Display substrate, preparation method thereof and display device

Abstract

The present disclosure provides a display substrate, a manufacturing method thereof and a display device, and belongs to the technical field of display. The display substrate comprises a substrate, a planar layer arranged on the substrate, and a light-emitting device arranged on a side of the planar layer away from the substrate. The light-emitting device comprises a first electrode, a light-emitting layer and a second electrode arranged in sequence on the side of the planar layer away from the substrate. The side of the planar layer away from the substrate has an annular groove, and an edge of the first electrode is located in the annular groove.

Description

Technical Field

[0001] This disclosure belongs to the field of display technology, specifically relating to a display substrate and its preparation method, and a display device. Background Technology

[0002] The yield rate of Organic Light-Emitting Diode (OLED) display products is a crucial factor affecting their cost and has always been a focus of attention. Many factors influence the yield rate of OLED displays, among which dark spots are a common adverse effect. While the formation of dark spots is complex, the underlying mechanism is relatively simple, typically caused by a short circuit between the anode and cathode. Several factors can cause this short circuit, with anode edge warping being a significant contributing factor. Summary of the Invention

[0003] This disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a display substrate and its preparation method, as well as a display device.

[0004] In a first aspect, embodiments of this disclosure provide a display substrate, which includes a substrate, a planarization layer disposed on the substrate, and a light-emitting device disposed on the planarization layer on a side away from the substrate; the light-emitting device includes a first electrode, a light-emitting layer, and a second electrode disposed sequentially on the planarization layer on the side away from the substrate.

[0005] The planarization layer has an annular groove on the side opposite to the substrate; the edge of the first electrode is located within the annular groove.

[0006] In some embodiments, the depth of the annular groove is greater than or equal to the thickness of the first electrode.

[0007] In some embodiments, the annular groove includes a first sidewall and a second sidewall;

[0008] The annular groove includes a first groove and a second groove disposed opposite to each other along a first direction; the width of the first groove and the width of the second groove are equal; the ratio of the width of the first groove and the width of the second groove to the maximum width of the second sidewall of the annular groove in the first direction is between 0.045 and 0.055.

[0009] The annular groove includes a third groove and a fourth groove disposed opposite to each other along a second direction; the width of the third groove and the width of the fourth groove are equal; the ratio of the width of the third groove and the width of the fourth groove to the maximum width of the second sidewall of the annular groove in the second direction is between 0.045 and 0.055.

[0010] In some embodiments, the orthographic projection of the edge of the first electrode onto the substrate covers the orthographic projection of the annular groove onto the substrate.

[0011] In some embodiments, the annular groove includes a first sidewall and a second sidewall;

[0012] The annular groove includes a first groove and a second groove disposed opposite to each other along a first direction; the depth of the first groove and the depth of the second groove are the same; the depth of the first groove and the depth of the second groove are both greater than the thickness of the first electrode, and the ratio of the depth of the first groove and the depth of the second groove to the maximum width of the second sidewall of the annular groove in the first direction is between 0.062 and 0.073.

[0013] The annular groove includes a third groove and a fourth groove disposed opposite to each other along a second direction; the depth of the third groove and the depth of the fourth groove are the same; the depth of the third groove and the depth of the fourth groove are both greater than the thickness of the first electrode, and the ratio of the depth of the third groove and the depth of the fourth groove to the maximum width of the second sidewall of the annular groove in the second direction is between 0.062 and 0.073.

[0014] In some embodiments, the orthographic projection of the edge of the first electrode onto the substrate covers a portion of the orthographic projection of the annular groove onto the substrate.

[0015] In some embodiments, the planarization layer includes a first surface and a second surface disposed opposite each other along a third direction, wherein the first surface is closer to the substrate than the second surface;

[0016] The second surface includes a first sub-surface and a second sub-surface disposed opposite to each other along a first direction, a third sub-surface connected to the first sub-surface and the second sub-surface respectively, a fourth sub-surface on the side away from the substrate and connected to the first sub-surface, and a fifth sub-surface on the side away from the substrate and connected to the second sub-surface.

[0017] The dihedral angle formed between the second sub-surface and the fifth sub-surface is either a rounded chamfer or a flat chamfer.

[0018] In some embodiments, the display substrate further includes a pixel definition layer; the pixel definition layer includes a first sub-definition layer and a second sub-definition layer; the first sub-definition layer is disposed on the side of the planarization layer opposite to the substrate; the second sub-definition layer is disposed on the side of the first electrode opposite to the substrate.

[0019] The orthogonal projection of the pixel definition layer on the substrate covers the orthogonal projection of the annular groove on the substrate.

[0020] In some embodiments, the light-emitting layer and the second electrode are sequentially disposed on the side of the pixel definition layer and the first electrode layer away from the substrate.

[0021] Secondly, embodiments of this disclosure also provide a method for preparing a display substrate, comprising:

[0022] A substrate is formed, and a planarization layer is formed on the substrate;

[0023] An annular groove is formed on the side of the planarization layer opposite to the substrate.

[0024] A first electrode, a light-emitting layer, and a second electrode of a light-emitting device are sequentially formed on the side of the planar layer opposite to the substrate; wherein the edge of the first electrode is located within the annular groove.

[0025] In some embodiments, the step of sequentially forming a first electrode, a light-emitting layer, and a second electrode of a light-emitting device on the side of the planarization layer opposite to the substrate includes:

[0026] The first electrode is formed on the side of the planarization layer opposite to the substrate.

[0027] A first sub-definition layer is formed on the side of the planarization layer opposite to the substrate, and a second sub-definition layer is formed on the side of the first electrode opposite to the substrate. The first sub-definition layer and the second sub-definition layer are an integral structure. The integral first sub-definition layer and the second sub-definition layer are used as pixel definition layers. The orthographic projection of the pixel definition layer on the substrate covers the orthographic projection of the annular groove on the substrate.

[0028] On the side of the pixel definition layer and the first electrode opposite to the substrate, the light-emitting layer and the second electrode of the light-emitting device are formed sequentially.

[0029] Thirdly, embodiments of this disclosure also provide a display device, which includes a display substrate as described in any of the preceding claims. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the dark spots caused by anode edge warping in related technologies.

[0031] Figure 2 A cross-sectional view of an anode in a display substrate provided in an embodiment of this disclosure;

[0032] Figure 3A top view of a flat layer provided in an embodiment of this disclosure;

[0033] Figure 4 An anode cross-sectional view with a relatively deep annular groove is provided for an embodiment of this disclosure;

[0034] Figure 5 Another anode cross-sectional view with a deeper annular groove provided for an embodiment of this disclosure;

[0035] Figures 6a to 6f A schematic diagram illustrating the fabrication process of a display substrate with a shallow annular groove depth, provided in an embodiment of this disclosure;

[0036] Figures 7a to 7f This is a schematic diagram illustrating the fabrication process of a display substrate with a relatively deep annular groove, provided in an embodiment of this disclosure.

[0037] The reference numerals in the figures are as follows: substrate 10; planarization layer PLN; pixel definition layer PDL; anode; cathode; light-emitting layer EL; annular groove 20; first groove 201; second groove 202; third groove 203; fourth groove 204; first sidewall 20a; second sidewall 20b; edge 11 of the first electrode; first inorganic encapsulation layer CVD1; organic encapsulation layer IJP; second inorganic encapsulation layer CVD2. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0039] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0040] In this disclosure, "multiple or several" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In related technologies, anode warpage is one of the important causes of short circuits between the anode and cathode. Figure 1 This is a schematic diagram illustrating the dark spots caused by anode edge warping in related technologies, such as... Figure 1 As shown, an anode is fabricated on a planarization layer, and then a stripping process is performed on the anode. At this point, because the adhesion between the edge of the anode and the planarization layer is lower than that at other locations, the high-pressure water washing process during stripping makes it easier for the edge of the anode to detach from the planarization layer, resulting in warping and causing dark spots. Subsequently, the pixel definition layer HPDL, the emitting layer EL, and the cathode are fabricated sequentially. Because the edge of the anode detaches from the planarization layer and warps, a short circuit can easily occur between the cathode and the anode.

[0042] Based on this, in a first aspect, this disclosure specifically provides a display substrate that substantially eliminates one or more of the problems caused by the limitations and defects of related technologies. Figure 2 This is a cross-sectional view of the anode in a display substrate provided in an embodiment of the present disclosure. Figure 3 A top view of a flat layer provided in an embodiment of this disclosure; as shown Figure 2 and Figure 3As shown, the display substrate includes a substrate 10, a planarization layer PLN disposed on the substrate 10, and a light-emitting device disposed on the side of the planarization layer PLN facing away from the substrate 10. The light-emitting device includes a first electrode, a light-emitting layer EL, and a second electrode sequentially disposed on the side of the planarization layer PLN facing away from the substrate 10. The side of the planarization layer PLN facing away from the substrate 10 has an annular groove 20; the edge of the first electrode is located within the annular groove 20. This embodiment of the present disclosure uses the first electrode as the anode of the light-emitting device and the second electrode as the cathode of the light-emitting device as an example for explanation.

[0043] This embodiment of the present disclosure increases the adhesion of the anode edge 11 to the planarization layer PLN by forming an annular groove 20 on the planarization layer PLN and then depositing the edge film layer of the anode in the annular groove 20, thereby preventing the anode from warping and thus avoiding the occurrence of dark spots as described above in the related art.

[0044] It should be noted that even if high-pressure water washing damages the film layer at the edge of the anode, the damaged part is not enough to warp to the point of short-circuiting with the cathode because the edge 11 of the anode has already been deposited in the annular groove 20, thus avoiding the occurrence of dark spots.

[0045] In some examples, the outline of the annular groove 20 can be rectangular, but it can also be other shapes, such as ellipse or circle. In this embodiment, only a rectangular outline of the annular groove 20 is used as an example. In this embodiment, a plurality of pixel units are arranged in an array on the display substrate, wherein the row direction of the array arrangement is the first direction X, and the column direction of the array arrangement is the second direction Y.

[0046] like Figure 2 As shown, the annular groove 20 includes a first sidewall 20a and a second sidewall 20b. The width of the annular groove 20 can be set according to the size of the first electrode in the first direction or according to the size of the first electrode in the second direction.

[0047] The annular groove 20 includes a first groove portion 201 and a second groove portion 202 disposed opposite to each other along a first direction. For example... Figure 3As shown, the first groove 201 and the second groove 202 are rectangular sub-recesses arranged opposite each other along the first direction X. The width W1 of the first groove 201 and the width W2 of the second groove 202 are equal; the ratios of the widths W1 of the first groove 201 and W2 of the second groove 202 to the maximum width W12 of the second sidewall 20b of the annular groove 20 in the first direction are both between 0.045 and 0.055. Here, the maximum width W12 can be considered as the maximum width of the anode in the first direction X. For example, given the dimensions of the anode, the widths W1 of the first groove 201 and W2 of the second groove 202 are set as the maximum width W12 of the anode in the first direction X.

[0048] The annular groove 20 includes a third groove portion 203 and a fourth groove portion 204 disposed opposite to each other along the second direction. For example... Figure 3 As shown, the third groove 203 and the fourth groove 204 are rectangular sub-recesses arranged opposite each other along the second direction Y. The width W3 of the third groove 203 and the width W4 of the fourth groove 204 are equal; the ratios of the widths W3 of the third groove 203 and W4 of the fourth groove 204 to the maximum width W34 of the second sidewall 20b of the annular groove 20 in the second direction Y are both between 0.045 and 0.055. Here, the maximum width W34 can be considered as the maximum width of the anode in the second direction X. For example, given the dimensions of the anode, the widths W3 of the third groove 203 and W4 of the fourth groove 204 are set as the maximum width W34 of the anode in the second direction Y.

[0049] Alternatively, the width of the annular groove 20 can be set to the maximum width of the first electrode in the first direction X. That is to say Alternatively, the width of the annular groove 20 can be set to the maximum width of the first electrode in the second direction Y. That is to say

[0050] In some embodiments, to mitigate damage to the first electrode caused by the strip process, the orthographic projection of the edge 11 of the first electrode onto the substrate 10 covers the orthographic projection of the annular groove 20 onto the substrate 10. That is, the edge 11 of the first electrode completely fills the bottom of the annular groove 20, such that the boundary of the first electrode abuts against the second sidewall 20b of the annular groove 20, thereby mitigating damage to the first electrode caused by the strip process.

[0051] In some embodiments, the depth of the annular groove 20 can be set to be greater than or equal to the thickness of the first electrode. Wherein, if the depth of the annular groove 20 is equal to or approximately equal to the thickness of the first electrode, the current depth of the annular groove 20 can be considered shallow. In this case, the edge 11 of the first electrode can completely fill the bottom of the annular groove 20 to reduce the damage to the first electrode caused by the strip process.

[0052] The depth of the annular groove 20 can be set according to the size of the first electrode in the first direction or according to the size of the first electrode in the second direction. Figure 4 An anode cross-sectional view with a relatively deep annular groove, provided for an embodiment of this disclosure, such as... Figure 4 As shown, the annular groove 20 includes a first sidewall 20a and a second sidewall 20b.

[0053] The annular groove 20 includes a first groove portion 201 and a second groove portion 202 arranged opposite each other along the first direction X; the depth H1 of the first groove portion 201 and the depth H2 of the second groove portion 202 are the same; the depth H1 of the first groove portion 201 and the depth H2 of the second groove portion 202 are both greater than the thickness of the first electrode, and the ratio of the depth H1 of the first groove portion 201 and the depth H2 of the second groove portion 202 to the maximum width W12 of the second sidewall 20b of the annular groove 20 in the first direction X is between 0.062 and 0.073. Here, the maximum width W12 can be considered as the maximum width of the anode in the first direction X. For example, given the dimensions of the anode, the depth H1 of the first groove portion 201 and the depth H2 of the second groove portion 202 are set as the maximum width W12 of the anode in the first direction X.

[0054] The annular groove 20 includes a third groove 203 and a fourth groove 204 disposed opposite to each other along the second direction Y; the depth H3 of the third groove 203 and the depth H4 of the fourth groove 204 are the same; the depth H3 of the third groove 203 and the depth H4 of the fourth groove 204 are both greater than the thickness of the first electrode, and the ratio of the depth H3 of the third groove 203 and the depth H4 of the fourth groove 204 to the maximum width W34 of the second sidewall 20b of the annular groove 20 in the second direction Y is between 0.062 and 0.073. Here, the maximum width W34 can be considered as the maximum width of the anode in the second direction X. For example, given the dimensions of the anode, the depth H3 of the third groove 203 and the depth H4 of the fourth groove 204 are set as the maximum width W34 of the anode in the second direction Y.

[0055] Alternatively, the depth of the annular groove 20 can be set to the maximum width of the first electrode in the first direction X. That is to say Alternatively, the depth of the annular groove 20 can be set to the maximum width of the first electrode in the second direction Y. That is to say

[0056] In some embodiments, the orthographic projection of the edge 11 of the first electrode onto the substrate 10 covers a portion of the orthographic projection of the annular groove 20 onto the substrate 10. In this case, a deeper annular groove 20 can be provided. One example is... Figure 4 As shown, the edge 11 of the anode is deposited at the junction of the annular groove 20 and the first sidewall 20a. During the strip process, the removal of photoresist from the anode surface will no longer exert an impact force on the edge 11 that would cause it to warp; instead, it will only increase the adhesion between the edge film and the planarization layer PLN, thus preventing the occurrence of dark spots. Another scenario... Figure 5 Another anode cross-sectional view with a deeper annular groove depth provided for embodiments of this disclosure, such as... Figure 5 As shown, the edge 11 of the anode is deposited in the annular groove 20 and covers part of the bottom of the pit. During the strip process, the use of deeper pits can reduce the damage to the anode caused by the stripping photoresist. Even if warping occurs, it will not reach the level of producing dark spots. Therefore, the occurrence of dark spots can be avoided.

[0057] In some embodiments, such as Figure 2 , Figure 4 or Figure 5 As shown, the planarization layer PLN includes a first surface and a second surface disposed opposite to each other along a third direction Z, with the first surface being closer to the substrate 10 than the second surface. The second surface includes a first sub-surface and a second sub-surface disposed opposite to each other along a first direction, a third sub-surface connected to the first sub-surface and the second sub-surface respectively, a fourth sub-surface on the side away from the substrate 10 and connected to the first sub-surface, and a fifth sub-surface on the side away from the substrate 10 and connected to the second sub-surface.

[0058] The dihedral angle formed between the second and fifth sub-surfaces is rounded or flat. This method of setting rounded or flat chamfers to achieve a smooth transition of the anode can reduce stress concentration at the bending point of the anode and effectively protect the anode.

[0059] In some embodiments, continue as follows Figure 2 , Figure 4 or Figure 5As shown, the display substrate also includes a pixel definition layer (PDL); the pixel definition layer (PDL) includes a first sub-definition layer and a second sub-definition layer; the first sub-definition layer is disposed on the side of the planarization layer (PLN) facing away from the substrate 10; the second sub-definition layer is disposed on the side of the first electrode facing away from the substrate 10. The orthographic projection of the pixel definition layer (PDL) on the substrate 10 covers the orthographic projection of the annular groove 20 on the substrate 10.

[0060] After the first electrode is fabricated on the planarization layer PLN, a pixel definition layer PDL is fabricated on the side of the planarization layer PLN and the first electrode facing away from the substrate 10. Part of the film layer in the pixel definition layer PDL covers the planarization layer PLN, part of the film layer covers the edge 11 of the first electrode (i.e., the first electrode located within the annular groove 20), and part of the film layer covers the portion of the electrode connected to the edge 11 of the first electrode, thus defining a pixel region. The pixel region is used to fabricate the light-emitting layer EL and the second electrode of the light-emitting device. Specifically, the light-emitting layer EL and the second electrode are sequentially disposed on the side of the pixel definition layer PDL and the first electrode layer facing away from the substrate 10.

[0061] In some embodiments, a pixel driving circuit is disposed on the side of the planarization layer PLN close to the substrate 10, and the pixel driving circuit is electrically connected to the light-emitting device. Specifically, the first electrode (i.e., the anode) of the light-emitting device is electrically connected to the driving thin-film transistor T2 in the pixel driving circuit through a via through the planarization layer PLN. The driving thin-film transistor T2 is used to drive the light-emitting device to emit light.

[0062] Taking a pixel driving circuit with a 2T1C structure (i.e., two thin-film transistors and one capacitor) as an example, the pixel driving circuit includes a switching thin-film transistor T1 for switching control and a driving thin-film transistor T2 for pixel driving. The drain of the switching thin-film transistor T1 is electrically connected to the gate of the driving thin-film transistor T2 and the first plate of the storage capacitor Cst; the source of the driving thin-film transistor T2 is electrically connected to the first power signal line Vdd to receive the power signal; the drain of the driving thin-film transistor T2 is electrically connected to the first electrode (i.e., the anode) of the light-emitting device to drive the light-emitting device to emit light. Specifically, the anode of the light-emitting device is electrically connected to the drain of the driving thin-film transistor in the pixel driving circuit through a first via through the planarization layer PLN; the second electrode (i.e., the cathode) of the light-emitting device and the second plate of the storage capacitor Cst are respectively electrically connected to the second power signal line Vss.

[0063] This concludes the introduction of the display substrate according to the embodiments of this disclosure.

[0064] The display substrate provided in this embodiment increases the adhesion of the anode edge 11 to the planarization layer PLN by forming an annular groove 20 on the planarization layer PLN and then depositing the edge film layer of the anode in the annular groove 20, thereby preventing the anode from warping and avoiding the occurrence of dark spots as described above in the related art.

[0065] Secondly, based on the same inventive concept, the present disclosure also provides a method for preparing a display substrate, firstly forming a substrate 10 and forming a planarization layer PLN on the substrate 10; then, forming an annular groove 20 on the side of the planarization layer PLN away from the substrate 10; then, sequentially forming a first electrode of a light-emitting device, a light-emitting layer EL, and a second electrode on the side of the planarization layer PLN away from the substrate 10; wherein, when forming the first electrode, the edge 11 of the first electrode is deposited in the annular groove 20.

[0066] In some embodiments, a light-emitting device is fabricated, specifically, a first electrode is formed on the side of the planarization layer PLN facing away from the substrate 10. A first sub-definition layer is formed on the side of the planarization layer PLN facing away from the substrate 10, and a second sub-definition layer is formed on the side of the first electrode facing away from the substrate 10. The first and second sub-definition layers are an integral structure. The integral first and second sub-definition layers are used as a pixel definition layer PDL. The orthographic projection of the pixel definition layer PDL on the substrate 10 covers the orthographic projection of the annular groove 20 on the substrate 10. On the side of the pixel definition layer PDL and the first electrode facing away from the substrate 10, the light-emitting layer EL and the second electrode of the light-emitting device are sequentially formed.

[0067] The following section uses different depths of the annular groove 20 as examples to illustrate the fabrication process of the display substrate.

[0068] Figures 6a to 6f This is a schematic diagram of the fabrication process of a display substrate with a shallow annular groove depth provided in an embodiment of the present disclosure. Specifically, as shown... Figure 6a As shown, a substrate 10 is first formed, and the pixel driving circuit (not shown in the figure) is fabricated on the substrate 10. Then, a polyimide (PI) organic film layer is formed on the substrate 10. The planarization layer PLN can be formed using only a mask process, such as exposure and development. Figure 6b As shown, a corresponding mask is fabricated to form a shallow recess, i.e., an annular groove 20, at the edge of the anode forming area. Figure 6c As shown, in Figure 6bThe first electrode (i.e., the anode) is fabricated on a planarization layer PLN. First, the anode material layer on the PLN is patterned, and then a stripping photoresist process is performed on the anode to obtain the anode. For example... Figure 6d As shown, a pixel definition layer (PDL) is formed on the planarization layer PLN, wherein a first sub-definition layer covers the planarization layer PLN, and a second sub-definition layer covers a portion of the electrode of the anode, which includes at least the edge 11 of the anode deposited within the annular groove 20. Figure 6e As shown, on the side of the pixel definition layer (PDL) and the anode facing away from the substrate 10, the light-emitting layer (EL) and the second electrode (i.e., the cathode) of the light-emitting device are sequentially deposited. Figure 6f As shown, an encapsulation layer is formed on the side of the cathode away from the substrate 10; the encapsulation layer includes a first inorganic encapsulation layer CVD1, an organic encapsulation layer IJP, and a second inorganic encapsulation layer CVD2, which are sequentially located away from the substrate 10.

[0069] Figures 7a to 7f This is a schematic diagram illustrating the fabrication process of a display substrate with a relatively deep annular groove, provided in an embodiment of this disclosure. Specifically, as shown... Figure 7a As shown, a substrate 10 is first formed, and the pixel driving circuit (not shown in the figure) is fabricated on the substrate 10. Then, a polyimide (PI) organic film layer is formed on the substrate 10. The planarization layer PLN can be formed using only a mask process, such as exposure and development. Figure 7b As shown, a corresponding mask is fabricated to form a deep recess, namely the annular groove 20, at the edge of the anode forming area. Figure 7c As shown, in Figure 7b The first electrode (i.e., the anode) is fabricated on a planarization layer PLN. First, the anode material layer on the PLN is patterned, and then a stripping photoresist process is performed on the anode to obtain the anode. For example... Figure 7d As shown, a pixel definition layer (PDL) is formed on the planarization layer PLN. A first sub-definition layer covers the planarization layer PLN, and a second sub-definition layer covers a portion of the anode electrode, including at least the edge 11 of the anode deposited within the annular groove 20. In this case, the pixel definition layer (PDL) and the anode edge 11 can completely fill the annular groove 20. Figure 7e As shown, on the side of the pixel definition layer (PDL) and the anode facing away from the substrate 10, the light-emitting layer (EL) and the second electrode (i.e., the cathode) of the light-emitting device are sequentially deposited. Figure 7fAs shown, an encapsulation layer is formed on the side of the cathode away from the substrate 10; the encapsulation layer includes a first inorganic encapsulation layer CVD1, an organic encapsulation layer IJP, and a second inorganic encapsulation layer CVD2, which are sequentially located away from the substrate 10.

[0070] Thirdly, embodiments of this disclosure also provide a display device, which includes the display substrate described in any of the above embodiments.

[0071] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A display substrate, comprising a substrate, a planarization layer disposed on the substrate, and a light-emitting device disposed on a side of the planarization layer opposite to the substrate; the light-emitting device comprising a first electrode, a light-emitting layer, and a second electrode sequentially disposed on the side of the planarization layer opposite to the substrate; the display substrate further comprising a pixel definition layer disposed on the side of the planarization layer opposite to the substrate; the first electrode being disposed between the planarization layer and the pixel definition layer; the adhesion between the edge of the first electrode and the planarization layer being lower than the adhesion between the middle region of the first electrode and the planarization layer; The planarization layer has an annular groove on the side opposite to the substrate; the edge of the first electrode is located in the annular groove, the annular groove includes a first sidewall and a second sidewall, and the boundary of the first electrode abuts against the second sidewall of the annular groove; the orthographic projection of the pixel definition layer on the substrate covers the orthographic projection of the annular groove on the substrate.

2. The display substrate according to claim 1, wherein, The depth of the annular groove is greater than or equal to the thickness of the first electrode.

3. The display substrate according to claim 1, wherein, The annular groove includes a first sidewall and a second sidewall; The annular groove includes a first groove and a second groove disposed opposite to each other along a first direction; the width of the first groove and the width of the second groove are equal; the ratio of the width of the first groove and the width of the second groove to the maximum width of the second sidewall of the annular groove in the first direction is between 0.045 and 0.

055. The annular groove includes a third groove and a fourth groove disposed opposite to each other along a second direction; the width of the third groove and the width of the fourth groove are equal; the ratio of the width of the third groove and the width of the fourth groove to the maximum width of the second sidewall of the annular groove in the second direction is between 0.045 and 0.

055.

4. The display substrate according to claim 3, wherein, The orthographic projection of the edge of the first electrode onto the substrate covers the orthographic projection of the annular groove onto the substrate.

5. The display substrate according to claim 2, wherein, The annular groove includes a first sidewall and a second sidewall; The annular groove includes a first groove and a second groove disposed opposite to each other along a first direction; the depth of the first groove and the depth of the second groove are the same; the depth of the first groove and the depth of the second groove are both greater than the thickness of the first electrode, and the ratio of the depth of the first groove and the depth of the second groove to the maximum width of the second sidewall of the annular groove in the first direction is between 0.062 and 0.

073. The annular groove includes a third groove and a fourth groove disposed opposite to each other along a second direction; the depth of the third groove and the depth of the fourth groove are the same; the depth of the third groove and the depth of the fourth groove are both greater than the thickness of the first electrode, and the ratio of the depth of the third groove and the depth of the fourth groove to the maximum width of the second sidewall of the annular groove in the second direction is between 0.062 and 0.

073.

6. The display substrate according to claim 5, wherein, The orthographic projection of the edge of the first electrode onto the substrate covers a portion of the orthographic projection of the annular groove onto the substrate.

7. The display substrate according to claim 1, wherein, The planarization layer includes a first surface and a second surface disposed opposite to each other along a third direction, wherein the first surface is closer to the substrate than the second surface; The second surface includes a first sub-surface and a second sub-surface disposed opposite to each other along a first direction, a third sub-surface connected to the first sub-surface and the second sub-surface respectively, a fourth sub-surface on the side away from the substrate and connected to the first sub-surface, and a fifth sub-surface on the side away from the substrate and connected to the second sub-surface. The dihedral angle formed between the second sub-surface and the fifth sub-surface is either a rounded chamfer or a flat chamfer.

8. The display substrate according to claim 1, wherein, The pixel definition layer includes a first sub-definition layer and a second sub-definition layer; the first sub-definition layer is disposed on the side of the planarization layer opposite to the substrate; the second sub-definition layer is disposed on the side of the first electrode opposite to the substrate.

9. The display substrate according to claim 8, wherein, The light-emitting layer and the second electrode are sequentially disposed on the side of the pixel definition layer and the first electrode layer away from the substrate.

10. A method for preparing a display substrate, wherein, include: A substrate is formed, and a planarization layer is formed on the substrate; An annular groove is formed on the side of the planarization layer opposite to the substrate. A first electrode of a light-emitting device is formed on the side of the planarization layer opposite to the substrate; wherein the edge of the first electrode is located within the annular groove; the adhesion between the edge of the first electrode and the planarization layer is lower than the adhesion between the middle region of the first electrode and the planarization layer; the annular groove includes a first sidewall and a second sidewall, and the boundary of the first electrode abuts against the second sidewall of the annular groove. A pixel definition layer is formed on the side of the first electrode opposite to the substrate; wherein the orthographic projection of the pixel definition layer on the substrate covers the orthographic projection of the annular groove on the substrate. On the side of the pixel definition layer opposite to the first electrode, the light-emitting layer and the second electrode of the light-emitting device are formed sequentially.

11. The method for preparing a display substrate according to claim 10, wherein, The first electrode, the light-emitting layer, and the second electrode of the light-emitting device are sequentially formed on the side of the planarization layer opposite to the substrate, including: The first electrode is formed on the side of the planarization layer opposite to the substrate. A first sub-definition layer is formed on the side of the planarization layer opposite to the substrate, and a second sub-definition layer is formed on the side of the first electrode opposite to the substrate. The first sub-definition layer and the second sub-definition layer are an integral structure. The integral first sub-definition layer and the second sub-definition layer are used as pixel definition layers. The orthographic projection of the pixel definition layer on the substrate covers the orthographic projection of the annular groove on the substrate. On the side of the pixel definition layer and the first electrode opposite to the substrate, the light-emitting layer and the second electrode of the light-emitting device are formed sequentially.

12. A display device, wherein, Includes the display substrate as described in any one of claims 1 to 9.

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