Display substrate, preparation method thereof and display device

Abstract

The invention discloses a display substrate, a preparation method thereof and a display device. The display substrate comprises a substrate body, a driving structure layer, a display structure layer and a polaroid, the driving structure layer, the display structure layer and the polaroid are sequentially arranged on the substrate body, the driving structure layer comprises a pixel driving circuit, and the display structure layer comprises a first electrode, a pixel defining layer, an isolation column, an organic light-emitting layer and a second electrode which are sequentially arranged in the direction away from the substrate body. The pixel definition layer comprises a plurality of pixel openings, the pixel openings expose the first electrodes, the organic light-emitting layer is at least arranged in the pixel openings, the isolation columns are located on the side, away from the substrate, of the pixel definition layer, and orthographic projections of the isolation columns on the substrate and orthographic projections of the pixel openings on the substrate are not overlapped; the first electrode is electrically connected with the pixel driving circuit; wherein in a plane parallel to the substrate, at least one isolation column and the second electrode are insulated from each other; or at least two adjacent isolation columns are insulated from each other.

Description

Technical Field

[0001] This article relates to but is not limited to the field of display technology, and in particular to a display substrate and a preparation method thereof, and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) is an active light-emitting display device with the advantages of self-luminescence, wide viewing angle, high contrast, low power consumption, and extremely high response speed. With the continuous development of display technology, display devices with OLED as the light-emitting element and thin film transistor (TFT) for signal control have become the mainstream products in the current display field.

[0003] However, display products have a problem of growing dark spots (GDS). Summary of the invention

[0004] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0005] The embodiments of the present disclosure provide a display substrate and a method for manufacturing the same, and a display device to solve the problem of GDS of display products.

[0006] In a first aspect, an embodiment of the present disclosure provides a display substrate, comprising: a base substrate, a driving structure layer, a display structure layer and a polarizer sequentially arranged on the base substrate, the driving structure layer comprising a pixel driving circuit, the display structure layer comprising a first electrode, a pixel definition layer, an isolation column, an organic light-emitting layer and a second electrode sequentially arranged in a direction away from the base substrate, the pixel definition layer comprising a plurality of pixel openings, the pixel openings exposing the first electrode, the organic light-emitting layer being at least arranged within the pixel openings, the isolation columns being located on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the isolation columns on the base substrate and the orthographic projection of the pixel openings on the base substrate do not overlap; the first electrode is electrically connected to the pixel driving circuit; wherein, in a plane parallel to the base substrate, at least one of the isolation columns and the second electrode are insulated from each other; or, at least two adjacent isolation columns are insulated from each other.

[0007] In an exemplary embodiment, the at least one isolation column and the second electrode are insulated from each other, including: the orthographic projection of at least one isolation column on the base substrate and the orthographic projection of the organic light-emitting layer on the base substrate do not overlap, and the orthographic projection of at least one isolation column on the base substrate and the orthographic projection of the second electrode on the base substrate do not overlap.

[0008] In an exemplary embodiment, at least one of the isolation columns is insulated from the second electrode, including: the display structure layer also includes at least one insulating wrapping layer, the insulating wrapping layer is wrapped around the surface of the isolation column, and is configured to insulate the isolation column from the second electrode.

[0009] In an exemplary embodiment, the shape of the insulating wrapping layer is the same as the shape of the isolation column.

[0010] In an exemplary embodiment, an orthographic projection of the insulating wrapping layer on the base substrate at least partially overlaps with an orthographic projection of the second electrode on the base substrate.

[0011] In an exemplary embodiment, at least two adjacent isolation columns are insulated from each other, including: the display structure layer also includes at least one isolation portion arranged on the side of the pixel definition layer away from the base substrate, the organic light-emitting layer and the second electrode cover the isolation portion and the isolation column, and the orthographic projection of the isolation portion on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; in a plane parallel to the base substrate, the isolation portion is located between adjacent isolation columns and is configured to disconnect the second electrode at its position.

[0012] In an exemplary embodiment, the plurality of isolation pillars are distributed in an array on the base substrate, and the plurality of partition portions and the plurality of isolation pillars are spaced apart from each other.

[0013] In a second aspect, an embodiment of the present disclosure provides a method for preparing a display substrate, comprising: forming a driving structure layer on a base substrate, the driving structure layer comprising a pixel driving circuit; forming a first electrode, a pixel definition layer, an isolation column, an organic light-emitting layer and a second electrode in sequence on the driving structure layer; wherein the first electrode is electrically connected to the pixel driving circuit; the pixel definition layer comprises a plurality of pixel openings, the pixel openings expose the first electrode, the organic light-emitting layer is at least arranged in the pixel openings, the isolation column is located on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the isolation column on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; attaching a polarizer on a side of the second electrode away from the base substrate; wherein, in a plane parallel to the base substrate, at least one of the isolation columns and the second electrode are insulated from each other; or, at least two adjacent isolation columns are insulated from each other.

[0014] In an exemplary embodiment, before forming the organic light-emitting layer and the second electrode, the method further includes: forming a protective layer on a side of at least one of the isolation columns away from the base substrate, wherein the protective layer covers the isolation column; after forming the second electrode, the method further includes: removing the protective layer to insulate the at least one isolation column from the second electrode.

[0015] In an exemplary embodiment, forming a protective layer on a side of at least one of the isolation columns away from the substrate includes: forming the protective layer using photoresist on a side of at least one of the isolation columns away from the substrate, wherein the area of ​​the cross-section of the protective layer parallel to the substrate gradually increases in a direction away from the substrate.

[0016] In an exemplary embodiment, before forming the organic light-emitting layer and the second electrode, the method further includes: forming an insulating wrapping layer on a side of at least one of the isolation columns away from the base substrate, wherein the insulating wrapping layer covers the isolation column and has the same shape as the isolation column, so that the at least one isolation column is insulated from the subsequently formed second electrode.

[0017] In an exemplary embodiment, before forming the organic light-emitting layer and the second electrode, the method further includes: forming at least one partition portion on a side of the pixel definition layer away from the base substrate, the orthographic projection of the partition portion on the base substrate and the orthographic projection of the pixel opening on the base substrate not overlapping; in a plane parallel to the base substrate, the partition portion is located between adjacent isolation columns, and the subsequently formed second electrode is disconnected at the partition portion, so that at least two adjacent isolation columns are insulated from each other.

[0018] In an exemplary embodiment, the volume of the material of the partition portion is different before and after power is supplied; after forming the second electrode, the method further includes: supplying power to the partition portion within a first time period, and disconnecting the second electrode at the location of the partition portion through the volume change of the partition portion before and after power is supplied.

[0019] In an exemplary embodiment, the material of the partition portion includes epoxy resin doped with metal particles.

[0020] In a third aspect, an embodiment of the present disclosure provides a display device, comprising the display substrate as described above, or comprising a display substrate obtained by the above preparation method.

[0021] The display substrate provided by the embodiment of the present disclosure cuts off the ion transmission channel between the isolation column and the second electrode by arranging at least one isolation column and is insulated from the second electrode, or at least two adjacent isolation columns are insulated from each other, so that even if iodine ions and potassium ions in the polarizer move to the second electrode, they will not move into the display area through multiple isolation columns, thereby avoiding GDS defects in the display substrate.

[0022] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings.

[0023] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 It is a structural schematic diagram of a display substrate; Figure 2 It is a schematic diagram of the planar structure of a display area in a display substrate; Figure 3 is a schematic diagram of an equivalent circuit of a pixel driving circuit; Figure 4 is a schematic structural diagram of a display substrate in an exemplary embodiment; Figure 5 In an exemplary embodiment Figure 4 A cross-sectional view of a display substrate along the BB direction; Figure 6 is a schematic diagram of a light emitting structure layer in an exemplary embodiment; Figure 7 is a cross-sectional view showing a substrate in an exemplary embodiment; Figure 8 is a cross-sectional view showing a substrate in yet another exemplary embodiment; Fig. 9 is a cross-sectional view showing a substrate in yet another exemplary embodiment; Fig.10 is a top view of a partition portion and a spacer column in an exemplary embodiment; Fig.11 is a cross-sectional view after forming a protective layer in an exemplary embodiment; Fig.12is a cross-sectional view after forming an organic light-emitting layer and a second electrode in an exemplary embodiment; Fig.13 is a cross-sectional view after removing the protective layer in an exemplary embodiment; Fig.14 is a cross-sectional view after forming an insulating wrap layer in an exemplary embodiment; Fig.15 is a cross-sectional view after forming an organic light-emitting layer and a second electrode in another exemplary embodiment; Fig.16 is a cross-sectional view after forming a partition portion in an exemplary embodiment; Fig.17 is a cross-sectional view after forming an organic light-emitting layer and a second electrode in another exemplary embodiment; Fig.18 FIG. 1 is a cross-sectional view of an organic light-emitting layer and a second electrode after being broken in an exemplary embodiment. DETAILED DESCRIPTION

[0026] The present disclosure describes multiple embodiments, but the description is exemplary rather than restrictive, and it is apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present disclosure. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0027] The present disclosure includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in the present disclosure may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present disclosure may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0028] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be appreciated by those of ordinary skill in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art can easily understand that these orders can be changed and still remain within the spirit and scope of the disclosed embodiments.

[0029] In the drawings, the size of one or more components, the thickness of a layer, or an area is sometimes exaggerated for the sake of clarity. Therefore, one embodiment of the present disclosure is not necessarily limited to the size, and the shape and size of one or more components 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.

[0030] The ordinal numbers such as "first", "second", and "third" in this specification are provided to avoid confusion of constituent elements, and are not intended to limit the quantity. The "plurality" in this disclosure means two or more.

[0031] 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" and the like 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 orientation of the constituent elements being described. Therefore, it is not limited to the words and phrases described in the specification, and can be appropriately replaced according to the circumstances.

[0032] 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 meanings of the above terms in this disclosure can be understood according to the circumstances.

[0033] 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 electrical signals between 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.

[0034] 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°.

[0035] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0036] Figure 1 FIG. 1 is a schematic diagram of the structure of a display substrate. Figure 1As shown, the display substrate 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 element connected to the circuit unit, the circuit unit may include at least a pixel driving circuit, and the pixel driving circuit is respectively connected to the scan signal line, the data signal line and the light emitting signal line. In an exemplary embodiment, the timing controller may provide a grayscale value and a control signal suitable for the specifications of the data driver to the data driver, may provide a clock signal suitable for the specifications of the scan driver, a scan start signal, etc. to the scan driver, and may provide a clock signal suitable for the specifications 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 constructed 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.

[0037] Figure 2 FIG. 1 is a schematic diagram of a planar structure of a display area in a display substrate. Figure 2As shown, 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 element, 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 element. The light-emitting element in each sub-pixel is respectively connected to the pixel driving circuit of the sub-pixel, and the light-emitting element is configured to emit light of corresponding brightness in response to the current output by the connected pixel driving circuit.

[0038] 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.

[0039] In an exemplary embodiment, a pixel unit may include four sub-pixels. For example, the four sub-pixels may include a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel emitting white (W) light. For another example, the four sub-pixels may include a red sub-pixel, a blue sub-pixel, and two green sub-pixels. In an exemplary embodiment, the four sub-pixels may be arranged in a horizontal parallel arrangement, a vertical parallel arrangement, a square shape, a diamond shape, etc., which is not limited in the present disclosure.

[0040] Figure 3 FIG. 1 is a schematic diagram of an equivalent circuit of a pixel driving circuit. In an exemplary embodiment, the pixel driving circuit may be a 3T1C, 4T1C, 5T1C, 5T2C, 6T1C, 7T1C or 8T1C structure. Figure 3 As shown, the pixel driving circuit may include 7 transistors (first transistor T1 to seventh transistor T7) and 1 storage capacitor C, and the pixel driving circuit is respectively connected to 6 signal lines (data signal line D, first scanning signal line S1, second scanning signal line S2, light emitting signal line E, initial signal line INIT and first power line VDD).

[0041] In an exemplary embodiment, the pixel driving circuit may include a first node N1, a second node N2, and a third node N3. The first node N1 is respectively connected to the first electrode of the third transistor T3, the second electrode of the fourth transistor T4, and the second electrode of the fifth transistor T5, the second node N2 is respectively connected to the second electrode of the first transistor, the first electrode of the second transistor T2, the gate electrode of the third transistor T3, and the second end of the storage capacitor C, and the third node N3 is respectively connected to the second electrode of the second transistor T2, the second electrode of the third transistor T3, and the first electrode of the sixth transistor T6.

[0042] In an exemplary embodiment, a first end of the storage capacitor C is connected to the first power line VDD, and a second end of the storage capacitor C is connected to the second node N2 , ie, the second end of the storage capacitor C is connected to the gate electrode of the third transistor T3 .

[0043] The gate electrode of the first transistor T1 is connected to the second scan signal line S2, the first electrode of the first transistor T1 is connected to the initial signal line INIT, and the second electrode of the first transistor is connected to the second node N2. When the on-level scan signal is applied to the second scan signal line S2, the first transistor T1 transmits the initial voltage to the gate electrode of the third transistor T3 to initialize the charge amount of the gate electrode of the third transistor T3.

[0044] The gate electrode of the second transistor T2 is connected to the first scan signal line S1, the first electrode of the second transistor T2 is connected to the second node N2, and the second electrode of the second transistor T2 is connected to the third node N3. When the on-level scan signal is applied to the first scan signal line S1, the second transistor T2 connects the gate electrode of the third transistor T3 to the second electrode.

[0045] The gate electrode of the third transistor T3 is connected to the second node N2, that is, the gate electrode of the third transistor T3 is connected to the second end of the storage capacitor C, the first electrode of the third transistor T3 is connected to the first node N1, and the second electrode of the third transistor T3 is connected to the third node N3. The third transistor T3 can be called a driving transistor, and the third transistor T3 determines the amount of driving current flowing between the first power line VDD and the second power line VSS according to the potential difference between its gate electrode and the first electrode.

[0046] The gate electrode of the fourth transistor T4 is connected to the first scan signal line S1, the first electrode of the fourth transistor T4 is connected to the data signal line D, and the second electrode of the fourth transistor T4 is connected to the first node N1. The fourth transistor T4 can be called a switching transistor, a scan transistor, etc. When the on-level scan signal is applied to the first scan signal line S1, the fourth transistor T4 enables the data voltage of the data signal line D to be input to the pixel driving circuit.

[0047] The gate electrode of the fifth transistor T5 is connected to the light emitting signal line E, the first electrode of the fifth transistor T5 is connected to the first power line VDD, and the second electrode of the fifth transistor T5 is connected to the first node N1. The gate electrode of the sixth transistor T6 is connected to the light emitting signal line E, the first electrode of the sixth transistor T6 is connected to the third node N3, and the second electrode of the sixth transistor T6 is connected to the first electrode of the light emitting element EL. The fifth transistor T5 and the sixth transistor T6 can be called light emitting transistors. When the on-level light emitting signal is applied to the light emitting signal line E, the fifth transistor T5 and the sixth transistor T6 form a driving current path between the first power line VDD and the second power line VSS to make the light emitting element EL emit light.

[0048] The gate electrode of the seventh transistor T7 is connected to the second scan signal line S2, the first electrode of the seventh transistor T7 is connected to the initial signal line INIT, and the second electrode of the seventh transistor T7 is connected to the first electrode of the light emitting element EL. When the on-level scan signal is applied to the second scan signal line S2, the seventh transistor T7 transmits the initial voltage to the first electrode of the light emitting element EL to initialize or release the charge accumulated in the first electrode of the light emitting element EL.

[0049] In an exemplary embodiment, the light-emitting element EL may be an OLED, including a stacked first electrode, an organic light-emitting layer, and a second electrode, or may be a QLED, including a stacked first electrode, a quantum dot light-emitting layer, and a second electrode. In this embodiment, the first electrode may be an anode and the second electrode may be a cathode, and the present disclosure does not limit this.

[0050] In an exemplary embodiment, the second electrode of the light emitting element EL is connected to the second power line VSS, the signal of the second power line VSS is a continuously provided low level signal, and the signal of the first power line VDD is a continuously provided high level signal.

[0051] In an exemplary embodiment, the first transistor T1 to the seventh transistor T7 may be a P-type transistor, or may be an N-type transistor. Using the same type of transistors in the pixel driving circuit can simplify the process flow, reduce the process difficulty of the display substrate, and improve the yield of the product. In some possible implementations, the first transistor T1 to the seventh transistor T7 may include a P-type transistor and an N-type transistor.

[0052] In an exemplary embodiment, the first transistor T1 to the seventh transistor T7 may be a low-temperature polysilicon thin film transistor, or an oxide thin film transistor, or a low-temperature polysilicon thin film transistor and an oxide thin film transistor. The active layer of the low-temperature polysilicon thin film transistor is low-temperature polysilicon (LTPS for short), and the active layer of the oxide thin film transistor is oxide semiconductor (Oxide). The low-temperature polysilicon thin film transistor has the advantages of high mobility and fast charging, and the oxide thin film transistor has the advantages of low leakage current. The low-temperature polysilicon thin film transistor and the oxide thin film transistor are integrated on a display substrate to form a low-temperature polycrystalline oxide (LTPO) display substrate, which can take advantage of the advantages of both, can achieve low-frequency driving, can reduce power consumption, and can improve display quality.

[0053] Taking the case where all 7 transistors are P-type transistors as an example, the operation process of the pixel driving circuit may include: The first stage A1 is called the reset stage. The signal of the second scanning signal line S2 is a low-level signal, and the signals of the first scanning signal line S1 and the light-emitting signal line E are high-level signals. The signal of the second scanning signal line S2 is a low-level signal, which turns on the first transistor T1 and the seventh transistor T7. The first transistor T1 is turned on so that the initial voltage of the initial signal line INIT is provided to the second node N2, the storage capacitor C is initialized, and the original data voltage in the storage capacitor is cleared. The seventh transistor T7 is turned on so that the initial voltage of the initial signal line INIT is provided to the first electrode of the OLED, the first electrode of the OLED is initialized (reset), and the pre-stored voltage inside it is cleared to complete the initialization. The signals of the first scanning signal line S1 and the light-emitting signal line E are high-level signals, which turns off the second transistor T2, the fourth transistor T4, the fifth transistor T5 and the sixth transistor T6. In this stage, the OLED does not emit light.

[0054] The second stage A2 is called the data writing stage or the threshold compensation stage. The signal of the first scanning signal line S1 is a low-level signal, the signals of the second scanning signal line S2 and the light-emitting signal line E are high-level signals, and the data signal line D outputs a data voltage. In this stage, since the second end of the storage capacitor C is at a low level, the third transistor T3 is turned on. The signal of the first scanning signal line S1 is a low-level signal, which turns on the second transistor T2 and the fourth transistor T4. The second transistor T2 and the fourth transistor T4 are turned on so that the data voltage output by the data signal line D is provided to the second node N2 through the first node N1, the turned-on third transistor T3, the third node N3, and the turned-on second transistor T2, and the difference between the data voltage output by the data signal line D and the threshold voltage of the third transistor T3 is charged into the storage capacitor C. The voltage of the second end (the second node N2) of the storage capacitor C is Vd-|Vth|, where Vd is the data voltage output by the data signal line D, and Vth is the threshold voltage of the third transistor T3. The signal of the second scanning signal line S2 is a high-level signal, which turns off the first transistor T1 and the seventh transistor T7. The signal of the light emitting signal line E is a high level signal, which turns off the fifth transistor T5 and the sixth transistor T6.

[0055] The third stage A3 is called the light-emitting stage. The signal of the light-emitting signal line E is a low-level signal, and the signals of the first scanning signal line S1 and the second scanning signal line S2 are high-level signals. The signal of the light-emitting signal line E is a low-level signal, which turns on the fifth transistor T5 and the sixth transistor T6. Since the voltage Vd-|Vth| is written to the second end of the storage capacitor C in the previous stage, the third transistor T3 can still remain in the on state in this stage. The power supply voltage output by the first power supply line VDD provides a driving voltage to the first electrode of the OLED through the turned-on fifth transistor T5, the third transistor T3 and the sixth transistor T6, driving the OLED to emit light.

[0056] During the driving process of the pixel driving circuit, the driving current flowing through the third transistor T3 (driving transistor) is determined by the voltage difference between its gate electrode and the first electrode. Since the voltage of the second node N2 is Vdata-|Vth|, the driving current of the third transistor T3 is:

[0057] I=K*(Vgs-Vth) 2 =K*[(Vdd-Vd+|Vth|)-Vth] 2 =K*(Vdd-Vd) 2 Among them, I is the driving current flowing through the third transistor T3, that is, the driving current driving the OLED, K is a constant, Vgs is the voltage difference between the gate electrode and the first electrode of the third transistor T3, Vth is the threshold voltage of the third transistor T3, Vd is the data voltage output by the data signal line D, and Vdd is the power supply voltage output by the first power supply line VDD.

[0058] A display substrate includes: a driving circuit layer arranged on a base substrate, a light-emitting element arranged on the driving circuit layer, an encapsulation layer arranged on the light-emitting element, and a polarizer arranged on the encapsulation layer, wherein the driving circuit layer includes a pixel driving circuit, the encapsulation layer is used to protect the light-emitting element, and the polarizer can control the light output of the display substrate to achieve clear display of the image. Studies have shown that the encapsulation effect of the encapsulation layer has a great influence on the display performance of the display device. If the encapsulation layer fails, such as a gap or a break in the encapsulation layer, water vapor in the atmosphere will enter the light-emitting element along the gap, causing the organic material in the light-emitting element to oxidize and fail, forming a failure area that cannot emit light. As water vapor continues to invade the light-emitting element along the gap, the failure area gradually expands, resulting in poor display on the display substrate, which is called a growing dark spot (GDS, Growing Dark Spot).

[0059] Figure 4 FIG. 1 is a schematic diagram showing the structure of a substrate in an exemplary embodiment. Figure 4 As shown, the display substrate includes a display area 100 and a peripheral area 200 surrounding the display area 100. The display area 100 includes at least a plurality of regularly arranged sub-pixels, the plurality of sub-pixels are configured to display dynamic pictures or still images, and the plurality of sub-pixels can be arranged in an array along a first direction X and a second direction Y, the first direction X and the second direction Y intersect, for example, the second direction Y can be perpendicular to the first direction X. The display area 100 can be referred to as an active area (AA). The peripheral area 200 can include a gate drive circuit, and an integrated circuit (IC) and a flexible printed circuit board (FPC) can be bound and connected to the peripheral area 200.

[0060] In an exemplary embodiment, the shape of the display area 100 may be a quadrilateral, a circle, an ellipse, a polygon of other shapes or an irregular shape, etc. The corner shape of the display area 100 may be rounded, and the edge shape of the display area may be different depending on the shape of the display area, for example, it may be a straight line, a curve, a fold line, etc., and the present disclosure is not limited thereto. In an exemplary embodiment, the display substrate may be deformable, for example, curled, bent, folded, or rolled up.

[0061] In an exemplary embodiment, the display substrate may be a foldable display substrate, for example, Figure 4As shown, the display substrate may have a folding line Ox, and the display substrate may be folded and unfolded along the folding line Ox to achieve different display forms, which is convenient for users to use. In other embodiments, the display substrate may have multiple folding lines Ox, and may be folded and unfolded multiple times along the multiple folding lines Ox. When the display substrate supports multiple folding, it can switch between more display forms, and can achieve more diverse functions. Figure 4 As shown, dark spots G are likely to appear on the display area 100, affecting the display effect of the display substrate.

[0062] Figure 5 In an exemplary embodiment Figure 4 A cross-sectional view of a display substrate along the BB direction. Figure 5 As shown, in a direction perpendicular to the display substrate, the display substrate includes a base substrate 10, a driving structure layer 20 disposed on the base substrate 10, a display structure layer 30 disposed on the driving structure layer 20, an encapsulation layer 40 disposed on the display structure layer 30, a touch layer 50 disposed on the encapsulation layer 40, and a polarizer 60 disposed on the touch layer 50. The driving structure layer 20 of the display area 100 includes a pixel driving circuit, the driving structure layer 20 of the peripheral area 200 may include a gate driving circuit, and the gate driving circuit may be connected to the corresponding pixel driving circuit to drive the light-emitting element to emit light. A first blocking dam 410 and a second blocking dam 420 may be disposed on the driving structure layer 20 of the peripheral area 200, and the second blocking dam 420 may be located on a side of the first blocking dam 410 away from the display area 100, and the first blocking dam 410 and the second blocking dam 420 may surround the display area 100. The display structure layer 30 is located in the display area 100, and includes a plurality of light-emitting elements distributed in the display area 100, the light-emitting elements are connected to the corresponding pixel driving circuits, the light-emitting elements are configured to emit light, and the pixel driving circuits are configured to drive the light-emitting elements. In an exemplary embodiment, the display unit includes a pixel driving circuit and a corresponding light-emitting element, and the pixel driving circuit may include a plurality of thin film transistors (Thin Film Transistor, referred to as TFT) and storage capacitors, which is not limited in the present disclosure. The display structure layer 30 includes a first electrode 31, a pixel definition layer 32, an isolation column 33, an organic light-emitting layer 34, and a second electrode 35. The pixel definition layer 32 includes a plurality of pixel openings, the pixel openings expose the first electrode 31, and the organic light-emitting layer 34 is disposed in the pixel openings, one end of the organic light-emitting layer 34 is electrically connected to the first electrode 31, and the other end of the organic light-emitting layer 34 is electrically connected to the second electrode 35. The isolation column 33 is located on the pixel definition layer 32, and the orthographic projection of the isolation column 33 on the base substrate 10 does not overlap with the orthographic projection of the pixel opening on the base substrate 10. In an exemplary embodiment, the first electrode 31 can be an anode and the second electrode 35 can be a cathode, which is not limited in the present disclosure.

[0063] In an exemplary embodiment, the encapsulation layer 40 may adopt a stacked structure of a first encapsulation layer 41, a second encapsulation layer 42, and a third encapsulation layer 43, wherein the first encapsulation layer 41 is made of an inorganic material, covers the display area 100, and wraps the first barrier dam 410 and the second barrier dam 420 in the peripheral area 200. The second encapsulation layer 42 is made of an organic material, covers the display area 100, and is located on the side of the first barrier dam 410 close to the display area 100. The third encapsulation layer 43 is made of an inorganic material, covering the first encapsulation layer 41 and the second encapsulation layer 42. The encapsulation layer 40 can ensure that external water vapor cannot enter the light-emitting element. In other embodiments, the encapsulation layer 40 may also adopt a five-layer stacked structure of inorganic / organic / inorganic / organic / inorganic, which is not limited by the present disclosure.

[0064] In an exemplary embodiment, the touch layer 50 and the polarizer 60 may sequentially cover the display area 100 and the peripheral area 200 in a direction away from the base substrate 10 .

[0065] In an exemplary embodiment, the polarizer 60 may include a first adhesive layer 61, a polarization generating layer 62, a second adhesive layer 63, and a polarization protection layer 64. The polarization generating layer 62 may be attached to the touch layer 50 through the first adhesive layer 61, and the polarization protection layer 64 may be attached to the polarization generating layer 62 through the second adhesive layer 63. In an exemplary embodiment, the first adhesive layer 61 may be a pressure sensitive adhesive (PSA), the material of the polarization generating layer 62 may be polyvinyl alcohol (PVA), the material of the second adhesive layer 63 may be an ultraviolet adhesive, and the material of the polarization protection layer 64 may be triacetyl cellulose (TAC).

[0066] The inventors of the present application have found through research that when the display substrate is deformable, for example, a foldable display substrate, when the display substrate is in a folded state, the multiple film layers of the polarizer 60 are prone to shifting, such as Figure 5 As shown by the middle arrow F1, the polarization generating layer 62 is easily contracted toward the display area 100 under force, driving the polarization protection layer 64 to shift toward the display area 100, and the iodine ions and potassium ions in the polarization generating layer 62 will move along the display area 100. Figure 5The path indicated by the middle arrow L1 enters the driving structure layer 20 from the side of the display substrate and is transmitted to the second electrode 35 of the display area 100 through the conductive film layer of the driving structure layer 20. The conductive film layer of the driving structure layer 20 may include a gate driving circuit and a signal transmission line. Since the isolation column 33 itself is conductive, there is an electric field between the isolation column 33 and the second electrode 35. Under the action of the electric field, the iodine ions will cause electrochemical corrosion to the film layer of the display substrate through which they move, causing damage to the film layer. If this electrochemical corrosion occurs in the film layer near the via, the damage to the film layer will be more serious. After the film layer is damaged, water vapor is more likely to invade the interior of the display substrate, resulting in GDS failure.

[0067] Figure 6 FIG. 1 is a schematic diagram of a light emitting structure layer in an exemplary embodiment, showing three light emitting elements on a display substrate, and omitting the other structures of the display substrate. Figure 6 As shown, the isolation column 33 is located on the side of the pixel definition layer 32 away from the base substrate 10, the organic light emitting layer 34 is located in the pixel opening of the pixel definition layer 32, and the orthographic projection of the isolation column 33 on the base substrate 10 and the orthographic projection of the pixel opening on the base substrate 10 do not overlap. In an exemplary embodiment, the isolation column 33 may be in a sideways "H" shape. Since the isolation column 33 is formed first and then the organic light emitting layer 34 and the second electrode 35 are formed during the preparation of the display substrate, a part of the organic light emitting layer 34 and the second electrode 35 also covers the top of the isolation column 33, and the second electrode 35 located on the side of the pixel opening away from the base substrate 10 overlaps with the adjacent isolation column 33. After the iodine ions and potassium ions move from the side of the display substrate to the second electrode 35, they can continue to move toward the inside of the display area 100 along the overlapping position of the second electrode 35 and the isolation column 33, and cause electrochemical corrosion to the film layer along the way, so that the entire display area 100 has a great risk of GDS failure.

[0068] The embodiment of the present disclosure provides a display substrate, comprising a base substrate, a driving structure layer, a display structure layer and a polarizer sequentially arranged on the base substrate, the driving structure layer comprising a pixel driving circuit, the display structure layer comprising a first electrode, a pixel definition layer, an isolation column, an organic light-emitting layer and a second electrode sequentially arranged in a direction away from the base substrate, the pixel definition layer comprising a plurality of pixel openings, the pixel openings exposing the first electrode, the organic light-emitting layer at least arranged in the pixel openings, the isolation column being located on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the isolation column on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; the first electrode is electrically connected to the pixel driving circuit; Wherein, in a plane parallel to the base substrate, at least one of the isolation pillars is insulated from the second electrode; or at least two adjacent isolation pillars are insulated from each other.

[0069] The display substrate provided by the embodiment of the present disclosure cuts off the ion transmission channel between the isolation column and the second electrode by arranging at least one isolation column and is insulated from the second electrode, or at least two adjacent isolation columns are insulated from each other, so that even if iodine ions and potassium ions in the polarizer move to the second electrode, they will not move into the display area through multiple isolation columns, thereby avoiding GDS defects in the display substrate.

[0070] In the exemplary embodiment, two spacer pillars are adjacent to each other, which means that no other spacer pillar exists between the two spacer pillars.

[0071] In an exemplary embodiment, at least one of the isolation columns is insulated from the second electrode, including: the orthographic projection of at least one of the isolation columns on the base substrate and the orthographic projection of the organic light-emitting layer on the base substrate do not overlap, and the orthographic projection of at least one of the isolation columns on the base substrate and the orthographic projection of the second electrode on the base substrate do not overlap.

[0072] In this embodiment, the orthographic projection of the isolation column on the base substrate and the orthographic projection of the organic light-emitting layer and the second electrode on the base substrate do not overlap, the isolation column and the second electrode are not in contact, and the ion transmission path between the isolation column and the second electrode is cut off. Even if the iodine ions and potassium ions in the polarizer move to the second electrode, they will not move further into the display area, thereby avoiding GDS defects in the display substrate.

[0073] In an exemplary embodiment, at least one of the isolation columns is insulated from the second electrode, including: the display structure layer further includes at least one insulating wrapping layer, the insulating wrapping layer is wrapped around the surface of the isolation column and is configured to insulate the isolation column from the second electrode.

[0074] In this embodiment, an insulating wrapping layer is provided on the surface of the isolation column so that the isolation column and other structures are insulated from each other, thereby cutting off the transmission path between the isolation column and the second electrode. Even if the iodine ions and potassium ions in the polarizer move to the second electrode, they will not move further into the display area, thereby avoiding GDS defects in the display substrate.

[0075] In an exemplary embodiment, an insulating wrapping layer can be formed on the isolation column by an atomic layer deposition method. The insulating wrapping layer formed by atomic layer deposition can grow along the morphology of the isolation column and can be coated on the surface of the isolation column while maintaining the morphology of the isolation column. The insulating wrapping layer can be made of insulating materials such as silicon oxide and silicon nitride. The present disclosure does not limit the process and materials for forming the insulating wrapping layer.

[0076] In an exemplary embodiment, at least two adjacent isolation columns are insulated from each other, including: the display structure layer also includes at least one isolation portion arranged on the side of the pixel definition layer away from the base substrate, the organic light-emitting layer and the second electrode cover the isolation portion and the isolation column, and the orthographic projection of the isolation portion on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; in a plane parallel to the base substrate, the isolation portion is located between adjacent isolation columns, and is configured to disconnect the second electrode at its position.

[0077] In this embodiment, a partition portion is provided between adjacent isolation columns, and the second electrode at the location of the partition portion is disconnected by the partition portion, so that adjacent isolation columns are insulated from each other, and the transmission path between the isolation column and the second electrode is cut off. Even if the iodine ions and potassium ions in the polarizer move to the second electrode, they will not move further into the display area, thereby avoiding GDS defects in the display substrate.

[0078] In an exemplary embodiment, the partition portion may have the property of thermal expansion and contraction. After the organic light-emitting layer and the second electrode are formed, the partition portion is expanded by heat to stretch the organic light-emitting layer and the second electrode at the location of the partition portion. After the partition portion contracts when cold, the organic light-emitting layer and the second electrode at the location of the partition portion will be broken, so that the organic light-emitting layer and the second electrode at the location of the partition portion are disconnected. For example, the material of the partition portion may include epoxy resin doped with metal particles. This material is conductive, expands when powered on, and contracts when powered off. A suitable partition portion material can be selected as needed, and the present disclosure does not limit this.

[0079] Figure 7 FIG. 1 is a cross-sectional view of a display substrate in an exemplary embodiment, showing three light emitting elements in a display area, and omitting the illustration of other structures of the display substrate. Figure 7 and Figure 5 The difference is that the structure of the display structure layer 30 is different, and the rest of the structure can refer to the above Figure 5 The description will not be repeated here.

[0080] In an exemplary embodiment, if Figure 7As shown, the orthographic projection of the isolation column 33 on the base substrate 10 does not overlap with the orthographic projection of the organic light-emitting layer 34 on the base substrate 10, and the orthographic projection of the isolation column 33 on the base substrate 10 does not overlap with the orthographic projection of the second electrode 35 on the base substrate 10. There is no organic light-emitting layer 34 and the second electrode 35 above the isolation column 33, and the isolation column 33 does not contact the second electrode 35, thereby cutting off the ion transmission path between the isolation column 33 and the second electrode 35, so that iodine ions and potassium ions from the polarizer 60 will not move into the display area, thereby avoiding GDS defects in the display substrate.

[0081] Figure 8 is a cross-sectional view showing a substrate in yet another exemplary embodiment, Figure 8 and Figure 5 The difference is that the structure of the display structure layer 30 is different, and the rest of the structure can refer to the above Figure 5 The description will not be repeated here.

[0082] In an exemplary embodiment, the display structure layer 30 further includes at least one insulating wrapping layer 36, which wraps around the surface of the isolation column 33 and maintains the morphology of the isolation column 33. The organic light-emitting layer 34 and the second electrode 35 may cover the insulating wrapping layer 36, and the second electrode 35 may overlap the insulating wrapping layer 36. By providing the insulating wrapping layer 36, the isolation column 33 is insulated from other structures, and the ion transmission path between the isolation column 33 and the second electrode 35 is cut off, so that the iodine ions and potassium ions from the polarizer 60 will not move into the display area, thereby avoiding GDS failure of the display substrate.

[0083] Fig. 9 is a cross-sectional view showing a substrate in yet another exemplary embodiment, Fig. 9 and Figure 5 The difference is that the structure of the display structure layer 30 is different, and the rest of the structure can refer to the above Figure 5 The description will not be repeated here.

[0084] In an exemplary embodiment, if Fig. 9 As shown, the display structure layer 30 also includes at least one partition portion 37 arranged on the side of the pixel definition layer 32 away from the base substrate 10, the organic light-emitting layer 34 and the second electrode 35 cover the partition portion 37 and the isolation column 33, and the orthographic projection of the partition portion 37 on the base substrate 10 and the orthographic projection of the pixel opening on the base substrate 10 do not overlap; in a plane parallel to the base substrate 10, the partition portion 37 is located between adjacent isolation columns 33, and is configured to disconnect the second electrode 35 at the position where the partition portion 37 itself is located.

[0085] In an exemplary embodiment, the partition portion 37 may have a property of thermal expansion and thermal contraction, such as Fig. 9As shown, after thermal expansion and contraction, the partition portion 37 can disconnect the organic light-emitting layer 34 and the second electrode 35 at its side, thereby insulating the isolation column and the second electrode from each other, cutting off the ion transmission path between the isolation column and the second electrode, so that iodine ions and potassium ions from the polarizer 60 will not move into the display area, avoiding GDS defects in the display substrate.

[0086] Fig.10 FIG. 1 is a top view of a partition portion and a spacer column in an exemplary embodiment, and other structures of a display substrate are omitted for illustration.

[0087] In an exemplary embodiment, if Fig.10 As shown, the plurality of isolation columns 33 on the display substrate may be arranged in an array, including a plurality of isolation column rows arranged along a first direction X and a plurality of isolation column columns arranged along a second direction Y, and a plurality of partition portions 37 may be arranged spaced apart from the plurality of isolation columns 33. Fig.10 As shown, the plurality of partition portions 37 may include a plurality of partition portion columns arranged along the second direction Y, and a single partition portion column and a single isolation column column may be alternately arranged in sequence along the first direction X. In other embodiments, the number and position distribution of the isolation columns 33 and the partition portions 37 may be set as required, and the present disclosure does not limit this.

[0088] In an exemplary embodiment, Fig.10 The dotted line in the figure can represent the direction of current movement. One or more rows of isolation columns 33 and partition parts 37 can be energized at one end along the first direction X. The partition parts 37 expand when energized and shrink when cooled when powered off, so that the organic light-emitting layer 34 and the second electrode 35 are disconnected at the side of the partition part 37, which is easy to operate.

[0089] 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".

[0090] In an exemplary embodiment, Figure 7 The manufacturing process of the display substrate shown may include the following steps.

[0091] (1) A driving structure layer 20 pattern is formed on the base substrate 10. In an exemplary embodiment, the driving structure layer 20 pattern may include a pixel driving circuit, a gate driving circuit, and various signal transmission lines.

[0092] In an exemplary embodiment, the substrate substrate may be a rigid substrate substrate or a flexible substrate substrate. The rigid substrate substrate may be made of materials such as glass or quartz, and the flexible substrate substrate may be made of materials such as polyimide (PI). The flexible substrate substrate may be a single-layer structure or a laminated structure consisting of an inorganic material layer and a flexible material layer, which is not limited in the present disclosure.

[0093] (2) Forming an electrode layer pattern on the base substrate 10 on which the aforementioned pattern is formed. In some exemplary embodiments, forming the electrode layer pattern may include:

[0094] A transparent conductive film is deposited on the base substrate 10 with the aforementioned pattern, and an electrode layer pattern is formed by patterning the transparent conductive film. The electrode layer pattern includes: a plurality of first electrodes 31 , and the first electrodes 31 can be connected to the driving structure layer 20 through vias.

[0095] In some examples, the transparent conductive film may be made of indium tin oxide (ITO) or indium zinc oxide (IZO), which is not limited in the present disclosure.

[0096] (3) Forming a pixel definition layer pattern on the base substrate 10 on which the aforementioned pattern is formed. In some exemplary embodiments, forming the pixel definition layer pattern includes:

[0097] A pixel definition film is coated on the base substrate 10 with the aforementioned pattern, and a mask, exposure, and development process are performed to form a pattern of a pixel definition layer 32. The pixel definition layer 32 is provided with a plurality of pixel openings, and the pixel definition layer 32 in the plurality of pixel openings is developed away to expose the surface of the first electrode 31.

[0098] In some examples, the pixel definition layer 32 may be made of materials such as polyimide, acrylic, or polyethylene terephthalate.

[0099] (4) Forming an isolation column pattern on the base substrate 10 on which the aforementioned pattern is formed. In some exemplary embodiments, forming the isolation column pattern includes:

[0100] A spacer column film is deposited on the base substrate 10 with the aforementioned pattern formed thereon, and the spacer column film is processed by a patterning process to form a spacer column pattern on a side of the pixel definition layer 32 away from the base substrate 10 . The spacer column pattern includes a plurality of spacer columns 33 .

[0101] (5) A photoresist is coated on the base substrate 10 on which the above-mentioned pattern is formed, and after exposure and development, a protection layer 301 covering the isolation column 33 is formed. Fig.11 FIG. 4 is a cross-sectional view after forming a protective layer in an exemplary embodiment.

[0102] In an exemplary embodiment, if Fig.11 As shown, a single protective layer 301 can be coated on the surface of a single isolation column 33 to isolate the isolation column 33 from other structures. The protective layer 301 can be in a shape that is wide at the top and narrow at the bottom, for example, it can be an inverted trapezoid, which is convenient for disconnecting the organic light-emitting layer and the second electrode later. The orthographic projection of the protective layer 301 on the base substrate 10 may not overlap with the orthographic projection of the pixel opening on the base substrate 10, and the present disclosure does not limit this.

[0103] Subsequently, an organic light emitting layer 34 is formed on the base substrate 10 on which the aforementioned pattern is formed. In some exemplary embodiments, forming the organic light emitting layer 34 includes:

[0104] On the base substrate 10 formed with the above pattern, an organic light emitting layer 34 pattern is formed in the display area by evaporation or inkjet printing, and the organic light emitting layer 34 is connected to the first electrode 31. Since the first electrode 31 is connected to the driving structure layer 20, the light emission control of the organic light emitting layer 34 is realized.

[0105] In an exemplary embodiment, the organic light emitting layer 34 may include a light emitting layer (EML), and any one or more of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL).

[0106] Subsequently, the second electrode 35 is formed on the base substrate 10 with the aforementioned pattern by evaporation with an open mask. A portion of the second electrode 35 is connected to the organic light emitting layer 34 , so that the organic light emitting layer 34 is connected to both the first electrode 31 and the second electrode 35 .

[0107] In some exemplary embodiments, the second electrode 35 may be made of any one or more of magnesium (Mg), silver (Ag), aluminum (Al), copper (Cu), and lithium (Li), or an alloy made of any one or more of the above metals.

[0108] Fig.12FIG. 1 is a cross-sectional view after forming an organic light-emitting layer and a second electrode in an exemplary embodiment. Fig.12 As shown, due to the provision of the protection layer 301 , the organic light emitting layer 34 and the second electrode 35 are separated, including a portion covering the pixel opening and a portion covering the protection layer 301 , and both are insulated from the isolation column 33 .

[0109] Subsequently, the substrate 10 with the aforementioned pattern is placed in a photoresist stripping solution to remove the protective layer 301 , and the organic light-emitting layer 34 and the second electrode 35 located above the protective layer 301 are removed together, and the remaining organic light-emitting layer 34 and the second electrode 35 are insulated from the isolation column 33 .

[0110] Fig.13 FIG. 1 is a cross-sectional view of an exemplary embodiment after removing the protective layer. Fig.13 As shown, the orthographic projection of the isolation column 33 on the base substrate 10 does not overlap with the orthographic projection of the organic light-emitting layer 34 on the base substrate 10 , and the orthographic projection of the isolation column 33 on the base substrate 10 does not overlap with the orthographic projection of the second electrode 35 on the base substrate.

[0111] (6) On the base substrate 10 formed with the aforementioned pattern, an encapsulation layer 40 and a touch layer 50 are sequentially formed, and a polarizer 60 is attached to form a Figure 7 The display substrate is shown.

[0112] In other embodiments, the display substrate may further include other film layer structures, such as a protective layer, etc., which is not limited in the present disclosure.

[0113] In an exemplary embodiment, forming Figure 8 The process of forming the display substrate shown in the figure is similar to that described above. Figure 7 The process of forming the display substrate is similar to that shown in FIG. 1 , except for step (5). Only step (5) is described below, and the remaining steps can refer to the above-mentioned steps for forming the display substrate. Figure 7 The description of the display substrate is not repeated here.

[0114] After the isolation column 33 is formed, an insulating wrapping layer pattern is formed on a side of the isolation column 33 away from the base substrate 10 by atomic layer deposition. The insulating wrapping layer pattern includes a plurality of insulating wrapping layers 36 .

[0115] In some examples, the insulating wrap layer 36 may be made of insulating materials, such as silicon oxide, silicon nitride, etc., which is not limited in the present disclosure.

[0116] Fig.14 FIG. 1 is a cross-sectional view of an exemplary embodiment after forming an insulating wrap layer. Fig.14 As shown, the insulating wrapping layer 36 wraps around the surface of the isolation column 33 and maintains the morphology of the isolation column 33 .

[0117] Subsequently, an organic light-emitting layer 34 and a second electrode 35 are formed on the base substrate 10 having the aforementioned pattern. The process and materials for forming the organic light-emitting layer 34 and the second electrode 35 can refer to the aforementioned description of step (5), which will not be described again.

[0118] Fig.15 FIG. 4 is a cross-sectional view after forming an organic light-emitting layer and a second electrode in another exemplary embodiment. Fig.15 As shown, the organic light emitting layer 34 and the second electrode 35 may cover the insulating wrapping layer 36. Fig.15 As shown, there can be contact between the second electrode 35 and the insulating wrapping layer 36, but because the insulating wrapping layer 36 is not conductive, a through ion transmission channel will not be formed between the second electrode 35 and the isolation column 33, and the film layer in the display area will not be electrochemically corroded by iodine ions, thereby avoiding GDS defects on the display substrate.

[0119] Subsequently, the encapsulation layer 40 and the touch layer 50 may be formed in sequence according to the aforementioned step (6), and the polarizer 60 may be attached to form a Figure 8 The display substrate is shown.

[0120] In an exemplary embodiment, forming Fig. 9 The process of forming the display substrate shown in the figure is similar to that described above. Figure 7 The process of forming the display substrate is similar to that shown in FIG. 1 , except for step (5). Only step (5) is described below, and the remaining steps can refer to the above-mentioned steps for forming the display substrate. Figure 7 The description of the display substrate is not repeated here.

[0121] After forming the isolation column 33 , a partition film is continuously coated on the base substrate 10 . After exposure and development and other processes, a partition pattern is formed on the side of the pixel definition layer 32 away from the base substrate 10 . The partition pattern includes at least one partition 37 .

[0122] In some examples, the partition portion 37 may be made of epoxy resin doped with metal particles, which is a stretchable conductive material that facilitates the subsequent disconnection of the organic light-emitting layer 34 and the second electrode 35 . The present disclosure does not limit the material of the partition portion.

[0123] Fig.16 FIG. 1 is a cross-sectional view after forming a partition portion in an exemplary embodiment. Fig.16 As shown, the orthographic projection of the partition portion 37 on the base substrate 10 and the orthographic projection of the pixel opening on the base substrate 10 do not overlap; in a plane parallel to the base substrate 10, the partition portion 37 is located between two adjacent isolation columns 33. For the position setting of the isolation column 33 and the partition portion 37, please refer to the previous description, which will not be repeated here.

[0124] Subsequently, an organic light-emitting layer 34 and a second electrode 35 are formed on the base substrate 10 having the aforementioned pattern. The process and materials for forming the organic light-emitting layer 34 and the second electrode 35 can refer to the aforementioned description of step (5), which will not be described again.

[0125] Fig.17 FIG. 4 is a cross-sectional view after forming an organic light-emitting layer and a second electrode in another exemplary embodiment. Fig.17 As shown, the organic light emitting layer 34 and the second electrode 35 may cover the partition part 37 and the isolation column 33 .

[0126] Subsequently, the partition part 37 is energized within a first time period, so that the partition part 37 expands due to the heat, thereby stretching out the organic light-emitting layer 34 and the second electrode 35 at the location of the partition part 37. After the power is turned off, the volume of the partition part 37 shrinks, and the organic light-emitting layer 34 and the second electrode 35 at the location of the partition part 37 break at a weak point, which is generally located near the side of the partition part 37. The size of the first time period can be set as needed. Fig.18 FIG. 1 is a cross-sectional view of an organic light-emitting layer and a second electrode after being broken in an exemplary embodiment. Fig.18 As shown, there can be contact between the second electrode 35 and the isolation column 33, but because the organic light-emitting layer 34 and the second electrode 35 are broken at the partition portion 37, a through ion transmission channel will not be formed between the second electrode 35 and the isolation column 33, and the film layer in the display area will not be electrochemically corroded by iodine ions, thereby avoiding GDS defects on the display substrate.

[0127] Subsequently, the encapsulation layer 40 and the touch layer 50 may be formed in sequence according to the aforementioned step (6), and the polarizer 60 may be attached to form a Fig. 9 The display substrate is shown.

[0128] The embodiment of the present disclosure also provides a method for preparing a display substrate, comprising: forming a driving structure layer on a base substrate, the driving structure layer comprising a pixel driving circuit; forming a first electrode, a pixel definition layer, an isolation column, an organic light-emitting layer and a second electrode in sequence on the driving structure layer; wherein the first electrode is electrically connected to the pixel driving circuit; the pixel definition layer comprises a plurality of pixel openings, the pixel openings expose the first electrode, the organic light-emitting layer is at least arranged in the pixel openings, the isolation column is located on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the isolation column on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; attaching a polarizer on a side of the second electrode away from the base substrate; wherein, in a plane parallel to the base substrate, at least one of the isolation columns and the second electrode are insulated from each other; or, at least two adjacent isolation columns are insulated from each other.

[0129] The method for preparing a display substrate provided by the embodiment of the present disclosure cuts off the ion transmission channel between the isolation column and the second electrode by forming a structure insulated from each other between at least one isolation column and the second electrode, or a structure insulated from each other between at least two adjacent isolation columns, so that even if iodine ions and potassium ions in the polarizer move to the second electrode, they will not move into the display area through multiple isolation columns, thereby avoiding GDS defects in the display substrate.

[0130] In an exemplary embodiment, before forming the organic light-emitting layer and the second electrode, the method further includes: forming a protective layer on a side of at least one of the isolation columns away from the base substrate, wherein the protective layer covers the isolation column; after forming the second electrode, the method further includes: removing the protective layer to insulate the at least one isolation column from the second electrode.

[0131] In an exemplary embodiment, forming a protective layer on a side of at least one of the isolation columns away from the substrate includes: forming the protective layer using photoresist on a side of at least one of the isolation columns away from the substrate, wherein the area of ​​the cross-section of the protective layer parallel to the substrate gradually increases in a direction away from the substrate.

[0132] In an exemplary embodiment, before forming the organic light-emitting layer and the second electrode, the method further includes: forming an insulating wrapping layer on a side of at least one of the isolation columns away from the base substrate, wherein the insulating wrapping layer covers the isolation column and has the same shape as the isolation column, so that the at least one isolation column is insulated from the subsequently formed second electrode.

[0133] In an exemplary embodiment, before forming the organic light-emitting layer and the second electrode, the method further includes: forming at least one partition portion on a side of the pixel definition layer away from the base substrate, the orthographic projection of the partition portion on the base substrate and the orthographic projection of the pixel opening on the base substrate not overlapping; in a plane parallel to the base substrate, the partition portion is located between adjacent isolation columns, and the subsequently formed second electrode is disconnected at the partition portion, so that at least two adjacent isolation columns are insulated from each other.

[0134] In an exemplary embodiment, the volume of the material of the partition portion is different before and after power is supplied; after forming the second electrode, the method further includes: supplying power to the partition portion within a first time period, and disconnecting the second electrode at the location of the partition portion through the volume change of the partition portion before and after power is supplied.

[0135] In an exemplary embodiment, the material of the partition portion includes epoxy resin doped with metal particles.

[0136] The embodiments of the present disclosure also provide a display device, including the display substrate described in any of the above embodiments. The display device can be: an OLED display, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, or any other product or component with a display function, and the embodiments of the present disclosure are not limited thereto.

[0137] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A display substrate, comprising: A base substrate, a driving structure layer, a display structure layer and a polarizer sequentially arranged on the base substrate, wherein the driving structure layer includes a pixel driving circuit, the display structure layer includes a first electrode, a pixel definition layer, an isolation column, an organic light-emitting layer and a second electrode sequentially arranged in a direction away from the base substrate, the pixel definition layer includes a plurality of pixel openings, the pixel openings expose the first electrode, the organic light-emitting layer is at least arranged in the pixel openings, the isolation column is located on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the isolation column on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; the first electrode is electrically connected to the pixel driving circuit; Wherein, in a plane parallel to the base substrate, at least one of the isolation pillars is insulated from the second electrode; or at least two adjacent isolation pillars are insulated from each other.

2. The display substrate according to claim 1, characterized in that: The at least one isolation column and the second electrode are insulated from each other, comprising: The orthographic projection of at least one of the isolation columns on the base substrate does not overlap with the orthographic projection of the organic light-emitting layer on the base substrate, and the orthographic projection of at least one of the isolation columns on the base substrate does not overlap with the orthographic projection of the second electrode on the base substrate.

3. The display substrate according to claim 1, characterized in that: The at least one isolation column and the second electrode are insulated from each other, comprising: The display structure layer further includes at least one insulating wrapping layer, which is wrapped around the surface of the isolation column and is configured to insulate the isolation column from the second electrode.

4. The display substrate according to claim 3, characterized in that: The shape of the insulating wrapping layer is the same as that of the isolation column.

5. The display substrate according to claim 3, characterized in that: An orthographic projection of the insulating wrap layer on the base substrate at least partially overlaps with an orthographic projection of the second electrode on the base substrate.

6. The display substrate according to claim 1, characterized in that: The at least two adjacent isolation columns are insulated from each other, comprising: The display structure layer also includes at least one partition portion arranged on the side of the pixel definition layer away from the base substrate, the organic light-emitting layer and the second electrode cover the partition portion and the isolation column, and the orthographic projection of the partition portion on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; in a plane parallel to the base substrate, the partition portion is located between adjacent isolation columns and is configured to disconnect the second electrode at its position.

7. The display substrate according to claim 6, characterized in that: The plurality of isolation columns are distributed in an array on the base substrate, and the plurality of partition portions and the plurality of isolation columns are arranged at intervals from each other.

8. A method for preparing a display substrate, comprising: Forming a driving structure layer on the base substrate, wherein the driving structure layer includes a pixel driving circuit; A first electrode, a pixel definition layer, an isolation column, an organic light-emitting layer and a second electrode are sequentially formed on the driving structure layer; wherein the first electrode is electrically connected to the pixel driving circuit; the pixel definition layer includes a plurality of pixel openings, the pixel openings expose the first electrode, the organic light-emitting layer is at least arranged in the pixel openings, the isolation column is located on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the isolation column on the base substrate does not overlap with the orthographic projection of the pixel opening on the base substrate; A polarizer is attached to a side of the second electrode away from the base substrate; Wherein, in a plane parallel to the base substrate, at least one of the isolation pillars is insulated from the second electrode; or at least two adjacent isolation pillars are insulated from each other.

9. The preparation method according to claim 8, characterized in that: Before forming the organic light-emitting layer and the second electrode, the method further includes: forming a protective layer on a side of at least one of the isolation columns away from the base substrate, wherein the protective layer covers the isolation column; After forming the second electrode, the method further includes: removing the protective layer to insulate the at least one isolation column from the second electrode.

10. The preparation method according to claim 9, characterized in that: The step of forming a protective layer on a side of at least one of the isolation pillars away from the base substrate comprises: The protection layer is formed by using photoresist on a side of at least one of the isolation pillars away from the base substrate, and the area of ​​the cross section of the protection layer parallel to the base substrate gradually increases in a direction away from the base substrate.

11. The preparation method according to claim 8, characterized in that: Before forming the organic light-emitting layer and the second electrode, the method further includes: An insulating wrapping layer is formed on a side of at least one of the isolation columns away from the base substrate, the insulating wrapping layer covers the isolation column and has the same shape as the isolation column, so that the at least one isolation column is insulated from the second electrode formed subsequently.

12. The preparation method according to claim 8, characterized in that: Before forming the organic light-emitting layer and the second electrode, the method further includes: At least one partition portion is formed on a side of the pixel definition layer away from the base substrate, and the orthographic projection of the partition portion on the base substrate and the orthographic projection of the pixel opening on the base substrate do not overlap; in a plane parallel to the base substrate, the partition portion is located between adjacent isolation columns, and the second electrode formed subsequently is disconnected at the partition portion, so that at least two adjacent isolation columns are insulated from each other.

13. The preparation method according to claim 12, characterized in that: The volume of the material of the partition portion is different before and after power is supplied; after forming the second electrode, the method further includes: The partition part is energized in a first time period, and the second electrode at the location of the partition part is disconnected due to the volume change of the partition part before and after the energization.

14. The preparation method according to claim 13, characterized in that: The partition part is made of epoxy resin doped with metal particles.

15. A display device, comprising the display substrate according to any one of claims 1 to 7, or comprising a display substrate obtained by the preparation method according to any one of claims 8 to 14.

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