Display panel and preparation method thereof

Abstract

The invention discloses a display panel and a preparation method thereof, and the display panel comprises a substrate, and a plurality of light-emitting elements and a plurality of pixel limiting structures which are arranged on one side of the substrate, each light-emitting element comprises a first electrode, and each pixel limiting structure is located between two adjacent first electrodes and along the thickness direction of the display panel. The pixel limiting structure is not overlapped with the first electrode; the distance between the surface of the side, away from the substrate, of the first electrode and the substrate is a first distance, and the distance between the surface of the side, away from the substrate, of the pixel limiting structure and the substrate is a second distance; the second distance is greater than the first distance. According to the technical scheme, on one hand, the first electrode can be utilized to the maximum, the light-emitting area is effectively increased, and the light-emitting efficiency is improved; on the other hand, the light of the light-emitting elements can be prevented from diffusing to the position above the pixel limiting structures, optical crosstalk between every two adjacent light-emitting elements is avoided, and the display effect of the display panel is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of displays, and in particular to a display panel and a method for preparing the same. Background Art

[0002] For display devices, color gamut and luminous efficiency are very important performance indicators.

[0003] In existing organic light-emitting display devices, the pixel defining layer covers part of the first electrode, which affects the light-emitting efficiency. In addition, the height of the pixel defining layer is low, and the large-angle light emitted by the light-emitting element will cause crosstalk above the pixel defining layer, reducing the display effect. Summary of the invention

[0004] The present invention provides a display panel and a preparation method thereof, so as to solve the technical problems that a pixel defining layer covers part of a first electrode, thereby affecting the luminous efficiency; and that the height of the pixel defining layer is low, and the large-angle light emitted by the light-emitting element causes crosstalk above the pixel defining layer, thereby reducing the display effect.

[0005] According to one aspect of the present invention, there is provided a display panel, comprising a substrate, and a plurality of light-emitting elements and a plurality of pixel defining structures arranged on one side of the substrate:

[0006] The light emitting element comprises a first electrode, the pixel defining structure is located between two adjacent first electrodes, and along the thickness direction of the display panel, the pixel defining structure does not overlap with the first electrode;

[0007] A first distance is defined between a surface of the first electrode away from the substrate and the substrate, and a second distance is defined between a surface of the pixel defining structure away from the substrate and the substrate; the second distance is greater than the first distance.

[0008] Optionally, the first distance is L1, and the second distance is L2;

[0009] Among them, L2 / L1≥2.

[0010] Optionally, 80nm≤L1≤100nm; 170nm≤L2≤300nm.

[0011] Optionally, the pixel defining structure comprises a side wall facing the first electrode, and at least a portion of the side wall is provided with a groove;

[0012] The light emitting element further comprises a light emitting layer disposed on a side of the first electrode away from the substrate, the light emitting layer comprises a common light emitting layer, and at least a portion of the common light emitting layer is disconnected at the groove.

[0013] Optionally, the pixel defining structure comprises a first pixel defining substructure and a second pixel defining substructure which are stacked, and the second pixel defining substructure is located on a side of the first pixel defining substructure away from the substrate;

[0014] The first pixel defining substructure and the second pixel defining substructure are made of different materials, and the groove is disposed on at least a portion of the sidewall of the first pixel defining substructure.

[0015] According to another aspect of the present invention, a method for preparing a display panel is provided, the method comprising:

[0016] providing a substrate;

[0017] Prepare a first electrode of the light-emitting element on one side of the substrate;

[0018] A pixel defining structure is prepared on one side of the substrate and between two adjacent first electrodes; along the thickness direction of the display panel, the pixel defining structure and the first electrode have no overlap; and the distance between the surface of the first electrode away from the substrate and the substrate is a first distance, and the distance between the surface of the pixel defining structure away from the substrate and the substrate is a second distance; the second distance is greater than the first distance.

[0019] Optionally, a pixel defining structure is prepared on one side of the substrate and between two adjacent first electrodes, including:

[0020] A first pixel defining layer is prepared on one side of the substrate and on a side of the first electrode away from the substrate; the first pixel defining layer includes a first defining sub-portion located on one side of the substrate and a second defining sub-portion located on a side of the first electrode away from the substrate; a third distance is defined between a surface of the first defining sub-portion away from the substrate and the substrate, and a fourth distance is defined between a surface of the second defining sub-portion away from the substrate and the substrate; the third distance is L3, and the fourth distance is L4; wherein |L4-L3| / L3≤20%;

[0021] Preparing a second pixel defining layer on a side of the first pixel defining layer away from the substrate;

[0022] The pixel defining structure is prepared by patterning the first pixel defining layer and the second pixel defining layer.

[0023] Optionally, preparing a first pixel defining layer on one side of the substrate and on a side of the first electrode away from the substrate includes:

[0024] Preparing a first pixel defining material layer on one side of the substrate and on a side of the first electrode away from the substrate;

[0025] preparing an organic layer on a side of the first pixel defining material layer away from the substrate;

[0026] The organic layer and the first pixel defining material layer are etched with a mixed etching gas to prepare the first pixel defining layer; the etching rate of the mixed etching gas on the organic layer is V1, and the etching rate of the mixed etching gas on the first pixel defining material layer is V2; wherein 0.8≤V1:V2≤1.2.

[0027] Optionally, the mixed etching gas includes carbon tetrafluoride, trifluoromethane, difluoromethane and oxygen.

[0028] Optionally, patterning the first pixel defining layer and the second pixel defining layer to obtain the pixel defining structure includes:

[0029] Photolithography and etching the first pixel defining layer and the second pixel defining layer using the same etching gas, wherein the etching rate of the etching gas on the first pixel defining layer is greater than the etching rate of the second pixel defining layer, so as to form a groove on at least a part of the side wall of the first pixel defining layer;

[0030] The preparation method further comprises:

[0031] A light-emitting layer is prepared on a side of the first electrode away from the substrate, wherein the light-emitting layer includes a common light-emitting layer, and at least a portion of the common light-emitting layer is disconnected at the groove.

[0032] In the embodiment of the present invention, the pixel defining structure is arranged to have no overlap with the first electrode, and compared with the prior art, the first electrode is utilized to the maximum extent, and the surface of the first electrode away from the substrate can be covered with a light-emitting layer, thereby effectively increasing the light-emitting area and improving the light-emitting efficiency. In addition, the pixel defining structure between two adjacent first electrodes is arranged to be higher than the first electrode, so that the pixel defining structure can reflect the large-angle light emitted by the light-emitting element, thereby preventing the light of the light-emitting element from being scattered above the pixel defining structure, causing optical crosstalk between two adjacent light-emitting elements, and improving the display effect of the display panel.

[0033] 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

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 It is a schematic diagram of a display panel structure in the prior art;

[0036] Figure 2 is a schematic diagram of a display panel structure provided according to an embodiment of the present invention;

[0037] Figure 3 is a schematic flow chart of a first method for preparing a display panel provided according to an embodiment of the present invention;

[0038] Figure 4 is a process flow chart of a first method for preparing a display panel provided according to an embodiment of the present invention;

[0039] Figure 5 is a schematic flow chart of a second method for preparing a display panel provided according to an embodiment of the present invention;

[0040] Figure 6 is a process flow chart of a second method for preparing a display panel provided according to an embodiment of the present invention;

[0041] Figure 7 is a schematic flow chart of a third method for preparing a display panel provided according to an embodiment of the present invention;

[0042] Figure 8 is a process flow chart of a third method for preparing a display panel provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0044] 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 process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] Figure 1 This is a schematic diagram of a display panel structure in the prior art. Figure 1 In the prior art, the pixel defining structure 3' and the first electrode 21' overlap along the thickness direction -Z' of the display panel, that is, the pixel defining structure 3' covers part of the first electrode 21'. Therefore, the area where the light-emitting layer 4' can be set on the side of the first electrode 21' away from the substrate is limited, which affects the luminous efficiency. In addition, the height of the pixel defining structure 3' is low, and since the light emitting direction of the light-emitting element 2' is relatively dispersed, the light of the light-emitting element 2' will diverge to the top of the pixel defining structure 3' and cause crosstalk, affecting the display effect.

[0046] In order to solve the above problems, Figure 2 is a schematic diagram of a display panel structure provided according to an embodiment of the present invention. Figure 2 The display panel includes: a substrate 1 and a plurality of light-emitting elements 2 and a plurality of pixel-defining structures 3 arranged on one side of the substrate: the light-emitting element 2 includes a first electrode 21, the pixel-defining structure 3 is located between two adjacent first electrodes 21, and along the thickness direction -Z of the display panel, the pixel-defining structure 3 has no overlap with the first electrode 21; the distance between the surface of the first electrode 21 away from the substrate 1 and the substrate 1 is a first distance, and the distance between the surface of the pixel-defining structure 3 away from the substrate 1 and the substrate 1 is a second distance; the second distance is greater than the first distance.

[0047] Specifically, Figure 2As shown, the display panel can be a Micro OLED display device, the substrate 1 can be a complementary metal oxide semiconductor (CMOS) substrate, also known as a silicon-based backplane, and the first electrode 21 can be an anode. The pixel defining structure 3 is located between two adjacent first electrodes 21, and controls the light-emitting area of ​​the light-emitting element 2. There is no overlap between the projections of the pixel defining structure 3 and the first electrode 21 along the thickness direction -Z. The advantage of this arrangement is that the pixel defining structure 3 will not occupy the area of ​​the first electrode 21 away from the substrate, and the light-emitting layer 4 can cover the area of ​​the first electrode 21 away from the substrate, effectively increasing the light-emitting area and improving the light-emitting efficiency.

[0048] Further, the distance between the surface of the first electrode 21 away from the substrate 1 and the substrate 1 is a first distance, which may be the thickness of the first electrode 21, and the distance between the surface of the pixel defining structure 3 away from the substrate 1 and the substrate 1 is a second distance, which may be the thickness of the pixel defining structure 3, wherein the second distance is greater than the first distance, that is, the thickness of the pixel defining structure 3 is greater than the first electrode 21. In the display panel configured in this way, the pixel defining structure 3 between two adjacent first electrodes 21 is higher than the first electrode 21, so that the pixel defining structure can reflect the light diverging obliquely upward from the light emitting element 2, and prevent the light of the light emitting element 2 from diagonally diverging above the pixel defining structure 3, causing optical crosstalk between two adjacent light emitting elements 2, so as to improve the display effect of the display panel.

[0049] In the embodiment of the present invention, the pixel defining structure is arranged to have no overlap with the first electrode, and compared with the prior art, the first electrode is utilized to the maximum extent, and the surface of the first electrode away from the substrate can be covered with a light-emitting layer, thereby effectively increasing the light-emitting area and improving the light-emitting efficiency. In addition, the pixel defining structure between two adjacent first electrodes is arranged to be higher than the first electrode, so that the pixel defining structure can reflect the light that is diagonally diverged from the light-emitting element upward, thereby preventing the light of the light-emitting element from diagonally diverging above the pixel defining structure, causing optical crosstalk between two adjacent light-emitting elements, and thus improving the display effect of the display panel.

[0050] Based on the above embodiment, the embodiment of the present invention further defines the heights of the first distance and the second distance, such as Figure 2 As shown, the first distance is L1, and the second distance is L2; ​​wherein, L2 / L1≥2.

[0051] Specifically, Figure 2As shown, in the embodiment of the present invention, the height of the pixel defining structure 3 between two adjacent first electrodes is at least twice the height of the first electrode 21, that is, the height of the pixel defining structure 3 in the embodiment of the present invention is much higher than the height of the first electrode 21. In this way, the height advantage of the pixel defining structure 3 can be used to effectively reflect the large-angle light diverged by the light-emitting element 2, thereby preventing the large-angle light diverged by the light-emitting element 2 from optical crosstalk above the pixel defining structure 3, thereby improving the display effect of the display panel.

[0052] Furthermore, 80nm≤L1≤100nm, 170nm≤L2≤300nm, for example, the first distance is set to 100nm, and the second distance is set to 200nm. At this time, the height of the pixel defining structure 3 is twice the height of the first electrode 21, ensuring that the height advantage of the pixel defining structure 3 can be utilized to effectively reflect the large-angle light emitted by the light-emitting element 2 to enhance the display effect of the display panel.

[0053] The embodiment of the present invention further describes the pixel definition structure. Figure 2 As shown, the pixel defining structure 3 includes a side wall 5 facing the first electrode 21, and a groove 6 is provided in at least a portion of the side wall 5; the light-emitting element 2 also includes a light-emitting layer 4 arranged on the side of the first electrode 21 away from the substrate 1, and the light-emitting layer 4 includes a common light-emitting layer (not shown in the figure), and at least a portion of the common light-emitting layer is disconnected at the groove 6.

[0054] Specifically, the light-emitting layer 4 also includes a common light-emitting layer and an excitation layer. The common light-emitting layer may include a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer arranged in a stacked manner. The excitation layer is located between the hole transport layer and the electron transport layer and overlaps with the first electrode. The holes transmitted by the hole transport layer and the electrons transmitted by the electron transport layer recombine in the excitation layer and emit light, thereby realizing normal light emission of the light-emitting layer 4. During the manufacturing process, the light-emitting layer 4 is prepared as a whole layer. Since the pixel defining structure 3 includes a side wall 5 facing the first electrode 21, at least part of the side wall 5 is provided with a groove 6. Therefore, during the manufacturing process, the common light-emitting layer is disconnected at the groove 6 to ensure that at least part of the common light-emitting layer is disconnected due to lateral leakage, for example, at least the hole injection layer and the hole transport layer are disconnected at the groove 6. The lateral leakage between two adjacent pixel areas is avoided. Among them, lateral leakage refers to the phenomenon that charges (such as holes or electrons) move laterally from one pixel area to another pixel area through the light-emitting layer 4 in the OLED panel. This phenomenon may cause problems such as image blurring and color distortion. It should be noted that a pixel region is usually composed of a first electrode 21, a light-emitting layer 4 and a cathode (not shown in the figure).

[0055] The embodiment of the present invention further describes the pixel definition structure. Figure 2As shown, the pixel defining structure 3 includes a first pixel defining substructure 31 and a second pixel defining substructure 32 which are stacked, and the second pixel defining substructure 32 is located on a side of the first pixel defining substructure 31 away from the substrate 1;

[0056] The first pixel defining substructure 31 and the second pixel defining substructure 32 are made of different materials. A groove 6 is disposed on at least a portion of a sidewall 5 of the first pixel defining substructure 31 .

[0057] Specifically, in the process of manufacturing the pixel defining structure 3, the first pixel defining substructure 31 and the second pixel defining substructure 32 are made of different materials and have different etching rates under the same etching conditions, for example, the etching rate of the first pixel defining substructure 31 is greater than the etching rate of the second pixel defining substructure 32, so as to form a groove 6 in at least a part of the sidewall 5 of the first pixel defining substructure 31. Exemplarily, the material of the first pixel defining substructure 31 may be a silicon nitride material, and the material of the second pixel defining substructure 32 may be a silicon dioxide material. Under the same etching conditions, the etching rate of the silicon nitride material is greater than that of the silicon dioxide material. Therefore, when etching for the same time, the etching amount of the silicon nitride material is greater than that of the silicon dioxide material. Based on this, the groove 6 can be formed in at least a part of the sidewall 5 of the first pixel defining substructure 31, so as to realize that at least part of the common light-emitting layer is disconnected at the groove 6, thereby avoiding lateral leakage between two adjacent pixel areas in the lateral direction, thereby improving the display effect.

[0058] Based on the above inventive concept, an embodiment of the present invention further provides a method for preparing a display panel. Figure 3 is a schematic flow chart of a first method for preparing a display panel according to an embodiment of the present invention. Figure 4 is a process flow chart of a first method for preparing a display panel provided according to an embodiment of the present invention.

[0059] like Figure 3 and Figure 4 As shown, the preparation method comprises:

[0060] S110, providing a substrate.

[0061] Specifically, Figure 4 As shown in step a1 in the figure, the substrate 1 can be a complementary metal oxide semiconductor (CMOS) substrate, also known as a silicon-based backplane, which not only serves as the basic supporting structure of the Micro OLED display device, but also integrates key electronic components and circuits. This substrate is made of single-crystal silicon material and uses mature integrated circuit CMOS technology to greatly improve the manufacturing yield and achieve high-resolution display effects.

[0062] S120, preparing a first electrode of the light-emitting element on one side of the substrate.

[0063] Specifically, Figure 4 As shown in step a2 in the process, aluminum (AL), titanium nitride (TIN) and indium tin oxide (ITO) are deposited from bottom to top on the substrate 1 to prepare the first electrode 21 of the light-emitting element.

[0064] S130, preparing a pixel definition structure on one side of the substrate and between two adjacent first electrodes.

[0065] Along the thickness direction of the display panel, the pixel defining structure 3 has no overlap with the first electrode; and the distance between the surface of the first electrode away from the substrate and the substrate is a first distance, and the distance between the surface of the pixel defining structure 3 away from the substrate and the substrate is a second distance; the second distance is greater than the first distance.

[0066] Specifically, Figure 4 As shown in step a3 in , a pixel defining structure 3 is prepared at the interval between two adjacent first electrodes 21, wherein the projection of the pixel defining structure 3 and the first electrode 21 along the thickness direction -Z does not overlap. The advantage of such a setting is that the pixel defining structure 3 will not occupy the area of ​​the first electrode 2 away from the substrate, and the light-emitting layer 4 can cover the area of ​​the first electrode 21 away from the substrate 1, effectively increasing the light-emitting area and improving the light-emitting efficiency. Furthermore, the distance between the surface of the first electrode 21 away from the substrate 1 and the substrate 1 is a first distance, which can be the thickness of the first electrode 21, and the distance between the surface of the pixel defining structure 3 away from the substrate 1 and the substrate 1 is a second distance, which can be the thickness of the pixel defining structure 3, wherein the second distance is greater than the first distance, that is, the thickness of the pixel defining structure 3 is greater than the first electrode 21. In the display panel configured in this way, the pixel defining structure 3 between two adjacent first electrodes 21 is higher than the first electrode 21, so that the pixel defining structure 3 can reflect the light diverging obliquely upward from the light-emitting element 2, thereby preventing the light of the light-emitting element 2 from diverging obliquely upward above the pixel defining structure 3, causing optical crosstalk between the two adjacent light-emitting elements 2, thereby improving the display effect of the display panel.

[0067] The embodiment of the present invention prepares the first electrode of the light-emitting element on one side of the substrate, and prepares the pixel-defining structure between two adjacent first electrodes. Along the thickness direction of the display panel, the pixel-defining structure does not overlap with the first electrode, and the pixel-defining structure arranged between the two adjacent first electrodes is higher than the first electrode. The above technical solution can maximize the use of the first electrode on the one hand, so that the surface of the first electrode away from the substrate can be covered with the light-emitting layer later, effectively increasing the light-emitting area. On the other hand, the pixel-defining structure reflects the light that is diverged obliquely upward from the light-emitting element, avoiding the light of the light-emitting element from diverging obliquely upward to the top of the pixel-defining structure, causing optical crosstalk between two adjacent light-emitting elements, so as to improve the display effect of the display panel.

[0068] Figure 5 is a schematic flow chart of a second method for preparing a display panel provided in accordance with an embodiment of the present invention. Figure 6 is a process flow chart of a second method for preparing a display panel according to an embodiment of the present invention. The embodiment of the present invention further describes how to form a pixel defining structure on a substrate. Figure 5 and Figure 6 As shown, the preparation method comprises:

[0069] S210, providing a substrate.

[0070] like Figure 6 As shown in step b1.

[0071] S220, preparing a first electrode of the light-emitting element on one side of the substrate.

[0072] like Figure 6 As shown in step b2.

[0073] S230 , preparing a first pixel defining layer on one side of the substrate and on a side of the first electrode away from the substrate.

[0074] The first pixel defining layer includes a first defining sub-portion located on one side of the substrate and a second defining sub-portion located on a side of the first electrode away from the substrate; the distance between the surface of the first defining sub-portion away from the substrate and the substrate is a third distance, and the distance between the surface of the second defining sub-portion away from the substrate and the substrate is a fourth distance; the third distance is L3, and the fourth distance is L4; wherein |L4-L3| / L3≤20%;

[0075] Specifically, Figure 6As shown in step b3, the first pixel defining layer 7 can be a silicon nitride pixel defining layer, and the first pixel defining layer 7 includes a first defining section 71 and a second defining section 72. The distance between the surface of the first defining section 71 away from the substrate 1 and the substrate 1 is a third distance L3, which can be the height of the surface of the first defining section 71 away from the substrate 1 relative to the substrate 1, and the distance between the surface of the second defining section 72 away from the substrate 1 and the substrate 1 is a fourth distance L4, which can be the height of the surface of the second defining section 72 away from the substrate 1 relative to the substrate 1, |L4-L3| / L3≤20%, that is, the distance between the surface of the first defining section 71 away from the substrate 1 and the substrate is not much different from the distance between the surface of the second defining section 72 away from the substrate 1 and the substrate, thereby ensuring that the upper surface of the first pixel defining layer is an approximately flat plane. Whether the first defined sub-section 71 is slightly higher than the second defined sub-section 72, or the first defined sub-section 71 is slightly lower than the second defined sub-section 72, as long as the ratio of the absolute value of the height difference between the first defined sub-section 71 and the second defined sub-section 72 to the height of the first defined sub-section 71 is less than or equal to 20%. Exemplarily, the third distance L3 can be 100nm, and the fourth distance L4 can be 90nm. At this time, the absolute value of the height difference between the first defined sub-section 71 and the second defined sub-section 72 and the height of the first defined sub-section 71 are 10%. At this time, the height difference between the prepared first defined sub-section 71 and the second defined sub-section 72 is not large, that is, the upper surface of the first pixel defining layer 7 is ensured to be approximately flat.

[0076] S240, preparing a second pixel defining layer on a side of the first pixel defining layer away from the substrate;

[0077] Specifically, Figure 6 As shown in step b4, a second pixel defining layer 8 is formed on the first pixel defining layer 7 by using plasma enhanced chemical vapor deposition (PECVD) technology. The second pixel defining layer 8 can be a silicon dioxide pixel defining layer with a thickness of 50nm-100nm. Plasma enhanced chemical vapor deposition (PECVD) is an advanced preparation technology that uses plasma to activate gas molecules and chemically reacts when they interact with solid surfaces to form a thin film. The advantage of forming the second pixel defining layer 8 on the first pixel defining layer 7 by PECVD technology is that the deposition rate is fast and the thickness and composition uniformity of the formed second pixel defining layer 8 are better.

[0078] S250 , patterning the first pixel defining layer and the second pixel defining layer to obtain a pixel defining structure.

[0079] Optionally, the first pixel defining layer and the second pixel defining layer are etched by photolithography and the same etching gas is used, and the etching rate of the etching gas on the first pixel defining layer is greater than the etching rate of the second pixel defining layer, so as to form a groove on at least a part of the side wall of the first pixel defining layer;

[0080] Specifically, Figure 6 As shown in step b5, after forming the second pixel defining layer 8, it is necessary to use a yellow light process for patterning, wherein the yellow light process is a photolithography process, which involves steps such as coating the silicon wafer with glue, soft baking, exposure, development, and hard baking, and uses yellow light as a light source to achieve high-precision patterning. A photoresist mask is formed above the spacing area between the first electrodes 21 for protection, and the remaining areas are subjected to development and degumming treatment, at which time the corresponding position of the first electrode 21 will be completely exposed. Then, an etcher is used to perform full-surface etching to form a pixel defining layer. Since the first pixel defining layer and the second pixel defining layer are etched using a mixed gas of nitrogen, oxygen, and trifluoromethane, under this condition, the etching rate of silicon nitride is greater than the etching rate of silicon dioxide, so after the etching is completed, a groove 6 will be formed on at least part of the sidewall 5 of the first pixel defining layer. This allows the common light-emitting layer of the light-emitting layer 4 to be disconnected at the groove 6 when the light-emitting layer 4 is subsequently prepared, thereby avoiding lateral leakage between two adjacent pixel areas in the lateral direction and improving the display effect.

[0081] S260, preparing a light-emitting layer on a side of the first electrode away from the substrate, the light-emitting layer including a common light-emitting layer, at least part of the common light-emitting layer being disconnected at the groove.

[0082] Specifically, Figure 6 As shown in step b6, the organic light-emitting material is deposited on the first electrode 21 and the pixel defining structure 3 using vacuum evaporation technology. Since the pixel defining layer 3 has a groove 6, at least part of the common light-emitting layer is disconnected at the groove 6. This avoids lateral leakage between two adjacent pixel regions.

[0083] The embodiment of the present invention first provides a substrate, then prepares a first electrode of a light-emitting element on one side of the substrate, prepares a first pixel defining layer on one side of the substrate and on a side of the first electrode away from the substrate, prepares a second pixel defining layer on a side of the first pixel defining layer away from the substrate, and then patterning the first pixel defining layer and the second pixel defining layer to obtain a pixel defining structure with a groove. When preparing the light-emitting layer, the common light-emitting layer of the light-emitting layer can be disconnected at the groove, thereby avoiding lateral leakage between two adjacent pixel areas and improving the display effect.

[0084] Figure 7 is a schematic flow chart of a third method for preparing a display panel according to an embodiment of the present invention. Figure 8is a process flow chart of a third method for preparing a display panel according to an embodiment of the present invention. The embodiment of the present invention further describes how to prepare a first pixel defining layer on one side of a substrate and on a side of a first electrode away from the substrate. Figure 7 and Figure 8 As shown, the preparation method comprises:

[0085] S310, providing a substrate.

[0086] like Figure 8 As shown in step c1.

[0087] S320, preparing a first electrode of the light-emitting element on one side of the substrate.

[0088] like Figure 8 As shown in step c2.

[0089] S330, preparing a first pixel defining material layer on one side of the substrate and on a side of the first electrode away from the substrate;

[0090] Specifically, Figure 8 As shown in step c3, a first pixel defining material layer 9 is prepared on one side of the substrate 1 and on the side of the first electrode 21 away from the substrate 1 by using plasma enhanced chemical vapor deposition (PECVD) technology. The first pixel defining material layer 9 can use silicon nitride material. The first pixel defining material layer 9 needs to be higher than the first electrode 21, and the thickness of the first pixel defining material layer 9 needs to be selected according to the thickness of the first electrode 21, and its thickness is generally set to 120nm-200nm. The advantage of forming the first pixel defining material layer 9 on the anode layer 2 by PECVD technology is that the deposition rate is fast and the thickness and composition uniformity of the first pixel defining material layer 9 are better. In addition, when depositing the first pixel defining material layer 9, the low temperature has little effect on the physical properties of the material of the first electrode 21, thereby increasing the stability of the first electrode 21.

[0091] S340, preparing an organic layer on a side of the first pixel defining material layer away from the substrate;

[0092] Specifically, Figure 8 As shown in step c4, after the first pixel defining material layer 9 is formed, a coating machine is used to coat an organic layer 10 on the side of the first pixel defining material layer 9 away from the substrate 1. The organic layer 10 can be a photoresist (PR). The photoresist has a certain fluidity, which enables it to be evenly coated on the surface of the first pixel defining material layer 9 and fill the depressions. Based on this, the organic layer 10 can fill the depressions on the surface of the first pixel defining material layer 9.

[0093] S350, using a mixed etching gas to etch the organic layer and the first pixel defining material layer to prepare a first pixel defining layer; the etching rate of the mixed etching gas on the organic layer is V1, and the etching rate of the mixed etching gas on the first pixel defining material layer is V2; wherein 0.8≤V1:V2≤1.2.

[0094] For example, Figure 8 In step c5, the first pixel defining material layer 9 is made of silicon nitride material, and the organic layer 10 is photoresist. By adjusting the gas ratio in the mixed etching gas, the first pixel defining material layer 9 and the organic layer 10 are etched at similar etching rates to form the first pixel defining layer 9. The mixed gas is carbon tetrafluoride, trifluoromethane, difluoromethane and oxygen.

[0095] It should be noted that the key to ensuring the surface flatness of the first pixel defining layer 7 is to fully etch the first pixel defining material layer 9 and the organic layer 10 at similar etching rates. The etching rate of the mixed etching gas on the organic layer is V1, and the etching rate of the first pixel defining material layer is V2; wherein, 0.8≤V1:V2≤1.2, the etching rates of the first pixel defining material layer 9 and the organic layer 10 can be similar by adjusting the ratio of the mixed gas. Since the organic layer 10 cannot be etched by using a mixed gas of carbon tetrafluoride, trifluoromethane and difluoromethane, the etching rate of the organic layer 10 can be increased by adding oxygen. If the etching rate V1 of the organic layer 10 is lower than the etching rate V2 of the first pixel defining material layer, the proportion of oxygen in the mixed gas is increased, so as to control the first pixel defining material layer 9 and the organic layer 10 to be etched at similar etching rates. For example, the etching rate V2 of the first pixel defining material layer 9 can be controlled to be 1, and the etching rate V2 of the organic layer 10 can be controlled to be 1, so that they are etched at an etching rate ratio of 1:1.

[0096] If the etching rate of the photoresist 10 is much higher than the etching rate of the first pixel defining layer 9, the etching depth will be deeper in the thicker area of ​​the organic light-emitting layer 10, that is, at the corresponding position of the spacer area of ​​the first electrode 21, affecting the flatness of the first pixel defining layer 7. In addition, compared with the traditional solution of forming a photoresist mask on the spacer area between the first electrodes 21 for protection, performing a development and degumming treatment on the remaining area, and then etching to form the first pixel defining layer 7, the etching solution of the embodiment of the present invention does not need to make a mask plate, has fewer steps, a simple process, and higher etching efficiency.

[0097] S360, preparing a second pixel defining layer on a side of the first pixel defining layer away from the substrate.

[0098] like Figure 8 As shown in step c6.

[0099] S370 , patterning the first pixel defining layer and the second pixel defining layer to obtain a pixel defining structure.

[0100] like Figure 8 As shown in step c7.

[0101] In the embodiment of the present invention, the first pixel defining material layer and the organic layer are etched at similar etching rates by preparing a mixed gas to form a first pixel defining layer. While ensuring the flatness of the first pixel defining layer, the process flow is simple and the etching efficiency is higher.

[0102] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0103] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A display panel, characterized in that: The invention comprises a substrate, a plurality of light-emitting elements and a plurality of pixel defining structures arranged on one side of the substrate: The light emitting element comprises a first electrode, the pixel defining structure is located between two adjacent first electrodes, and along the thickness direction of the display panel, the pixel defining structure does not overlap with the first electrode; A first distance is defined between a surface of the first electrode away from the substrate and the substrate, and a second distance is defined between a surface of the pixel defining structure away from the substrate and the substrate; the second distance is greater than the first distance.

2. The display panel according to claim 1, characterized in that: The first distance is L1, and the second distance is L2; Among them, L2 / L1≥2.

3. The display panel according to claim 2, characterized in that: 80nm≤L1≤100nm; 170nm≤L2≤300nm.

4. The display panel according to claim 1, characterized in that: The pixel defining structure comprises a side wall facing the first electrode, and at least a portion of the side wall is provided with a groove; The light-emitting element further includes a light-emitting layer disposed on a side of the first electrode away from the substrate, the light-emitting layer includes a common light-emitting layer, and at least a portion of the common light-emitting layer is disconnected at the groove.

5. The display panel according to claim 4, characterized in that: The pixel definition structure comprises a first pixel definition substructure and a second pixel definition substructure which are stacked, wherein the second pixel definition substructure is located on a side of the first pixel definition substructure away from the substrate; The first pixel defining substructure and the second pixel defining substructure are made of different materials, and the groove is disposed on at least a portion of the sidewall of the first pixel defining substructure.

6. A method for preparing a display panel, characterized in that: The preparation method comprises: providing a substrate; Prepare a first electrode of the light-emitting element on one side of the substrate; A pixel defining structure is prepared on one side of the substrate and between two adjacent first electrodes; along the thickness direction of the display panel, the pixel defining structure and the first electrode have no overlap; and the distance between the surface of the first electrode away from the substrate and the substrate is a first distance, and the distance between the surface of the pixel defining structure away from the substrate and the substrate is a second distance; the second distance is greater than the first distance.

7. The preparation method according to claim 6, characterized in that: A pixel defining structure is prepared on one side of the substrate and between two adjacent first electrodes, comprising: A first pixel defining layer is prepared on one side of the substrate and on a side of the first electrode away from the substrate; the first pixel defining layer includes a first defining sub-portion located on one side of the substrate and a second defining sub-portion located on a side of the first electrode away from the substrate; a third distance is defined between a surface of the first defining sub-portion away from the substrate and the substrate, and a fourth distance is defined between a surface of the second defining sub-portion away from the substrate and the substrate; the third distance is L3, and the fourth distance is L4; wherein |L4-L3| / L3≤20%; Preparing a second pixel defining layer on a side of the first pixel defining layer away from the substrate; The pixel defining structure is prepared by patterning the first pixel defining layer and the second pixel defining layer.

8. The preparation method according to claim 7, characterized in that: Preparing a first pixel defining layer on one side of the substrate and on a side of the first electrode away from the substrate, comprising: Preparing a first pixel defining material layer on one side of the substrate and on a side of the first electrode away from the substrate; preparing an organic layer on a side of the first pixel defining material layer away from the substrate; The organic layer and the first pixel defining material layer are etched with a mixed etching gas to prepare the first pixel defining layer; the etching rate of the mixed etching gas on the organic layer is V1, and the etching rate of the mixed etching gas on the first pixel defining material layer is V2; wherein 0.8≤V1:V2≤1.

2.

9. The preparation method according to claim 8, characterized in that: The mixed etching gas includes carbon tetrafluoride, trifluoromethane, difluoromethane and oxygen.

10. The preparation method according to claim 7, characterized in that: Patterning the first pixel defining layer and the second pixel defining layer to obtain the pixel defining structure includes: Photolithography and etching the first pixel defining layer and the second pixel defining layer using the same etching gas, wherein the etching rate of the etching gas on the first pixel defining layer is greater than the etching rate of the second pixel defining layer, so as to form a groove on at least a part of the side wall of the first pixel defining layer; The preparation method further comprises: A light-emitting layer is prepared on a side of the first electrode away from the substrate, wherein the light-emitting layer includes a common light-emitting layer, and at least a portion of the common light-emitting layer is disconnected at the groove.

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