Array substrate, display panel, and method for manufacturing array substrate

Abstract

The present invention relates to an array substrate, a display panel and a method for manufacturing the array substrate. The array substrate comprises: a base substrate; a pixel definition layer arranged on the base substrate, wherein the pixel definition layer has openings defining sub-pixels and protrusions located between the openings; a light-emitting device layer arranged on the pixel definition layer, wherein the light-emitting device layer has a first portion arranged in the openings and a second portion located on the protrusions, wherein the conductivity of the second portion in a direction parallel to the base substrate is lower than the conductivity of the first portion in a direction parallel to the base substrate.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more particularly to an array substrate, a display panel and a method for manufacturing the array substrate. Background Art

[0002] Compared with other types of display devices (e.g., liquid crystal display units), organic light emitting display devices (OLED display devices) are widely studied and initially applied as the next generation of displays due to their advantages of lightness, low power consumption, high contrast, and high color gamut. Another advantage of OLED display devices over liquid crystal display devices is that they do not require backlighting. Summary of the invention

[0003] An embodiment of the present invention provides an array substrate. The array substrate according to the embodiment of the present invention comprises: a base substrate; a pixel definition layer disposed on the base substrate, wherein the pixel definition layer has openings defining sub-pixels and protrusions located between the openings; a light-emitting device layer disposed on the pixel definition layer, wherein the light-emitting device layer has a first portion disposed in the openings and a second portion located on the protrusions, wherein the conductivity of the second portion in a direction parallel to the base substrate is lower than the conductivity of the first portion in a direction parallel to the base substrate.

[0004] In some embodiments, the light-emitting device layer includes: a first electrode located in the opening; a hole transport layer located on a surface of the first electrode away from the substrate; a light-emitting layer located on a surface of the hole transport layer away from the substrate; an electron transport layer located on a surface of the light-emitting layer away from the substrate; and a second electrode located on a surface of the electron transport layer away from the substrate.

[0005] Among them, the conductivity of at least one of the hole transport layer, the light-emitting layer, and the electron transport layer on the protrusion in a direction parallel to the base substrate is lower than the conductivity of the portion thereof in the opening in a direction parallel to the base substrate.

[0006] In some embodiments, the hole transport layer has a space located on the protrusion, and wherein a projection of the space of the hole transport layer on the substrate at least partially overlaps with a projection of a surface of the protrusion away from the substrate on the substrate.

[0007] In some embodiments, the hole transport layer also functions as a hole injection layer.

[0008] In some embodiments, the light emitting device layer further includes a hole injection layer located between the hole transport layer and the first electrode, wherein the hole injection layer exposes at least a portion of a surface of the protrusion away from the base substrate.

[0009] In some embodiments, the light-emitting device layer also includes an auxiliary light-emitting layer located between the hole transport layer and the light-emitting layer, wherein the conductivity of a portion of the auxiliary light-emitting layer on the protrusion in a direction parallel to the base substrate is lower than the conductivity of a portion of the auxiliary light-emitting layer in the opening in a direction parallel to the base substrate.

[0010] In some embodiments, the electron transport layer also functions as an electron injection layer.

[0011] In some embodiments, the light emitting device layer further includes an electron injection layer disposed between the electron transport layer and the second electrode.

[0012] In some embodiments, the electron transport layer and / or the electron injection layer have a gap located on the protrusion, and wherein a projection of the gap of the electron transport layer and / or the electron injection layer on the substrate at least partially overlaps with a projection of a surface of the protrusion away from the substrate on the substrate.

[0013] An embodiment of the present invention further provides a display panel. The display panel may include the array substrate described above.

[0014] An embodiment of the present invention also provides a method for manufacturing an array substrate. The method for manufacturing an array substrate comprises: providing a base substrate; forming a pixel definition layer on the base substrate, wherein the pixel definition layer has openings defining sub-pixels and protrusions located between the openings; forming a light-emitting device layer on the pixel definition layer, wherein the light-emitting device layer has a first portion disposed in the opening and a second portion located on the protrusion, wherein the conductivity of the second portion in a direction parallel to the base substrate is lower than the conductivity of the first portion in a direction parallel to the base substrate.

[0015] In some embodiments, forming the light-emitting device layer on the pixel definition layer includes: forming a first electrode in the opening of the pixel definition layer; forming a hole transport layer on the first electrode; forming a light-emitting layer on the hole transport layer; forming an electron transport layer on the light-emitting layer; forming a second electrode on the electron transport layer, wherein a portion of at least one of the hole transport layer, the light-emitting layer, and the electron transport layer on the protrusion has a lower conductivity in a direction parallel to the substrate than a portion thereof in the opening in a direction parallel to the substrate.

[0016] In some embodiments, forming a hole transport layer includes forming the hole transport layer to have a gap located on the protrusion, and wherein a projection of the gap of the hole transport layer on the base substrate at least partially overlaps with a projection of a surface of the protrusion away from the base substrate on the base substrate.

[0017] In some embodiments, forming the hole transport layer includes: using a first mask having a hollow portion, and forming the hole transport layer by aligning the hollow portion with the opening.

[0018] In some embodiments, the first mask includes a fine metal mask.

[0019] In some embodiments, the hole transport layer also functions as a hole injection layer.

[0020] In some embodiments, forming the light emitting device layer further comprises: forming a hole injection layer between the hole transport layer and the first electrode, wherein the hole injection layer exposes at least a portion of the surface of the protrusion away from the base substrate.

[0021] In some embodiments, forming the light-emitting device layer further comprises: forming an auxiliary light-emitting layer between the hole transport layer and the light-emitting layer.

[0022] In some embodiments, the method further includes forming a capping layer covering the light emitting device layer on the second electrode.

[0023] In some embodiments, the method further comprises, after forming the covering layer,

[0024] A second mask having a light-shielding portion and a light-transmitting portion is used, the light-transmitting portion of the second mask is aligned with the protrusion and the light-shielding portion of the second mask is aligned with the opening, and light is used to illuminate the light-emitting device layer from a side of the second mask away from the light-emitting device layer to change the conductivity of the portion of the light-emitting device layer located on the protrusion to form the second portion.

[0025] In some embodiments, the light comprises ultraviolet light. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below. It should be noted that the drawings described below only relate to some embodiments of the present invention, but are not intended to limit the present invention, wherein:

[0027] Figure 1 is a schematic diagram of an array substrate according to an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of an array substrate according to an embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of an array substrate according to an embodiment of the present invention;

[0030] Figure 4 is a schematic diagram of an array substrate according to an embodiment of the present invention;

[0031] Figure 5 is a schematic diagram of a display device according to an embodiment of the present invention;

[0032] Figure 6 is a schematic flow chart of a method for manufacturing an array substrate according to an embodiment of the present invention;

[0033] Figure 7 A schematic diagram of a method for forming a light-emitting device layer on a pixel definition layer according to an embodiment of the present invention;

[0034] Figure 8 is a schematic diagram of a method for manufacturing an array substrate according to an embodiment of the present invention;

[0035] FIG9( a ) is a fluorescence image of a conventional array substrate;

[0036] FIG. 9( b ) is a fluorescence image of the array substrate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work also fall within the scope of protection of the present invention.

[0038] When introducing elements of the present invention and embodiments thereof, the articles "a," "an," "the," and "said" are intended to indicate that there are one or more elements. The terms "comprising," "including," "containing," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0039] For the purpose of the following surface description, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom" and their derivatives shall refer to the invention as they are oriented in the accompanying drawings. The terms "overlying", "on top of", "positioned on" or "positioned on top of" mean that a first element such as a first structure is present on a second element such as a second structure, wherein an intermediate element such as an interface structure may exist between the first element and the second element. The term "contacting" means connecting a first element such as a first structure and a second element such as a second structure, and there may or may not be other elements at the interface of the two elements.

[0040] Figure 1 FIG. 2 is a schematic diagram of an array substrate according to an embodiment of the present invention. Figure 1 As shown, the array substrate according to the embodiment of the present invention may include: a base substrate 1; a pixel definition layer 2 disposed on the base substrate, wherein the pixel definition layer 2 has an opening 21 defining a sub-pixel PIX and a protrusion 22 located between the openings 21; a light emitting device layer 3 disposed on the pixel definition layer 2, wherein the light emitting device layer 3 has a first portion P31 disposed in the opening 21 and a second portion P2 disposed on the protrusion 22, wherein the conductivity of the second portion P2 in a direction parallel to the base substrate 1 is lower than the conductivity of the first portion P1 in a direction parallel to the base substrate 1. Through such a configuration, the lateral leakage current between different sub-pixels of the array substrate can be reduced, and the quality of the array substrate can be improved.

[0041] Figure 2 FIG. 2 is a schematic diagram of an array substrate according to an embodiment of the present invention. Figure 2 As shown, the light-emitting device layer 3 of the array substrate according to the embodiment of the present invention may include: a first electrode 31 located in the opening 21; a hole transport layer 32 located on the surface of the first electrode 31 away from the base substrate 1; a light-emitting layer 33 located on the surface of the hole transport layer 32 away from the base substrate 1; an electron transport layer 34 located on the surface of the light-emitting layer 33 away from the base substrate 1; and a second electrode 35 located on the surface of the electron transport layer 34 away from the base substrate 1. The electrical conductivity of the portion of at least one of the hole transport layer 32, the light-emitting layer 33, and the electron transport layer 34 on the protrusion 22 in the direction parallel to the base substrate 1 is lower than the electrical conductivity of the portion thereof in the opening 21 in the direction parallel to the base substrate 1.

[0042] like Figure 2As shown, the hole transport layer 32 may have a gap G1 located on the protrusion 22. The projection of the gap G1 of the hole transport layer on the base substrate 1 at least partially overlaps with the projection of the protrusion 22 on the base substrate 1. In this way, the hole transport layer can at least expose a portion of the surface of the protrusion 22 away from the base substrate 1, thereby blocking the lateral leakage channel in the hole transport layer.

[0043] Generally speaking, the hole mobility of the hole transport layer material is one order of magnitude higher than the electron mobility of the electron transport layer material. Therefore, the lateral leakage current in the hole transport layer has a greater impact on the array substrate than the lateral leakage current in the electron transport layer. By improving the hole transport layer as in the embodiment of the present invention, a good effect of reducing the lateral leakage current of the array substrate can be achieved.

[0044] In some embodiments, the hole transport layer may also be used as a hole injection layer. In other embodiments, the light emitting device layer may further include a hole injection layer between the hole transport layer 32 and the first electrode 31 .

[0045] Figure 3 FIG. 2 is a schematic diagram of an array substrate according to an embodiment of the present invention. Figure 3 As shown, the light emitting device layer may further include a hole injection layer 36 between the hole transport layer 32 and the first electrode 31, wherein the hole injection layer 36 at least exposes a portion of the surface of the protrusion 22 away from the substrate 1. In this way, the lateral leakage resistance in the hole injection layer may also be cut off.

[0046] Figure 4 FIG. 2 is a schematic diagram of an array substrate according to an embodiment of the present invention. Figure 4 As shown, the light-emitting device layer may further include an auxiliary light-emitting layer 37 located between the hole transport layer 32 and the light-emitting layer 33. The conductivity of the auxiliary light-emitting layer on the protrusion 22 in a direction parallel to the base substrate 1 is lower than the conductivity of the auxiliary light-emitting layer in the opening in a direction parallel to the base substrate 1. In this way, the lateral leakage current in the auxiliary light-emitting layer can be blocked. In some embodiments, a method such as ultraviolet light irradiation can be adopted to make the part of the auxiliary light-emitting layer located on the protrusion at least partially ineffective, that is, its conductivity is reduced. It is also possible to effectively reduce the incidence of color mixing without affecting the optical properties of the array substrate and the life of the array substrate.

[0047] The auxiliary light-emitting layer may also be called a Prime layer, which can be used to lengthen the hole transport path. The material of the auxiliary light-emitting layer may be the same as that of the hole transport layer, or may be different from that of the hole transport layer.

[0048] like Figure 4As shown, the array substrate may further include a covering layer 38 disposed on a surface of the second electrode away from the base substrate 1. The covering layer may prevent water and oxygen from entering the light emitting device layer.

[0049] In some embodiments, the electron transport layer 34 can also be used as an electron injection layer. In other embodiments, the light emitting device layer further includes an electron injection layer 39 disposed between the electron transport layer 34 and the second electrode 35. The electron transport layer 34 can also be used as a hole blocking layer.

[0050] The electron transport layer 34 and / or the electron injection layer 39 have a gap located on the protrusion 22, and wherein the projection of the gap of the electron transport layer 34 and / or the electron injection layer 39 on the base substrate 1 at least partially overlaps with the projection of the surface of the protrusion 22 away from the base substrate 1 on the base substrate 1. In this way, lateral leakage current in the electron transport layer and / or the electron injection layer can also be blocked.

[0051] Figure 5 Schematic diagram of a display device according to an embodiment of the present invention. Figure 5 As shown, the display device 100 according to the embodiment of the present invention may include an array substrate 200. The array substrate 200 may be Figure 1-Figure 4 Any array substrate shown in .

[0052] An embodiment of the present invention further provides a method for manufacturing an array substrate. Figure 6 FIG. 1 is a flow chart of a method for manufacturing an array substrate according to an embodiment of the present invention. Figure 6 As shown, the method for manufacturing an array substrate according to an embodiment of the present invention includes:

[0053] S1. providing a substrate;

[0054] S3, forming a pixel definition layer on the base substrate, wherein the pixel definition layer has openings defining sub-pixels and protrusions located between the openings;

[0055] S5. Forming a light emitting device layer on the pixel definition layer, wherein the light emitting device layer has a first portion disposed in the opening and a second portion disposed on the protrusion, wherein the conductivity of the second portion in a direction parallel to the base substrate is lower than the conductivity of the first portion in a direction parallel to the base substrate.

[0056] Figure 7 FIG. 2 is a schematic diagram of a method for forming a light-emitting device layer on a pixel definition layer according to an embodiment of the present invention. Figure 7 As shown, in some embodiments, forming a light-emitting device layer on a pixel definition layer includes: S31, forming a first electrode in an opening of the pixel definition layer;

[0057] S33, forming a hole transport layer on the first electrode;

[0058] S35, forming a light-emitting layer on the hole transport layer;

[0059] S37, forming an electron transport layer on the light-emitting layer;

[0060] S39, forming a second electrode on the electron transport layer,

[0061] The conductivity of the portion of at least one of the hole transport layer, the light emitting layer, and the electron transport layer on the protrusion in a direction parallel to the base substrate is lower than the conductivity of the portion in the opening in a direction parallel to the base substrate. In this way, the lateral leakage current of the array substrate can be reduced and the quality of the array substrate can be improved.

[0062] refer to Figure 2 In some embodiments, forming the hole transport layer includes forming the hole transport layer 32 to have a gap G1 located on the protrusion 22. The projection of the gap G1 of the hole transport layer on the base substrate 1 at least partially overlaps with the projection of the surface of the protrusion 22 away from the base substrate on the base substrate 1. Specifically, a first mask having a hollow portion may be used to form the hole transport layer by aligning the hollow portion with the opening (for example, by evaporation). The first mask may include a fine metal mask FMM (fine metal mask).

[0063] In some embodiments, the hole transport layer also serves as a hole injection layer. In other embodiments, a separate hole injection layer is provided. Figure 3 The forming of the light emitting device layer may further include: forming a hole injection layer 36 between the hole transport layer 32 and the first electrode 31 , wherein the hole injection layer 36 at least exposes a portion of the surface of the protrusion 22 away from the substrate.

[0064] In some embodiments, reference Figure 4 The forming of the light emitting device layer further includes forming an auxiliary light emitting layer 37 between the hole transport layer 32 and the light emitting layer 33. In some embodiments, the method for manufacturing an array substrate further includes forming a covering layer 38 on the second electrode 35 to cover the light emitting device layer.

[0065] Figure 8 FIG. 2 is a schematic diagram of a method for manufacturing an array substrate according to an embodiment of the present invention. Figure 8As shown, the method for manufacturing an array substrate according to an embodiment of the present invention further includes, after forming the cover layer 38, using a second mask having a light shielding portion M1 and a light transmitting portion M2, aligning the light transmitting portion M2 of the second mask with the protrusion and aligning the light shielding portion M1 with the opening, irradiating the light emitting device layer with light from a side of the second mask away from the light emitting device layer to change the conductivity of the portion of the light emitting device layer located on the protrusion to form a second portion. For example, ultraviolet light may be used for irradiation.

[0066] By adopting a method such as ultraviolet light irradiation, the portion of the auxiliary light-emitting layer located on the protrusion can be at least partially ineffective, that is, its conductivity is reduced. It can also effectively reduce the occurrence rate of color mixing without affecting the optical properties of the array substrate and the life of the array substrate.

[0067] The first electrode may be an anode. For example, the anode may be formed by magnetron sputtering. The material of the anode may be a transparent conductive material such as ITO. The second mask may be the same mask as the mask used when forming the anode.

[0068] FIG9(a) is a fluorescence image of a conventional array substrate. FIG9(b) is a fluorescence image of an array substrate according to an embodiment of the present invention. By comparing FIG9(a) and FIG9(b), it can be seen that the brightness value of the array substrate according to the embodiment of the present invention is significantly improved. This further verifies that the array substrate according to the embodiment of the present invention can reduce lateral leakage current and improve the quality of the array substrate.

[0069] The inventors also conducted RGC (Red Gray Crush) tests on conventional array substrates (also referred to as comparative examples) and array substrates according to embodiments of the present invention. The brightness values ​​of different monochromatic lights at the center of the array substrate were measured in a low brightness mode (e.g., 4 nit), and the following Table 1 was obtained:

[0070] Table 1 Resistance Rs test and RGC value of the top of the protrusion of the pixel definition layer (PDL) before and after improvement

[0071] project PDL raised upper Rs RGC value Comparative Example 1.2E9Ω 0.41 Embodiments of the present invention 7.38E10Ω 0.61

[0072] It can be seen from Table 1 that, compared with the conventional array substrate as a comparative example, the resistance value above the protrusion of the pixel definition layer of the array substrate of the embodiment of the present invention is increased, so that its leakage current is reduced and the display brightness is improved.

[0073] Certain specific embodiments have been described, which are presented by way of example only and are not intended to limit the scope of the invention. In fact, the novel embodiments described herein may be implemented in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the embodiments described herein may be made without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover such forms or modifications that fall within the scope and spirit of the invention.

Claims

1. An array substrate, comprising: substrate substrate; A pixel definition layer disposed on the base substrate, wherein the pixel definition layer has openings defining sub-pixels and protrusions located between the openings; and a light emitting device layer disposed on the pixel definition layer, wherein the light emitting device layer has a first portion disposed in the opening and a second portion located on the protrusion, wherein the conductivity of the second portion in a direction parallel to the base substrate is lower than the conductivity of the first portion in a direction parallel to the base substrate, Wherein, the light emitting device layer comprises: a first electrode located in the opening; a hole transport layer located on a surface of the first electrode away from the substrate; A light-emitting layer located on a surface of the hole transport layer away from the substrate; An electron transport layer located on the light-emitting layer and away from the substrate; a second electrode located on a surface of the electron transport layer away from the substrate, Among them, the conductivity of at least one of the hole transport layer, the light-emitting layer, and the electron transport layer on the protrusion in a direction parallel to the base substrate is lower than the conductivity of the portion thereof in the opening in a direction parallel to the base substrate.

2. The array substrate according to claim 1, wherein: The hole transport layer has a space on the protrusion, and a projection of the space on the substrate of the hole transport layer at least partially overlaps with a projection of a surface of the protrusion away from the substrate on the substrate of the protrusion.

3. The array substrate according to claim 2, wherein: The hole transport layer also functions as a hole injection layer.

4. The array substrate according to claim 2, wherein: The light emitting device layer further includes a hole injection layer located between the hole transport layer and the first electrode, wherein the hole injection layer exposes at least a portion of a surface of the protrusion away from the base substrate.

5. The array substrate according to claim 1, wherein: The light-emitting device layer also includes an auxiliary light-emitting layer located between the hole transport layer and the light-emitting layer, wherein the conductivity of a portion of the auxiliary light-emitting layer on the protrusion in a direction parallel to the base substrate is lower than the conductivity of a portion of the auxiliary light-emitting layer in the opening in a direction parallel to the base substrate.

6. The array substrate according to claim 1, wherein: The electron transport layer also functions as an electron injection layer.

7. The array substrate according to claim 1, wherein: The light emitting device layer further includes an electron injection layer disposed between the electron transport layer and the second electrode.

8. The array substrate according to claim 6 or 7, wherein: The electron transport layer and / or the electron injection layer have a gap located on the protrusion, and wherein a projection of the gap of the electron transport layer and / or the electron injection layer on the substrate at least partially overlaps with a projection of a surface of the protrusion away from the substrate on the substrate.

9. A display panel comprising the array substrate according to any one of claims 1 to 8.

10. A method for manufacturing an array substrate, comprising: providing a substrate base plate; forming a pixel definition layer on the base substrate, wherein the pixel definition layer has openings defining sub-pixels and protrusions located between the openings; forming a light emitting device layer on the pixel definition layer, wherein the light emitting device layer has a first portion disposed in the opening and a second portion located on the protrusion, wherein the conductivity of the second portion in a direction parallel to the base substrate is lower than the conductivity of the first portion in a direction parallel to the base substrate, Wherein, forming the light emitting device layer on the pixel definition layer comprises: forming a first electrode in the opening of the pixel definition layer; forming a hole transport layer on the first electrode; forming a light-emitting layer on the hole transport layer; forming an electron transport layer on the light-emitting layer; forming a second electrode on the electron transport layer, Among them, the conductivity of at least one of the hole transport layer, the light-emitting layer, and the electron transport layer on the protrusion in a direction parallel to the base substrate is lower than the conductivity of the portion thereof in the opening in a direction parallel to the base substrate.

11. The method according to claim 10, wherein: Forming a hole transport layer includes forming the hole transport layer to have a space located on the protrusion, and wherein a projection of the space of the hole transport layer on the base substrate at least partially overlaps a projection of a surface of the protrusion away from the base substrate on the base substrate.

12. The method according to claim 11, wherein: Forming the hole transport layer includes: using a first mask having a hollow portion, and aligning the hollow portion with the opening to form the hole transport layer.

13. The method according to claim 12, wherein: The first mask includes a fine metal mask.

14. The method according to claim 10, wherein: The hole transport layer also functions as a hole injection layer.

15. The method according to claim 10, wherein: Forming the light emitting device layer further includes: forming a hole injection layer between the hole transport layer and the first electrode, wherein the hole injection layer at least exposes a portion of the surface of the protrusion away from the base substrate.

16. The method according to any one of claims 10 to 15, wherein: The forming of the light emitting device layer further includes: forming an auxiliary light emitting layer between the hole transport layer and the light emitting layer.

17. The method according to claim 16, further comprising: A capping layer covering the light emitting device layer is formed on the second electrode.

18. The method according to claim 17, further comprising: After forming the covering layer, A second mask having a light-shielding portion and a light-transmitting portion is used, the light-transmitting portion of the second mask is aligned with the protrusion and the light-shielding portion of the second mask is aligned with the opening, and light is used to illuminate the light-emitting device layer from a side of the second mask away from the light-emitting device layer to change the conductivity of the portion of the light-emitting device layer located on the protrusion to form the second portion.

19. The method according to claim 18, wherein: The light includes ultraviolet light.

Images