Electroluminescent display panel, display device and manufacturing method

Abstract

The present invention discloses an electroluminescent display panel, a display device and a manufacturing method, wherein the display panel of one embodiment includes a plurality of sub-pixels arranged in an array, the display panel includes a first electrode corresponding to each sub-pixel arranged on a substrate; a pixel defining layer, forming a plurality of openings corresponding to each sub-pixel; a light-emitting functional layer arranged in the opening and at least partially covering the pixel defining layer; and a second electrode covering the light-emitting functional layer; wherein, in a direction perpendicular to the substrate, adjacent first color sub-pixels and second color sub-pixels are included, the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the first color sub-pixel is greater than the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the second color sub-pixel, and the thickness of the pixel defining layer corresponding to the first color sub-pixel is less than the thickness of the pixel defining layer corresponding to the second color sub-pixel. The embodiments provided by the present invention can effectively improve the display effect and have a wide range of application prospects.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to an electroluminescent display panel, a display device and a manufacturing method. Background Art

[0002] Organic electroluminescent (OLED) flexible display is a new generation of new display technology, which has the advantages of lightness, impact resistance, rollability, high luminous efficiency, short response time, high clarity and contrast, wide operating temperature range, and transparent preparation, which can make the display device thinner, portable, beautiful and fashionable, and has broad development space. The structure of the tandem organic electroluminescent device (Tandem OLED) is prepared by connecting two or more single-layer electroluminescent units in series through a charge generation layer. Compared with single-layer electroluminescent devices, it has the advantages of high efficiency, high brightness, and long life. However, due to the use of different numbers of single-layer electroluminescent units, there is a problem of poor display. Summary of the invention

[0003] In order to solve at least one of the above problems, the present invention provides an electroluminescent display panel in a first aspect, comprising pixel units arranged in an array, each pixel unit comprising a plurality of sub-pixels, the display panel comprising a light-emitting device layer disposed on a substrate, comprising:

[0004] a first electrode corresponding to each sub-pixel;

[0005] A pixel defining layer, forming a plurality of openings corresponding to each sub-pixel;

[0006] A light emitting function layer disposed in the opening and at least partially covering the pixel defining layer; and

[0007] A second electrode covering the light-emitting functional layer; wherein,

[0008] In a direction perpendicular to the substrate, it includes adjacent first color sub-pixels and second color sub-pixels, the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the first color sub-pixel is greater than the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the second color sub-pixel, and the thickness of the pixel defining layer corresponding to the first color sub-pixel is less than the thickness of the pixel defining layer corresponding to the second color sub-pixel.

[0009] Furthermore, the display panel is a laminated display panel, and the light-emitting functional layers of sub-pixels of different colors include at least two light-emitting material layers;

[0010] The thickness of the pixel defining layer in the sub-pixel region of different color sub-pixels varies with the thickness of the light-emitting functional layer covering it, so that the surfaces of the light-emitting functional layers covering the pixel defining layer in two adjacent sub-pixels away from the substrate are flush.

[0011] Furthermore, in two adjacent sub-pixels, the thickness of the pixel defining layer of the different color sub-pixels and the thickness of the light-emitting functional layer covering them are the same, so that the surface of the second electrode covering the two adjacent sub-pixels close to the substrate has the same height relative to the substrate.

[0012] Furthermore, the surface of the second electrode covering the pixel defining layer close to the substrate has the same height relative to the substrate, and the plurality of sub-pixels include a red sub-pixel, a green sub-pixel and a blue sub-pixel, wherein

[0013] In a direction perpendicular to the substrate, the thickness of the pixel defining layer corresponding to the red sub-pixel is smaller than the thickness of the pixel defining layer corresponding to the green sub-pixel, and the thickness of the pixel defining layer corresponding to the green sub-pixel is smaller than the thickness of the pixel defining layer corresponding to the blue sub-pixel.

[0014] Furthermore, the light-emitting functional layer of each sub-pixel further includes a charge generation layer disposed between at least two light-emitting material layers.

[0015] In two adjacent sub-pixels, the sub-pixel regions of the sub-pixels of different colors further include an isolation column that separates the charge generation layer and the light-emitting material layer.

[0016] Furthermore, the isolation column separates the pixel defining layer between the pixel regions of the sub-pixels of different colors.

[0017] Furthermore, the isolation column is arranged on the pixel defining layer.

[0018] Furthermore, the isolation column is a column structure or a prism structure.

[0019] Furthermore, two adjacent sub-pixels include a third color sub-pixel and a fourth color sub-pixel, and the isolation column includes a first side surface facing the third color sub-pixel and a second side surface facing the fourth color sub-pixel, and at least one of the first side surface and the second side surface is a curved surface recessed toward the center of the isolation column.

[0020] Furthermore, the two adjacent sub-pixels include a fifth color sub-pixel and a sixth color sub-pixel, wherein

[0021] The fifth color sub-pixel includes a first pixel defining layer, and a first light-emitting material layer, a first charge generating layer, and a second light-emitting material layer which are stacked;

[0022] The sixth color sub-pixel includes a second pixel defining layer, and a third light-emitting material layer, a second charge generating layer and a fourth light-emitting material layer which are stacked;

[0023] In a direction perpendicular to the substrate, the sum of the thicknesses of the first pixel defining layer, the first light-emitting material layer, the first charge generating layer and the second light-emitting material layer is the same as the sum of the thicknesses of the second pixel defining layer, the third light-emitting material layer, the second charge generating layer and the fourth light-emitting material layer.

[0024] Furthermore, the two adjacent sub-pixels include a seventh color sub-pixel and an eighth color sub-pixel, wherein

[0025] The seventh color sub-pixel includes a third pixel defining layer, and a fifth light-emitting material layer, a third charge generating layer and a sixth light-emitting material layer which are stacked;

[0026] The eighth color sub-pixel includes a fourth pixel defining layer, and a seventh light-emitting material layer, a fourth charge generating layer, an eighth light-emitting material layer, a fifth charge generating layer and a ninth light-emitting material layer which are stacked;

[0027] In the direction perpendicular to the substrate, the sum of the thicknesses of the third pixel defining layer, the fifth light-emitting material layer, the third charge generating layer and the sixth light-emitting material layer is the same as the sum of the thicknesses of the fourth pixel defining layer, the seventh light-emitting material layer, the fourth charge generating layer, the eighth light-emitting material layer, the fifth charge generating layer and the ninth light-emitting material layer.

[0028] A second aspect of the present invention provides a display device, comprising the electroluminescent display panel as described in the first aspect.

[0029] A third aspect of the present invention provides a method for manufacturing the electroluminescent display panel as described in the first aspect, comprising:

[0030] forming a first electrode corresponding to each sub-pixel on the substrate;

[0031] forming a pixel defining layer having a plurality of openings corresponding to each sub-pixel on the substrate, wherein the pixel defining layer partially covers the first electrode;

[0032] A light-emitting functional layer is formed in the opening and at least partially covers the pixel defining layer, including adjacent first color sub-pixels and second color sub-pixels in a direction perpendicular to the substrate, the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the first color sub-pixel is greater than the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the second color sub-pixel, and the thickness of the pixel defining layer corresponding to the first color sub-pixel is less than the thickness of the pixel defining layer corresponding to the second color sub-pixel;

[0033] A second electrode is formed to cover the light emitting functional layer of each sub-pixel.

[0034] The beneficial effects of the present invention are as follows:

[0035] In view of the existing problems, the present invention develops an electroluminescent display panel, a display device and a manufacturing method. By setting a pixel defining layer with a thickness corresponding to the thickness of the light-emitting functional layer in each sub-pixel area, the display effect is effectively improved, and the problem of poor display caused by cathode rupture due to the step difference between two adjacent sub-pixels caused by the different thicknesses of the light-emitting functional layers and the same thickness of the pixel defining layer can be solved. In particular, in a laminated display panel, when the light-emitting functional layer of sub-pixels of different colors includes at least two light-emitting material layers, the thickness of the pixel defining layer in the sub-pixel area of ​​the sub-pixels of different colors varies with the thickness of the light-emitting functional layer covering it, so that the surface of the light-emitting functional layer covering the pixel defining layer in two adjacent sub-pixels away from the substrate is flush, and the connection position between the two adjacent sub-pixels is further flattened, thereby compensating for the problems existing in the prior art and having broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. 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.

[0037] Figure 1a-1b It is a schematic diagram of the structure of a laminated electroluminescent display panel in the related art;

[0038] Figure 2 A schematic diagram showing the structure of a laminated electroluminescent display panel according to an embodiment of the present invention is shown;

[0039] Figure 3 A schematic structural diagram of a laminated electroluminescent display panel according to another embodiment of the present invention is shown;

[0040] Figure 4 A schematic structural diagram of a laminated electroluminescent display panel according to another embodiment of the present invention is shown;

[0041] Figure 5 A schematic diagram showing the structure of an isolation column according to an embodiment of the present invention is shown;

[0042] Figure 6 A schematic diagram showing a sub-pixel arrangement according to an embodiment of the present invention;

[0043] Figure 7 A flow chart showing a manufacturing method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0045] It should be noted that the terms “on…”, “formed on…” and “disposed on…” described herein may indicate that one layer is directly formed or disposed on another layer, or may indicate that one layer is indirectly formed or disposed on another layer, i.e., there are other layers between the two layers. In this article, unless otherwise specified, the term “located on the same layer” used means that two layers, parts, components, elements or parts can be formed by the same patterning process, and the two layers, parts, components, elements or parts are generally formed of the same material. In this article, unless otherwise specified, the expression “patterning process” generally includes steps such as coating, exposure, development, etching and stripping of photoresist. The expression “one-time patterning process” means a process of forming patterned layers, parts, components, etc. using a mask.

[0046] like Figure 1a As shown in FIG. 1 , it is a schematic cross-sectional view of each sub-pixel of a laminated electroluminescent display panel, and three sub-pixels are shown in the figure, specifically red sub-pixel R, green sub-pixel G and blue sub-pixel B, where 101 is the anode of the sub-pixel, 102 is the luminescent material layer of the sub-pixel, 103 is the intermediate connection layer, 104 is the isolation column between different pixels, 105 is the cathode, 106 is the pixel definition layer, 107 is the driving circuit layer, and 108 is the substrate. At the junction of sub-pixels of different colors, such as the position outlined by the dotted line in the figure, there is a step difference. Figure 1b As shown, Figure 1a A local enlarged view of the F position shows that the cathode 105 is broken at the step difference, resulting in poor display of the stacked electroluminescent display device.

[0047] In response to the above situation, the inventor pointed out that in the stacked electroluminescent device, the thickness of the light-emitting materials used in sub-pixels of different colors is different, while the thickness of the pixel defining layer of each color sub-pixel is consistent. As a result, the light-emitting materials covered on the pixel defining layer of two adjacent sub-pixels of different colors have a step difference on the side away from the substrate. Therefore, the cathode between adjacent pixels is easily disconnected during cathode vapor deposition, resulting in an increase in the cross-voltage and deterioration in the uniformity of the stacked electroluminescent display device.

[0048] According to the above questions, if Figure 2 As shown, an embodiment of the present invention provides an electroluminescent display panel, including pixel units arranged in an array, each pixel unit including a plurality of sub-pixels, and the display panel includes a light-emitting device layer disposed on a substrate, including:

[0049] a first electrode corresponding to each sub-pixel;

[0050] A pixel defining layer, forming a plurality of openings corresponding to each sub-pixel;

[0051] A light emitting function layer disposed in the opening and at least partially covering the pixel defining layer; and

[0052] A second electrode covering the light-emitting functional layer; wherein,

[0053] In a direction perpendicular to the substrate, it includes adjacent first color sub-pixels and second color sub-pixels, the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the first color sub-pixel is greater than the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the second color sub-pixel, and the thickness of the pixel defining layer corresponding to the first color sub-pixel is less than the thickness of the pixel defining layer corresponding to the second color sub-pixel.

[0054] In this embodiment, a pixel defining layer having a thickness corresponding to that of the light-emitting functional layer is provided in each sub-pixel region, that is, in two adjacent sub-pixels, the relationship between the thickness of the pixel defining layer of the first color sub-pixel and the thickness of the pixel defining layer of the second color sub-pixel is determined according to the relationship between the thickness of the light-emitting functional layer of the first color sub-pixel and the thickness of the light-emitting functional layer of the second color sub-pixel, that is, the thickness of the light-emitting functional layer of the first color sub-pixel is greater than the thickness of the light-emitting functional layer of the second color sub-pixel, and the thickness of the pixel defining layer of the first color sub-pixel is less than the thickness of the pixel defining layer of the second color sub-pixel. In this embodiment, pixel defining layers of different thicknesses are provided for sub-pixels of different colors, so as to form a flat surface for evaporating the second electrode.

[0055] In an optional embodiment, the display panel is a laminated display panel, and the light-emitting functional layers of sub-pixels of different colors include at least two light-emitting material layers;

[0056] The thickness of the pixel defining layer in the sub-pixel region of different color sub-pixels varies with the thickness of the light-emitting functional layer covering it, so that the surfaces of the light-emitting functional layers covering the pixel defining layer in two adjacent sub-pixels away from the substrate are flush.

[0057] In this embodiment, for a laminated display panel having at least two light-emitting material layers, a complementary pixel defining layer is provided according to the light-emitting functional layer of sub-pixels of different colors, so that the light-emitting functional layers of two adjacent sub-pixels are leveled by the pixel defining layer. In other words, this embodiment makes the surfaces of the light-emitting functional layers covering the pixel defining layer in two adjacent sub-pixels away from the substrate flush, and the second electrode is formed on the flat surface, thereby effectively improving the display effect, and can solve the problem of poor display caused by the step difference between two adjacent sub-pixels due to different thicknesses of the light-emitting functional layers and the same thickness of the pixel defining layers, thereby making up for the problems existing in the prior art and having broad application prospects.

[0058] In a specific embodiment, Figure 2 2 is a schematic cross-sectional view of two adjacent sub-pixels of different colors, for example, including a green sub-pixel 100 and a red sub-pixel 200, and the manufacture of the laminated electroluminescent display panel of this embodiment is taken as an example for description.

[0059] In the first step, a driving circuit layer 20 is formed on a substrate 10 .

[0060] In the second step, a first electrode 31 corresponding to each sub-pixel is formed on the driving circuit layer 20 .

[0061] In the third step, a pixel defining layer is formed on the driving circuit layer 20 and a portion of the first electrode 31 , and the pixel defining layer is formed into a plurality of openings corresponding to each sub-item.

[0062] Taking into account the different thicknesses of the light-emitting functional layers of different color sub-pixels of the laminated electroluminescent display panel, for example, the light-emitting functional layer 331 of the green sub-pixel 100 includes light-emitting material layers 3311 and 3313, and the light-emitting functional layer 332 of the red sub-pixel 200 includes light-emitting material layers 3321 and 3323, and the thicknesses of the light-emitting material layers 3311 and 3313, and the light-emitting material layers 3321 and 3323 are different. When forming the pixel defining layer, the pixel defining layer in the sub-pixel area of ​​the different color sub-pixels is set according to the thickness of the light-emitting functional layer of the different color sub-pixels. For example, when the light-emitting functional layer 332 of the red sub-pixel 200 is thicker, the corresponding pixel defining layer is thinner; for example, when the light-emitting functional layer 331 of the green sub-pixel 100 is thinner, the corresponding pixel defining layer is thicker, thereby forming that the light-emitting functional layer covering the pixel defining layer in two adjacent sub-pixels is flush with the surface on the side away from the substrate 10, thereby solving the problem of poor display caused by cathode breakage due to different thicknesses of the light-emitting functional layer and the same thickness of the pixel defining layer, and effectively improving the display effect of the laminated electroluminescent display panel.

[0063] In an optional embodiment, in two adjacent sub-pixels, the thickness of the pixel defining layer of the different color sub-pixels and the thickness of the light-emitting functional layer covering them are the same, so that the surface of the second electrode covering the two adjacent sub-pixels close to the substrate side has the same height relative to the substrate.

[0064] In this embodiment, by limiting the sum of the thickness of the pixel defining layer and the thickness of the light-emitting functional layer in the sub-pixel area of ​​different sub-pixels, specifically, the sum of the thickness of the pixel defining layer and the light-emitting functional layer covering the pixel defining layer of adjacent sub-pixels of different colors is the same, that is, the light-emitting functional layers of adjacent sub-pixels of different colors form a flat surface, so that the surface of the second electrode evaporated thereon close to the substrate side has the same height relative to the substrate, thereby avoiding the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors.

[0065] Considering the manufacturing process of the laminated electroluminescent display panel, in an optional embodiment, the surface of the second electrode covering the pixel defining layer close to the substrate has the same height relative to the substrate.

[0066] In this embodiment, the sum of the thickness of the pixel defining layer in the pixel area of ​​different color sub-pixels and the thickness of the light-emitting functional layer covering the pixel defining layer is set to the same value, that is, the surface of the light-emitting functional layer of each sub-pixel away from the substrate is at the same height relative to the substrate. In other words, the surface of the second electrode of the laminated display panel away from the substrate is parallel to the substrate.

[0067] Further, in an optional embodiment, the plurality of sub-pixels of the laminated display panel include a red sub-pixel, a green sub-pixel and a blue sub-pixel, wherein

[0068] In a direction perpendicular to the substrate, the thickness of the pixel defining layer corresponding to the red sub-pixel is smaller than the thickness of the pixel defining layer corresponding to the green sub-pixel, and the thickness of the pixel defining layer corresponding to the green sub-pixel is smaller than the thickness of the pixel defining layer corresponding to the blue sub-pixel.

[0069] In the present embodiment, since the thickness of the light-emitting functional layer of the red sub-pixel is greater than that of the green sub-pixel, and the thickness of the light-emitting functional layer of the green sub-pixel is greater than that of the blue sub-pixel, the thickness of the pixel defining layer of each sub-pixel is limited. Relative to the substrate, the pixel defining layer of the red sub-pixel is the thinnest, followed by the pixel defining layer of the green sub-pixel, and the pixel defining layer of the blue sub-pixel is the thinnest, thereby achieving the complementarity of the pixel defining layers of sub-pixels of different colors and the corresponding light-emitting functional layers, that is, the light-emitting functional layers of adjacent sub-pixels of different colors form a flat surface, thereby avoiding the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors.

[0070] In the process of forming the pixel definition layer in this embodiment, the manufacturing working parameters are adjusted, such as changing the exposure time, to form the pixel definition layer with different thicknesses for each sub-pixel. For example, the longer the exposure time, the thinner the pixel definition layer.

[0071] In a fourth step, a light-emitting functional layer is formed in the opening of the pixel defining layer and at least partially covers the pixel defining layer.

[0072] In this embodiment, the light-emitting functional layer of each color sub-pixel is fabricated in each sub-pixel region, such as Figure 2 As shown, the light-emitting functional layer 331 of the green sub-pixel 100 includes light-emitting material layers 3311 and 3313, and a charge generating layer 3312 arranged between the light-emitting material layers 3311 and 3313. When the green sub-pixel is manufactured, the light-emitting material layer 3311, the charge generating layer 3312 and the light-emitting material layer 3313 are formed respectively; similarly, the light-emitting functional layer 332 of the red sub-pixel 200 includes light-emitting material layers 3321 and 3323, and a charge generating layer 3322 arranged between the light-emitting material layers 3321 and 3323. When the red sub-pixel is manufactured, the light-emitting material layer 3321, the charge generating layer 3322 and the light-emitting material layer 3323 are formed respectively. Moreover, the sum of the thicknesses of the light-emitting functional layer 332 and the corresponding pixel defining layer of the red sub-pixel 200 is the same as the sum of the thicknesses of the light-emitting functional layer 331 and the corresponding pixel defining layer of the green sub-pixel 100, thereby achieving complementarity between the pixel defining layers and the corresponding light-emitting functional layers of sub-pixels of different colors, thereby avoiding the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors.

[0073] Considering that the charge generation layer causes significant lateral crosstalk, in an alternative embodiment, as Figure 3 As shown, in two adjacent sub-pixels, the sub-pixel regions of the sub-pixels of different colors further include an isolation column 35 that separates the charge generation layer and the light-emitting material layer.

[0074] In the present embodiment, the charge generation layer and the light-emitting material layer between adjacent sub-pixels are separated by isolation columns, thereby alleviating lateral crosstalk and improving the display effect. In the present embodiment, the isolation column 35 is arranged on the driving circuit layer. For example, a hole is opened after the pixel defining layer is formed, and the isolation column 35 is formed in the hole. The height of the isolation column is flush with the surface of the light-emitting functional layer of the two adjacent sub-pixels away from the substrate side, thereby forming a flat surface; the isolation column 35 can separate the light-emitting material layer 3311, the charge generation layer 3312 and the light-emitting material layer 3313 of the green sub-pixel 100 from the light-emitting material layer 3321, the charge generation layer 3322 and the light-emitting material layer 3323 of the red sub-pixel 200, thereby effectively improving lateral crosstalk, thereby avoiding the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors. Figure 3As shown, the light-emitting functional layer also includes functional film layers other than the light-emitting material layer, such as an electron transport layer 333 made in one layer, and there are residues on the isolation column 35 .

[0075] In an optional embodiment, if Figure 4 As shown, the isolation column is arranged on the pixel defining layer.

[0076] In this embodiment, in order to simplify the manufacturing process, after forming the pixel defining layer, an isolation column 35 is formed on the pixel defining layer, so that the light-emitting material layer 3311, the charge generation layer 3312 and the light-emitting material layer 3313 of the green sub-pixel 100 are separated from the light-emitting material layer 3321, the charge generation layer 3322 and the light-emitting material layer 3323 of the red sub-pixel 200 by the isolation column 35, effectively improving the lateral crosstalk, thereby avoiding the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors. Figure 3 As shown, the light-emitting functional layer also includes functional film layers other than the light-emitting material layer, such as an electron transport layer 333 made in one layer, and there are residues on the isolation column 35 .

[0077] It is worth noting that the present application does not specifically limit the position of the isolation column. The isolation column can be set in the pixel area of ​​a sub-pixel or between the pixel areas of two adjacent sub-pixels. At the same time, the present application does not specifically limit the morphology of the isolation column. The isolation column can be a column structure, such as Figure 3 and Figure 4 In the figure, according to the pixel area of ​​each sub-pixel, the isolation column can be a rectangular column or a circular cylinder, and the isolation column can also be a prism structure, such as a prism with an inverted trapezoidal or inverted triangular cross-section; technical personnel in this field should select an appropriate position or morphology to set the isolation column according to actual application requirements, which will not be repeated here.

[0078] Taking into account the isolation function of the isolation column for isolating the charge generation layer and the light-emitting material layer of sub-pixels of different colors, in an optional embodiment, two adjacent sub-pixels include a third color sub-pixel and a fourth color sub-pixel, and the isolation column includes a first side facing the third color sub-pixel and a second side facing the fourth color sub-pixel, and at least one of the first side and the second side is a curved surface that is concave toward the center of the isolation column.

[0079] In this embodiment, the isolation column is formed as follows Figure 5 Any of the morphologies shown can more effectively isolate the charge generation layer and the light-emitting material layer of adjacent sub-pixels through the isolation columns of the morphology, improve the lateral crosstalk problem, and enhance the display effect.

[0080] It is worth noting that the present application does not specifically limit the arrangement of the sub-pixels, which can be as follows: Figure 6The arrangement shown includes a red sub-pixel R, a green sub-pixel G, and a blue sub-pixel B; it can also be a Stripe RGB arrangement, a Delta RGB arrangement, a GGRB arrangement, a diamond arrangement, or a pearl arrangement. Those skilled in the art should select an appropriate sub-pixel arrangement according to actual application requirements, which will not be described in detail here.

[0081] Taking into account that different sub-pixels include different numbers of light-emitting material layers, the adjacent red sub-pixel and green sub-pixel are still taken as an example for explanation. The red sub-pixel includes three layers of light-emitting material and two layers of charge generating layers, and the green sub-pixel includes two layers of light-emitting material and one layer of charge generating layer. The corresponding pixel defining layers are set according to the thickness of the light-emitting functional layer of the red sub-pixel and the thickness of the light-emitting functional layer of the green sub-pixel, respectively, so that the sum of the thickness of the light-emitting functional layer of the red sub-pixel and the corresponding pixel defining layer is the same as the sum of the thickness of the light-emitting functional layer of the green sub-pixel and the corresponding pixel defining layer, thereby achieving the complementarity of the pixel defining layers and the corresponding light-emitting functional layers of sub-pixels of different colors, which can avoid the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors.

[0082] The fifth step is to form a second electrode covering the light-emitting functional layer of each sub-pixel.

[0083] In this embodiment, the second electrode is formed on a flat surface with the same height formed between adjacent sub-pixels in a direction perpendicular to the substrate, thereby avoiding the problem of the second electrode being broken due to the step difference between adjacent sub-pixels of different colors.

[0084] It is worth noting that one of the first electrode and the second electrode of this embodiment can be a cathode, and the other electrode can be an anode. In this embodiment of the present invention, the first electrode is an anode and the second electrode is a cathode. Those skilled in the art should make settings according to actual application requirements, which will not be described in detail here.

[0085] At this point, the manufacture of the laminated electroluminescent display panel is completed. This embodiment arranges a pixel defining layer having a thickness corresponding to the thickness of the light-emitting functional layer in each sub-pixel region, so that the light-emitting functional layer covering the pixel defining layer in two adjacent sub-pixels is flush with the surface away from the substrate, which effectively improves the display effect and can solve the problem of poor display caused by cathode rupture due to the step difference between two adjacent sub-pixels caused by different light-emitting functional layer thicknesses and the same pixel defining layer thickness, thereby making up for the problems existing in the prior art and having broad application prospects.

[0086] Corresponding to the electroluminescent display panel provided in the above-mentioned embodiments, an embodiment of the present application further provides a method for manufacturing the above-mentioned electroluminescent display panel. Since the manufacturing method provided in the embodiment of the present application corresponds to the electroluminescent display panels provided in the above-mentioned embodiments, the previous implementation mode is also applicable to the manufacturing method provided in this embodiment and will not be described in detail in this embodiment.

[0087] like Figure 7 As shown, one embodiment of the present application further provides a method for manufacturing the electroluminescent display panel, comprising:

[0088] forming a first electrode corresponding to each sub-pixel on the substrate;

[0089] Forming a pixel defining layer having a plurality of openings corresponding to each sub-pixel on the substrate, wherein the pixel defining layer partially covers the first electrode, and the thickness of the pixel defining layer is inversely proportional to the thickness of the light-emitting functional layer of the corresponding color in the sub-pixel region;

[0090] forming a light-emitting functional layer located in the opening and at least partially covering the pixel defining layer, wherein the light-emitting functional layers of sub-pixels of different colors include at least two light-emitting material layers, and surfaces of the light-emitting functional layers covering the pixel defining layer in two adjacent sub-pixels away from the substrate are flush;

[0091] A second electrode is formed to cover the light emitting functional layer of each sub-pixel.

[0092] The electroluminescent display panel formed in this embodiment provides a pixel defining layer having a thickness corresponding to that of the light-emitting functional layer in each sub-pixel region, so that the light-emitting functional layer covering the pixel defining layer in two adjacent sub-pixels is flush with the surface away from the substrate side, thereby effectively improving the display effect and solving the problem of poor display caused by cathode breakage due to the step difference between two adjacent sub-pixels caused by the different thickness of the light-emitting functional layer and the same thickness of the pixel defining layer, thereby compensating for the problems existing in the prior art and having broad application prospects.

[0093] Another embodiment of the present invention provides a display device, including the above-mentioned electroluminescent display panel, and the display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame or a navigator.

[0094] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. An electroluminescent display panel, comprising pixel units arranged in an array, each pixel unit comprising a plurality of sub-pixels, characterized in that: The display panel includes a light emitting device layer disposed on a substrate, including: a first electrode corresponding to each sub-pixel; A pixel defining layer, forming a plurality of openings corresponding to each sub-pixel; A light emitting function layer disposed in the opening and at least partially covering the pixel defining layer; and A second electrode covering the light-emitting functional layer; wherein, In a direction perpendicular to the substrate, the adjacent first color sub-pixel and second color sub-pixel are included, the thickness of the light-emitting function layer covering the pixel defining layer corresponding to the first color sub-pixel is greater than the thickness of the light-emitting function layer covering the pixel defining layer corresponding to the second color sub-pixel, and the thickness of the pixel defining layer corresponding to the first color sub-pixel is less than the thickness of the pixel defining layer corresponding to the second color sub-pixel; The display panel is a laminated display panel, and the light-emitting functional layers of sub-pixels of different colors include at least two light-emitting material layers; The thickness of the pixel defining layer in the sub-pixel region of different color sub-pixels varies with the thickness of the light-emitting functional layer covering it, so that the surfaces of the light-emitting functional layers covering the pixel defining layer in two adjacent sub-pixels away from the substrate are flush.

2. The display panel according to claim 1, characterized in that: In two adjacent sub-pixels, the thickness of the pixel defining layer of the sub-pixels of different colors and the thickness of the light-emitting functional layer covering them are the same, so that the surface of the second electrode covering the two adjacent sub-pixels close to the substrate has the same height relative to the substrate.

3. The display panel according to claim 2, characterized in that: The surface of the second electrode covering the pixel defining layer close to the substrate has the same height relative to the substrate, and the plurality of sub-pixels include a red sub-pixel, a green sub-pixel and a blue sub-pixel, wherein In a direction perpendicular to the substrate, the thickness of the pixel defining layer corresponding to the red sub-pixel is smaller than the thickness of the pixel defining layer corresponding to the green sub-pixel, and the thickness of the pixel defining layer corresponding to the green sub-pixel is smaller than the thickness of the pixel defining layer corresponding to the blue sub-pixel.

4. The display panel according to any one of claims 1 to 3, characterized in that: The light-emitting functional layer of each sub-pixel further includes a charge generation layer disposed between at least two light-emitting material layers. In two adjacent sub-pixels, the sub-pixel regions of the sub-pixels of different colors further include an isolation column that separates the charge generation layer and the light-emitting material layer.

5. The display panel according to claim 4, characterized in that: The isolation column separates the pixel defining layer between the pixel regions of sub-pixels of different colors.

6. The display panel according to claim 4, characterized in that: The isolation column is disposed on the pixel defining layer.

7. The display panel according to claim 5, characterized in that: The isolation column is a column structure or a prism structure.

8. The display panel according to claim 5, characterized in that: Two adjacent sub-pixels include a third color sub-pixel and a fourth color sub-pixel, and the isolation column includes a first side surface facing the third color sub-pixel and a second side surface facing the fourth color sub-pixel, and at least one of the first side surface and the second side surface is a curved surface recessed toward the center of the isolation column.

9. The display panel according to claim 4, characterized in that: The two adjacent sub-pixels include a fifth color sub-pixel and a sixth color sub-pixel, wherein The fifth color sub-pixel includes a first pixel defining layer, and a first light-emitting material layer, a first charge generating layer, and a second light-emitting material layer which are stacked; The sixth color sub-pixel includes a second pixel defining layer, and a third light-emitting material layer, a second charge generating layer and a fourth light-emitting material layer which are stacked; In a direction perpendicular to the substrate, the sum of the thicknesses of the first pixel defining layer, the first light-emitting material layer, the first charge generating layer and the second light-emitting material layer is the same as the sum of the thicknesses of the second pixel defining layer, the third light-emitting material layer, the second charge generating layer and the fourth light-emitting material layer.

10. The display panel according to claim 4, characterized in that: The two adjacent sub-pixels include a seventh color sub-pixel and an eighth color sub-pixel, wherein The seventh color sub-pixel includes a third pixel defining layer, and a fifth light-emitting material layer, a third charge generating layer and a sixth light-emitting material layer which are stacked; The eighth color sub-pixel includes a fourth pixel defining layer, and a seventh light-emitting material layer, a fourth charge generating layer, an eighth light-emitting material layer, a fifth charge generating layer and a ninth light-emitting material layer which are stacked; In the direction perpendicular to the substrate, the sum of the thicknesses of the third pixel defining layer, the fifth light-emitting material layer, the third charge generating layer and the sixth light-emitting material layer is the same as the sum of the thicknesses of the fourth pixel defining layer, the seventh light-emitting material layer, the fourth charge generating layer, the eighth light-emitting material layer, the fifth charge generating layer and the ninth light-emitting material layer.

11. A display device, characterized in that: Comprising the electroluminescent display panel as claimed in any one of claims 1 to 10.

12. A method for manufacturing an electroluminescent display panel as claimed in any one of claims 1 to 10, characterized in that: include: forming a first electrode corresponding to each sub-pixel on the substrate; forming a pixel defining layer having a plurality of openings corresponding to each sub-pixel on the substrate, wherein the pixel defining layer partially covers the first electrode; A light-emitting functional layer is formed in the opening and at least partially covers the pixel defining layer, including adjacent first color sub-pixels and second color sub-pixels in a direction perpendicular to the substrate, the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the first color sub-pixel is greater than the thickness of the light-emitting functional layer covering the pixel defining layer corresponding to the second color sub-pixel, and the thickness of the pixel defining layer corresponding to the first color sub-pixel is less than the thickness of the pixel defining layer corresponding to the second color sub-pixel; the display panel is a laminated display panel, the light-emitting functional layers of sub-pixels of different colors include at least two light-emitting material layers, and the thickness of the pixel defining layer in the sub-pixel region of the sub-pixels of different colors varies with the thickness of the light-emitting functional layer covering it, so that the surfaces of the light-emitting functional layers covering the pixel defining layers in two adjacent sub-pixels away from the substrate are flush; A second electrode is formed to cover the light emitting functional layer of each sub-pixel.

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