixel driving circuit of the sub-pixel.

[0061] In an exemplary embodiment, the first sub-pixel P1 may be a red sub-pixel (R) emitting red light, the second sub-pixel P2 may be a blue sub-pixel (B) emitting blue light, and the third sub-pixel P3 may be a green sub-pixel (G) emitting green light. In an exemplary embodiment, the shape of the sub-pixels may be rectangular, rhombus, pentagonal or hexagonal, and the three sub-pixels may be arranged in a horizontal parallel, vertical parallel or triangular manner, which is not limited in the present disclosure.

[0062] In an exemplary embodiment, a pixel unit may include four sub-pixels, and the four sub-pixels may be arranged in a horizontal parallel arrangement, a vertical parallel arrangement, or a square arrangement, etc., which is not limited in the present disclosure.

[0063] Figure 3 FIG. 1 is a schematic diagram of a cross-sectional structure of a display substrate, illustrating the structure of three sub-pixels in the display substrate. Figure 3 As shown, on a plane perpendicular to the display substrate, the display area of ​​the display substrate may include a driving circuit layer 102 disposed on a substrate 101, a light emitting structure layer 103 disposed on a side of the driving circuit layer 102 away from the substrate 101, and an encapsulation structure layer 104 disposed on a side of the light emitting structure layer 103 away from the substrate 101. In some possible implementations, the display substrate may include other film layers, such as a touch structure layer, etc., which is not limited in the present disclosure.

[0064] In an exemplary embodiment, the substrate 101 may be a flexible substrate, or may be a rigid substrate. The driving circuit layer 102 may include a plurality of circuit units, the circuit units may include at least a pixel driving circuit, and the pixel driving circuit may include a plurality of transistors and a storage capacitor. The light-emitting structure layer 103 may include a plurality of light-emitting units, the light-emitting units may include at least a light-emitting device, and the light-emitting device may include an anode, an organic light-emitting layer, and a cathode, the anode is connected to the pixel driving circuit, the organic light-emitting layer is connected to the anode, the cathode is connected to the organic light-emitting layer, and the organic light-emitting layer emits light of corresponding colors under the drive of the anode and the cathode. The encapsulation structure layer 104 may include a first encapsulation layer, a second encapsulation layer, and a third encapsulation layer stacked, the first encapsulation layer and the third encapsulation layer may be made of inorganic materials, the second encapsulation layer may be made of organic materials, and the second encapsulation layer is arranged between the first encapsulation layer and the third encapsulation layer to form an inorganic material / organic material / inorganic material stacked structure, which can ensure that external water vapor cannot enter the light-emitting structure layer 103.

[0065] In an exemplary embodiment, the organic light emitting layer may include a light emitting layer (EML) and any one or more of the following: a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and a charge generation layer (CGL).

[0066] An exemplary embodiment of the present disclosure provides a display substrate, comprising a substrate, a pixel definition layer, an isolation structure and a support structure arranged on one side of the substrate, wherein the support structure is configured to support a mask, and the isolation structure is configured to block at least a portion of an organic light-emitting layer;

[0067] The support structure comprises a first support layer and a second support layer which are stacked, the first support layer is located on a side of the second support layer close to the substrate, the first support layer and the pixel definition layer have substantially the same thickness, and a vertical distance from a surface of the second support layer away from the substrate to the surface of the substrate is greater than a vertical distance from a surface of the isolation structure away from the substrate to the surface of the substrate;

[0068] A vertical distance between a surface of the isolation structure close to the substrate and the substrate surface is L1, a vertical distance between a surface of the second supporting layer close to the substrate and the substrate surface is L2, and L1 is smaller than L2.

[0069] In an exemplary embodiment, there may be a certain error between the thickness of the first supporting layer and the thickness of the pixel definition layer. For example, the ratio of the thickness of the first supporting layer to the thickness of the pixel definition layer may be 0.9 to 1.1, and the difference between the thickness of the first supporting layer and the thickness of the pixel definition layer may be 0.3 micrometers to -0.3 micrometers.

[0070] The solution of this embodiment is described below by means of some examples.

[0071] Figure 5 The figure is a schematic cross-sectional structure diagram of a display substrate according to an exemplary embodiment of the present disclosure. Figure 5 Schematic diagram of the structure of three sub-pixels in a display substrate. In an exemplary embodiment, as Figure 5 As shown, on a plane perpendicular to the substrate direction, the exemplary embodiment of the present disclosure shows that the substrate may include a substrate 101, a driving circuit layer 102 disposed on one side of the substrate 101, a light-emitting device disposed on a side of the driving circuit layer 102 away from the substrate 101, a pixel definition layer 23, an isolation structure 24, and a support structure 25. The support structure 25 is configured to support a mask, and the isolation structure 24 is configured to block at least a portion of the organic light-emitting layer.

[0072] In an exemplary embodiment, the light-emitting device includes a first electrode 22, an organic light-emitting layer (not shown in the figure), and a second electrode (not shown in the figure) which are sequentially stacked along the thickness direction of the substrate. The first electrode 22 can be used as an anode, and the second electrode can be used as a cathode. The first electrode 22 is electrically connected to the driving circuit layer 102, and the first electrodes 22 of adjacent sub-pixels are disconnected from each other. The second electrode is arranged on the entire surface, and multiple sub-pixels can share one second electrode. The organic light-emitting layer includes at least a light-emitting layer, and the organic light-emitting layers of adjacent sub-pixels are disconnected from each other by an isolation structure 24.

[0073] In an exemplary embodiment, the pixel definition layer 23 is disposed on a side of the first electrode 22 away from the substrate, and a pixel opening is disposed in the pixel definition layer 23, and the pixel opening exposes at least a portion of the surface of the first electrode 12. The pixel definition layers 23 of adjacent sub-pixels are arranged at intervals along the first direction D1, and the pixel definition layers 23 of adjacent sub-pixels are disconnected from each other.

[0074] In an exemplary embodiment, the light emitting device may be an organic light emitting diode (Tandem OLED). The organic light emitting layer of the light emitting device is disposed on a side of the pixel definition layer 23 away from the substrate, and at least a portion of the organic light emitting layer is disposed in a pixel opening of the pixel definition layer 23 and connected to the first electrode 22. The organic light emitting layer may include at least two light emitting layers stacked along the thickness direction of the substrate and a charge generation layer (CGL) located between adjacent light emitting layers. The charge generation layer (CGL) is used to enhance the conduction capability of charges along the thickness direction of the substrate.

[0075] In an exemplary embodiment, the isolation structure 24 is disposed on a side of the driving circuit layer 102 away from the substrate 101. In a direction parallel to the substrate 101, the isolation structure 24 is located on a side of the pixel definition layer 23 away from the first electrode 22, and the isolation structure 24 does not overlap with the orthographic projections of the pixel definition layer 23 and the first electrode 22 on the substrate 101. Part of the film layer of the organic light-emitting layer (e.g., the charge generation layer) is blocked by the isolation structure 24, that is, part of the film layer of the organic light-emitting layer (e.g., the charge generation layer) is broken at the isolation structure 24, thereby avoiding lateral conduction of charges and solving the problem of charge crosstalk. For example, the isolation structure 24 at least blocks the charge generation layer of the organic light-emitting layer.

[0076] In an exemplary embodiment, in a direction parallel to the substrate 101 , the isolation structure 24 is ring-shaped, and the isolation structure 24 is disposed around the periphery of the light emitting device.

[0077] Figure 6 for Figure 5 In an exemplary embodiment, as shown in FIG. Figure 5 and Figure 6 As shown, in a cross section perpendicular to the substrate direction, the main part of the pixel definition layer 23 can be a regular trapezoid. The pixel definition layer 23 includes an inner side surface 231 and an outer side surface 232 arranged opposite to each other in the first direction D1, and the inner side surface 231 is located on the side of the outer side surface 232 close to the first electrode 22. The slope angles formed by the inner side surface 231 and the outer side surface 232 and the plane where the substrate 101 is located are both acute angles. Part of the film layer of the organic light-emitting layer (such as the charge generation layer) climbs the slope at the inner side surface 231 and the outer side surface 232 without breaking.

[0078] In an exemplary embodiment, the pixel definition layer 23 is a single-layer structure, and the pixel definition layer 23 may be made of a positive optical adhesive.

[0079] In an exemplary embodiment, in a cross section perpendicular to the substrate direction, the isolation structure 24 may be columnar, and the isolation structure 24 is in a shape that is larger on the side away from the substrate and smaller on the side close to the substrate. For example, the isolation structure 24 may be in an inverted trapezoidal shape, and the slope angle of the sidewall 241 of the isolation structure 24 is 60 to 80 degrees. The isolation structure 24 includes a sidewall 241, and the slope angle formed by the sidewall 241 and the plane where the substrate 101 is located is an obtuse angle. Part of the film layer of the organic light-emitting layer (for example, the charge generation layer) is blocked at the isolation structure 24, thereby preventing the charge from being conducted laterally along the organic light-emitting layer, solving the problem of charge crosstalk.

[0080] In an exemplary embodiment, the isolation structure 24 further includes a bottom wall, the length of the bottom wall of the isolation structure 24 in the first direction D1 is greater than 0.6 micrometers, and the thickness h1 of the isolation structure 24 is 1.2 micrometers to 2 micrometers. The bottom wall refers to the surface close to the substrate side.

[0081] In an exemplary embodiment, the isolation structure 24 is a single-layer structure, and the isolation structure 24 may be made of a negative optical adhesive.

[0082] In an exemplary embodiment, if Figure 5 and Figure 6 As shown, the support structure 25 is disposed on a side of the driving circuit layer 102 away from the substrate 101, the support structure 25 is located between adjacent pixel definition layers 23, and the support structure 25 does not overlap with the orthographic projections of the isolation structure 24, the pixel definition layer 23, and the first electrode 22 on the substrate 101. The support structure 25 is used to support a mask, which can be used to subsequently form an organic light-emitting layer.

[0083] In an exemplary embodiment, the support structure 25 includes a first support layer 251 and a second support layer 252 which are sequentially stacked along the thickness direction of the substrate, and the first support layer 251 is located on the side of the second support layer 252 close to the substrate. The thickness of the first support layer 251 is h2, the thickness of the pixel definition layer 23 is h3, and the thickness of the second support layer 252 is h4. The thickness h2 of the first support layer 251 may be equal to the thickness h3 of the pixel definition layer 23, the vertical distance from the surface of the second support layer 252 away from the substrate to the surface of the substrate 101 is greater than the vertical distance from the surface of the pixel definition layer 23 away from the substrate to the surface of the substrate 101, and the vertical distance from the surface of the second support layer 252 away from the substrate to the surface of the substrate 101 is greater than the vertical distance from the surface of the isolation structure 24 away from the substrate to the surface of the substrate 101. The sum of the thickness h2 of the first supporting layer 251 and the thickness h4 of the second supporting layer 252 is greater than the thickness h1 of the isolation structure 24, and the sum of the thickness h2 of the first supporting layer 251 and the thickness h4 of the second supporting layer 252 is greater than the thickness h3 of the pixel definition layer 23. The surface of the substrate 101 refers to the surface of the substrate 101 close to the driving circuit layer 102.

[0084] In an exemplary embodiment, a vertical distance between a surface of the isolation structure 24 close to the substrate and the substrate surface is L1, and a vertical distance between a surface of the second support layer 252 close to the substrate and the substrate surface is L2, and L1 is smaller than L2.

[0085] In an exemplary embodiment, the difference between L2 and L1 is equal to the thickness h2 of the first supporting layer.

[0086] In an exemplary embodiment, the difference between L2 and L1 is 0.8 micrometers to 1 micrometer.

[0087] The disclosed embodiment shows that the height difference between the isolation structure 24 and the support structure 25 is increased by making the vertical distance L1 between the surface of the isolation structure 24 close to the substrate side and the substrate surface smaller than the vertical distance L2 between the surface of the second support layer 252 close to the substrate side and the substrate surface, thereby avoiding friction between the mask and the isolation structure 24, thereby making the subsequently formed film layer smooth, ensuring the continuity of the power signal line without breakage, and improving the yield.

[0088] In an exemplary embodiment, the first support layer 251 and the second support layer 252 of the support structure 25 may be connected as one body. The first support layer 251 and the second support layer 252 are combined to form the support structure 25 in a regular trapezoidal shape in a cross section perpendicular to the substrate.

[0089] In some embodiments, the first support layer 251 and the second support layer 252 are located in different film layers. The first support layer 251 and the second support layer 252 are located in different film layers, which means that the first support layer 251 and the second support layer 252 can be made of different materials and prepared by two patterning processes.

[0090] In an exemplary embodiment, the support structure 25 and the pixel definition layer 23 may be located in the same film layer, thereby simplifying the process and reducing costs. The support structure 25 and the pixel definition layer 23 being located in the same film layer means that the support structure 25 and the pixel definition layer 23 may be made of the same material and through the same patterning process.

[0091] In an exemplary embodiment, the support structure 25 is a single-layer structure, and the support structure 25 may be made of a positive optical adhesive.

[0092] In an exemplary embodiment, a first interval 111 is provided between at least some adjacent light-emitting devices, part of the isolation structure 24 is provided in the first interval 111, and the support structure 25 is not provided in the first interval 111, that is, in the first interval 111, only part of the isolation structure 24 is provided, and no support structure 25 is provided.

[0093] In an exemplary embodiment, a second interval 112 is provided between at least some adjacent light-emitting devices, and portions of the isolation structure 24 and the support structure 25 are provided in the second interval 112, that is, portions of the isolation structure 24 and portions of the support structure 25 are respectively provided in the second interval 112, and the orthographic projections of the isolation structure 24 and the support structure 25 on the substrate do not overlap.

[0094] In an exemplary embodiment, in the second interval 112, the minimum distance from the edge of the bottom wall of the isolation structure 24 to the edge of the bottom wall of the adjacent support structure 25 is 1.5 microns to 3 microns, and exemplary, the minimum distance from the edge of the bottom wall of the isolation structure 24 to the edge of the bottom wall of the support structure 25 is 2 microns to 2.5 microns.

[0095] In an exemplary embodiment, in the second spacer 112, the minimum distance from the edge of the bottom wall of the isolation structure 24 to the edge of the bottom wall of the adjacent pixel definition layer 23 is 1.5 microns to 3 microns, and exemplary, the minimum distance from the edge of the bottom wall of the isolation structure 24 to the edge of the bottom wall of the pixel definition layer 23 is 2 microns to 2.5 microns.

[0096] The following is an exemplary explanation through the preparation process of the display substrate. The "patterning process" mentioned in the present disclosure includes processes such as coating photoresist, mask exposure, development, etching, and stripping photoresist for metal materials, inorganic materials or transparent conductive materials, and includes processes such as coating organic materials, mask exposure and development for organic materials. Deposition can be any one or more of sputtering, evaporation, and chemical vapor deposition, coating can be any one or more of spraying, spin coating and inkjet printing, and etching can be any one or more of dry etching and wet etching, which are not limited in the present disclosure. "Thin film" refers to a layer of thin film made by deposition, coating or other processes of a certain material on a substrate. If the "thin film" does not require a patterning process during the entire production process, the "thin film" can also be called a "layer". If the "thin film" requires a patterning process during the entire production process, it is called a "thin film" before the patterning process and a "layer" after the patterning process. The "layer" after the patterning process contains at least one "pattern". The "A and B are arranged in the same layer" mentioned in the present disclosure means that A and B are formed simultaneously through the same patterning process, and the "thickness" of the film layer is the size of the film layer in the direction perpendicular to the display substrate. In the exemplary embodiments of the present disclosure, "the orthographic projection of B is within the range of the orthographic projection of A" or "the orthographic projection of A includes the orthographic projection of B" means that the boundary of the orthographic projection of B falls within the boundary of the orthographic projection of A, or the boundary of the orthographic projection of A overlaps with the boundary of the orthographic projection of B.

[0097] The disclosed embodiment shows that the basic preparation process includes:

[0098] (1) Forming an insulating film.

[0099] The insulating film is formed by first forming a driving circuit layer 102 on the substrate 101; then forming a first electrode 22 on the driving circuit layer 102; then depositing an insulating film 31 covering the first electrode 22 on the substrate 101. Figure 7a shown.

[0100] (2) Forming pixel definition layer and support structure.

[0101] The formation of the pixel definition layer and the support structure includes: on the substrate formed with the aforementioned pattern, the insulating film is formed into the pixel definition layer 23 and the support structure 25 respectively through a composition process, and the orthographic projections of the pixel definition layer 23 and the support structure 25 on the substrate do not overlap, such as Figure 7b As shown. A pixel opening is provided in the pixel definition layer 23, and the pixel opening exposes at least a portion of the surface of the first electrode 12. The thickness of the support structure 25 is greater than the thickness of the pixel definition layer 23, and the distance from the surface of the support structure 25 away from the substrate to the surface of the substrate 101 is greater than the distance from the surface of the pixel definition layer 23 away from the substrate to the surface of the substrate 101.

[0102] (3) Form an isolation structure.

[0103] Forming the isolation structure includes: forming an isolation structure 24 on the driving circuit layer 102 on the substrate on which the aforementioned pattern is formed, the isolation structure 24 being located between adjacent pixel definition layers 23, and the isolation structure 24 not overlapping with the orthographic projections of the pixel definition layer 23, the first electrode 22 and the support structure 25 on the substrate 101, such as Figure 5 shown.

[0104] Figure 8 FIG. 2 is a schematic cross-sectional structure diagram of another display substrate according to an exemplary embodiment of the present disclosure. Figure 8 As shown, this exemplary embodiment shows the structure of the substrate and Figure 5 The embodiments shown are basically the same, except that the first support layer 251 and the second support layer 252 of the support structure 25 are located in different film layers, wherein the first support layer 251 and the second support layer 252 are located in different film layers means that the first support layer 251 and the second support layer 252 are made of different materials and are prepared separately through two patterning processes. The difference between the vertical distance L1 between the surface of the isolation structure 24 close to the substrate side and the substrate surface and the vertical distance L2 between the surface of the second support layer 252 close to the substrate side and the substrate surface is the thickness of the first support layer 251.

[0105] In an exemplary embodiment, the first support layer 251 may be located in the same film layer as the pixel definition layer 23. The first support layer 251 and the pixel definition layer 23 being located in the same film layer means that the first support layer 251 and the pixel definition layer 23 are made of the same material and through the same patterning process. For example, the first support layer 251 and the pixel definition layer 23 are both made of positive optical adhesive.

[0106] In an exemplary embodiment, the second support layer 252 and the isolation structure 24 may be located in the same film layer. The second support layer 252 and the isolation structure 24 being located in the same film layer means that the second support layer 252 and the isolation structure 24 are made of the same material and prepared by the same patterning process. For example, the second support layer 252 and the isolation structure 24 are both made of negative optical adhesive.

[0107] In an exemplary embodiment, in a cross section perpendicular to the substrate, the second supporting layer 252 is in a shape that is larger on a side away from the substrate and smaller on a side close to the substrate. For example, the second supporting layer 252 may be in an inverted trapezoidal shape.

[0108] In an exemplary embodiment, in a cross section perpendicular to the substrate, the isolation structure 24 is in a shape that is larger on a side away from the substrate and smaller on a side close to the substrate. For example, the isolation structure 24 may be in an inverted trapezoidal shape.

[0109] In an exemplary embodiment, the display substrate of the embodiment of the present disclosure further includes a color filter structure layer, and the color filter structure layer is arranged on the side of the light-emitting device away from the substrate. The color filter structure layer includes a filter layer and a photoresist layer, and the photoresist layer is arranged around the filter layer. The pixel definition layer 23 of the display substrate of the embodiment of the present disclosure can be made of a photoresist material, such as a black photosensitive resin, and the pixel definition layer 23 can be used as a photoresist layer in the color filter structure layer, thereby simplifying the process and reducing costs.

[0110] Fig. 9 FIG. 2 is a schematic cross-sectional structure diagram of another display substrate according to an exemplary embodiment of the present disclosure. Fig. 9 As shown, this exemplary embodiment shows the structure of the substrate and Figure 8 The illustrated embodiments are basically the same, except that the display substrate of this exemplary embodiment further includes a dielectric layer 26, which is disposed on the side of the isolation structure 24 close to the driving circuit layer 102, that is, the dielectric layer 26 is stacked between the isolation structure 24 and the driving circuit layer 102, and the surface of the isolation structure 24 close to the substrate is in contact with the dielectric layer 26. The thickness of the dielectric layer 26 is less than the thickness of the first supporting layer 251 of the supporting structure 25. The difference between the vertical distance L1 between the surface of the isolation structure 24 close to the substrate and the substrate surface and the vertical distance L2 between the surface of the second supporting layer 252 close to the substrate and the substrate surface is less than the thickness of the first supporting layer 251.

[0111] In an exemplary embodiment, the dielectric layer 26 may be connected to the first support layer 251 of the support structure 25 and the pixel definition layer 23 as a whole. The connection as a whole means that the dielectric layer 26, the first support layer 251 and the pixel definition layer 23 are made of the same material and prepared by the same patterning process to form an integrated film layer; or the dielectric layer 26, the first support layer 251 and the pixel definition layer 23 are made of different materials and are connected to form an integrated film layer after being prepared by different patterning processes.

[0112] In an exemplary embodiment, the dielectric layer 26 , the first supporting layer 251 and the pixel definition layer 23 are all positive optical adhesives, and the isolation structure 24 and the second supporting layer 252 are all negative optical adhesives.

[0113] The present disclosure also provides a method for preparing a display substrate, so as to prepare the display substrate provided by the above embodiment.

[0114] In an exemplary embodiment, a method of preparing a display substrate may include:

[0115] forming a pixel definition layer, a support structure, and an isolation structure on a substrate;

[0116] The support structure is configured to support a mask, and the isolation structure is configured to block at least a portion of the organic light-emitting layer; the support structure includes a first support layer and a second support layer stacked in layers, the first support layer is located on a side of the second support layer close to the substrate, and the first support layer and the pixel definition layer have substantially the same thickness;

[0117] A vertical distance between a surface of the isolation structure close to the substrate and the substrate surface is smaller than a vertical distance between a surface of the second supporting layer close to the substrate and the substrate surface.

[0118] The embodiment of the present invention further provides a display device, comprising any of the above-mentioned display substrates. The display device includes a mobile phone, a tablet computer, a smart wearable product (such as a smart watch, a bracelet, etc.), a personal digital assistant (PDA), a car computer, etc. The embodiment of the present application does not impose any special restrictions on the specific form of the above-mentioned foldable display device.

[0119] The drawings in this disclosure only relate to the structures involved in this disclosure, and other structures can refer to the general design. In the absence of conflict, the embodiments of this disclosure, that is, the features in the embodiments, can be combined with each other to obtain new embodiments.

[0120] Those skilled in the art should understand that the technical solutions of the present disclosure may be modified or replaced by equivalents 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.

Claims

1. A display substrate, characterized in that: The device comprises a substrate and a pixel definition layer, an isolation structure and a support structure arranged on one side of the substrate, wherein the support structure is configured to support a mask, and the isolation structure is configured to block at least a portion of an organic light-emitting layer; The support structure comprises a first support layer and a second support layer which are stacked, the first support layer is located on a side of the second support layer close to the substrate, the first support layer and the pixel definition layer have substantially the same thickness, and a vertical distance from a surface of the second support layer away from the substrate to the surface of the substrate is greater than a vertical distance from a surface of the isolation structure away from the substrate to the surface of the substrate; A vertical distance between a surface of the isolation structure close to the substrate and the substrate surface is L1, a vertical distance between a surface of the second supporting layer close to the substrate and the substrate surface is L2, and L1 is smaller than L2.

2. The display substrate according to claim 1, characterized in that: The first supporting layer and the second supporting layer are connected as one body.

3. The display substrate according to claim 2, characterized in that: The support structure and the pixel definition layer are located in the same film layer and are made of the same material.

4. The display substrate according to claim 1, characterized in that: The first supporting layer and the second supporting layer are located in different film layers.

5. The display substrate according to claim 4, characterized in that: The first supporting layer and the pixel definition layer are located in the same film layer and are made of the same material.

6. The display substrate according to claim 4, characterized in that: The second supporting layer and the isolation structure are located in the same film layer and are made of the same material.

7. The display substrate according to claim 6, characterized in that: In a cross section perpendicular to the substrate, the second supporting layer and the isolation structure both have a shape that is larger on a side away from the substrate and smaller on a side close to the substrate.

8. The display substrate according to any one of claims 1 to 7, characterized in that: The difference between L2 and L1 is 0.8 micrometers to 1 micrometer.

9. The display substrate according to any one of claims 1 to 7, characterized in that: The invention also includes a dielectric layer, which is disposed between the isolation structure and the substrate, and the dielectric layer is in contact with the isolation structure.

10. The display substrate according to claim 9, characterized in that: The medium layer and the first supporting layer are both positive optical adhesives, and the isolation structure and the second supporting layer are both negative optical adhesives.

11. The display substrate according to claim 9, characterized in that: The medium layer and the first supporting layer are connected as one body.

12. The display substrate according to claim 9, characterized in that: The medium layer and the pixel definition layer are connected as one body.

13. The display substrate according to any one of claims 1 to 7, characterized in that: The organic light emitting layer includes at least a charge generation layer, and the isolation structure is configured to block at least a portion of the charge generation layer.

14. The display substrate according to any one of claims 1 to 7, characterized in that: The invention also includes a plurality of light emitting devices, wherein a first interval is arranged between at least some of the adjacent light emitting devices, and a portion of the isolation structure is arranged at the first interval.

15. The display substrate according to any one of claims 1 to 7, characterized in that: The invention also comprises a plurality of light emitting devices, wherein a second interval is arranged between at least some of the adjacent light emitting devices, and parts of the isolation structure and the support structure are arranged at the second interval.

16. The display substrate according to claim 15, characterized in that: In the second interval, a minimum distance between an edge of the bottom wall of the isolation structure and an edge of the bottom wall of the adjacent support structure is 1.5 micrometers to 3 micrometers.

17. The display substrate according to claim 15, characterized in that: In the second interval, a minimum distance between an edge of a bottom wall of the isolation structure and an edge of a bottom wall of an adjacent pixel definition layer is 2 micrometers to 2.5 micrometers.

18. The display substrate according to any one of claims 1 to 7, characterized in that: In a cross section perpendicular to the substrate, the isolation structure is in an inverted trapezoidal shape, and a slope angle of a side wall of the isolation structure is 60 degrees to 80 degrees.

19. The display substrate according to any one of claims 1 to 7, characterized in that: The thickness of the isolation structure is 1.2 microns to 2 microns.

20. A display device, characterized in that: A display substrate comprising any one of claims 1 to 19.

21. A method for preparing a display substrate, characterized in that: include: forming a pixel definition layer, a support structure, and an isolation structure on a substrate; The support structure is configured to support a mask, and the isolation structure is configured to block at least a portion of the organic light-emitting layer; the support structure includes a first support layer and a second support layer stacked in layers, the first support layer is located on a side of the second support layer close to the substrate, and the first support layer and the pixel definition layer have substantially the same thickness; A vertical distance between a surface of the isolation structure close to the substrate and the substrate surface is smaller than a vertical distance between a surface of the second supporting layer close to the substrate and the substrate surface.

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