Display panel, preparation method thereof and display device

Abstract

The embodiment of the invention provides a display panel, a preparation method thereof and a display device. The display panel comprises a driving substrate and a plurality of light-emitting elements, the driving substrate comprises a pixel defining layer; the light-emitting element comprises a first electrode, a light-emitting layer and a second electrode which are stacked, and the second electrode is located on the side, away from the driving substrate, of the light-emitting layer in the first direction; the pixel defining layer comprises a plurality of pixel openings and a pixel defining structure surrounding the pixel openings, and the pixel openings expose part of the first electrode; the pixel limiting structure comprises a side wall close to one side of the pixel opening, the display panel further comprises an undercut structure which is located in the pixel limiting structure and penetrates through at least partial area of the side wall, the depth of the undercut structure in the first direction is L1, and the thickness of the light-emitting layer in the first direction is L2; wherein L1 is greater than or equal to L2. By arranging the undercut structure and adjusting the position and depth of the undercut structure, the situation of transverse flow leakage of the display panel can be reduced or avoided, and the display effect of the display panel is improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of display technology, and in particular to a display panel and a manufacturing method thereof, and a display device. Background Art

[0002] With the continuous development of display technology, display panels have been widely used in people's production and life. In order to better meet people's needs, the display panel can be adjusted, for example, some film layers in the display panel can be adjusted to improve the overall effect of the display panel. Summary of the invention

[0003] Embodiments of the present invention provide a display panel and a method for manufacturing the same, and a display device. An undercut structure is provided in a pixel defining structure and at least partially through a side wall, which can reduce lateral leakage of the display panel and improve the display effect of the display panel.

[0004] In a first aspect, an embodiment of the present invention provides a display panel, including a driving substrate and a plurality of light-emitting elements;

[0005] The driving substrate includes a pixel defining layer;

[0006] The light emitting element comprises a first electrode, a light emitting layer and a second electrode which are stacked, and the second electrode is located on a side of the light emitting layer away from the driving substrate along a first direction; the first direction is a thickness direction of the display panel;

[0007] The pixel defining layer includes a plurality of pixel openings and a pixel defining structure surrounding the pixel openings, wherein the pixel openings expose a portion of the first electrode;

[0008] The pixel defining structure includes a side wall close to one side of the pixel opening, and the display panel also includes an undercut structure located in the pixel defining structure and penetrating at least a portion of the side wall, the depth of the undercut structure in the first direction is L1, and the thickness of the light-emitting layer in the first direction is L2; ​​wherein L1≥L2.

[0009] In a second aspect, an embodiment of the present invention provides a method for manufacturing a display panel, comprising:

[0010] Prepare a driving substrate, wherein the driving substrate includes a pixel defining layer, and the pixel defining layer covers the first electrode of the light emitting element;

[0011] The pixel defining layer is patterned to form a pixel opening, an undercut structure, and a pixel defining structure in the pixel defining layer; the pixel opening exposes a portion of the first electrode; the pixel defining structure surrounds the pixel opening and includes a sidewall close to one side of the pixel opening; the undercut structure is located in the pixel defining structure and penetrates at least a portion of the sidewall and is connected to the pixel opening;

[0012] A light-emitting layer and a second electrode of the light-emitting element are prepared, wherein the light-emitting layer at least covers the pixel opening, and along a first direction, the second electrode is located on a side of the light-emitting layer away from the driving substrate; the depth of the undercut structure in the first direction is L1, and the thickness of the light-emitting layer in the first direction is L2, L1≥L2; the first direction is the thickness direction of the display panel.

[0013] In a third aspect, an embodiment of the present invention provides a display device, comprising the display panel described in the first aspect.

[0014] An embodiment of the present invention provides a display panel, wherein a pixel defining layer of the display panel includes a plurality of pixel openings and a pixel defining structure, wherein the pixel opening can expose a portion of the first electrode in the light-emitting element; further, the pixel defining structure also includes a sidewall near the pixel opening, and the display panel also includes an undercut structure, the undercut structure is located in the pixel defining structure and penetrates at least a portion of the sidewall, and along the thickness direction of the display panel, the depth of the undercut structure is higher than the depth of the light-emitting layer in the light-emitting element. By setting the undercut structure, and the depth of the undercut structure is greater than the depth of the light-emitting layer in the light-emitting element, at least a portion of the film layers in the light-emitting layers of different light-emitting elements can be disconnected at the undercut structure, thereby avoiding or reducing the leakage transmission of holes or electrons between different light-emitting elements, thereby avoiding the situation of crosstalk between different light-emitting elements, and thereby ensuring the overall display effect of the display panel.

[0015] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required to describe the embodiments. Obviously, the drawings introduced are only drawings of a part of the embodiments to be described in the present invention, rather than all the drawings. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1is a schematic structural diagram of a first display panel provided by an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 A schematic diagram of a first cross section along the section line A-A';

[0019] Figure 3 yes Figure 2 An enlarged schematic diagram of a middle pixel opening;

[0020] Figure 4 is a schematic structural diagram of a light-emitting element provided by an embodiment of the present invention;

[0021] Figure 5 yes Figure 1 A schematic diagram of a first cross section along the section line BB';

[0022] Figure 6 yes Figure 1 A schematic diagram of the first cross section along the section line C-C';

[0023] Figure 7 is a comparison diagram of different light-emitting elements provided by an embodiment of the present invention;

[0024] Figure 8 yes Figure 1 A schematic diagram of a first cross section along the section line D-D';

[0025] Fig. 9 is a schematic top view of a display panel provided by an embodiment of the present invention;

[0026] Fig.10 yes Figure 1 A schematic diagram of a first cross section along the section line F-F';

[0027] Fig.11 is a schematic diagram of a first method for preparing a display panel provided by an embodiment of the present invention;

[0028] Fig.12 is a schematic diagram of a second method for manufacturing a display panel provided by an embodiment of the present invention;

[0029] Fig.13 is a schematic diagram of a first display panel manufacturing process provided by an embodiment of the present invention;

[0030] Fig.14 is a schematic diagram of a third method for manufacturing a display panel provided by an embodiment of the present invention;

[0031] Fig.15 is a schematic diagram of a second display panel manufacturing process provided by an embodiment of the present invention;

[0032] Fig.16A schematic diagram of a fourth method for manufacturing a display panel provided by an embodiment of the present invention;

[0033] Fig.17 is a schematic diagram of steps in a display panel manufacturing process provided by an embodiment of the present invention;

[0034] Fig.18 is a schematic diagram of steps in another display panel manufacturing process provided by an embodiment of the present invention;

[0035] Fig.19 A schematic diagram of a fifth method for manufacturing a display panel provided by an embodiment of the present invention;

[0036] Fig. 20 is a schematic diagram of a third display panel manufacturing process provided by an embodiment of the present invention;

[0037] Fig.21 It is a structural schematic diagram of a display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0039] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a system, product or device comprising a series of units is not necessarily limited to those steps or units clearly listed, but may include other units that are not clearly listed or inherent to these products or devices.

[0040] Figure 1 is a schematic structural diagram of a first display panel provided by an embodiment of the present invention, Figure 2 yes Figure 1 The first cross-sectional diagram along the section line A-A' is shown in FIG. Figure 3 yes Figure 2 An enlarged schematic diagram of the pixel opening in the middle, Figure 4 is a schematic diagram of the structure of a light emitting element provided by an embodiment of the present invention, with reference to Figures 1 to 4As shown, an embodiment of the present invention provides a display panel 10, which includes a driving substrate 100 and a plurality of light-emitting elements 200; the driving substrate 100 includes a pixel defining layer 110; the light-emitting element 200 includes a first electrode 210, a light-emitting layer 220 and a second electrode 230 which are stacked, and along a first direction X1, the second electrode 230 is located on a side of the light-emitting layer 220 away from the driving substrate 100; the first direction X1 is a thickness direction of the display panel 10; the pixel defining layer 110 includes a plurality of pixel openings 110a and a pixel defining structure 111 surrounding the pixel openings 110a, and the pixel openings 110a expose a portion of the first electrode 210; the pixel defining structure 111 includes a side wall 111a close to one side of the pixel opening 110a, and the display panel 10 also includes an undercut structure 112 located in the pixel defining structure 111 and penetrating at least a portion of the side wall 111a, the depth of the undercut structure 112 in the first direction X1 is L1, and the thickness of the light-emitting layer 220 in the first direction X1 is L2; ​​wherein L1≥L2.

[0041] Among them, reference Figure 1 As shown, the display panel 10 includes a driving substrate 100 and a plurality of light-emitting elements 200. The driving substrate 100 can drive the light-emitting elements 200 to perform light-emitting display, thereby achieving the display effect of the display panel 10. Further, the plurality of light-emitting elements 200 can have light-emitting elements 200 of different colors, such as red light-emitting elements, blue light-emitting elements, green light-emitting elements, and white light-emitting elements, etc. By driving the light-emitting elements 200 of different colors to perform light-emitting display, the color display effect of the display panel 10 can be achieved. There are also various arrangements of the plurality of light-emitting elements 200 of different colors in the display panel 10, and the embodiments of the present invention will not illustrate them one by one.

[0042] For further reference, Figure 2 and Figure 3 As shown, the light emitting element 200 includes a first electrode 210, a light emitting layer 220 and a second electrode 230 which are stacked, wherein the first electrode 210 is located on a side of the light emitting layer 220 close to the driving substrate 100, and the light emitting layer 220 is located between the first electrode 210 and the second electrode 230. Figure 3As shown, the light-emitting layer 220 may include a plurality of film layers. Along the direction from the first electrode 210 to the second electrode 230, the light-emitting layer 220 may be, in sequence: a hole injection layer (Hole Injection Layer, HIL) 221, a hole transport layer (HTL) 222, a compensation layer (Prime) 223, a light-emitting film layer (Emitting Layer, EML) 224, a hole blocking layer (Hole Block Layer, HBL) 225, an electron transport layer (Electron Transport Layer, ETL) 226, and an electron injection layer (Electron Inject Layer, EIL) 227. Among them, corresponding to the light-emitting elements 200 of different colors, the compensation layer 223 includes a red compensation layer (R-Prime), a blue compensation layer (B-Prime) and a green compensation layer (G-Prime), etc., which are respectively used to adjust the cavity length of each light-emitting element 200, and then adjust the optical performance. The light-emitting film layer 224 includes a red light-emitting layer (R-EML), a blue light-emitting layer (B-EML) and a green light-emitting layer (G-EML), so as to achieve light-emitting effects of different colors of the light-emitting element 200. The compensation layer 223 and the light-emitting film layer 224 are stacked, and the side walls can be aligned. Specifically, the light-emitting principle of the light-emitting element 200 can be understood as follows: a certain voltage is applied to the first electrode 210 and the second electrode 230 respectively, holes from the first electrode 210 are injected into the hole transport layer 222 through the hole injection layer 221, and electrons from the second electrode 230 are injected into the electron transport layer 226 through the electron injection layer 227, and holes and electrons migrate to the light-emitting film layer 224 through the hole transport layer 222 and the electron transport layer 226 respectively, and form excitons in the light-emitting film layer 224, and the excitons excite the light-emitting molecules in the light-emitting film layer 224 to emit light. Among them, the hole blocking layer 225 is used to block holes from passing through the light-emitting film layer 224 and entering the electron transport layer 226, so that holes and electrons are combined in the light-emitting film layer 224 to form excitons.

[0043] Optionally, the display panel 10 may also be a tandem display panel (Tandem OLED), that is, the light-emitting element 200 is a stacked light-emitting element, and the display panel 10 that uses the stacked light-emitting element to emit light is called a tandem display panel, that is, multiple light-emitting layers are stacked in series through a charge generation layer (CGL) in the light-emitting element 200. Among them, the tandem display panel can enable the light-emitting element 200 to be driven at the same current density, so that the brightness of the display panel 10 is greatly improved. Specifically, when multiple light-emitting film layers 224 are connected in series in the light-emitting element 200 of the tandem display panel, for example, when two light-emitting film layers 224 are connected in series, the voltage of the second electrode 230 applied will become twice, the current efficiency will also become twice, and the constant current life decay is consistent, so the corresponding constant brightness life will be more than doubled, the potential for life improvement is greater, and the power consumption is also advantageous.

[0044] Specifically, when the display panel 10 is a tandem display panel, Figure 4 As shown, multiple film layers are stacked in sequence, and a charge generation layer 240 that can be electrically connected is provided between the film layers. Figure 4 In the figure, two charge generation layers 240 are used as an example. Further, Figure 4 A schematic diagram of the structure of a light-emitting element 200 in a tandem display panel 10 is shown. Along the direction from the first electrode 210 to the second electrode 230, the film structure may be a hole injection layer 221, a hole transport layer 222, a compensation layer 223, a light-emitting film layer 224, a hole blocking layer 225, an electron transport layer 226, two charge generation layers 240, a hole transport layer 222, a compensation layer 223, a light-emitting film layer 224, an electron transport layer 226 and an electron injection layer 227. Among them, the charge generation layer 240 may include a P-type charge generation layer (CGL-P) and an N-type charge generation layer (CGL-N), which are used to generate holes and electrons, respectively, and a light-emitting film layer 224 is provided between the electron transport layer 226 and the hole transport layer 222. It should be noted that, Figure 3 and Figure 4 In the embodiment, the light-emitting film layer 224 in the light-emitting element 200 can be a light-emitting layer of red light, a light-emitting layer of blue light, or a light-emitting layer of green light, which is not specifically limited in the embodiment of the present invention. Further, the light-emitting element 200 in the display panel 10 can also include a light-emitting layer of red light, a light-emitting layer of blue light, and a light-emitting layer of green light, and finally display white light, etc.

[0045] The light emitting element 200 in the display panel 10 provided in the embodiment of the present invention may be as follows: Figure 3 The light emitting element 200 shown may also be Figure 4The light emitting element 200 shown in the figure does not specifically limit the specific structure of the light emitting element 200 in the embodiment of the present invention, and the film layer in the light emitting element 200 can be adaptively adjusted according to different actual requirements.

[0046] For further reference, Figure 2 and Figure 3 As shown, the driving substrate 100 in the display panel 10 further includes a pixel defining layer 110, and the pixel defining layer 110 includes a plurality of pixel openings 110a, and the pixel openings 110a are used to expose a portion of the first electrode 210, and the exposed first electrode 210 can be understood as the setting area of ​​the light-emitting element 200, that is, the pixel opening 110a defines the size of the light-emitting element 200. Further, the pixel defining layer 110 further includes a pixel defining structure 111, and the pixel defining structure 111 is arranged around the pixel opening 110a.

[0047] Specifically, refer to Figure 2 and Figure 3 As shown, the pixel defining structure 111 further includes a side wall 111a close to the pixel opening 110a, and the side wall 111a corresponds to the edge cutoff position of the pixel defining structure 111. The edge cutoff positions of two adjacent pixel defining structures 111 correspond to the pixel opening 110a. Figure 2 and Figure 3 As shown, the display panel 10 is further provided with an undercut structure 112, which is located in the pixel defining structure 111 and penetrates at least a part of the area of ​​the side wall 111a, that is, it can be understood that the pixel defining structure 111 has a break area near the pixel opening 110a or near the light-emitting layer 220, so that the light-emitting layer 220 arranged on the side of the first electrode 210 away from the driving substrate 100 can be ensured to be disconnected at the undercut structure 112, so that the leakage transmission of holes or electrons between different light-emitting elements 200 can be avoided, thereby avoiding the situation of crosstalk between different light-emitting elements 200, thereby ensuring the display effect of the display panel 10. Alternatively, the light-emitting layer 220 is not disconnected at the undercut structure 112, but the area at the undercut structure 112 is filled, so that the transmission path of the light-emitting layer 220 is increased, and the leakage transmission of holes or electrons between different light-emitting elements 200 can also be reduced, thereby improving the overall display effect of the display panel 10.

[0048] It should be noted that the light-emitting layer 220 is disconnected at the undercut structure 112, which may be that at least part of the film layers in the light-emitting layer 220 are disconnected, for example, only the hole injection layer 221 and the hole transport layer 222 are disconnected. For the disconnection of the specific film layers in the light-emitting layer 220 at the undercut structure 112, the process can be adjusted according to different requirements to achieve different film layer disconnection conditions.

[0049] Further, combined with Figure 4 As shown, when the display panel 10 is a series display panel, the voltage of the second electrode 230 at the light-emitting element 200 will be doubled, so the display panel will generate a larger leakage current, resulting in more serious light leakage between different light-emitting elements 200. Therefore, by providing the undercut structure 112, the leakage transmission of holes or electrons between different light-emitting elements 200 can be effectively reduced or avoided, thereby ensuring the overall display effect of the display panel 10.

[0050] Optionally, if the display panel 10 is displayed at low grayscale brightness or driven by a small driving voltage, since the transmitted voltage and current are small, if there is leakage current, it will have a greater impact on the display effect of the display panel 10. Therefore, by setting the bottom cut structure 112, the generation of leakage current between different light-emitting elements 200 can be reduced or avoided, thereby improving the display effect of the display panel 10 under low grayscale brightness or small driving voltage.

[0051] Among them, reference Figure 3 As shown, the depth of the undercut structure 112 in the first direction X1 is L1, and the thickness of the light-emitting layer 220 in the first direction X1 is L2; ​​wherein L1 ≥ L2. In this way, the depth of the undercut structure 112 is greater than or equal to the depth of the light-emitting layer 220, so that when preparing the light-emitting layer 220, the light-emitting layer 220 can be more easily disconnected at the undercut structure 112; or more light-emitting layers 220 can be accommodated at the undercut structure 112, which is equivalent to increasing the overall transmission path of the light-emitting layer 220. Therefore, the undercut structure 112 is set, and the depth of the undercut structure 112 is adjusted, so as to better avoid or reduce the leakage transmission of holes or electrons between different light-emitting elements 200, and ensure the overall display effect of the display panel 10.

[0052] In summary, the display panel provided by the embodiment of the present invention has an undercut structure, and the depth of the undercut structure is greater than or equal to the depth of the light-emitting layer in the light-emitting element. In this way, at least part of the film layers in the light-emitting layers of different light-emitting elements can be disconnected at the undercut structure, thereby avoiding or reducing the direct leakage transmission of holes or electrons between different light-emitting elements, thereby avoiding the direct crosstalk between different light-emitting elements, and ensuring the overall display effect of the display panel.

[0053] Continue to refer Figures 1 to 3 As shown, the thickness of the second electrode 230 in the first direction X1 is L3; wherein L1≤L2+L3.

[0054] Specifically, refer to Figure 2 and Figure 3As shown, along the first direction X1, the thickness of the second electrode 230 is L3, that is, along the thickness direction of the display panel 10, the thickness of the second electrode 230 is L3. For the depth of the undercut structure 112 in the first direction X1, when L1≥L2 is satisfied, L1≤L2+L3 can also be satisfied. That is, the depth of the undercut structure 112 in the first direction X1 is greater than or equal to the thickness of the light-emitting layer 220, and the depth is less than or equal to the sum of the thickness of the light-emitting layer 220 and the second electrode 230. It can also be understood that the depth L1 of the undercut structure 112 in the first direction X1 is less than or equal to the distance L4 between the surface of the second electrode 230 away from the driving substrate 100 and the driving substrate 100.

[0055] Furthermore, the depth of the undercut structure 112 is adjusted not to exceed the distance between the surface of the second electrode 230 away from the driving substrate 100 and the driving substrate 100, that is, the second electrode 230 prepared on the entire surface has good flatness at the undercut structure 112, and is not easy to be disconnected at the position of the undercut structure 112, or there will not be too much second electrode 230 deposited at the undercut structure, thereby ensuring the flatness and continuity of the entire surface of the second electrode 230, thereby ensuring the regularity of the overall structure of the display panel 10 and the display effect.

[0056] Figure 5 yes Figure 1 The first cross-sectional diagram along the section line B-B', refer to Figures 1 to 5 As shown, the driving substrate 100 also includes a driving circuit 120; the first electrode 210 includes a connected electrode main body portion 210a and an electrode connecting portion 210b, along the first direction X1, the electrode main body portion 210a covers the pixel opening 110a, and the electrode connecting portion 210b is electrically connected to the driving circuit 120; the electrode main body portion 210a includes a connected exposed portion 210a1 and a covered portion 210a2, the pixel opening 110a exposes the exposed portion 210a1, and the pixel defining structure 111 covers the covered portion 210a2; the covered portion 210a2 includes a first covered sub-portion 210a21 and a second covered sub-portion 210a22, the first The covering section 210a21 is connected to the electrode connecting section 210b, and the second covering section 210a22 and the first covering section 210a21 are both connected to the exposed section 210a1; the pixel defining structure 111 includes a first defining section 111a1 and a second defining section 111a2 connected, the first defining section 111a1 covers the first covering section 210a21, and the second defining section 111a2 covers the second covering section 210a22; no undercut structure 112 is provided on the side wall 111a of the first defining section 111a1, and an undercut structure 112 is provided on the side wall 111a of the second defining section 111a2.

[0057] Specifically, refer to Figure 2As shown, the driving substrate 100 includes a driving circuit 120, which is used to be electrically connected to the first electrode 210 in the light-emitting element 200 to provide a driving current for the light-emitting element 200, thereby ensuring the normal display of the display panel 10. Further, the driving circuit 120 may include "4T1C", "7T1C" and "8T1C", etc., where "T" represents a transistor and "C" represents a capacitor. Figure 2 The driving circuit 120 is not specifically shown in the figure, and a transistor 121 is used as an example. Further, the driving substrate 100 includes a plurality of stacked film layers, such as a substrate 101, a gate insulating layer 102, an interlayer insulating layer 103, a first planarization layer 104, and a second planarization layer 105. The specific film layer type and quantity in the driving substrate 100 can be adaptively adjusted according to different requirements, and the embodiment of the present invention does not specifically limit it here. Further, Figure 2 The transistor 121 shown in the driving circuit 120 includes: an active layer 121a, a gate 121b, a source 121c and a drain 121d. The specific configuration of the transistor 121 can also be adaptively adjusted according to requirements, and the embodiment of the present invention does not specifically limit this.

[0058] Specifically, refer to Figure 2 and Figure 3 As shown, the first electrode 210 includes an electrode main body portion 210a and an electrode connecting portion 210b connected, wherein the electrode main body portion 210a covers the pixel opening 110a along the first direction X1. The electrode connecting portion 210b is electrically connected to the driving circuit 120, that is, the first electrode 210 obtains the driving current provided by the driving circuit 120 through the electrode connecting portion 210b. For example, refer to Figure 2 As shown, the electrode connecting portion 210b and the driving circuit 120 can be electrically connected through the connecting wire 130. It can be understood that the electrode main body 210a is a film layer structure arranged on the side of the second planarization layer 105 away from the substrate 100, and the electrode connecting portion 210b is a bridging portion for realizing electrical connection between different film layers.

[0059] For further reference, Figure 3As shown, the electrode main body 210a includes an exposed portion 210a1 and a covered portion 210a2, wherein the exposed portion 210a1 can be understood as the first electrode 210 exposed at the pixel opening 110a, and the covered portion 210a2 can be understood as the pixel defining structure 111 existing on the side of the covered portion 210a2 away from the driving substrate 100. At the same time, the covered portion 210a2 includes a first covered sub-portion 210a21 and a second covered sub-portion 210a22, and the first covered sub-portion 210a21 is connected to the electrode connecting portion 210b, that is, the driving current provided by the driving circuit 120 is sequentially transmitted to the first covered sub-portion 210a21 through the electrode connecting portion 210b. Further, the second covered sub-portion 210a22 and the first covered sub-portion 210a21 are both connected to the exposed portion 210a1, so that the balance of signal transmission on the first electrode 210 can be ensured.

[0060] Furthermore, the pixel defining structure 111 includes a first defining section 111a1 and a second defining section 111a2 that are connected, wherein the first defining section 111a1 covers the first covering section 210a21, that is, the first defining section 111a1 is located on a side of the first covering section 210a21 away from the driving substrate 100; the second defining section 111a2 covers the second covering section 210a22, that is, the second defining section 111a2 is located on a side of the second covering section 210a22 away from the driving substrate 100. The first covering section 210a21 is electrically connected to the electrode connecting section 210b, that is, the first covering section 210a21 is relatively close to the electrode connecting section 210b for cross-layer arrangement. Therefore, the first limiting section 111a1 located on the side of the first covering section 210a21 away from the driving substrate 100 has a relatively small space for setting the undercut structure 112. In view of the difficulty of process preparation, the undercut structure 112 is not set on the side wall 111a of the first limiting section 111a1. On the one hand, the preparation process of the undercut structure 112 can be simplified, and on the other hand, it is conducive to ensuring the continuity of the evaporation molding of the second electrode 230. The undercut structure 112 is set on the side wall 111a of the second covering section 210a22, so that the light-emitting layer 220 can be disconnected at the undercut structure 112, so that the leakage transmission of holes or electrons between different light-emitting elements 200 can be avoided, thereby avoiding the situation of crosstalk between different light-emitting elements 200, thereby ensuring the display effect of the display panel 10. Alternatively, the light-emitting layer 220 is not separated from the bottom cut structure 112, but the area at the bottom cut structure 112 is filled, thereby increasing the transmission path of the light-emitting layer 220 and reducing the leakage transmission of holes or electrons between different light-emitting elements 200, thereby improving the overall display effect of the display panel 10.

[0061] For further reference, Figure 5 As shown, Figure 5The first electrode 210 shown has second covering sections 210a22 on both sides of the exposed section 210a1, that is, an undercut structure 112 is provided on the sidewall 111a of the corresponding second defining section 111a2. It should be noted that: Figure 5 FIG. 2 shows a cross-sectional view of the light emitting element 200 from another angle. Figure 5 The electrode connection portion 210b is not shown, and the first covering portion 210a21 is not shown. That is, along the direction perpendicular to the first direction X1, when both sides of the exposed area 210a1 are the second covering portions 210a22, the sidewalls 111a on the second limiting portions 111a2 on both sides may be provided with undercut structures 112.

[0062] Figure 6 yes Figure 1 The first cross-sectional diagram along the section line C-C' is shown in FIG. Figure 7 is a comparison diagram of different light-emitting elements provided by an embodiment of the present invention, referring to Figure 6 and Figure 7 As shown, the light-emitting element 200 includes a first light-emitting element 200A and a second light-emitting element 200B, the first light-emitting element 200A includes a first light-emitting layer 220A, and the second light-emitting element 200B includes a second light-emitting layer 220B; the display panel 10 includes a first undercut structure 112A and a second undercut structure 112B, at least part of the film layer in the first light-emitting layer 220A is disconnected at the position of the first undercut structure 112A, and at least part of the film layer in the second light-emitting layer 220B is disconnected at the position of the second undercut structure 112B; along the first direction X1, the thickness of the first light-emitting layer 220A is greater than the thickness of the second light-emitting layer 220B, and the depth of the first undercut structure 112A is greater than the depth of the second undercut structure 112B.

[0063] Specifically, refer to Figure 1 As shown, the light emitting element 200 includes a first light emitting element 200A and a second light emitting element 200B, wherein the first light emitting element 200A and the second light emitting element 200B can be understood as light emitting elements 200 of different colors. For example, the first light emitting element 200A can be a red light emitting element, and the second light emitting element 200B can be a blue light emitting element.

[0064] For further reference, Figure 6 As shown, the first light emitting element 200A includes a first light emitting layer 220A, and the second light emitting element 200B includes a second light emitting layer 220B. Since the light emitting colors of the first light emitting element 200A and the second light emitting element 200B are different, the corresponding light emitting layers 220 are also different. Figure 6 As shown, along the first direction X1, the thickness of the first light emitting layer 220A is greater than the thickness of the second light emitting layer 220B. It should be noted that, Figure 6In order to highlight the difference in thickness of the light emitting layer 220 between different light emitting elements 200 , the second electrode 230 is not shown.

[0065] Exemplary, reference Figure 7 As shown, Figure 7 2 shows light emitting elements 200 of different colors, Figure 7 201B can be understood as the corresponding blue light emitting element, 201G can be understood as the corresponding green light emitting element, and 201R can be understood as the corresponding red light emitting element. Figure 7 As shown, there is a difference in thickness of the light-emitting layer 220 in the light-emitting elements 200 of different colors, that is, the thickness of the light-emitting layer 220 of the red light-emitting element is greater than the thickness of the light-emitting layer 220 of the green light-emitting element, and the thickness of the light-emitting layer 220 of the green light-emitting element is greater than the thickness of the light-emitting layer 220 of the blue light-emitting element. Specifically, in a feasible implementation, the difference in thickness of the light-emitting layer 220 of the light-emitting elements 200 of different colors is formed by the hole transport layer 222, that is, the thickness of the hole transport layer 222 of the red light-emitting element is greater than the thickness of the hole transport layer 222 of the green light-emitting element, and the thickness of the hole transport layer 222 of the green light-emitting element is greater than the thickness of the hole transport layer 222 of the blue light-emitting element.

[0066] As mentioned above, the light emitted by the light-emitting layer 220 can be modulated in the microcavity structure formed between the first electrode 210 and the second electrode 230 to improve the light emission effect. Specifically, different light-emitting elements 200 emit light of different colors, and light of different colors has different wavelengths, wherein the phase shift generated by the light emitted from the light-emitting layer 220 reflected between the first electrode 210 and the second electrode 230 is φ radians, and the optical path of the resonant part is L, that is, along the thickness direction of the display panel 10, the transmission distance of the light between the first electrode 210 and the second electrode 230 is L. If the wavelength of the target light is λ, the optical path of the resonant part should satisfy the following formula: 2L / λ+φ / 2π=p (p is an integer). Moreover, the larger the m value is, the better the color purity of the light output by the resonant part can be, but it will lead to a decrease in display brightness and an increase in the dependence on the viewing angle. In order to ensure a balanced display effect of multiple light-emitting elements 200 in the display panel 10, the p values ​​of different light-emitting elements 200 can be adjusted to be similar or the same, and then the thickness of the light-emitting layer 230 of the light-emitting elements 200 of different colors can be adjusted based on different wavelengths λ, that is, the optical path L in the above formula is adjusted, thereby ensuring that the output effects of light with different wavelengths λ are similar, thereby ensuring the overall display effect of the display panel 10.

[0067] For further reference, Figure 6As shown, the display panel 10 includes a first undercut structure 112A and a second undercut structure 112B, wherein at least part of the film layer in the first light-emitting layer 220A is disconnected at the position of the first undercut structure 112A, and at least part of the film layer in the second light-emitting layer 220B is disconnected at the position of the second undercut structure 112B. Wherein, when there is a difference in thickness between the first light-emitting layer 220A and the second light-emitting layer 220B, in order to ensure that both the first light-emitting layer 220A and the second light-emitting layer 220B can disconnect at least part of the film layer at the corresponding undercut structure 112 or increase the extension path of the film layer, the first undercut structure 112A and the second undercut structure 112B can be adjusted to have different depths. That is, the depth of the undercut structure 112 can be adaptively adjusted according to the thickness of the light-emitting layer 220 disposed adjacent thereto. When the thickness of the first light-emitting layer 220A is greater than the thickness of the second light-emitting layer 220B along the first direction X1, the depth of the first undercut structure 112A is adjusted to be greater than the depth of the second undercut structure 112B. It can be ensured that there is no leakage or less leakage in the first light emitting element 200A and the second light emitting element 200B, thereby ensuring the overall display effect of the display panel 10 .

[0068] In the embodiment of the present invention, the undercut structure 112 is adjusted more finely according to different light emitting elements 200 , so as to better ensure the overall display effect of the display panel 10 .

[0069] Continue to refer Figure 3 As shown, the side surface of the undercut structure 112 includes a curved surface 1121; the curved surface 1121 includes a first curved surface position a1 and a second curved surface position a2, the curvature radius of the first curved surface position a1 is R1, the curvature radius of the second curved surface position a2 is R2, and |R1-R2| / R1≤20%.

[0070] Specifically, refer to Figure 3 As shown, the side of the undercut structure 112 includes a curved surface 1121, that is, the side of the undercut structure 112 near the pixel opening 110a. The curved surface 1121 includes a first curved surface position a1 and a second curved surface position a2, and the curvature radius of the first curved surface position a1 is R1, and the curvature radius of the second curved surface position a2 is R2, satisfying: |R1-R2| / R1≤20%. That is, the curvature radius of the first curved surface position a1 is the same as or similar to the curvature radius of the second curved surface position a2, so it can be understood that the side of the undercut structure 112 can be theoretically considered to be a spherical surface, or an approximate spherical surface, that is, the set undercut structure 112 has regularity.

[0071] Exemplarily, the undercut structure 112 can be prepared by wet etching. Since wet etching has the isotropic characteristic, it can ensure that the curvature radius of each arc surface position of the arc surface 1121 of the prepared undercut structure 112 is the same or similar, that is, the side surface of the undercut structure 112 is a sphere or an approximate sphere.

[0072] Figure 8 yes Figure 1 The first cross-sectional diagram along the section line D-D', see Figure 1 and Figure 8 As shown, the pixel defining structure 111 between two adjacent pixel openings 110a includes a third defining sub-portion 111a3 and a fourth defining sub-portion 111a4, the third defining sub-portion 111a3 is located on a side of the fourth defining sub-portion 111a4 close to the pixel opening 110a; and along the first direction X1, the third defining sub-portion 111a3 covers the edge of the first electrode 210; the driving substrate 100 also includes a substrate 101, the third defining sub-portion 111a3 includes a first surface 113 on a side away from the substrate 101, and the fourth defining sub-portion 111a4 includes a second surface 113 on a side away from the substrate 101. 14, the distance between the first surface 113 and the substrate 101 is greater than the distance between the second surface 114 and the substrate 101; the display panel 10 also includes a packaging structure 300, the packaging structure 300 is located on the side of the second electrode 230 away from the driving substrate 100, the packaging structure 300 includes a first packaging layer 310 close to the side of the pixel defining layer 110, the surface of the first packaging layer 310 facing away from the substrate 101 has a protrusion 311 protruding away from the side of the substrate 101, and along the first direction X1, the protrusion 311 overlaps with the third limiting portion 111a3 and overlaps with the edge of the first electrode 210.

[0073] Specifically, refer to Figure 8 As shown, the pixel defining structure 111 between two adjacent pixel openings 110a includes a third defining sub-portion 111a3 and a fourth defining sub-portion 111a4, wherein the third defining sub-portion 111a3 is closer to the pixel opening 110a than the fourth defining sub-portion 111a4. Figure 8 As shown, the projection of the third defined portion 111a3 onto the substrate 101 at least partially overlaps with the projection of the first electrode 210 onto the substrate 101 , that is, along the first direction X1 , the third defined portion 111a3 covers the edge of the first electrode 210 .

[0074] The third defined section 111a3 includes a first surface 113, and the fourth defined section 111a4 includes a second surface 114. Figure 8As shown, the first surface 113 is the surface of the third defining sub-portion 111a3 away from the substrate 101, and the second surface 114 is the surface of the fourth defining sub-portion 111a4 away from the substrate 101. Further, the distance between the first surface 113 and the substrate 101 is greater than the distance between the second surface 114 and the substrate 101, that is, the surface of the third defining sub-portion 111a3 away from the substrate 101 is convex compared to the surface of the fourth defining sub-portion 111a4 away from the substrate 101, that is, the surface of the pixel defining structure 111 between two adjacent pixel openings 110a away from the substrate 101 is convex at the third defining sub-portion 111a3.

[0075] For further reference, Figure 8 As shown, the display panel 10 also includes a packaging structure 300, and the packaging structure 300 is used to package and protect the entire display panel 10. Among them, the packaging structure 300 also includes a first packaging layer 310, and the first packaging layer 310 is located on the side of the second electrode 230 away from the substrate 101, that is, the first packaging layer 310 covers the second electrode 230. Exemplarily, the first packaging layer 310 can be an inorganic metal layer, which is prepared by chemical vapor deposition. Furthermore, the first packaging layer 310 is arranged on the entire surface, that is, the first packaging layer 310 will cover the third defining section 111a3. Since the third defining section 111a3 is a protruding structure compared to the fourth defining section 111a4 in the pixel defining structure 111, it is equivalent to padding at the third defining section 111a3, and then the first packaging layer 310 will also have a protruding structure in the corresponding setting area of ​​the third defining section 111a3. Specifically, refer to Figure 8 As shown, the surface of the first encapsulation layer 310 facing away from the substrate 101 has a protrusion 311 protruding away from the substrate 101. The protrusion 311 is equivalent to a microprism. When the light emitted from the pixel opening 110a is transmitted to the protrusion 311, the light can be adjusted, that is, the light output angle of the large viewing angle can be adjusted. For example, refer to Figure 8 As shown in the figure, when the light m is transmitted to the protrusion 311, the light routing is adjusted. During the light transmission process, the incident angle of the light is smaller than the refraction angle. After the light passes through the protrusion 311, the light transmission path is deflected toward the direction of zero viewing angle, which can ensure that the light emitted by the light-emitting element 200 in the display panel 10 has a better light-emitting effect, that is, the light-emitting efficiency is improved and the dispersion is reduced, thereby ensuring the overall display effect of the display panel 10.

[0076] Optionally, since the third limiting sub-portion 111a3 is raised, the height of the raised area is also adjusted when preparing the first encapsulation layer 310, that is, the first encapsulation layer 310 is also raised at the place where it covers the third limiting sub-portion 111a3. And the transmission of light can also be adjusted accordingly, so as to ensure the overall display effect of the display panel 10. It should be noted that the shape of the protrusion 311 can be as follows: Figure 8 As shown in the semicircle, the specific shape of the protrusion 311 can be adaptively adjusted according to different processes.

[0077] Fig. 9 is a schematic top view of a display panel provided by an embodiment of the present invention, with reference to Figure 1 , Figure 8 and Fig. 9 As shown, the light emitting element 200 includes a third light emitting element 200C and a fourth light emitting element 200D, the pixel opening 110a includes a first pixel opening 110a1 and a second pixel opening 110a2, the first pixel opening 110a1 exposes a portion of the first electrode 210C of the third light emitting element 200C, and the second pixel opening 110a2 exposes a portion of the first electrode 210D of the fourth light emitting element 200D; the opening area of ​​the first pixel opening 110a1 is greater than the opening area of ​​the second pixel opening 110a2; the third limiting sub-portion 111a3 includes a third A limiting sub-portion 111a31 and a third B limiting sub-portion 111a32, the third A limiting sub-portion 111a31 covers the edge of the first electrode 210C of the third light emitting element 200C, and the third B limiting sub-portion 111a32 covers the fourth light emitting element 2 00D; the protrusion 311 includes a first protrusion 311a and a second protrusion 311b. Along the first direction X1, the first protrusion 311a overlaps with the third A-defining section 111a31 and overlaps with the edge of the first electrode 210C of the third light-emitting element 200C, and the second protrusion 311b overlaps with the third B-defining section 111a32 and overlaps with the edge of the first electrode 210D of the fourth light-emitting element 200D; the projection area of ​​the orthographic projection of the third A-defining section 111a31 on the plane where the substrate 101 is located is greater than the projection area of ​​the orthographic projection of the third B-defining section 111a32 on the plane where the substrate 101 is located, and the projection area of ​​the orthographic projection of the first protrusion 311a on the plane where the substrate 101 is located is greater than the projection area of ​​the orthographic projection of the second protrusion 311b on the plane where the substrate 101 is located.

[0078] Specifically, the light-emitting element 200 includes a third light-emitting element 200C and a fourth light-emitting element 200D, wherein the third light-emitting element 200C and the fourth light-emitting element 200D can be understood as light-emitting elements 200 with different luminous colors. Further, the pixel opening 110a includes a first pixel opening 110a1 and a second pixel opening 110a2, and the first pixel opening 110a1 exposes a portion of the first electrode 210C of the third light-emitting element 200C, that is, the light of the third light-emitting element 200C is emitted through the first pixel opening 110a1. The second pixel opening 110a2 exposes a portion of the first electrode 210D of the fourth light-emitting element 200D, that is, the light of the fourth light-emitting element 200D is emitted through the second pixel opening 110a2. Further, for light-emitting elements 200 of different colors, the opening areas of the corresponding pixel openings 110a are different. Exemplarily, if the third light-emitting element 200C is considered to be a blue light-emitting element and the fourth light-emitting element 200D is considered to be a red light-emitting element, the opening area of ​​the pixel opening corresponding to the blue light-emitting element may be larger than the opening area of ​​the pixel opening corresponding to the red light-emitting element.

[0079] Further, the third limiting sub-portion 111a3 includes a third A limiting sub-portion 111a31 and a third B limiting sub-portion 111a32, and correspondingly, the third A limiting sub-portion 111a31 covers the edge of the first electrode 210C of the third light-emitting element 200C. The first encapsulation layer 310 is provided with a first protrusion 311a at a position corresponding to the third A limiting sub-portion 111a31, that is, along the first direction X1, the first protrusion 311a overlaps with the third A limiting sub-portion 111a31 and overlaps with the edge of the first electrode 210C of the third light-emitting element 200C. Similarly, the third B limiting sub-portion 111a32 covers the edge of the first electrode 210D of the fourth light-emitting element 200D. The first encapsulation layer 310 is provided with a second protrusion 311b at a position corresponding to the third B-defining portion 111a32, that is, along the first direction X1, the second protrusion 311b overlaps with the third B-defining portion 111a32 and overlaps with the edge of the first electrode 210D of the fourth light-emitting element 200D.

[0080] Further, the opening areas of the pixel openings 110a corresponding to different light-emitting elements 200 can be set differently. When the projection area of ​​the orthographic projection of the third A limiting section 111a31 on the plane where the substrate 101 is located is greater than the projection area of ​​the orthographic projection of the third B limiting section 111a32 on the plane where the substrate 101 is located, the projection area of ​​the protrusion 311 can be adaptively adjusted. Specifically, the projection area of ​​the orthographic projection of the first protrusion 311a on the plane where the substrate 101 is located is greater than the projection area of ​​the orthographic projection of the second protrusion 311b on the plane where the substrate 101 is located. Among them, since the opening areas of the pixel openings 110a corresponding to light-emitting elements 200 of different colors are different, the light emitting angles of the wide-angle light of the light-emitting elements 100 of different colors are different, and the protrusion 311 provided can adaptively adjust the light emitted by the light-emitting element 200, that is, according to the light-emitting conditions of different light-emitting elements 200, the protrusion 311 is more finely adaptively adjusted to ensure the overall display effect of the display panel 10. Specifically, the larger the coverage area of ​​the protrusion 311 of the light emitting element 200 with a larger opening area, the wider the adjustment range of the light, thereby ensuring the overall display effect of the display panel 10. Alternatively, it can be understood that the larger the opening area of ​​the pixel opening 110a corresponding to the light emitting element 200, the greater the adjustment of the light can be combined with the protrusion 311 with a larger projection area, thereby further ensuring the overall display effect of the display panel 10.

[0081] Exemplary, reference Fig. 9 As shown, Fig. 9 It can be understood as Figure 8 The top view corresponding to the cross-sectional view, combined with Figure 8 and Fig. 9 As shown, the opening area of ​​the first pixel opening 110a1 is larger than the opening area of ​​the second pixel opening 110a2, and at the same time, the projection area of ​​the orthographic projection of the third A-limiting section 111a31 on the plane where the substrate 101 is located is larger than the projection area of ​​the orthographic projection of the third B-limiting section 111a32 on the plane where the substrate 101 is located. Fig. 9 The projection 311 is not shown in the figure, but the size of the projection 311 is directly related to the size of the third limiting section 111a3. The larger the size of the third limiting section 111a3, the larger the size of the corresponding projection 311. Figure 8 As shown, the projection area of ​​the orthographic projection of the first protrusion 311a on the plane where the substrate 101 is located is greater than the projection area of ​​the orthographic projection of the second protrusion 311b on the plane where the substrate 101 is located.

[0082] Fig.10 yes Figure 1 The first cross-sectional diagram along the section line F-F', see Figure 1 and Fig.10As shown, the light emitting element 200 includes a fifth light emitting element 200E, the pixel opening 110a includes a third pixel opening 110a3, and the third pixel opening 110a3 exposes a portion of the first electrode 210E of the fifth light emitting element 200E; the third defining section 111a3 includes a third third defining section 111a33, and the protrusion 311 includes a third protrusion 311c, and along the first direction X1, the third protrusion 311c overlaps with the third third defining section 111a33 and overlaps with the edge of the first electrode 210E of the fifth light emitting element 200E; The third protrusion 311c includes a first protrusion edge 311c1 and a second protrusion edge 311c2, and the orthographic projection of the first protrusion edge 311c1 on the plane where the substrate 101 is located is located on the side of the orthographic projection of the second protrusion edge 311c2 on the plane where the substrate 101 is located away from the center of the third pixel opening 110a3; the angle between the maximum viewing angle ray of the fifth light-emitting element 200E and the first electrode 210E is α, and the angle between the normal of the tangent plane at the position of the first protrusion edge 311c1 and the first electrode 210E is β; wherein β<α.

[0083] Furthermore, the light emitting element 200 further includes a fifth light emitting element 200E, and the pixel opening 110a includes a third pixel opening 110a3, which exposes a portion of the first electrode 210E of the fifth light emitting element 200E, that is, the light of the fifth light emitting element 200E is emitted through the third pixel opening 110a3.

[0084] Further, the third limiting sub-portion 111a3 includes a third C limiting sub-portion 111a33, and correspondingly, the third C limiting sub-portion 111a33 covers the edge of the first electrode 210E of the fifth light-emitting element 200E. The first encapsulation layer 310 is provided with a third protrusion 311c at a position corresponding to the third A limiting sub-portion 111a31, that is, along the first direction X1, the third protrusion 311c overlaps with the third C limiting sub-portion 111a33 and overlaps with the edge of the first electrode 210E of the fifth light-emitting element 200E.

[0085] Specific, combined Fig.10 As shown, the third protrusion 311c includes a first protrusion edge 311c1 and a second protrusion edge 311c2, wherein the orthographic projection of the first protrusion edge 311c1 on the plane where the substrate 101 is located is located on the side of the orthographic projection of the second protrusion edge 311c2 on the plane where the substrate 101 is located away from the center of the third pixel opening 110a3. That is, the first protrusion edge 311c1 can be understood as an edge of the third protrusion 311c that is farthest from the third pixel opening 110a3. Further, in combination with Fig.10As shown, the angle between the maximum viewing angle light of the fifth light emitting element 200E and the first electrode 210E is α, that is, the light emitted from a position farthest from the third protrusion 311c in the third pixel opening 100a3 to the edge 311c1 of the first protrusion (reference Fig.10 The angle between the light path indicated by the mark m2 in FIG. 2 and the first electrode 210E before passing through the third protrusion 311c is α. The normal line of the tangent plane at the position of the first protrusion edge 311c1 (reference Fig.10 The angle between the straight line indicated by the mark F in the figure and the first electrode 210E is β; wherein β<α, which can be understood as that the angle between the light ray m2 and the first electrode 210 is greater than the angle between the normal F corresponding to the tangent plane of the first protrusion edge 311c1 and the first electrode 210, and referring to the light transmission path after the light ray m2 passes through the third protrusion 311c, it can be known that it is deflected perpendicular to the first direction X1, that is, it is ensured that the transmission path of the light ray m3 is closer to the third pixel opening 110a3 than before passing through the third protrusion 311c, that is, by limiting the first protrusion edge 311c1 in the third protrusion 311c, it is ensured that the light emitted through the third protrusion 311c is closer to the third pixel opening 110a3, that is, the overall light is adjusted to be emitted at a light output angle with a large viewing angle, thereby improving the overall display effect of the display panel 10.

[0086] Continue to refer Figure 8 As shown, the encapsulation structure 300 includes a first inorganic encapsulation layer 3101, an organic encapsulation layer 320 and a second inorganic encapsulation layer 330 which are stacked. The first inorganic encapsulation layer 3101 is located on a side of the organic encapsulation layer 320 close to the pixel defining layer 110; the first encapsulation layer 310 includes the first inorganic encapsulation layer 3101.

[0087] Among them, reference Figure 8 As shown, the encapsulation structure 300 includes a first inorganic encapsulation layer 3101, an organic encapsulation layer 320 and a second inorganic encapsulation layer 330, wherein the first inorganic encapsulation layer 3101 is located on a side of the organic encapsulation layer 320 close to the pixel defining layer 110, and the organic encapsulation layer 320 is located between the first inorganic encapsulation layer 3101 and the second inorganic encapsulation layer 330.

[0088] Further, the first encapsulation layer 310 includes a first inorganic encapsulation layer 3101, that is, the first inorganic encapsulation layer 311 includes a protrusion 311, which is used to adjust the light transmitted to the protrusion 311 to ensure the overall display effect of the display panel 10. Among them, the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 are sequentially located on the side of the first encapsulation layer 310 away from the pixel defining layer 110, and the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 can be used to adjust the encapsulation structure 300 as a whole to a relatively flat morphology, that is, the first encapsulation layer 310 originally provided with the protrusion 311 is flattened by the organic encapsulation layer 320 and the second inorganic encapsulation layer 330, so that the overall flatness of the display panel 10 can be ensured. Further, by setting the protrusion 311 and adjusting the light, the organic encapsulation layer 320 and the second inorganic encapsulation layer 330 are set, while ensuring the flatness, and will not have other effects on the light, so that the overall display effect of the display panel 10 can still be ensured. Furthermore, the encapsulation structure 300 includes a first inorganic encapsulation layer 3101, an organic encapsulation layer 320 and a second inorganic encapsulation layer 330, that is, the encapsulation structure 300 as a whole is an inorganic-organic-inorganic structure, which can effectively block water vapor and oxygen, prevent the film layer in the display panel 10 from being peeled off due to the influence of water vapor, and thus ensure the overall structural stability of the display panel 10.

[0089] Based on the same inventive concept, an embodiment of the present invention further provides a method for preparing a display panel. Fig.11 is a schematic diagram of a first display panel manufacturing method provided by an embodiment of the present invention, with reference to Fig.11 As shown, the method for preparing the display panel includes:

[0090] S110, preparing a driving substrate.

[0091] Among them, the prepared display panel will include a driving substrate and a light-emitting element, and the driving substrate can drive the light-emitting element to perform light-emitting display, thereby achieving the display effect of the display panel. Further, the driving substrate also includes a driving circuit, which is used to be electrically connected to the light-emitting element to provide a driving current for the light-emitting element, thereby ensuring the normal display of the display panel. Further, the driving circuit may include "4T1C", "7T1C" and "8T1C", etc., where "T" represents a transistor and "C" represents a capacitor. Further, the driving substrate includes a plurality of stacked film layers, such as a substrate, a gate insulating layer, an interlayer insulating layer, a first planarization layer and a second planarization layer. The specific film layer setting type and quantity in the driving substrate can be adaptively adjusted according to different requirements, and the embodiment of the present invention does not make specific limitations here. Further, the transistor in the driving circuit includes: an active layer, a gate, a source and a drain. The specific setting of the transistor can also be adaptively adjusted according to requirements, and the embodiment of the present invention does not make specific limitations on this.

[0092] Furthermore, the light-emitting elements in the display panel may have light-emitting elements of different colors, such as red light-emitting elements, blue light-emitting elements, green light-emitting elements, and white light-emitting elements, etc. By driving the light-emitting elements of different colors to emit light for display, a color display effect of the display panel can be achieved. There are also various arrangements of light-emitting elements of different colors in the display panel, which are not described one by one in the embodiments of the present invention.

[0093] Optionally, the prepared light-emitting element includes a first electrode, a light-emitting layer, and a second electrode arranged in a stacked manner, wherein the first electrode is located on a side of the light-emitting layer close to the driving substrate, and the light-emitting layer is located between the first electrode and the second electrode. Exemplarily, the light-emitting layer may include a plurality of film layers, and along the direction from the first electrode to the second electrode, the light-emitting layer may be, in sequence: a hole injection layer (HIL), a hole transport layer (HTL), a compensation layer (Prime), an emitting film layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). Among them, corresponding to the light-emitting elements of different colors, the compensation layer includes a red compensation layer (R-Prime), a blue compensation layer (B-Prime) and a green compensation layer (G-Prime), etc., which are respectively used to adjust the cavity length of each light-emitting element, and then adjust the optical performance. The light-emitting film layer includes a red light-emitting layer (R-EML), a blue light-emitting layer (B-EML) and a green light-emitting layer (G-EML), so as to achieve the light-emitting effect of different colors of the light-emitting element. The compensation layer and the light-emitting film layer are stacked and the side walls can be aligned. Specifically, the light emission of the light-emitting element can be understood as: applying a certain voltage to the first electrode and the second electrode respectively, the holes from the first electrode are injected into the hole transport layer through the hole injection layer, and the electrons from the second electrode are injected into the electron transport layer through the electron injection layer. The holes and electrons migrate to the light-emitting film layer through the hole transport layer and the electron transport layer, respectively, and form excitons in the light-emitting film layer. The excitons excite the light-emitting molecules in the light-emitting film layer to emit light. The hole blocking layer is used to block holes from passing through the light-emitting film layer and entering the electron transport layer, so that holes and electrons are combined in the light-emitting film layer to form excitons.

[0094] Optionally, the display panel may also be a tandem display panel (Tandem OLED), that is, the light-emitting element is a stacked light-emitting element, and a display panel that uses a stacked light-emitting element to emit light is called a tandem display panel, that is, multiple light-emitting layers are stacked in series through a charge generation layer (CGL) in the light-emitting element. Among them, the tandem display panel can enable the light-emitting element to be driven at the same current density, thereby greatly improving the brightness of the display panel. Specifically, when multiple light-emitting film layers are connected in series in the light-emitting element of the tandem display panel, for example, when two light-emitting film layers are connected in series, the applied second electrode voltage will become twice, the current efficiency will also become twice, and the constant current life decay is consistent, so the corresponding constant brightness life will be more than doubled, the potential for life improvement is greater, and the power consumption is also advantageous.

[0095] Specifically, when the display panel is a series display panel, along the direction from the first electrode to the second electrode, the film structure may be a hole injection layer, a hole transport layer, a compensation layer, a luminescent film layer, a hole blocking layer, an electron transport layer, two charge generation layers, a hole transport layer, a compensation layer, a luminescent film layer, an electron transport layer and an electron injection layer in sequence. Among them, the charge generation layer may include a P-type charge generation layer (CGL-P) and an N-type charge generation layer (CGL-N), which are used to generate holes and electrons, respectively, and a luminescent film layer is provided between the electron transport layer and the hole transport layer. It should be noted that the luminescent film layer in the light-emitting element may be a light-emitting layer of red light, a light-emitting layer of blue light or a light-emitting layer of green light, and the embodiment of the present invention does not specifically limit this. Furthermore, the light-emitting element in the display panel may also include a light-emitting layer of red light, a light-emitting layer of blue light and a light-emitting layer of green light at the same time, and finally displays white light, etc.

[0096] The display panel prepares the pixel definition layer after preparing the first electrode, and then prepares the light emitting layer and the second electrode. The drive substrate includes the pixel definition layer, and the pixel definition layer covers the first electrode of the light emitting element.

[0097] S120 , patterning the pixel defining layer to form a pixel opening, an undercut structure, and a pixel defining structure in the pixel defining layer.

[0098] Further, the pixel defining layer is patterned, that is, the morphology of the pixel defining layer is further adjusted, and after the pixel defining layer is patterned and etched, corresponding pixel openings, undercut structures and pixel defining structures are formed respectively. Among them, the pixel opening exposes part of the first electrode, and the exposed first electrode can be understood as the setting area of ​​the light-emitting element, that is, the pixel opening defines the size of the light-emitting element. Further, the pixel defining layer also includes a pixel defining structure, and the pixel defining structure is arranged around the pixel opening. Among them, the pixel defining structure also includes a side wall close to one side of the pixel opening, and the side wall is equivalent to the edge cutoff position of the pixel defining structure. The edge cutoffs of two adjacent pixel defining structures correspond to the pixel opening. Further, the display panel is also provided with an undercut structure, which is located in the pixel defining structure and runs through at least part of the side wall, that is, it can be understood that the pixel defining structure is close to the pixel opening, or it can be understood that there is a fracture area near the light-emitting layer. And the undercut structure is connected to the pixel opening.

[0099] S130, preparing a light-emitting layer and a second electrode of the light-emitting element.

[0100] Furthermore, the light-emitting layer and the second electrode in the light-emitting element are prepared, wherein the light-emitting layer at least covers the pixel opening, and along the first direction, the second electrode is located on a side of the light-emitting layer away from the driving substrate.

[0101] Among them, by forming an undercut structure in the pixel defining layer, it can be ensured that the light-emitting layer arranged on the side of the first electrode away from the driving substrate is disconnected at the undercut structure, so that the leakage transmission of holes or electrons between different light-emitting elements can be avoided, thereby avoiding the situation of crosstalk between different light-emitting elements, thereby ensuring the display effect of the display panel. Alternatively, the light-emitting layer is not disconnected at the undercut structure, but the area at the undercut structure is filled, thereby increasing the transmission path of the light-emitting layer, and can also reduce the leakage transmission of holes or electrons between different light-emitting elements, thereby improving the overall display effect of the display panel.

[0102] It should be noted that the light-emitting layer is disconnected at the undercut structure, which may be at least part of the film layers in the light-emitting layer disconnected, for example, only the hole injection layer and the hole transport layer are disconnected. For the disconnection of the specific film layers in the light-emitting layer at the undercut structure, the process can be adjusted according to different requirements to achieve different film layer disconnection conditions.

[0103] Furthermore, when the display panel is a series display panel, the voltage of the second electrode at the light-emitting element will be doubled, so the display panel will generate a larger leakage current, resulting in more serious light leakage between different light-emitting elements. Therefore, by setting the undercut structure, the leakage transmission of holes or electrons between different light-emitting elements can be effectively reduced or avoided, thereby ensuring the overall display effect of the display panel.

[0104] Optionally, if the display panel is displayed at low grayscale brightness or driven by a small driving voltage, since the transmitted voltage and current are small, if there is leakage current, it will have a greater impact on the display effect of the display panel. Therefore, by setting a bottom cut structure, the generation of leakage current between different light-emitting elements can be reduced or avoided, thereby improving the display effect of the display panel under low grayscale brightness or small driving voltage.

[0105] Furthermore, the depth of the undercut structure in the first direction is, and the thickness of the light-emitting layer in the first direction is; wherein, L1≥L2. In this way, the depth of the undercut structure is greater than or equal to the depth of the light-emitting layer, so that when preparing the light-emitting layer, the light-emitting layer can be more easily disconnected at the undercut structure; or more light-emitting layers can be accommodated at the undercut structure, which is equivalent to increasing the overall transmission path of the light-emitting layer. Therefore, the undercut structure is set and the depth of the undercut structure is adjusted, which can better avoid or reduce the leakage transmission of holes or electrons between different light-emitting elements, and ensure the overall display effect of the display panel.

[0106] In summary, the method for preparing a display panel provided in an embodiment of the present invention, by setting up an undercut structure, and the depth of the undercut structure is greater than or equal to the depth of the light-emitting layer in the light-emitting element, so that at least part of the film layers in the light-emitting layers of different light-emitting elements can be disconnected at the undercut structure, thereby avoiding or reducing the direct leakage transmission of holes or electrons in different light-emitting elements, thereby avoiding the situation where different light-emitting elements directly have crosstalk, thereby ensuring the overall display effect of the display panel.

[0107] Fig.12 is a schematic diagram of a second method for preparing a display panel provided by an embodiment of the present invention, Fig.13 is a schematic diagram of a first display panel manufacturing process provided by an embodiment of the present invention, with reference to Fig.12 and Fig.13 As shown, the preparation method provided in the embodiment of the present invention also includes:

[0108] S210, preparing a driving substrate.

[0109] Exemplary, reference Fig.13 As shown in step a, a driving substrate 100 is prepared, and the driving substrate 100 includes a pixel defining layer 110 , and the pixel defining layer 110 covers the first electrode 210 of the light emitting element 200 .

[0110] S220 , patterning the pixel defining layer using a half mask process to form a first transition pixel opening in the pixel defining layer.

[0111] Exemplary, reference Fig.13 As shown in step b, the pixel defining layer 110 is first patterned and etched using a half mask process to form a first transition pixel opening 110b as shown in the figure. The first transition pixel opening 110b can be understood as a structure formed in the process of preparing the pixel opening of the pixel defining layer 110.

[0112] S230, preparing an etching protection layer and patterning the etching protection layer.

[0113] Exemplary, reference Fig.13 As shown in step c, an etching protection layer 400 is prepared on the side of the pixel defining layer 110 away from the first anode 210. The etching protection layer 400 may be an inorganic etching protection layer. Fig.13 As shown in step d, the etching protection layer 400 is pattern-etched, and the etched etching protection layer 400 at least exposes the pixel defining layer 110 located in the first transition pixel opening 110 b.

[0114] S240 , etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process to form a second transition pixel opening and a portion of the undercut structure.

[0115] Exemplary, reference Fig.13 As shown in step e, an isotropic etching process is used to etch a portion of the thickness of the pixel defining layer 110 located in the first transition pixel opening 110b to form a second transition pixel opening 110c and a portion of the undercut structure 112. Along the first direction X1, the depth of the second transition pixel opening 110c is less than the thickness of the pixel defining layer 110.

[0116] Specifically, the pixel defining layer 110 in the first transition pixel opening 110b is etched by an isotropic etching process. On the one hand, the pixel defining layer 110 in the first transition pixel opening 110b can be further thinned to form a second transition pixel opening 110c. On the other hand, a partial undercut structure 112 can be formed at the edge of the second transition pixel opening 110c.

[0117] Optionally, etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process may include:

[0118] A wet etching process is used to etch a portion of the pixel defining layer located in the first transition pixel opening.

[0119] Among them, the wet etching process can ensure isotropy during the etching process. Therefore, when etching the first transition pixel opening, the wet etching process can be used to form the second transition pixel opening and a partial undercut structure. Wet etching can be understood as an etching method that uses a specific solution to chemically react with the unprotected part of the material to remove it.

[0120] S250 , etching the protection layer and a partial thickness of the pixel defining layer located in the second transition pixel opening to form a pixel opening and an undercut structure.

[0121] Exemplary, reference Fig.13 As shown in step f, the remaining etching protection layer and part of the pixel defining layer 110 are etched, that is, the part of the pixel defining layer 110 remaining in the second transition pixel opening is etched away, and the etching of the undercut structure 112 is further improved, thereby realizing the preparation of the undercut structure 112.

[0122] Optionally, etching the etching protection layer and a portion of the pixel defining layer located in the second transition pixel opening may include:

[0123] The protective layer and a portion of the pixel defining layer located in the second transition pixel opening are etched by a dry etching process.

[0124] The pixel defining layer remaining in the second transition pixel opening may be removed by dry etching, for example, by using plasma to perform thin film etching.

[0125] S260, preparing a light-emitting layer and a second electrode of the light-emitting element.

[0126] Exemplary, reference Fig.13 As shown in step g, a light-emitting layer 220 is prepared on the side of the first electrode 210 away from the pixel defining layer 110, and a second electrode 230 is prepared on the side of the light-emitting layer 220 away from the first electrode 210, wherein the light-emitting layer 220 is disconnected at the undercut structure 112 due to the existence of the undercut structure 112, thereby avoiding the situation where the light-emitting layer 220 has lateral leakage between adjacent light-emitting elements 200. Or at least part of the light-emitting layer 220 is deposited in the undercut structure 112, thereby increasing the transmission path of the current. All of the above can improve the display effect of the display panel 10.

[0127] Fig.14 is a schematic diagram of a third method for preparing a display panel provided by an embodiment of the present invention, Fig.15 is a schematic diagram of a second display panel manufacturing process provided by an embodiment of the present invention, with reference to Fig.14 and Fig.15 As shown, the method for preparing the display panel 10 further includes:

[0128] S310, preparing a driving substrate.

[0129] Exemplary, reference Fig.15 As shown in step a, the first electrode 210 includes a connected electrode main body 210a and an electrode connecting portion 210b, wherein the electrode main body 210a covers the pixel opening 110a along the first direction X1. The electrode connecting portion 210b is electrically connected to the driving circuit 120, that is, the first electrode 210 obtains the driving current provided by the driving circuit 120 through the electrode connecting portion 210b. Exemplarily, the electrode connecting portion 210b and the driving circuit 120 can be electrically connected by connecting the wiring 130. It can be understood that the electrode main body 210a is a film layer structure arranged on the side of the second planarization layer 105 away from the substrate 100, and the electrode connecting portion 210b is a bridging portion for realizing electrical connection between different film layers.

[0130] For further information, please refer to Fig.15 Step b in , or the corresponding reference Figure 2 and Figure 3As shown, the electrode main body 210a includes an exposed portion 210a1 and a covered portion 210a2, wherein the exposed portion 210a1 can be understood as the first electrode 210 exposed at the pixel opening 110a prepared later, and the covered portion 210a2 can be understood as the pixel defining structure 111 existing on the side of the covered portion 210a2 away from the driving substrate 100. At the same time, the covered portion 210a2 includes a first covered sub-portion 210a21 and a second covered sub-portion 210a22, and the first covered sub-portion 210a21 is connected to the electrode connecting portion 210b, that is, the driving current provided by the driving circuit 120 is sequentially transmitted to the first covered sub-portion 210a21 through the electrode connecting portion 210b. Further, the second covered sub-portion 210a22 and the first covered sub-portion 210a21 are both connected to the exposed portion 210a1, so that the balance of signal transmission on the first electrode 210 can be ensured.

[0131] For further information, please refer to Fig.15 Step b in , or the corresponding reference Figure 2 and Figure 3 As shown, the pixel defining structure 111 includes a first defining section 111a1 and a second defining section 111a2 that are connected, wherein the first defining section 111a1 covers the first covering section 210a21, that is, the first defining section 111a1 is located on a side of the first covering section 210a21 away from the driving substrate 100; the second defining section 111a2 covers the second covering section 210a22, that is, the second defining section 111a2 is located on a side of the second covering section 210a22 away from the driving substrate 100.

[0132] S320 , patterning the pixel defining layer using a half mask process to form a first transition pixel opening in the pixel defining layer.

[0133] Exemplary, reference Fig.15 As shown in step b.

[0134] S330, preparing an etching protection layer and patterning the etching protection layer.

[0135] Exemplary, reference Fig.15 As shown in step c, an etching protection layer 400 is prepared and patterned. The etching protection layer 400 includes a first etching protection section 401 covering the first defined section 111a1 and a second etching protection section 402 covering the second defined section 111a2. The first etching protection section 401 covers the side walls of the first defined section 111a1 and a portion of the bottom surface located in the first transition pixel opening 110b, and the second etching protection section 402 covers the side walls of the second defined section 111a2.

[0136] Among them, the first covering sub-portion 210a21 is electrically connected to the electrode connecting portion 210b, that is, the first covering sub-portion 210a21 is relatively close to the electrode connecting portion 210b for cross-layer arrangement, so the first limiting sub-portion 111a1 located on the side of the first covering sub-portion 210a21 away from the driving substrate 100 has a smaller space for setting the undercut structure 112. Considering the difficulty of process preparation, the undercut structure 112 is not set on the side wall 111a of the first limiting sub-portion 111a1. Therefore, the first etching protection sub-portion 401 covers the side wall of the first limiting sub-portion 111a1 and the part of the bottom surface located in the first transition pixel opening 110b, and thus the undercut structure 112 will not be formed at the corresponding position, which is conducive to reducing the process difficulty on the one hand, and on the other hand, it is conducive to ensuring the continuity of the evaporation molding of the second electrode 230. The sidewall 111a of the second covering sub-portion 210a22 is provided with an undercut structure 112, so that the light-emitting layer 220 can be disconnected at the undercut structure 112, so that the leakage transmission of holes or electrons between different light-emitting elements 200 can be avoided, thereby avoiding the situation of crosstalk between different light-emitting elements 200, thereby ensuring the display effect of the display panel 10. Alternatively, the light-emitting layer 220 is not disconnected at the undercut structure 112, but the area at the undercut structure 112 is filled, so that the transmission path of the light-emitting layer 220 is increased, and the leakage transmission of holes or electrons between different light-emitting elements 200 can also be reduced, thereby improving the overall display effect of the display panel 10. Therefore, the second etching protection sub-portion 402 only covers the sidewall of the second limiting sub-portion 111a2.

[0137] S340 , etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process to form a second transition pixel opening and a portion of the undercut structure.

[0138] Exemplary, reference Fig.15 As shown in step d, an isotropic etching process is used to etch a portion of the pixel defining layer located in the first transition pixel opening 110b to form a second transition pixel opening 110c and a partial undercut structure 112 that penetrates at least a portion of the sidewall of the second defining portion 111a2.

[0139] S350 , etching the protection layer and a partial thickness of the pixel defining layer located in the second transition pixel opening to form a pixel opening and an undercut structure.

[0140] Exemplary, reference Fig.15 Step e.

[0141] S360, preparing a light-emitting layer and a second electrode of the light-emitting element.

[0142] Exemplary, reference Fig.15 Step f.

[0143] Fig.16 A schematic diagram of a fourth display panel manufacturing method provided by an embodiment of the present invention is shown in FIG. Fig.16 As shown, the method for manufacturing a display panel provided in an embodiment of the present invention further includes:

[0144] S410, preparing a driving substrate.

[0145] S420 , patterning the pixel defining layer using a first half mask to form a first A transition pixel opening in the pixel defining layer.

[0146] S430 , patterning the pixel defining layer using a second half mask to form a first B-transition pixel opening in the pixel defining layer.

[0147] Among them, the transmittance of the first half mask is less than the transmittance of the second half mask. When etching is performed using masks with different transmittances, the thickness of the film layer formed is different. Specifically, the pixel defining layer is patterned using the first half mask with relatively low transmittance, and a first A transition pixel opening is correspondingly formed in the pixel defining layer, and the corresponding first pixel opening can be formed through the subsequent etching process. The pixel defining layer is patterned using the second half mask with relatively high transmittance to form a first B transition pixel opening in the pixel defining layer, and the corresponding second pixel opening can be formed through the subsequent etching process.

[0148] Fig.17 is a schematic diagram of steps in a display panel manufacturing process provided by an embodiment of the present invention, with reference to Fig.17 As shown, after the pixel defining layer is patterned using the first half mask and the second half mask, a first A transition pixel opening 115 and a first B transition pixel opening 116 are formed correspondingly. Since the transmittances of the first half mask and the second half mask are different, the depths of the first A transition pixel opening 115 and the first B transition pixel opening 116 formed correspondingly are different. Among them, the transmittance of the first half mask is less than the transmittance of the second half mask, so the depth of the first A transition pixel opening 115 is less than the depth of the first B transition pixel opening 116, or it can be understood that the thickness of the pixel defining layer 110 remaining in the first A transition pixel opening 115 is greater than the thickness of the pixel defining layer 110 remaining in the first B transition pixel opening 116.

[0149] The process from S410 to S420 can be referred to Fig.13 or Fig.15 shown.

[0150] Further, the display panel includes a plurality of light-emitting elements, and the light-emitting elements include a first light-emitting element and a second light-emitting element, wherein the first light-emitting element and the second light-emitting element can be understood as light-emitting elements of different colors. Exemplarily, the first light-emitting element can be a red light-emitting element, and the second light-emitting element can be a blue light-emitting element. The first light-emitting element prepared later will include a first light-emitting layer, and the second light-emitting element prepared later will include a second light-emitting layer. Since the light-emitting colors of the first light-emitting element and the second light-emitting element are different, the corresponding light-emitting layers also have differences. For example, along the first direction, the thickness of the first light-emitting layer is greater than the thickness of the second light-emitting layer. The display panel finally prepared has flatness. Under different light-emitting elements, if the corresponding light-emitting layer thicknesses are different, in order to ensure the display effect of the display surface, the undercut structure prepared later can effectively block leakage by adjusting the depth of the undercut structure when corresponding to different light-emitting layer thicknesses. Specifically, if the thickness of the first light-emitting layer is greater than the thickness of the second light-emitting layer, the depth of the undercut structure prepared later near the first light-emitting layer should be greater than the depth of the undercut structure near the second light-emitting layer. In order to ensure the preparation of undercut structures of different depths, masks with different transmittances can be used to etch pixel defining layers of different depths, corresponding to pixel defining layers of different depths remaining in the first A transition pixel opening and the first B transition pixel opening, thereby facilitating the preparation of undercut structures of different depths.

[0151] S440, preparing an etching protection layer and patterning the etching protection layer.

[0152] S450, using an isotropic etching process to etch a portion of the pixel defining layer located in the first A transition pixel opening and the first B transition pixel opening respectively, to form a portion of the first undercut structure and a portion of the second undercut structure.

[0153] Furthermore, an isotropic etching process is used to etch a portion of the pixel defining layer located in the first A transition pixel opening and the first B transition pixel opening, that is, the pixel defining layer remaining at the first A transition pixel opening and the pixel defining layer remaining at the first B transition pixel opening are removed, and different undercut structures are formed correspondingly. Specifically, a portion of the first undercut structure is formed at the first A transition pixel opening, and a portion of the second undercut structure is formed at the first B transition pixel opening.

[0154] S460, etching the protective layer and the pixel defining layer with a partial thickness located in the first transition pixel opening to form a pixel opening and an undercut structure. Etching the protective layer, the pixel defining layer with a partial thickness located in the first A transition pixel opening, and the pixel defining layer with a partial thickness located in the first B transition pixel opening to form a first undercut structure and a second undercut structure, respectively.

[0155] Fig.18is a schematic diagram of steps in another display panel manufacturing process provided by an embodiment of the present invention, with reference to Fig.18 As shown, all the pixel defining layers remaining in the first transition pixel opening are etched, that is, a portion of the thickness of the pixel defining layer in the first A transition pixel opening is etched to form a first pixel opening 110a1; and a portion of the thickness of the pixel defining layer in the first B transition pixel opening is etched to form a second pixel opening 110a2. And a first undercut structure 112A can be formed on the side wall of the pixel defining structure at the corresponding first pixel opening 110a1, and a second undercut structure 112B can be formed on the side wall of the pixel defining structure at the corresponding second pixel opening 110a2. At least part of the film layer in the first light-emitting layer 220A in the first light-emitting element 200A is disconnected at the position of the first undercut structure 112A, and at least part of the film layer in the second light-emitting layer 220B in the second light-emitting element 200B is disconnected at the position of the second undercut structure 112B.

[0156] Among them, when there is a difference in thickness between the first light-emitting layer and the second light-emitting layer, in order to ensure that the first light-emitting layer and the second light-emitting layer can disconnect at least part of the film layer at the corresponding undercut structure or increase the extension path of the film layer, the first undercut structure and the second undercut structure can be adjusted to have different depths. That is, the depth of the undercut structure can be adaptively adjusted according to the thickness of the adjacent light-emitting layer. In the case where the thickness of the first light-emitting layer is greater than the thickness of the second light-emitting layer along the first direction, the depth of the first undercut structure is adjusted to be greater than the depth of the second undercut structure. It can be ensured that there is no or less leakage in the first light-emitting element and the second light-emitting element, thereby ensuring the overall display effect of the display panel. The rest of the preparation process can also refer to Fig.13 or Fig.15 shown.

[0157] S470, preparing a light-emitting layer and a second electrode of the light-emitting element.

[0158] Fig.19 A schematic diagram of a fifth method for manufacturing a display panel provided by an embodiment of the present invention, Fig. 20 is a schematic diagram of a third display panel manufacturing process provided by an embodiment of the present invention, with reference to Fig.19 and Fig. 20 As shown, the method for preparing a display panel provided in an embodiment of the present invention further includes:

[0159] S510, preparing a driving substrate.

[0160] Exemplary, reference Fig. 20 As shown in step a.

[0161] S520 , patterning the pixel defining layer using a half mask process to form a first transition pixel opening in the pixel defining layer.

[0162] Exemplary, reference Fig. 20 As shown in step b, a first transition pixel opening 110 b is formed in the pixel defining layer 110 .

[0163] S530 , preparing an etching protection layer and patterning the etching protection layer.

[0164] The pixel defining structure between two adjacent pixel openings includes a third defining sub-section and a fourth defining sub-section, wherein the third defining sub-section is closer to the first transition pixel opening, that is, closer to the subsequently prepared pixel opening, than the fourth defining sub-section. The projection of the third defining sub-section onto the substrate at least partially overlaps with the projection of the first electrode onto the substrate, that is, and along the first direction, the third defining sub-section covers the edge of the first electrode.

[0165] Exemplary, reference Fig. 20 As shown in step c, combined Figure 8 The schematic diagram of the structure after preparation is shown. Figure 8 Only one pixel opening 110 is shown in the figure, wherein the third defining subsection 111a3 can be understood as an area in the pixel defining layer 110, close to the first transition pixel opening 110b and covering the etching protection layer 400. The fourth defining subsection 114a4 can be understood as a side of the third defining subsection 111a3 in the pixel defining layer 110, which is away from the first transition pixel opening 110b. Specifically, an etching protection layer is prepared and patterned, and the pixel defining structure covered by the etching protection layer, that is, the pixel defining structure that is not etched is the third defining subsection, and the pixel defining structure that is not protected by the etching protection layer and etched is the fourth defining subsection. There are also some pixel defining structures that are not etched in the first transition pixel opening. That is, after the etching process, part of the pixel defining layer located in the first transition pixel opening is also included.

[0166] S540 , etching the fourth defining portion and a portion of the pixel defining layer located in the first transition pixel opening by using an isotropic etching process.

[0167] Exemplary, reference Fig. 20 As shown in step d, the fourth defining section 114a4 and a portion of the pixel defining layer 110 located in the first transition pixel opening 110b are etched by an isotropic etching process to initially thin the fourth defining section 114a4 and form a second transition pixel opening 110c and a portion of the undercut structure 112.

[0168] S550 , etching the protection layer, the fourth defining portion, and a pixel defining layer with a partial thickness located in the second transition pixel opening.

[0169] Exemplary, reference Fig. 20 As shown in step e.

[0170] The protective layer 400, the fourth defining sub-portion 114a4 and the pixel defining layer 110 of a portion of thickness located in the second transition pixel opening 110c are etched to thin the fourth defining sub-portion 114a4 again and form the pixel opening 110a and the undercut structure 112. Figure 8 As shown, the third defining sub-section includes a first surface, and the fourth defining sub-section includes a second surface, the first surface is a surface of the third defining sub-section away from the substrate, and the second surface is a surface of the fourth defining sub-section away from the substrate. Further, the distance between the first surface and the substrate is greater than the distance between the second surface and the substrate, that is, the surface of the third defining sub-section away from the substrate is convex compared to the surface of the fourth defining sub-section away from the substrate, that is, the surface of the pixel defining structure between two adjacent pixel openings away from the substrate is convex at the third defining sub-section.

[0171] S560, preparing a light-emitting layer and a second electrode of the light-emitting element.

[0172] Exemplary, reference Fig. 20 As shown in step f, a light-emitting layer 220 is prepared on the side of the first electrode 210 away from the substrate 101, and a second electrode is prepared on the side of the light-emitting layer 220 away from the first electrode 210. S570, preparing a packaging structure.

[0173] Exemplary, reference Fig. 20 Specifically, a packaging structure 300 is prepared on the side of the second electrode away from the driving substrate, the packaging structure includes a first packaging layer 310 close to the pixel defining layer, and the surface of the first packaging layer on the side away from the driving substrate includes a protrusion 311 protruding from the side away from the substrate, and along the first direction, the protrusion 311 overlaps with the edge of the third defining portion 111a3 and the first electrode 210.

[0174] Specifically, the display panel also includes a packaging structure, which is used to package and protect the entire display panel. Among them, the packaging structure also includes a first packaging layer, and the first packaging layer is located on the side of the second electrode away from the substrate, that is, the first packaging layer covers the second electrode. Exemplarily, the first packaging layer can be an inorganic metal layer, which is prepared by chemical vapor deposition. Further, the second electrode and the first packaging layer are arranged uniformly, that is, the second electrode and the first packaging layer will cover the third limiting division. Since the third limiting division is a protruding structure compared to the fourth limiting division in the pixel limiting structure, that is, it is equivalent to padding at the third limiting division, and then the first packaging layer will also have a protruding structure in the corresponding setting area of ​​the third limiting division. Specifically, the surface of the first packaging layer facing away from the substrate side is a protrusion protruding away from the substrate side, and the protrusion is equivalent to a microprism, which can adjust the light emitted from the pixel opening when transmitting it to the protrusion, that is, adjust the light output angle of the large viewing angle, improve the light output efficiency and reduce the dispersion, so as to ensure the overall display effect of the display panel 10.

[0175] Optionally, since the third defined portion is padded, the height of the padded area is also adjusted when preparing the first encapsulation layer, that is, the first encapsulation layer is also padded at the third defined portion. And the transmission of light can also be adjusted accordingly to ensure the overall display effect of the display panel. It should be noted that the shape of the protrusion can be semicircular or trapezoidal, and the specific morphology of the protrusion can be adaptively adjusted according to different processes.

[0176] In summary, the display panel provided by the embodiment of the present invention can further ensure the overall display effect of the display panel through the design and adjustment of the undercut structure and the protrusion of the structure at the first packaging layer.

[0177] Based on the same inventive concept, an embodiment of the present invention further provides a display device, Fig.21 is a schematic diagram of the structure of a display device provided by an embodiment of the present invention, such as Fig.21 As shown, the display device 1 includes the display panel 10 described in any of the above embodiments. Therefore, the display device 1 provided in the embodiment of the present invention has the corresponding beneficial effects of the above embodiments, which will not be repeated here. The display device 1 can be an electronic device such as a mobile phone, a computer, a smart wearable device (for example, a smart watch), and a car display device.

[0178] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A display panel, characterized in that: It includes a driving substrate and a plurality of light-emitting elements; The driving substrate includes a pixel defining layer; The light emitting element comprises a first electrode, a light emitting layer and a second electrode which are stacked, and the second electrode is located on a side of the light emitting layer away from the driving substrate along a first direction; the first direction is a thickness direction of the display panel; The pixel defining layer includes a plurality of pixel openings and a pixel defining structure surrounding the pixel openings, wherein the pixel openings expose a portion of the first electrode; The pixel defining structure includes a side wall close to one side of the pixel opening, and the display panel also includes an undercut structure located in the pixel defining structure and penetrating at least a portion of the side wall, the depth of the undercut structure in the first direction is L1, and the thickness of the light-emitting layer in the first direction is L2; ​​wherein L1≥L2.

2. The display panel according to claim 1, characterized in that: The thickness of the second electrode in the first direction is L3; Among them, L1≤L2+L3.

3. The display panel according to claim 1, characterized in that: The driving substrate further includes a driving circuit; The first electrode comprises an electrode main body portion and an electrode connecting portion connected to each other, the electrode main body portion covers the pixel opening along the first direction, and the electrode connecting portion is electrically connected to the driving circuit; The electrode main body portion includes an exposed portion and a covered portion that are connected, the pixel opening exposes the exposed portion, and the pixel defining structure covers the covered portion; the covered portion includes a first covering sub-portion and a second covering sub-portion, the first covering sub-portion is connected to the electrode connecting portion, and the second covering sub-portion and the first covering sub-portion are both connected to the exposed portion; The pixel defining structure comprises a first defining sub-portion and a second defining sub-portion connected, wherein the first defining sub-portion covers the first covering sub-portion, and the second defining sub-portion covers the second covering sub-portion; The undercut structure is not arranged on the side wall of the first defining section, and the undercut structure is arranged on the side wall of the second defining section.

4. The display panel according to claim 1, characterized in that: The light-emitting element includes a first light-emitting element and a second light-emitting element, the first light-emitting element includes a first light-emitting layer, and the second light-emitting element includes a second light-emitting layer; The display panel comprises a first undercut structure and a second undercut structure, at least a portion of the film layer in the first light-emitting layer is disconnected at the position of the first undercut structure, and at least a portion of the film layer in the second light-emitting layer is disconnected at the position of the second undercut structure; Along the first direction, the thickness of the first light-emitting layer is greater than the thickness of the second light-emitting layer, and the depth of the first undercut structure is greater than the depth of the second undercut structure.

5. The display panel according to claim 1, characterized in that: The side surface of the undercut structure includes a curved surface; The arc surface includes a first arc surface position and a second arc surface position, the curvature radius of the first arc surface position is R1, the curvature radius of the second arc surface position is R2, and |R1-R2| / R1≤20%.

6. The display panel according to claim 1, characterized in that: The pixel defining structure between two adjacent pixel openings comprises a third defining sub-section and a fourth defining sub-section, wherein the third defining sub-section is located on a side of the fourth defining sub-section close to the pixel opening; and along the first direction, the third defining sub-section covers an edge of the first electrode; The driving substrate further comprises a substrate, the third defined sub-portion comprises a first surface facing away from the substrate, the fourth defined sub-portion comprises a second surface facing away from the substrate, and a distance between the first surface and the substrate is greater than a distance between the second surface and the substrate; The display panel also includes a packaging structure, which is located on a side of the second electrode away from the driving substrate; the packaging structure includes a first packaging layer close to the pixel defining layer, and a surface of the first packaging layer facing away from the substrate includes a protrusion protruding away from the substrate, and along the first direction, the protrusion overlaps with the third defining portion and overlaps with an edge of the first electrode.

7. The display panel according to claim 6, characterized in that: The light emitting element includes a third light emitting element and a fourth light emitting element, the pixel opening includes a first pixel opening and a second pixel opening, the first pixel opening exposes a portion of the first electrode of the third light emitting element, and the second pixel opening exposes a portion of the first electrode of the fourth light emitting element; The opening area of ​​the first pixel opening is larger than the opening area of ​​the second pixel opening; The third defining sub-section includes a third A defining sub-section and a third B defining sub-section, the third A defining sub-section covers the edge of the first electrode of the third light-emitting element, and the third B defining sub-section covers the edge of the first electrode of the fourth light-emitting element; the protrusion includes a first protrusion and a second protrusion, along the first direction, the first protrusion overlaps with the third A defining sub-section and the edge of the first electrode of the third light-emitting element, and the second protrusion overlaps with the third B defining sub-section and the edge of the first electrode of the fourth light-emitting element; The projection area of ​​the orthographic projection of the third A limiting section on the plane where the substrate is located is larger than the projection area of ​​the orthographic projection of the third B limiting section on the plane where the substrate is located, and the projection area of ​​the orthographic projection of the first protrusion on the plane where the substrate is located is larger than the projection area of ​​the orthographic projection of the second protrusion on the plane where the substrate is located.

8. The display panel according to claim 6, characterized in that: The light emitting element includes a fifth light emitting element, the pixel opening includes a third pixel opening, and the third pixel opening exposes a portion of the first electrode of the fifth light emitting element; The third defining section includes a third C defining section, the protrusion includes a third protrusion, and along the first direction, the third protrusion overlaps with the third C defining section and overlaps with an edge of the first electrode of the fifth light-emitting element; The third protrusion includes a first protrusion edge and a second protrusion edge, wherein the orthographic projection of the first protrusion edge on the plane where the substrate is located is located on a side of the orthographic projection of the second protrusion edge on the plane where the substrate is located away from the center of the third pixel opening; The angle between the maximum viewing angle light of the fifth light-emitting element and the first electrode is α, and the angle between the normal line of the tangent plane at the edge of the first protrusion and the first electrode is β; Where β<α.

9. The display panel according to claim 6, characterized in that: The encapsulation structure comprises a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer which are stacked, wherein the first inorganic encapsulation layer is located on a side of the organic encapsulation layer close to the pixel defining layer; The first encapsulation layer includes the first inorganic encapsulation layer.

10. A method for preparing a display panel, characterized in that: include: Prepare a driving substrate, wherein the driving substrate includes a pixel defining layer, and the pixel defining layer covers the first electrode of the light emitting element; patterning the pixel defining layer to form a pixel opening, an undercut structure, and a pixel defining structure in the pixel defining layer; The pixel opening exposes a portion of the first electrode; The pixel definition structure surrounds the pixel opening and includes a side wall close to one side of the pixel opening; the undercut structure is located in the pixel definition structure and penetrates at least a portion of the side wall and is connected to the pixel opening; A light-emitting layer and a second electrode of the light-emitting element are prepared, wherein the light-emitting layer at least covers the pixel opening, and along a first direction, the second electrode is located on a side of the light-emitting layer away from the driving substrate; the depth of the undercut structure in the first direction is L1, and the thickness of the light-emitting layer in the first direction is L2, L1≥L2; the first direction is the thickness direction of the display panel.

11. The preparation method according to claim 10, characterized in that: Patterning the pixel defining layer to form a pixel opening, an undercut structure, and a pixel defining structure in the pixel defining layer, comprising: The pixel defining layer is patterned by a half-mask process to form a first transition pixel opening in the pixel defining layer; along the first direction, the first transition pixel opening overlaps the first electrode, and the depth of the first transition pixel opening is less than the thickness of the pixel defining layer; Preparing an etching protection layer and patterning the etching protection layer, wherein the etching protection layer at least exposes the pixel defining layer located in the first transition pixel opening; Etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process to form a second transition pixel opening and a portion of the undercut structure, wherein the depth of the second transition pixel opening along the first direction is less than the thickness of the pixel defining layer; The etching protection layer and a portion of the thickness of the pixel defining layer located in the second transition pixel opening are etched to form the pixel opening and the undercut structure.

12. The preparation method according to claim 11, characterized in that: The driving substrate further includes a driving circuit; The first electrode comprises an electrode main body portion and an electrode connecting portion connected to each other, the electrode main body portion covers the pixel opening along the first direction, and the electrode connecting portion is electrically connected to the driving circuit; The electrode main body portion includes an exposed portion and a covered portion that are connected, the pixel opening exposes the exposed portion, and the pixel defining structure covers the covered portion; the covered portion includes a first covering sub-portion and a second covering sub-portion, the first covering sub-portion is connected to the electrode connecting portion, and the second covering sub-portion is connected to the first covering sub-portion; The pixel defining structure comprises a first defining sub-portion and a second defining sub-portion connected, wherein the first defining sub-portion covers the first covering sub-portion, and the second defining sub-portion covers the second covering sub-portion; Preparing an etching protection layer and patterning the etching protection layer, wherein the etching protection layer at least exposes the pixel defining layer located in the first transition pixel opening, comprises: Prepare an etching protection layer and pattern the etching protection layer, wherein the etching protection layer includes a first etching protection sub-portion covering the first limiting sub-portion and a second etching protection sub-portion covering the second limiting sub-portion, wherein the first etching protection sub-portion covers the sidewall of the first limiting sub-portion and a portion of the bottom surface located in the first transition pixel opening, and the second etching protection sub-portion covers the sidewall of the second limiting sub-portion; Etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process to form a second transition pixel opening and a portion of the undercut structure, comprising: The pixel defining layer having a partial thickness located in the first transition pixel opening is etched by an isotropic etching process to form a second transition pixel opening and a portion of the undercut structure penetrating through at least a portion of the sidewall of the second defining section.

13. The preparation method according to claim 11, characterized in that: The light-emitting element includes a first light-emitting element and a second light-emitting element, the first light-emitting element includes a first light-emitting layer, the second light-emitting element includes a second light-emitting layer, and along the first direction, the thickness of the first light-emitting layer is greater than the thickness of the second light-emitting layer; Patterning the pixel defining layer using a half mask process to form a first transition pixel opening in the pixel defining layer, comprising: Patterning the pixel defining layer using a first half mask to form a first A transition pixel opening in the pixel defining layer, wherein the first A transition pixel opening overlaps the first electrode of the first light-emitting element along the first direction; The pixel defining layer is patterned using a second half mask to form a first B transition pixel opening in the pixel defining layer, wherein the first B transition pixel opening overlaps the first electrode of the second light emitting element along the first direction; the transmittance of the first half mask is less than the transmittance of the second half mask; Etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process to form a portion of the undercut structure, comprising: The pixel defining layer having a portion of thickness located in the first A transition pixel opening and the first B transition pixel opening is etched by an isotropic etching process to form a portion of a first undercut structure and a portion of a second undercut structure; along the first direction, the depth of the first undercut structure is greater than the depth of the second undercut structure; Etching the etching protection layer and a portion of the thickness of the pixel defining layer located in the second transition pixel opening to form the undercut structure, comprising: The etching protection layer, the pixel defining layer with a partial thickness located in the first A transition pixel opening, and the pixel defining layer with a partial thickness located in the first B transition pixel opening are etched to form a first undercut structure and a second undercut structure, respectively; along the first direction, the depth of the first undercut structure is greater than the depth of the second undercut structure.

14. The preparation method according to claim 11, characterized in that: Etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process, comprising: Etching a portion of the pixel defining layer located in the first transition pixel opening by a wet etching process; Etching the etching protection layer and a portion of the thickness of the pixel defining layer located in the second transition pixel opening, comprising: The etching protection layer and a portion of the pixel defining layer located in the second transition pixel opening are etched using a dry etching process.

15. The preparation method according to claim 11, characterized in that: After preparing the light-emitting layer and the second electrode of the light-emitting element, the method further comprises: A packaging structure is prepared, the packaging structure comprising a first packaging layer close to the pixel defining layer, the surface of the first packaging layer facing away from the driving substrate comprising a protrusion protruding away from the driving substrate, and along the first direction, the protrusion overlaps with the edge of the first electrode.

16. The preparation method according to claim 15, characterized in that: The pixel defining structure between two adjacent pixel openings comprises a third defining sub-section and a fourth defining sub-section, wherein the third defining sub-section is located on a side of the fourth defining sub-section close to the pixel opening; and along the first direction, the third defining sub-section covers an edge of the first electrode; Preparing an etching protection layer and patterning the etching protection layer, wherein the etching protection layer at least exposes the pixel defining layer located in the first transition pixel opening, comprises: preparing an etching protection layer and patterning the etching protection layer, wherein the etching protection layer covers the third defining sub-portion, exposes the fourth defining sub-portion and the pixel defining layer located in the first transition pixel opening; Etching a portion of the pixel defining layer located in the first transition pixel opening by an isotropic etching process to form a second transition pixel opening and a portion of the undercut structure, comprising: Etching the fourth defined sub-portion and a portion of the pixel defined layer located in the first transition pixel opening by an isotropic etching process, so as to initially thin the fourth defined sub-portion and form a second transition pixel opening and a portion of the undercut structure; Etching the etching protection layer and a portion of the thickness of the pixel defining layer located in the second transition pixel opening to form the pixel opening and the undercut structure, comprising: The etching protection layer, the fourth defining sub-portion, and a portion of the pixel defining layer located in the second transition pixel opening are etched to thin the fourth defining sub-portion again and form the pixel opening and the undercut structure; the driving substrate further comprises a substrate, the third defining sub-portion comprises a first surface facing away from the substrate, the fourth defining sub-portion comprises a second surface facing away from the substrate, and the distance between the first surface and the substrate is greater than the distance between the second surface and the substrate; A packaging structure is prepared, wherein the packaging structure includes a first packaging layer close to a side of the pixel defining layer, and a surface of the first packaging layer on a side away from the driving substrate includes a protrusion protruding away from a side of the substrate, and along the first direction, the protrusion overlaps with an edge of the first electrode, including: A packaging structure is prepared on the side of the second electrode away from the driving substrate, the packaging structure includes a first packaging layer close to the pixel defining layer, the surface of the first packaging layer on the side away from the driving substrate includes a protrusion protruding away from the substrate side, and along the first direction, the protrusion overlaps with the edge of the third defining portion and the first electrode.

17. A display device, characterized in that: A display panel comprising any one of claims 1 to 9.

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