Display panel

Abstract

A display panel (100), comprising a substrate (10), a first electrode (31), a light-emitting layer (50), a second electrode (70), a covering layer (60), a thin film packaging layer (80), and a first retaining wall (91). The covering layer (60) comprises a first sub-covering layer (61), a second sub-covering layer (62), and a third sub-covering layer (63); the refractive index of the second sub-covering layer (62) is greater than the refractive indexes of the first and third sub-covering layers (61, 63); and the thin film packaging layer (80) comprises a first inorganic packaging layer (81) covering the light-emitting layer (50).

Description

Display panel

[0001] This application claims priority to Chinese patent application No. 202410703803.7, filed on May 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of display technology, and more particularly to a display panel. Background Technology

[0003] With continuous improvements in OLED (organic light-emitting diode) luminescent materials, the luminous efficiency, lifespan, and display quality of OLED devices have been enhanced to some extent. To further improve the light extraction efficiency of OLEDs, a high-refractive-index capping layer (CPL) is typically placed above the luminescent structure in the display area of ​​the OLED device. A barrier is usually placed outside the display area to prevent the organic encapsulation material of the thin-film encapsulation layer from overflowing during inkjet printing, thus confining the organic material within a certain area. Invention Overview

[0004] To prevent water and oxygen intrusion, the inorganic encapsulation layer of a typical thin-film encapsulation layer extends beyond the barrier, covering it. This barrier is usually formed using an organic film layer on the array substrate; that is, the barrier is generally made of organic material. There is contact between the inorganic encapsulation layer and the organic barrier, and the adhesion between them is relatively poor, posing a risk of film peeling or breakage.

[0005] This application provides a display panel, including a display area and a non-display area located on at least one side of the display area, the display panel comprising:

[0006] Substrate;

[0007] The first electrode is disposed on the substrate and located in the display area;

[0008] A light-emitting layer is disposed on the first electrode;

[0009] The second electrode is disposed on the light-emitting layer;

[0010] A capping layer, comprising a first sub-capping layer, a second sub-capping layer, and a third sub-capping layer sequentially stacked on the second electrode, wherein the refractive index of the second sub-capping layer is greater than the refractive index of the first sub-capping layer and the refractive index of the second sub-capping layer; and

[0011] The first barrier is disposed on the substrate and located in the non-display area;

[0012] A thin-film encapsulation layer is disposed on the cover layer, including a first inorganic encapsulation layer, the first inorganic encapsulation layer covering the light-emitting layer and the first conductive layer;

[0013] Wherein, the edge portion of at least one of the first sub-cover layer and the third sub-cover layer overlaps with the first barrier in a direction perpendicular to the substrate. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments disclosed. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 is a schematic diagram of the first structure of the display panel provided in an embodiment of this application.

[0016] Figure 2 is a schematic diagram of the first structure of the edge covering part provided in the embodiment of this application.

[0017] Figure 3 is an enlarged structural diagram of the middle cover corresponding to the third light-emitting unit in Figure 1.

[0018] Figure 4 is a schematic diagram of a second structure of the edge covering part provided in an embodiment of this application.

[0019] Figure 5 is a schematic diagram of the pixel driving layer provided in an embodiment of this application. Embodiments of the present invention

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0021] In the description of this application, it should be understood that the terms "upper," "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Reference numerals and / or reference letters may be repeated in different embodiments of this application. Such repetition is for the purpose of simplification and clarity and does not in itself indicate the relationship between the various implementations and / or settings discussed.

[0023] This application provides a display panel, including a display area and a non-display area located on at least one side of the display area, the display panel comprising:

[0024] Substrate;

[0025] The first electrode is disposed on the substrate and located in the display area;

[0026] A light-emitting layer is disposed on the first electrode;

[0027] The second electrode is disposed on the light-emitting layer;

[0028] A capping layer, comprising a first sub-capping layer, a second sub-capping layer, and a third sub-capping layer sequentially stacked on the second electrode, wherein the refractive index of the second sub-capping layer is greater than the refractive index of the first sub-capping layer and the refractive index of the second sub-capping layer; and

[0029] The first barrier is disposed on the substrate and located in the non-display area;

[0030] A thin-film encapsulation layer is disposed on the cover layer, including a first inorganic encapsulation layer, the first inorganic encapsulation layer covering the light-emitting layer and the first conductive layer;

[0031] Wherein, the edge portion of at least one of the first sub-cover layer and the third sub-cover layer overlaps with the first barrier in a direction perpendicular to the substrate.

[0032] In some embodiments of this application, the display panel includes a first conductive layer located between the substrate and the light-emitting layer. The first conductive layer includes a plurality of first electrodes located in the display area and a signal line located in the non-display area. The light-emitting layer includes a plurality of light-emitting units corresponding one-to-one with the plurality of first electrodes. The orthographic projection of the end of the signal line away from the display area on the substrate is located within the orthographic projection of the edge portion on the substrate.

[0033] In some embodiments of this application, the signal line is located on the side of the first barrier wall near the display area, the first barrier wall includes a first surface on the side away from the substrate, the first end of the edge portion away from the display area extends to the first surface, and the orthographic projection of the first end on the substrate is located within the orthographic projection of the first surface on the substrate.

[0034] In some embodiments of this application, the distance between the orthographic projection of the first end on the first barrier wall and the end of the first surface near the display area in a first direction is 1 / 3 to 2 / 3 of the width of the first surface in the first direction, where the first direction is the direction from the non-display area to the display area.

[0035] In some embodiments of this application, the edge of the second sub-cover layer does not overlap with the first barrier in a direction perpendicular to the substrate.

[0036] In some embodiments of this application, the edge of the second sub-covering layer extends between the first boundary and the first barrier, the first boundary being the boundary between the display area and the non-display area.

[0037] In some embodiments of this application, the cover layer includes a plurality of intermediate cover portions located in the display area, each intermediate cover portion corresponding to a light-emitting unit, and each intermediate cover portion at least covers the corresponding light-emitting unit; the first sub-cover layer includes a plurality of first sub-cover portions, the second sub-cover layer includes a plurality of second sub-cover portions, and the third sub-cover layer includes a plurality of third sub-cover portions; wherein each intermediate cover portion includes a first sub-cover portion, a second sub-cover portion, and a third sub-cover portion; a second sub-cover portion of the second sub-cover layer near the first barrier partially overlaps with the signal line in a direction perpendicular to the substrate.

[0038] In some embodiments of this application, a first sub-covering portion of the first sub-covering layer, near the first barrier, extends from the display area to the non-display area, and the first sub-covering portion overlaps with the first barrier in a direction perpendicular to the substrate; and / or

[0039] The third sub-covering portion of the third sub-covering layer, which is close to the first barrier, extends from the display area to the non-display area, and the third sub-covering portion overlaps with the first barrier in a direction perpendicular to the substrate.

[0040] In some embodiments of this application, the plurality of first sub-covering portions are spaced apart; and / or the plurality of third sub-covering portions are spaced apart; and / or the plurality of second sub-covering portions are interconnected.

[0041] In some embodiments of this application, the first sub-coating layer, the second sub-coating layer, and the third sub-coating layer comprise fluorinated organic materials, wherein the fluorine content of the first sub-coating layer is less than that of the second sub-coating layer, and the fluorine content of the third sub-coating layer is less than that of the second sub-coating layer.

[0042] In some embodiments of this application, the thickness of the first sub-covering layer is less than the thickness of the second sub-covering layer, and the thickness of the third sub-covering layer is less than the thickness of the second sub-covering layer.

[0043] The beneficial effects of this application are as follows: The display panel of this application embodiment includes a substrate, a first electrode, a light-emitting layer, a second electrode, a cover layer, a thin-film encapsulation layer, and a first barrier wall disposed on the substrate, stacked sequentially; the cover layer includes a first sub-cover layer, a second sub-cover layer, and a third sub-cover layer stacked sequentially on the second electrode, wherein the refractive index of the second sub-cover layer is greater than the refractive index of the first sub-cover layer and the refractive index of the second sub-cover layer; the first barrier wall is located in the non-display area; the thin-film encapsulation layer includes a first inorganic encapsulation layer covering the light-emitting layer; wherein, at least one of the first sub-cover layer and the third sub-cover layer has its edge portion overlapping the first barrier wall in a direction perpendicular to the substrate. By overlapping the sub-cover layer with a lower refractive index in the cover layer with the first barrier wall, direct contact between the first barrier wall and the first inorganic encapsulation layer is avoided, which can enhance the adhesion between the first barrier wall and the first inorganic encapsulation layer, prevent film layer breakage, and improve encapsulation performance.

[0044] Please refer to Figure 1, which is a schematic diagram of a first structure of a display panel 100 provided in an embodiment of this application. The display panel 100 includes a display area AA and a non-display area NA located on at least one side of the display area AA. The display panel 100 includes a substrate 10, a first conductive layer 30, a light-emitting layer 50, a second electrode 70, a cover layer 60, a thin film encapsulation layer 80, and a first barrier 91.

[0045] Specifically, the substrate 10 can be a rigid substrate, such as a glass substrate; or it can be a flexible substrate. The materials of the flexible substrate include, but are not limited to, polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and polyetherimide (PEI). The substrate 10 can include a multilayer stacked structure. Specifically, as shown in FIG5, the substrate 10 can include a first flexible substrate 11, an intermediate layer 12, and a second flexible substrate 13 stacked sequentially. The first flexible substrate 11 and the second flexible substrate 13 can be formed of polyimide, and the intermediate layer 12 can be formed of inorganic materials such as silicon nitride and silicon oxide.

[0046] The first conductive layer 30 is disposed on the substrate 10, and includes a plurality of first electrodes 31 and signal lines 32. The plurality of first electrodes 31 are located in the display area AA, and the first electrodes 31 are spaced apart. The signal lines 32 are located in the non-display area NA. The first electrodes 31 may be anodes. The signal lines 32 may be peripheral signal lines, used by peripheral circuits to input voltage signals to the panel (display area AA), for example, to supply power to the cathode or anode through the signal lines 32. The signal lines 32 may be low-potential constant voltage signal lines, electrically connected to the second electrode 70, and providing the second electrode 70 with a VSS voltage signal. The first electrodes 31 may be reflective anodes, and the first electrodes 31 and the signal lines 32 may be ITO / Ag / ITO three-layer composite films.

[0047] The light-emitting layer 50 is disposed on the first conductive layer 30. The light-emitting layer 50 may include: a hole injection layer, a hole transport layer, an organic light-emitting material layer, an electron transport layer, and an electron injection layer stacked sequentially. The hole injection layer, the hole transport layer, the electron transport layer, and the electron injection layer may be a continuous, full-surface pattern. The organic light-emitting material layer is located only in the pixel area corresponding to the first electrode 31, and the organic light-emitting material layers are spaced apart. The light-emitting layer 50 includes a plurality of light-emitting units, and the light-emitting units are disposed one-to-one with the first electrode 31.

[0048] The second electrode 70 is disposed on the light-emitting layer 50. The second electrode 70 and the first electrode 31 form an electric field, driving the light-emitting layer 50 to emit light. The second electrode 70 can be a cathode, and can be made of a material with a low work function to facilitate electron injection. For example, it can be one of the following metals: silver (Ag), aluminum (Al), lithium (Li), magnesium (Mg), ytterbium (Yb), calcium (Ca), indium (In), or an alloy of the aforementioned metals, such as magnesium-silver alloy (Mg / Ag) or lithium-aluminum alloy (Li / Al). The second electrode 70 can pass through a corresponding via and connect to the signal line 32 below, so that the VSS voltage signal can be input to the second electrode 70.

[0049] The cover layer 60 is disposed on the second electrode 70, and the material of the cover layer 60 may include fluorine-containing organic materials. The cover layer 60 is used to improve the light extraction efficiency of the light-emitting layer 50. The cover layer 60 includes a first sub-cover layer 61, a second sub-cover layer 62, and a third sub-cover layer 63 sequentially stacked on the second electrode 70. The refractive index of the first sub-cover layer 61 and the refractive index of the third sub-cover layer 63 are lower than the refractive index of the second sub-cover layer 62. The combination of multiple sub-cover layers 60 with high and low refractive indices facilitates light extraction and effectively improves the light extraction efficiency of the display panel 100. The cover layer 60 includes multiple intermediate cover portions 602, each intermediate cover portion 602 corresponding to a light-emitting unit, and each intermediate cover portion 602 at least covers the corresponding light-emitting unit to improve the light extraction efficiency of the corresponding light-emitting unit.

[0050] The thin-film encapsulation layer 80 is disposed on the cover layer 60 to prevent external moisture from penetrating into the interior of the display panel 100. The thin-film encapsulation layer 80 includes a first inorganic encapsulation layer 81, an organic encapsulation layer 82, and a second inorganic encapsulation layer 83 stacked sequentially. The materials of the first inorganic encapsulation layer 81 and the second inorganic encapsulation layer 83 may include any one of SiNx, Al2O3, SiO2, and TiO2. The material of the organic encapsulation layer 82 may include any one of, for example, polyethylene terephthalate, polyimide, polycarbonate (PC), epoxy resin, polyethylene (PE), and polyacrylate (PA).

[0051] As shown in Figure 1, the first barrier 91 is used to prevent the organic encapsulation material of the thin-film encapsulation layer 80 from overflowing during inkjet printing. The first barrier 91 is located in the non-display area NA. The first barrier 91 is further away from the display area AA relative to the first conductive layer 30.

[0052] Both the first inorganic encapsulation layer 81 and the second inorganic encapsulation layer 83 extend to the outside of the first barrier wall 91, that is, the first inorganic encapsulation layer 81 and the second inorganic encapsulation layer 83 cover the first barrier wall.

[0053] The display panel 100 also includes a multilayer insulating layer located between the first conductive layer 30 and the substrate 10. This multilayer insulating layer includes, but is not limited to, a planarization layer 28 and a pixel definition layer 40. Typically, the planarization layer 28 and the pixel definition layer 40 are organic materials. The first barrier 91 can be formed using film layers such as the planarization layer 28 and the pixel definition layer 40 (described later through specific embodiments). The upper first inorganic encapsulation layer is an inorganic material, while the lower first barrier 91 is an organic material. The adhesion between the two is relatively poor, posing a risk of film layer detachment and breakage. To address the above defects, this application overlaps the edge portion 601 of at least one of the first sub-cover layer 61 and the third sub-cover layer 63 with the first barrier 91 in a direction perpendicular to the substrate 10. By extending the low-refractive-index sub-cover layer of the cover layer 60 beyond the display area and extending onto and overlapping the first barrier 91, this application can improve the adhesion between the cover layer 61 and the lower barrier (91) and the upper first inorganic encapsulation layer, thus helping to improve encapsulation performance.

[0054] Furthermore, metal particles will precipitate from the conductive layer below the edge of the display area and adsorb onto the mask used to prepare the inorganic encapsulation layer. Due to electrostatic repulsion, the inorganic particles cannot be deposited on the substrate, which will affect the uniformity of the film thickness of the inorganic encapsulation layer between the edge and center of the display area, resulting in uneven color display between the edge and center of the display area and abnormal display at the edge of the display area.

[0055] By overlapping the edge portion 601 of at least one of the first sub-cover layer 61 and the third sub-cover layer 63 with the first barrier 91 in a direction perpendicular to the substrate 10, on the one hand, the low emissivity sub-cover layers (61 and / or 63) can be used to shield the first conductive layer 30 in the non-display area NA, which can improve the adhesion between the cover layer 61 and the lower barrier (91) and the upper inorganic encapsulation layer, thus helping to improve the encapsulation performance; on the other hand, the cover layer 60 can also be used to shield the lower first conductive layer 30, preventing the metal particles precipitated at the edge of the first conductive layer 30 from escaping upward and adsorbing onto the mask used for inorganic encapsulation layer deposition, thereby improving the uniformity of the inorganic encapsulation layer at the edge and center of the display area AA, thereby improving the display quality of the display panel, without increasing the process or production cost.

[0056] Specifically, the first barrier 91 includes a first surface 901, which is the surface of the first barrier 91 facing away from the substrate 10. The first surface 901 is higher than the surface of the second electrode 70 facing away from the substrate 10. Further, the first barrier 91 may be a closed barrier to effectively confine the material of the organic encapsulation layer 82 during inkjet printing within the closed area formed by the first barrier 91.

[0057] As shown in Figure 1, the display panel 100 may further include a second barrier 92, located on the side of the first barrier 91 away from the display area AA. The surface of the second barrier 92 facing away from the substrate 10 is higher than the first surface 901 of the first barrier 91, to further block inkjet-printed organic encapsulation material overflowing from the first barrier 91. It is understood that the second barrier 92 may also be a closed barrier, thus effectively confining the inkjet-printed organic encapsulation material overflowing from the first barrier 91 within the second barrier 92. The second barrier 92 may also be formed using film layers such as a planarization layer 28 and a pixel definition layer 40.

[0058] Referring to Figure 1, the first inorganic encapsulation layer 81 and the second inorganic encapsulation layer 83 of the thin-film encapsulation layer 80 can be deposited over the entire surface. In addition to covering the light-emitting layer 50, the first inorganic encapsulation layer 81 extends beyond the display area AA, reaching the outer sides of the first barrier 91 and the second barrier 92. That is, the first inorganic encapsulation layer 81 covers the light-emitting layer 50, the signal line 32, the first barrier 91, and the second barrier 92.

[0059] Furthermore, the orthographic projection of the end of the signal line 32 away from the display area AA on the substrate 10 lies within the orthographic projection of the edge portion 601 on the substrate 10. Although metal particles may precipitate from the first electrode 31 of the first conductive layer 30 located in the display area AA, this is blocked by the upper intermediate cover portion 602. However, since the signal line 32 of the first conductive layer 30 located in the non-display area NA is close to the edge of the display area AA, if the metal particles of the signal line 32 precipitate upwards, it will cause the metal particles to adhere to the photomask during the deposition of the inorganic encapsulation layer. This will adversely affect the deposition of the inorganic film layer corresponding to the edge of the display area AA, resulting in inconsistent film thickness between the edge and center of the display area AA. To address this deficiency, this application embodiment, through the above design, covers the end of the signal line 32 away from the display area AA with the edge portion 601 of at least one of the first sub-cover layer 61 and the third sub-cover layer 63. This allows the metal particles (such as silver particles) deposited from the signal line 32 to be blocked by the upper edge portion 601 during the subsequent deposition of the first inorganic encapsulation layer 81. This prevents the metal particles from adsorbing onto the photomask of the first inorganic encapsulation layer 81. Due to electrostatic repulsion, the inorganic particles cannot fall vertically during deposition, resulting in a difference in film thickness between the display area AA (i.e., the edge of the display area AA) near the signal line 32 and the first inorganic encapsulation layer 81 formed at the center of the display area AA. This avoids abnormal color display at the edge of the display area AA.

[0060] Referring to Figure 2, specifically, in some embodiments, the edge portion 601 includes a first end 6021, which is the end of the edge portion 601 away from the display area AA. The first end 6021 extends to the first surface 901 of the first barrier 91, and the orthographic projection of the first end 6021 on the substrate 10 lies within the orthographic projection of the first surface 901 on the substrate 10. This design allows the portion of the signal line 32 closest to the first barrier 91 to be effectively shielded by the edge portion 601, preventing metal particles precipitated from the signal line 32 from adsorbing onto the metal mask during the high-temperature deposition of the first inorganic encapsulation layer 81. This avoids differences in the film layer between the edge and center of the display area AA of the formed first inorganic encapsulation layer 81, thus improving display quality.

[0061] Further, as shown in FIG3, the first sub-covering layer 61 includes a plurality of first sub-covering portions 611, the second sub-covering layer 62 includes a plurality of second sub-covering portions 621, and the third sub-covering layer 63 includes a plurality of third sub-covering portions 631.

[0062] Referring to Figures 1 and 3, each intermediate cover portion 602 includes at least one of a first sub-cover portion 611, a second sub-cover portion 621, and a third sub-cover portion 623. Different intermediate cover portions 602 may include different sub-cover portions, and the number of sub-cover layers may also be different.

[0063] Referring to Figures 1 and 2, in some embodiments, a first sub-covering portion 611 of the first sub-covering layer 61 near the first barrier 91 may extend from the display area AA to the non-display area NA, and the first sub-covering portion 61 overlaps with the first barrier 91 in a direction perpendicular to the substrate 10.

[0064] As shown in FIG4, in some other embodiments, a third sub-covering portion 631 of the third sub-covering layer 63 near the first barrier 91 may extend from the display area AA to the non-display area NA, and the third sub-covering portion 631 overlaps with the first barrier 91 in a direction perpendicular to the substrate 10.

[0065] By extending the first sub-cover portion 611 and the third sub-cover portion 631 located at the edge of the display area AA from the display area AA to the surface of the first barrier 91, a continuous barrier can be formed, which fully ensures that the part of the signal line 32 not covered by the middle cover portion 602 can be covered by the edge portion 601, thereby ensuring the uniformity of the film formation of the first inorganic encapsulation layer 81.

[0066] As shown in Figures 2 and 4, optionally, a second sub-cover portion 621 of the second sub-cover layer 62 near the first baffle 91 partially overlaps with the signal line 32 in a direction perpendicular to the substrate 10. That is, the second sub-cover portion 621 at the edge of the display area AA can extend into the non-display area NA, but does not overlap with the first baffle 91.

[0067] Since the refractive indices of the first and third sub-cover layers are less than those of the second sub-cover layer 62, their physical properties are between those of organic and inorganic materials. The adhesion between the first sub-cover layer 61, the third sub-cover layer 63 and the upper first inorganic encapsulation layer 81 and the lower first barrier 91 (the pixel definition layer 40 and the planarization layer 28 are organic materials) is better than that between the first sub-cover layer 62 and the second sub-cover layer 62. Therefore, the edge portion 601 is selected to extend to the first surface 901 of the first sub-cover portion 611 and the third sub-cover portion 631 at the edge of the display area AA (near the non-display area NA), which can enhance the adhesion performance between the cover layer 60 and the upper and lower film layers.

[0068] The first sub-coating layer 61, the second sub-coating layer 62, and the third sub-coating layer 63 comprise fluorinated organic materials, which may be selected as fluorinated small-molecule organic materials. The fluorine content of the first sub-coating layer 61 and the third sub-coating layer 63 is less than that of the second sub-coating layer 62, resulting in the physical properties of the first sub-coating layer 61 and the third sub-coating layer 63 being intermediate between those of inorganic and organic materials. This, in turn, ensures good adhesion between the first sub-coating layer 61 and the third sub-coating layer 63 and both inorganic and organic layers. "Fluorine content" refers to the mass content of fluorine.

[0069] As shown in Figure 2, in some embodiments, the distance between the orthographic projection of the first end 6021 of the edge portion 601 onto the first barrier 91 and the end of the first surface 901 near the display area AA in the first direction is 1 / 3 to 2 / 3 of the width W1 of the first surface 901 in the first direction, where the first direction is the direction from the non-display area NA to the display area AA. That is, the first end 6021 of the edge portion 601 extends to 1 / 3 to 2 / 3 of the first surface 901. This design prevents the vapor-deposited material from depositing outside the first barrier 91 during the formation of the cover layer 60, thus avoiding any impact on the device's packaging performance. It can be understood that the width W1 refers to the projected width of the first surface 901 on the substrate. When the first surface 901 is circular, the width W refers to the diameter of the circle; when the first surface 901 is elliptical, it refers to the maximum width of the first surface 901 in the first direction; when the first surface 901 is other irregular shapes, it refers to the maximum width of the first surface 901 in the first direction.

[0070] Furthermore, since the light emission efficiency of light-emitting units with different emission wavelengths is different, the number of sub-covering layers and the refractive index of each light-emitting unit can be differentiated according to the different wavelengths of the light-emitting units. This can improve the light emission efficiency of each light-emitting unit while making the light emission efficiency of each light-emitting unit similar, thereby improving the uniformity of light emission in all parts of the display panel 100 and improving the display quality.

[0071] Please refer to Figures 1 and 3 simultaneously. The intermediate cover portion 602 corresponding to the first light-emitting unit 51 may include a second sub-cover portion 621. The intermediate cover portion 602 corresponding to the second light-emitting unit 52 includes a second sub-cover portion 621. The intermediate cover portion 602 corresponding to the third light-emitting unit 53 includes a first sub-cover portion 611, a second sub-cover portion 621, and a third sub-cover portion 631 stacked sequentially. For the same cover layer material, the shorter the wavelength of the incident light, the higher the light extraction efficiency; for the same wavelength of incident light, the higher the refractive index of the cover layer material, the higher the light extraction efficiency. Therefore, the design of light-emitting units with different wavelengths combined with different sub-cover portions can maximize the overall light extraction efficiency of the display panel 100 while ensuring the uniformity of light extraction from the display panel 100.

[0072] As shown in Figure 1, in some embodiments, the second sub-covering portions 621 of the second sub-covering layer 62 can be connected to each other (interconnected), and the first sub-covering portions 611 of the first sub-covering layer 61 and the third sub-covering portions 631 of the third sub-covering layer 63 can be disconnected from each other (spaced apart).

[0073] In other embodiments, the second sub-covering portions 621 of the second sub-covering layer 62 may be disconnected from each other, the first sub-covering portions 611 of the first sub-covering layer 61 may be connected to each other, and the third sub-covering portions 631 of the third sub-covering layer 63 may be connected to each other.

[0074] The thickness of the first sub-covering layer 61 and the thickness of the third sub-covering layer 63 are less than the thickness of the second sub-covering layer 62. By combining the thickness and refractive index, the light emission efficiency of the display panel 100 can be further improved.

[0075] In some embodiments, the thickness of the first sub-covering layer 61 and the thickness of the third sub-covering layer 63 may be the same, the refractive index of the first sub-covering layer 61 may be the same as the refractive index of the third sub-covering layer 63, and the material of the first sub-covering layer 61 may be the same as the material of the third sub-covering layer 63.

[0076] The refractive index of the first sub-coating layer 61 and the third sub-coating layer 63 can be 1.2-1.6, specifically 1.2, 1.3, 1.4, 1.5 or 1.6.

[0077] The refractive index of the second sub-capping layer 62 can be 1.6-2.2, specifically 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 or 2.2.

[0078] The thickness of the first sub-covering layer 61 and the third sub-covering layer 63 can be 5-50 nm, specifically 5-40 nm, 5-30 nm, 10-30 nm, 20-30 nm or any value between the two extremes mentioned above.

[0079] The thickness of the second sub-covering layer 62 can be 40-80 nm, specifically 50-80 nm, 60-80 nm, 70-80 nm or any value between the two extremes mentioned above.

[0080] Referring to Figure 5, the display panel 100 may further include a pixel driving layer 20, which includes a barrier layer 21, a buffer layer 22, an active layer 291, a first insulating layer 23, a first metal layer M1, a second insulating layer 24, a second metal layer M2, a third insulating layer 25, a third metal layer M3, and a planarization layer 28, which are sequentially stacked on the substrate 10.

[0081] The barrier layer 21 prevents impurities or moisture from penetrating from the substrate 10 into the light-emitting unit. The barrier layer 21 can be a single layer or multiple sublayers, and it comprises inorganic insulating materials such as silicon nitride, silicon oxide, and silicon oxynitride. The sublayers closer to the substrate 10 can be formed of silicon oxide to enhance the bonding performance between the barrier layer 21 and the substrate 10, while the sublayers farther from the substrate 10 can be formed of silicon nitride to enhance the bonding performance between the barrier layer 21 and the upper layer.

[0082] The buffer layer 22 is used to further enhance the barrier effect against impurities and moisture, and to provide a flat surface for the subsequently formed film layer. The buffer layer 22 comprises inorganic insulating materials such as silicon nitride, silicon oxide, and silicon oxynitride.

[0083] The active layer 291 is disposed on the buffer layer 22. The material of the active layer 291 can be polycrystalline silicon (P-Si) or indium gallium zinc oxide (IGZO) or other metal oxide semiconductors. To reduce the influence of light on the active layer 291, a light-shielding layer can be disposed above or below the buffer layer 22, so that the vertical projection of the light-shielding layer and the active layer 291 on the array substrate 10 overlaps, thereby reducing the illumination of light on the active layer 291 and ensuring the performance stability of the pixel driving layer 20.

[0084] The first insulating layer 23 is disposed on the active layer 291. The first insulating layer 23 can be silicon nitride, silicon oxide, or a stacked structure of silicon nitride and silicon oxide.

[0085] The first metal layer M1 is disposed on the first insulating layer 23 and can be patterned to form a first gate 292. The material of the first metal layer M1 may include molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), titanium (Ti), tantalum (Ta), tungsten (W), copper (Cu), or alloys thereof. The first metal layer M1 may include a single-layer or multi-layer metal structure.

[0086] The second insulating layer 24 is disposed on the first metal layer M1. The second insulating layer 24 can be silicon nitride, silicon oxide, or a stacked structure of silicon nitride and silicon oxide.

[0087] The second metal layer M2 is disposed on the second insulating layer 24 and can be patterned to form the second gate 293. Specifically, the second metal layer M2 is disposed opposite to the first metal layer M1, forming a dual-gate structure. The material of the second metal layer M2 may include molybdenum, aluminum, platinum, palladium, silver, magnesium, gold, nickel, neodymium, iridium, chromium, titanium, tantalum, tungsten, copper, or alloys thereof. The second metal layer M2 may include a single-layer or multi-layer metal structure.

[0088] The third insulating layer 25 is disposed on the second metal layer M2. The material of the third insulating layer 25 can be silicon nitride, silicon oxide, or a stacked structure of silicon nitride and silicon oxide.

[0089] A third metal layer M3 is disposed on the third insulating layer 25, and can be patterned to form a source metal layer 295 and a drain metal layer 294 spaced apart. Specifically, the third metal layer M3 is connected to the active layer 291 through vias, thereby forming a thin-film transistor together with the first gate 292, the second gate 293, the source metal layer 295, and the drain metal layer 294. The material of the third metal layer M3 may include molybdenum, aluminum, platinum, palladium, silver, magnesium, gold, nickel, neodymium, iridium, chromium, titanium, tantalum, tungsten, copper, or alloys thereof. The third metal layer M3 may comprise a single-layer or multi-layer metal structure.

[0090] The planarization layer 28 provides a flat surface for the subsequently formed first conductive layer 30. The material of the planarization layer 28 can be an organic material with a low dielectric constant, such as polyimide. The planarization layer 28 may include a first planarization layer 281 and a second planarization layer 282 to further improve surface flatness and provide a smoother surface for the subsequently formed first conductive layer 30. When the planarization includes a multilayer structure, a contact metal layer CM can also be provided between the first conductive layer 30 and the third metal layer M3. The first electrode 31 is connected to the contact metal layer CM, and the contact metal layer CM is connected to the third metal layer M3, thereby facilitating wiring connections between multilayer film structures.

[0091] A pixel definition layer 40 is disposed on the planarization layer 28. The pixel definition layer 40 includes multiple openings located in the display area. Each opening corresponds to a portion of the first electrode 31, and the opening exposes a portion of the corresponding first electrode 31. The light-emitting material layer is located within the corresponding opening. The pixel definition layer 40 is made of an organic material, including but not limited to hexamethyl dimethyl ether, epoxy resin, or polyimide.

[0092] When the signal line 32 is used to transmit the voltage signal of the cathode, the pixel definition layer 40 may further include vias and multiple openings located in the non-display area. The vias are used to expose at least a portion of the signal line 32, and the second electrode 70 is connected to the signal line 32 through the vias to enable the signal line 32 to input a VSS voltage signal to the second electrode 70. The multiple openings are used to release gas in the pixel definition layer 40 to prevent gas from affecting the lifetime of the light-emitting material. Metal particles (in ionic form) in the signal line 32 may escape through the aforementioned vias or openings and be adsorbed onto the metal mask of the first inorganic encapsulation layer 81. Therefore, the design of the edge portion 601 in this embodiment can effectively block the metal particles escaping from below.

[0093] In some embodiments, the first barrier 91 may be formed using a film layer of the pixel definition layer 40, and the second barrier 92 may be formed using a planarization layer 28 and a film layer of the pixel definition layer 40. It is understood that the first barrier 91 and the second barrier 92 may also be formed using other organic or inorganic film layers of the pixel driving layer 20. However, it must be ensured that the first surface 901 of the first barrier 91 is higher than the surface of the second electrode 70 facing away from the substrate 10, and the surface of the second barrier 92 facing away from the substrate 10 is higher than the first surface 901 of the first barrier 91.

[0094] In summary, this application provides a display panel comprising a substrate, a first electrode, a light-emitting layer, a second electrode, a cover layer, a thin-film encapsulation layer, and a first barrier wall disposed on the substrate, all stacked sequentially. The first electrode is located in the display area. The cover layer includes a first sub-cover layer, a second sub-cover layer, and a third sub-cover layer stacked sequentially on the second electrode, wherein the refractive index of the second sub-cover layer is greater than the refractive indices of the first and second sub-cover layers. The first barrier wall is located in the non-display area. The thin-film encapsulation layer includes a first inorganic encapsulation layer covering the light-emitting layer. At least one of the first and third sub-cover layers has an edge portion that overlaps with the first barrier wall in a direction perpendicular to the substrate. By overlapping the sub-cover layer with a lower refractive index in the cover layer with the first barrier wall, direct contact between the first barrier wall and the first inorganic encapsulation layer is avoided, enhancing the adhesion between the first barrier wall and the first inorganic encapsulation layer, preventing film breakage, and improving encapsulation performance.

[0095] In summary, although the present application discloses the preferred embodiments as described above, the above preferred embodiments are not intended to limit the present application. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application is based on the scope defined by the claims.

Claims

1. A display panel, comprising a display area and a non-display area located on at least one side of the display area, the display panel comprising: Substrate; The first electrode is disposed on the substrate and located in the display area; A light-emitting layer is disposed on the first electrode; The second electrode is disposed on the light-emitting layer; The capping layer includes a first sub-capping layer, a second sub-capping layer, and a third sub-capping layer sequentially stacked on the second electrode, wherein the refractive index of the second sub-capping layer is greater than the refractive index of the first sub-capping layer and the refractive index of the second sub-capping layer. The first barrier is disposed on the substrate and located in the non-display area; as well as A thin-film encapsulation layer is disposed on the cover layer, including a first inorganic encapsulation layer covering the light-emitting layer; Wherein, the edge portion of at least one of the first sub-cover layer and the third sub-cover layer overlaps with the first barrier in a direction perpendicular to the substrate.

2. The display panel according to claim 1, wherein, The display panel includes a first conductive layer located between the substrate and the light-emitting layer. The first conductive layer includes a plurality of first electrodes located in the display area and signal lines located in the non-display area. The light-emitting layer includes a plurality of light-emitting units corresponding one-to-one with the plurality of first electrodes. Wherein, the orthographic projection of the end of the signal line away from the display area on the substrate is located within the orthographic projection of the edge portion on the substrate.

3. The display panel according to claim 2, wherein, The signal line is located on the side of the first barrier wall near the display area. The first barrier wall includes a first surface on the side away from the substrate. The first end of the edge portion away from the display area extends to the first surface. The orthographic projection of the first end on the substrate is located within the orthographic projection of the first surface on the substrate.

4. The display panel according to claim 3, wherein, The distance between the orthographic projection of the first end on the first barrier wall and the end of the first surface near the display area in the first direction is 1 / 3 to 2 / 3 of the width of the first surface in the first direction, where the first direction is the direction from the non-display area to the display area.

5. The display panel according to claim 2, wherein, The edge of the second sub-covering layer does not overlap with the first barrier in a direction perpendicular to the substrate.

6. The display panel according to claim 5, wherein, The cover layer includes a plurality of intermediate cover portions located in the display area, each intermediate cover portion corresponding to a light-emitting unit, and each intermediate cover portion at least covers the corresponding light-emitting unit; The first sub-covering layer includes a plurality of first sub-covering portions, the second sub-covering layer includes a plurality of second sub-covering portions, and the third sub-covering layer includes a plurality of third sub-covering portions; Each of the intermediate covering portions includes at least one of the first sub-covering portion, the second sub-covering portion, and the third sub-covering portion; In the second sub-cover layer, a second sub-cover portion near the first barrier partially overlaps with the signal line in a direction perpendicular to the substrate.

7. The display panel according to claim 6, wherein, In the first sub-cover layer, a first sub-cover portion near the first barrier extends from the display area to the non-display area, and the first sub-cover portion overlaps with the first barrier in a direction perpendicular to the substrate; and / or The third sub-covering portion of the third sub-covering layer, which is close to the first barrier, extends from the display area to the non-display area, and the third sub-covering portion overlaps with the first barrier in a direction perpendicular to the substrate.

8. The display panel according to claim 6, wherein, The plurality of first sub-covering portions are spaced apart; and / or The plurality of third sub-covering portions are spaced apart; and / or The plurality of second sub-covering sections are interconnected.

9. The display panel according to claim 6, wherein, The first sub-coating layer, the second sub-coating layer, and the third sub-coating layer comprise fluorinated organic materials, wherein the fluorine content of the first sub-coating layer is less than that of the second sub-coating layer, and the fluorine content of the third sub-coating layer is less than that of the second sub-coating layer.

10. The display panel according to claim 2, wherein, The edge of the second sub-covering layer extends between the first boundary and the first barrier, where the first boundary is the boundary between the display area and the non-display area.

11. The display panel according to claim 10, wherein, The cover layer includes a plurality of intermediate cover portions located in the display area, each intermediate cover portion corresponding to a light-emitting unit, and each intermediate cover portion at least covers the corresponding light-emitting unit; The first sub-covering layer includes a plurality of first sub-covering portions, the second sub-covering layer includes a plurality of second sub-covering portions, and the third sub-covering layer includes a plurality of third sub-covering portions; Each of the intermediate covering portions includes at least one of the first sub-covering portion, the second sub-covering portion, and the third sub-covering portion; In the second sub-cover layer, a second sub-cover portion near the first barrier partially overlaps with the signal line in a direction perpendicular to the substrate.

12. The display panel according to claim 11, wherein, In the first sub-cover layer, a first sub-cover portion near the first barrier extends from the display area to the non-display area, and the first sub-cover portion overlaps with the first barrier in a direction perpendicular to the substrate; and / or The third sub-covering portion of the third sub-covering layer, which is close to the first barrier, extends from the display area to the non-display area, and the third sub-covering portion overlaps with the first barrier in a direction perpendicular to the substrate.

13. The display panel according to claim 11, wherein, The plurality of first sub-covering portions are spaced apart; and / or The plurality of third sub-covering portions are spaced apart; and / or The plurality of second sub-covering sections are interconnected.

14. The display panel according to claim 11, wherein, The first sub-coating layer, the second sub-coating layer, and the third sub-coating layer comprise fluorinated organic materials, wherein the fluorine content of the first sub-coating layer is less than that of the second sub-coating layer, and the fluorine content of the third sub-coating layer is less than that of the second sub-coating layer.

15. The display panel according to claim 4, wherein, The thickness of the first sub-covering layer is less than the thickness of the second sub-covering layer, and the thickness of the third sub-covering layer is less than the thickness of the second sub-covering layer.

16. The display panel as claimed in claim 15, wherein, The thickness of the first sub-covering layer is greater than or equal to 5 nanometers and less than or equal to 50 nanometers, the thickness of the second sub-covering layer is greater than or equal to 40 nanometers and less than or equal to 80 nanometers, and the thickness of the third sub-covering layer is greater than or equal to 5 nanometers and less than or equal to 50 nanometers.

17. The display panel as claimed in claim 16, wherein, The thickness of the first sub-covering layer is the same as the thickness of the third sub-covering layer.

18. The display panel as claimed in claim 15, wherein, The refractive index of the first sub-capping layer is greater than or equal to 1.2 and less than or equal to 1.6, the refractive index of the second sub-capping layer is greater than or equal to 1.6 and less than or equal to 2.2, and the refractive index of the third sub-capping layer is greater than or equal to 1.2 and less than or equal to 1.

6.

19. The display panel as claimed in claim 18, wherein, The refractive index of the first sub-capping layer is the same as that of the third sub-capping layer.

20. The display panel as claimed in claim 16, wherein, The material of the first sub-covering layer is the same as the material of the third sub-covering layer.

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