Display panel, preparation method thereof and display device

Abstract

The invention provides a display panel, a preparation method thereof and a display device. The display panel comprises a pixel definition layer, the pixel definition layer is provided with a plurality of pixel openings and spacer regions located between every two adjacent pixel openings, and each spacer region comprises a heat shrinkage material; the anode layer comprises a wrinkle part, and the wrinkle part is located in the pixel opening; the light-emitting layer is arranged on one side of the wrinkle part in a shape-following laminated mode; and under the thermal shrinkage effect of the spacer region in the direction parallel to the anode layer, the wrinkle part and the light-emitting layer can extend and unfold along the direction parallel to the anode layer. The display panel provided by the invention has a relatively high pixel aperture ratio, so that the light passing rate is improved, the light emitting brightness is increased, the driving power is reduced, the display service life of the display panel is remarkably prolonged, and the product competitiveness of the display panel is further improved.

Description

Technical Field

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

[0002] In the related technology, in the OLED preparation process, FMM (Fine Metal Mask) is the most important existence, which can prevent the color mixing between sub-pixels and accurately locate the evaporation position of each sub-pixel. However, due to the strength requirements of FMM itself, a large gap needs to be retained between each pixel hole of FMM, which makes the actual light-emitting area (aperture ratio) of each sub-pixel in the current OLED display device small, thereby limiting the luminous brightness and service life of OLED. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a display panel and a display device, which can reliably increase the aperture ratio of the sub-pixel through the thermal contraction of the spacer area of ​​the pixel definition layer and the extension and expansion of the wrinkled portion of the anode layer, thereby improving the light transmittance and increasing the luminous brightness, which is conducive to reducing the driving power and significantly improving the display life of the display panel, thereby improving the product competitiveness of the display panel.

[0004] In a first aspect, the present invention provides a display panel, comprising:

[0005] A pixel definition layer, the pixel definition layer having a plurality of pixel openings and a spacing region between two adjacent pixel openings, the spacing region comprising a heat shrink material;

[0006] an anode layer, the anode layer comprising a corrugated portion, the corrugated portion being located in the pixel opening;

[0007] A light-emitting layer, the light-emitting layer is arranged in a conformal lamination on one side of the folded portion;

[0008] Under the effect of heat shrinkage of the spacer in the direction parallel to the anode layer, the wrinkled portion and the light-emitting layer can extend and expand in the direction parallel to the anode layer.

[0009] As an optional solution, the pixel definition layer includes a main material, and the heat shrink material is doped in the main material.

[0010] As an alternative, the heat shrinkable material includes polyethylene, ethylene-vinyl acetate copolymer, aluminum hydroxide and red phosphorus;

[0011] As an optional solution, the mass ratio of polyethylene, ethylene-vinyl acetate copolymer, aluminum hydroxide and red phosphorus is 20:80:40:10.

[0012] As an optional solution, the thermal shrinkage deformation range of the spacer region is 10%-30% of the initial volume.

[0013] As an optional solution, the anode layer includes a main layer and at least a thin film layer stacked on the main layer and located inside the pixel opening, the thin film layer includes an organic conductive polymer layer, and the wrinkled portion is formed by increasing the surface roughness of the organic conductive polymer layer through heat treatment.

[0014] As an optional solution, the thin film layer also includes a graphene layer, the graphene layer is stacked on the main layer, and the organic conductive polymer layer is stacked on the side of the graphene layer away from the main layer. The wrinkled portion is formed by heat treating the organic conductive polymer layer and the graphene layer to increase the surface roughness.

[0015] As an optional solution, the region of the anode layer located in the pixel opening is in a continuous wavy shape, and the region of the anode layer in a continuous wavy shape is configured as a fold portion;

[0016] As an optional solution, the region of the anode layer located within the pixel opening includes a plurality of periodically changing crests and troughs.

[0017] As an option, the roughness of the corrugated portion is 100 nm-400 nm.

[0018] In a second aspect, the present invention provides a method for preparing the display panel of the first aspect, which specifically comprises the following steps:

[0019] forming a pixel definition layer, the pixel definition layer comprising a plurality of pixel openings and a spacer region between two adjacent pixel openings, the spacer region comprising a heat shrink material;

[0020] forming an anode layer, the anode layer comprising a corrugated portion, the corrugated portion being located within each pixel opening;

[0021] forming a light-emitting layer, wherein the light-emitting layer is arranged in a conformal lamination on one side of the folded portion;

[0022] The spacer area is heated, and under the effect of heat shrinkage of the spacer area, the wrinkled portion and the light-emitting layer can extend and expand in a direction parallel to the anode layer.

[0023] As an optional solution, the pixel definition layer further includes a bulk material, and the pixel definition layer is formed, including:

[0024] The heat shrink material is doped into the main material to form a pixel definition layer.

[0025] As an optional solution, the anode layer includes a main layer and at least a thin film layer stacked on the main layer and located inside the pixel opening, the thin film layer includes an organic conductive polymer layer and a graphene layer, forming the anode layer, including:

[0026] forming the main body layer;

[0027] After the organic conductive polymer and the graphene layer are stacked and heat treated to increase the surface roughness, a wrinkled portion is formed in the area of ​​the main layer located inside the pixel opening.

[0028] In a third aspect, the present invention provides a display device comprising the display panel of the first aspect.

[0029] In the display panel of the present invention, the spacer of the pixel definition layer includes a heat shrink material, the anode layer includes a folded portion, the folded portion is located in the pixel opening, and the light-emitting layer is arranged on one side of the folded portion in a conformal stack. Under the heat shrinkage of the spacer in a direction parallel to the anode layer, the folded portion and the light-emitting layer can extend and expand in a direction parallel to the anode layer. In this way, the shrinkage of the spacer reduces the size of the spacer, and the extension and expansion of the folded portion and the light-emitting layer increase the pixel opening. On the one hand, it is conducive to improving the light transmission rate, thereby increasing the light brightness, and the processing is convenient. On the basis of maintaining the current OLED light-emitting layer evaporation process, there is no need to change the structure of the FMM (precision metal mask), and the aperture rate can be reliably increased; on the other hand, it is conducive to reducing the driving power of the display panel, significantly improving the display life of the display panel, and thus helping to improve the product competitiveness of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0031] Figure 1 A schematic diagram of the structure of a display panel according to an embodiment of the present application (the spacing area is not heated);

[0032] Figure 2 A schematic diagram of the structure of a display panel according to an embodiment of the present application (after the spacing area is heated);

[0033] Figure 3 The pixel arrangement of Example 1;

[0034] Figure 4 The pixel arrangement of Example 2;

[0035] Figure 5 A schematic diagram of a fold portion of an embodiment of the present application;

[0036] Figure 6 The morphology of the conductive polymer on the glass substrate; (a) is the optical microscope morphology; (d) is the scanning electron microscope morphology; (g) is the atomic force microscope morphology;

[0037] Figure 7The morphology of the conductive polymer on the SU-8 substrate; (b) is the optical microscope morphology; (e) is the scanning electron microscope morphology; (h) is the atomic force microscope morphology;

[0038] Figure 8 The morphology of the conductive polymer on the graphene substrate; among them, (c) is the optical microscope morphology; (f) is the scanning electron microscope morphology; (i) is the atomic force microscope morphology.

[0039] In the figure,

[0040] 100. Display panel;

[0041] 10. substrate, 20. driving layer;

[0042] 30. pixel definition layer, 31. pixel opening, 32. spacer;

[0043] 40, anode layer, 41, folded portion;

[0044] 50. Luminescent layer;

[0045] 60. pixel basic unit, 61. first sub-pixel, 62. second sub-pixel, 63. third sub-pixel. DETAILED DESCRIPTION

[0046] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0047] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0048] In the related technology, in the preparation process of OLED, FMM (precision metal mask) is the most important existence, which can prevent the color mixing between sub-pixels and accurately locate the evaporation position of each sub-pixel. However, due to the strength requirements of FMM itself, a large gap needs to be retained between each pixel hole on FMM, resulting in the actual light-emitting area (aperture ratio) of each sub-pixel in the current OLED display panel being small, thereby limiting the light-emitting brightness and service life of the OLED display panel.

[0049] In order to solve the impact of the limitation of FMM itself on the small aperture ratio of OLED devices, related technologies have proposed FMM-free lithography technology, aiming to achieve full colorization of OLED devices by replacing FMM with lithography technology. However, this technology still uses coating technology. Almost every sub-pixel of a color needs to be encapsulated, and the other sub-pixel areas after encapsulation need to be etched, polished and cleaned, so that the anode of the last coated sub-pixel has at least 2 peeling exposure losses. As a result, the process currently faces a huge yield risk.

[0050] Based on the above problems, an embodiment of the present application provides a display panel, such as Figure 1 and 2 As shown, including:

[0051] A pixel definition layer 30, the pixel definition layer 30 has a plurality of pixel openings 31 and a spacer 32 between two adjacent pixel openings 31, and the spacer 32 includes a heat shrink material;

[0052] an anode layer 40, wherein the anode layer 40 comprises a folded portion 41, and the folded portion 41 is located in the pixel opening 31;

[0053] The light-emitting layer 50 is disposed on one side of the folded portion 41 in a conformal stacking manner;

[0054] Under the effect of heat shrinkage of the spacer 32 in the direction parallel to the anode layer 40 , the wrinkled portion 41 and the light emitting layer 50 can extend and expand in the direction parallel to the anode layer 40 .

[0055] It should be noted that the pixel definition layer 30 is mainly used to define and limit the size and shape of the pixel area; the pixel definition layer 30 can generally be an organic material such as polyimide, acrylic, polyethylene terephthalate, polyamide, phenolic resin, etc.; of course, the pixel definition layer 30 can also be an inorganic material such as silicon nitride, silicon oxynitride, silicon oxide, etc.

[0056] It is understandable that a plurality of openings are provided at intervals on the pixel definition layer 30 to form a pixel opening 31, and the area between two adjacent pixel openings 31 is a spacing area 32. The spacing area 32 includes a heat shrinkable material, which means that after heating the material, the material will shrink and deform to a certain extent. The heat shrinkable material can be a mixture of one or two or more materials. For example, the heat shrinkable material can be, but is not limited to, an organic material such as polyethylene, polyvinyl chloride, etc., and of course, the heat shrinkable material can also be a combination of the above organic material and an inorganic material.

[0057] In actual processing, heat shrinkable material can be used directly as the material of the spacer area 32 of the pixel definition layer 30; of course, the heat shrinkable material can be mixed with the material of the above-mentioned pixel definition layer 30 as the material of the spacer area 32 of the pixel definition layer 30; or the heat shrinkable material can be coated on the outside of the material of the pixel definition layer 30.

[0058] It can also be understood that after the anode layer 40 is formed in the entire layer, the anode layer 40 is patterned to ensure that the anode layer 40 located in the pixel opening 31 includes a wrinkle 41. The wrinkle 41 can be understood as a partial area of ​​the anode layer 40 being stacked in a direction parallel to the anode layer 40 so that the surface roughness of the anode layer 40 in this area is increased. The wrinkle 41 and the anode layer 40 can be integrally formed. Of course, the wrinkle 41 can also be formed in the area of ​​the anode layer 40 located in the pixel opening 31 after the anode layer 40 is patterned. The structure of the anode layer 40 can be a composite structure composed of a transparent conductive oxide film / metal film / transparent conductive oxide film stacked in sequence. The material of the transparent conductive oxide film is, for example, any one of ITO (Indium tin oxide) and IZO (Indium zinc oxide), and the material of the metal film is, for example, any one of gold (Au), silver (Ag), nickel (Ni) and platinum (Pt). For another example, the structure of the anode may also be a single-layer structure, and the material of the single-layer structure may be any one of ITO, IZO, Au, Ag, Ni, and Pt.

[0059] It should be noted that, in some embodiments, the wrinkled portion 41 may be formed by processing the area where the anode layer 40 structure is located within the pixel opening 31 (for example, but not limited to extrusion stacking, etc.); in other embodiments, the wrinkled portion 41 may also be formed by separately forming a composite coating on the area where the anode layer 40 structure is located inside the pixel opening 31, and the composite coating may be, but not limited to, an organic conductive polymer, etc. The wrinkled portion 41 in this embodiment is easy to process, and the composite coating has good deformation ability relative to metal materials, which is beneficial to the anode layer 40 and the light-emitting layer 50 not being damaged during the extension and expansion process.

[0060] The folded portion 41 may be a region of the anode layer 40 located in the pixel opening 31 that is entirely folded, and of course the folded portion 41 may also be a region of the anode layer 40 located in the pixel opening 31 that is partially folded. For example, the folded portion 41 may be, but is not limited to, a wave shape, a sawtooth shape, or a fin shape.

[0061] The light-emitting layer 50 includes an organic light-emitting material. The light-emitting layer 50 is formed on the anode layer 40 by evaporation. Due to the existence of the wrinkled portion 41 of the anode layer 40, the light-emitting layer 50 also has a wrinkled region after being formed on the anode layer 40. Since the heat deformation ability of the organic light-emitting material is better than that of the metal material, the spacer 32 is parallel to the direction of the anode layer 40 (such as Figure 1 Under the action of thermal contraction (in the X direction or in the X direction of 2), the wrinkled portion 41 and the light-emitting layer 50 can be extended in a direction parallel to the anode layer 40, thereby increasing the size of the pixel opening 31 while ensuring that the light-emitting layer 50 is not broken, thereby ensuring the quality of the display panel.

[0062] The size of the pixel opening 31 may be the size of the pixel opening 31 in a direction parallel to the anode layer 40 (eg Figure 1 or the X direction in 2) or the area of ​​the pixel opening 31.

[0063] The display panel of the embodiment of the present application solves the problem that the pixel opening 31 of the display panel in the prior art is small in size, has low luminous efficiency, and has high driving efficiency but low service life. In the display panel of the embodiment of the present application, the spacer 32 of the pixel definition layer 30 includes a heat shrink material, the anode layer 40 includes a folded portion 41, the folded portion 41 is located in the pixel opening 31, and the light-emitting layer 50 is conformally stacked and arranged on one side of the folded portion 41. Under the heat shrinkage effect of the spacer 32 in the direction parallel to the anode layer 40, the folded portion 41 and the light-emitting layer 50 can extend and expand in the direction parallel to the anode layer 40. In this way, the contraction of the spacer 32 reduces the size of the spacer 32, and at the same time, the extension and expansion of the fold portion 41 and the light-emitting layer 50 enlarges the pixel opening 31. On the one hand, it is beneficial to improve the light transmittance, thereby increasing the luminous brightness, and is easy to process. On the basis of maintaining the current OLED light-emitting layer 50 evaporation process, there is no need to change the FMM (precision metal mask) structure, and the aperture rate can be reliably increased; on the other hand, it is beneficial to reduce the driving power of the display panel, significantly improve the display life of the display panel, and thus help to improve the product competitiveness of the display panel.

[0064] In some embodiments, the display panel further includes a substrate 10 and a driving layer 20 disposed on the substrate 10 , and the pixel definition layer 30 is disposed on a side of the driving layer 20 facing away from the substrate 10 .

[0065] The substrate 10 may be a flexible substrate, and the flexible substrate may include, for example, a PET substrate, a PEN (Polyethylene naphthalate diformic acid glycol ester) substrate, or a PI substrate. It should be noted that the substrate 10 may be a one-layer structure or a multi-layer structure. For example, the substrate 10 may include at least one flexible substrate and at least one buffer layer, and the flexible substrate and the buffer layer are alternately stacked. Of course, the substrate 10 may also be a rigid substrate, such as but not limited to a glass, a silicon-based substrate, etc.

[0066] The driving layer 20 may include a plurality of pixel driving circuits distributed in an array. The pixel driving circuit may include a plurality of electronic components such as transistors and capacitors. For example, each pixel driving circuit may include three transistors and one capacitor, forming a 3T1C (i.e., one driving transistor, two switching transistors and one capacitor). It may also include more than three transistors and at least one capacitor, such as a 4T1C (i.e., one driving transistor, three switching transistors and one capacitor), a 5T1C (i.e., one driving transistor, four switching transistors and one capacitor) or a 7T1C (i.e., one driving transistor, six switching transistors and one capacitor), etc. Among them, the transistor may be a thin film transistor (TFT for short).

[0067] It can be understood that the thin film transistor may include a control electrode, a first electrode and a second electrode, wherein the control electrode is the gate electrode of the thin film transistor, the first electrode is one of the source electrode and the drain electrode of the thin film transistor, and the second electrode is the other of the source electrode and the drain electrode of the thin film transistor.

[0068] In some embodiments, the driving layer 20 may include an active layer, a first gate metal layer (Gate1), a second gate metal layer (Gate2), a first metal wiring layer (SD1), and a second metal wiring layer (SD2), and these film layers are configured to form a thin film transistor, a capacitor, and a plurality of signal lines for pixel driving in a pixel driving circuit. For example, the plurality of signal lines may include: a power signal line, a data signal line, a reset signal line, a scan signal line, an enable signal line, and an initialization signal line. The driving layer 20 may also include an insulating layer separating these film layers.

[0069] It can be understood that a cathode layer is provided on the side of the light-emitting layer 50 facing away from the substrate 10, and the material of the cathode layer can be any one of aluminum (Al), silver (Ag) and magnesium (Mg), or any one of magnesium-silver alloy and aluminum-lithium alloy, and the cathode layers of the light-emitting layer 50 located in each pixel opening 31 can be electrically connected to each other to form an integrated structure. The anode layer 40, the light-emitting layer 50 and the cathode layer constitute a light-emitting device.

[0070] In some embodiments, the display panel further includes an encapsulation layer and a color filter layer. The encapsulation layer is located on the side of the cathode layer away from the substrate 10 to protect the light-emitting device, and the color filter layer is located on the side of the encapsulation layer away from the substrate 10 .

[0071] Among them, the encapsulation layer may include a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer. For example, the first inorganic encapsulation layer and the second inorganic encapsulation layer may be made of inorganic materials such as nitrides, oxides, oxynitrides, nitrates, carbides or any combination thereof, and the preparation process may adopt a chemical vapor deposition (CVD) process, such as a plasma enhanced chemical vapor deposition (PECVD) process. For example, the organic insulating layer may be made of materials such as acrylic, hexamethyldisiloxane, polyacrylates, polycarbonates, polystyrene, etc., and the preparation process may adopt an inkjet printing (IJP) process.

[0072] The color filter layer 13 may include a first color filter unit, a second color filter unit, and a third color filter unit. The first color filter unit, the second color filter unit, and the third color filter unit are color filter units of different colors. The first color filter unit, the second color filter unit, and the third color filter unit may have different thicknesses or the same thickness, or two of them may have the same thickness and the other may have a different thickness;

[0073] In some other embodiments, adjacent color filter units of the color film layer 13 do not overlap each other, and the color film layer 13 also includes a black matrix arranged between adjacent color filter units to absorb ambient light, reduce ambient light reflection of the display panel, and realize that the screen is dark when it is turned off. Of course, in other embodiments, the first color filter unit and the second color filter unit may have a first overlapping area, the second color filter unit and the third color filter unit may have a second overlapping area, and the third color filter unit and the first color filter unit may have a third overlapping area. When two filter units of different colors overlap, the light transmittance of the overlapping area is low, so it can be used as a black matrix, so that the first overlapping area, the second overlapping area, and the third overlapping area of ​​the display panel can all be used as a black matrix to achieve a light shielding effect without the need to set up an additional black matrix.

[0074] In some other embodiments, the display panel further includes a touch layer, which is used to implement a touch function. The touch layer can be disposed between the encapsulation layer and the color filter layer to implement an in-screen touch structure, which is beneficial for reducing the thickness of the display panel. Of course, in other embodiments, the touch layer can also be disposed at other positions of the display panel, which is not limited in the embodiments of the present application.

[0075] As an implementable manner, the pixel definition layer 30 includes a main material, and the heat shrink material is doped into the main material.

[0076] The main body material refers to the material of the existing conventional pixel definition layer 30, such as but not limited to polyimide, acrylic, polyethylene terephthalate, polyamide, phenolic resin and other organic materials; of course, the main body material can also be inorganic materials such as silicon nitride, silicon oxynitride, silicon oxide, etc.

[0077] Before preparing the pixel definition layer 30, the heat shrinkable material is mixed and doped into the main material through any kind of treatment. The operation is simple and the processing is convenient. This is conducive to ensuring the physical properties of the pixel definition layer 30 itself, while making the spacing area 32 of the pixel definition layer 30 have reliable heat shrinkage performance. After heating, the spacing can reliably deform and shrink, thereby reliably increasing the size of the pixel opening 31 and improving the pixel opening ratio.

[0078] In some embodiments, the heat shrink material includes polyethylene, ethylene vinyl acetate copolymer, aluminum hydroxide, and red phosphorus.

[0079] The heat shrinkable material in this embodiment includes polyethylene, ethylene-vinyl acetate copolymer, aluminum hydroxide and red phosphorus. The combination of organic materials and inorganic materials is conducive to ensuring gentle shrinkage of the spacer area 32 and avoiding large shrinkage deformation, resulting in the formation of a gap between the pixel definition layer 30 and the light-emitting layer 50, which is conducive to ensuring the quality of the display panel and improving the processing yield rate.

[0080] In a preferred embodiment, the mass ratio of polyethylene, ethylene-vinyl acetate copolymer, aluminum hydroxide and red phosphorus is 20:80:40:10.

[0081] The proportion of the heat shrinkable material disclosed in this embodiment enables the heat shrinkable material to have a suitable thermal shrinkage rate and thermal recovery rate, thereby reliably avoiding the generation of gaps after the pixel definition layer 30 is heated, further ensuring that the pixel opening 31 rate is reliably improved while ensuring that the display panel has good processing quality.

[0082] Experimental tests show that the tensile strength of the heat shrinkable material is 11.54 MPa, the heat shrinkage rate is 66.15% at a temperature of 120°C, and the heat shrinkage reduction rate is 98.76%, which further illustrates that the heat shrinkable material of the embodiment of the present application has good heat shrinkage performance.

[0083] As an achievable manner, the thermal shrinkage deformation range of the spacer 32 is 10%-30% of the initial volume.

[0084] The thermal shrinkage deformation range of the spacer 32 of this embodiment is conducive to ensuring the structural stability of the pixel definition layer 30 without generating gaps.

[0085] Specifically, the thermal shrinkage deformation of the spacer 32 may be, but is not limited to, 10%, 15%, 20%, 25% or 30% of the initial volume.

[0086] In some embodiments, the volume doping ratio of the heat shrinkable material in the entire pixel definition layer 30 may be 20%-60%.

[0087] For example, taking the volume doping ratio of the heat shrinkable material as 60% as an example, the shrinkage rate of the spacer region 32 of the pixel definition layer 30 can be calculated by the following formula:

[0088]

[0089] Among them, V C is the shrinkage rate; V C1 is the initial volume of the heat shrinkable material; V C2 V is the volume of heat shrinkable material after shrinkage; P is the volume of the PDL part (bulk material volume); V A is the initial total volume of the heat-shrinkable PDL.

[0090] In this way, the PDL Gap (the spacing region 32 of the pixel definition layer 30) is parallel to the direction of the anode layer 40 (eg Figure 3 Taking the dimension d1 of 18 μm (in the X direction) as an example, when the heat shrinkage rate is 21%, the PDL Gap becomes 14.22 μm after heat shrinkage, which is shortened by 3.78 μm.

[0091] As a feasible method, the anode layer 40 includes a main layer and at least a thin film layer stacked on the main layer and located inside the pixel opening 31, the thin film layer includes an organic conductive polymer layer, and the wrinkled portion 41 is formed by increasing the surface roughness of the organic conductive polymer layer through heat treatment.

[0092] The main layer may be a metal or a metal oxide, such as but not limited to any one of ITO and IZO, Au, Ag, Ni and Pt.

[0093] It is understood that the heat treatment may be, but is not limited to, rapid annealing or the like.

[0094] The thin film layer includes an organic conductive polymer, which may be, but is not limited to, any one or two or more of PH1000 (a mixture of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonate (PSS)), polyaniline, polyacetylene, polythiophene, polypyrrole, polyphenylene sulfide and polyfuran.

[0095] In this embodiment, a thin film layer is formed on the main layer in the area within the pixel opening 31. The wrinkled portion 41 of the anode layer 40 is formed by heat treating the thin film layer to generate wrinkles and increase the roughness. This is easy to process and will not affect the structure of the main layer.

[0096] It is understandable that the thin film layer can be formed on the main layer after the heat treatment is completed and wrinkles are generated; of course, the thin film layer can also be formed on the substrate 10 after the main layer and the main layer are heat treated together to generate the wrinkled portion 41.

[0097] In the actual processing, considering that different cross-linked gels or double-layer films with different mechanical properties can generate stress under heating, solvent immersion, mechanical stretching / compression or capillary action, when the residual stress exceeds the critical value of the organic conductive polymer material, the organic conductive polymer is deformed by the stress.

[0098] For example, after rapid annealing of the organic conductive polymer PH1000 on a glass substrate, its film morphology was characterized by optical microscopy, scanning electron microscopy, and atomic force microscopy, respectively. Figure 6 As shown in the figure, it can be seen that the surface morphology is flat without any wrinkle structure, and the surface roughness is about 1.5nm;

[0099] As another example, after rapid annealing of the organic conductive polymer PH1000 on the SU-8 substrate, the film morphology was characterized by optical microscopy, scanning electron microscopy, and atomic force microscopy, respectively. Figure 7 As shown in the figure, it can be seen that its surface morphology is non-uniformly distributed spider web-like, and the maximum surface roughness is 950nm;

[0100] As another example, on a graphene substrate, an organic conductive polymer PH1000 was rapidly annealed, and its film morphology was characterized by optical microscopy, scanning electron microscopy, and atomic force microscopy, respectively. Figure 8 As shown in the figure, it can be seen that the surface morphology is unevenly distributed in a spider web shape, and the surface roughness can be controlled within 100nm-400nm according to the annealing rate.

[0101] In some embodiments, the thin film layer also includes a graphene layer, the graphene layer is stacked on the main layer, and the organic conductive polymer layer is stacked on the side of the graphene layer away from the main layer. The wrinkled portion 41 is formed by heat treating the organic conductive polymer layer and the graphene layer to increase the surface roughness.

[0102] It can be understood that the graphene layer has a good lubricating effect. The graphene and the organic conductive polymer form a composite thin film layer. After heat treatment, the wrinkled portion 41 can be reliably formed with appropriate surface roughness, which is beneficial to ensure that the wrinkled portion 41 of the organic material anode layer 40 of the light-emitting layer 50 does not break during the extension and expansion process, and the structure is intact.

[0103] In this embodiment, the thin film layer includes a graphene layer, and graphene has good lubrication and conductivity properties. In this way, the thin film layer can be reliably bonded to the main layer to form a wrinkled portion 41. At the same time, under the thermal contraction of the spacer area 32, the wrinkled portion 41 can extend and expand in a direction parallel to the anode layer 40.

[0104] In some embodiments, Figure 5 As shown, the area of ​​the anode layer 40 located in the pixel opening 31 is in a continuous wavy shape, and the area of ​​the anode layer in the continuous wavy shape is configured as a fold portion 41 .

[0105] In the present embodiment, the area of ​​the anode layer 40 located within the pixel opening 31 is in a continuous wavy shape, and the folded portion 41 has a regular structure, which is conducive to reliable extension and flattening of the whole under the action of thermal contraction of the spacing area 32 of the pixel definition layer 30, thereby avoiding local force extension of the area of ​​the anode layer 40 located within the pixel opening 31, resulting in gaps between the light-emitting layer 50 or damage to the structure of the anode layer 40.

[0106] In a preferred embodiment, the region of the anode layer 40 located within the pixel opening 31 includes a plurality of periodically changing peaks and valleys.

[0107] Furthermore, the roughness of the wrinkled portion 41 is 100 nm-400 nm.

[0108] The roughness of the wrinkled portion 41 refers to the size of the crest in its extending direction, and the variation period of the crest and the trough may be 1 μm.

[0109] For example, Figure 5 As shown, assuming that the wrinkled portion 41 of the anode layer 40 is in a trigonometric function shape, the pixel opening 31 is parallel to the anode layer 40 (eg Figure 1 Taking the dimension d2 of 10 μm (in the X direction or 2) as an example, the dimension d of the wrinkled portion 41 of the anode layer 40 after being extended and flattened can be calculated according to the following formula:

[0110]

[0111] Where x is the initial length of the unit undulation period of the anode layer in the X direction;

[0112] Therefore, it can be obtained that, based on the maximum shrinkage rate of 21% of the spacer 32 of the pixel definition layer 30, in order to ensure that the dimensions of the wrinkled portion 41 of the pixel definition layer 30 and the anode layer 40 are matched after extension and expansion, the initial length of the anode layer 40 is 10 μm, the initial length of the spacer 32 of the pixel definition layer 30 is 18 μm, the wrinkled portion 41 of the anode layer 40 is set to 400 nm, the change period of the peak and the trough is 1 μm, and the maximum deformation is 2.8 μm.

[0113] In summary, in the display panel of the embodiment of the present application, the spacer 32 of the pixel definition layer 30 includes a heat shrink material, the anode layer 40 includes a folded portion 41, the folded portion 41 is located in the pixel opening 31, and the light-emitting layer 50 is conformally stacked and arranged on one side of the folded portion 41. Under the heat shrinkage of the spacer 32 in the direction parallel to the anode layer 40, the folded portion 41 and the light-emitting layer 50 can extend and expand in the direction parallel to the anode layer 40. In this way, the shrinkage of the spacer 32 reduces the size of the spacer 32, and the extension and expansion of the folded portion 41 and the light-emitting layer 50 increase the pixel opening 31. On the one hand, it is conducive to improving the light transmission rate, thereby increasing the light brightness, and it is convenient to process. On the basis of maintaining the current OLED light-emitting layer 50 evaporation process, there is no need to change the structure of the FMM (precision metal mask), and the aperture rate can be reliably increased; on the other hand, it is conducive to reducing the driving power of the display panel, significantly improving the display life of the display panel, and thus helping to improve the product competitiveness of the display panel;

[0114] In addition, the anode layer 40 includes a main layer and a thin film layer stacked on the main layer, and the thin film layer includes a stacked graphene layer and an organic conductive polymer layer, which further ensures that the folded portion 41 has good performance and ensures that the material structure of the light-emitting layer 50 is intact and not broken during the extension and expansion of the folded portion 41.

[0115] In a second aspect, an embodiment of the present application provides a method for preparing the display panel of the first aspect, which specifically comprises the following steps:

[0116] Step S10, forming a pixel definition layer 30, wherein the pixel definition layer 30 includes a plurality of pixel openings 31 and a spacer 32 located between two adjacent pixel openings 31, wherein the spacer 32 includes a heat shrinkable material;

[0117] It is understandable that the process of forming the pixel definition layer 30 adopts the existing conventional process. Among them, the pixel definition layer 30 can be obtained by using a heat shrink material to prepare a film and then performing a graphic design; of course, the heat shrink material can also be mixed with the material of the above-mentioned pixel definition layer 30 to prepare a film and then perform a graphic design to obtain the pixel definition layer 30; or after the pixel definition layer 30 is formed, the heat shrink material can be coated on the outside of the spacer 32 of the pixel definition layer 30.

[0118] Step S20, forming an anode layer 40, wherein the anode layer 40 includes a folded portion 41, and the folded portion 41 is located in each pixel opening 31;

[0119] It can be understood that the corrugated portion 41 can be formed by first forming the anode layer 40, and then forming the area of ​​the anode layer 40 located within the pixel opening 31 through processing (for example but not limited to extrusion stacking, etc.); in some other embodiments, the corrugated portion 41 can also be formed by first forming the anode layer 40, and then forming a composite coating separately on the area of ​​the anode layer 40 located inside the pixel opening 31.

[0120] Step S30, forming a light-emitting layer 50, wherein the light-emitting layer 50 is conformally laminated and arranged on one side of the folded portion;

[0121] Step S40 , heating the spacer 32 , and under the heat shrinkage of the spacer 32 , the wrinkled portion 41 and the light-emitting layer 50 can extend and expand in a direction parallel to the anode layer 40 .

[0122] The heating temperature is determined according to the material of the spacer 32 .

[0123] In the method for preparing the display panel of the present embodiment, the spacer region 32 of the pixel definition layer 30 includes a heat shrinkable material, and the anode layer 40 forms a wrinkled portion 41, so that by heating the spacer region 32, the spacer region 32 undergoes heat shrinkage, driving the wrinkled portion 41 of the anode layer 40 and the light-emitting layer 50 to extend and expand in a direction parallel to the anode layer 40, thereby facilitating a reliable increase in the aperture ratio.

[0124] In some embodiments, the pixel definition layer 30 further includes a bulk material, and the pixel definition layer 30 is formed by:

[0125] The heat shrink material is doped into the main material to form the pixel definition layer 30 .

[0126] In some embodiments, the anode layer 40 includes a main layer and at least a thin film layer stacked on the main layer and located inside the pixel opening 31, the thin film layer includes an organic conductive polymer layer and a graphene layer, and the anode layer 40 is formed, including:

[0127] forming the main body layer;

[0128] The organic conductive polymer and the graphene layer are laminated and then heat treated to increase the surface roughness, and then formed in the area of ​​the main layer located inside the pixel opening 31 to obtain the wrinkled portion 41.

[0129] The heat treatment method may be, but is not limited to, rapid annealing.

[0130] In this embodiment, the region of the anode layer 40 located within the pixel opening 31 forms a composite electrode, which helps to ensure that the extension size of the folded portion 41 of the anode layer 40 matches the contraction size of the spacing region 32 of the pixel definition layer 30 .

[0131] The display panel of the embodiment of the present application is described below through specific embodiments.

[0132] Example 1

[0133] like Figure 3 As shown, the pixel unit in the OLED display panel is arranged in the RGB standard, that is, the R sub-pixel, the G sub-pixel and the B sub-pixel are arranged side by side. When the pixel resolution is 300ppi, the size of the spacer 32 of the pixel definition layer 30 in the direction parallel to the anode layer 40 is 18, and the size of the pixel opening 31 does not exceed 10μm at most. The ratio of the pixel opening 31 is as follows:

[0134]

[0135] The pixel definition layer 30 includes low density polyethylene (LDPE), ethylene vinyl acetate copolymer (EVA), aluminum hydroxide (ATH), and red phosphorus (RP) in a mass ratio of 20:80:40:10.

[0136] The area of ​​the anode layer 40 located in the pixel opening 31 is formed into a composite electrode by annealing the conductive polymer PH1000 and graphene. The conductive polymer PH1000 is annealed on the graphene layer to form a wrinkle portion 41 with a roughness of 400nm and an undulation period of 1μm.

[0137] After heating the spacer 32, the elongation of the wrinkled portion 41 of the anode layer 40 is 28%.

[0138] Example 2

[0139] The difference between this embodiment and embodiment 1 is that the pixel units are arranged in a honeycomb arrangement, such as Figure 4 As shown, the pixel basic unit 60 is hexagonal, and the pixel basic unit 60 includes two first sub-pixels 61, one second sub-pixel 62 and one third sub-pixel 63; its aperture ratio can be increased from about 30% to 53.50%, which is increased by nearly 2 times.

[0140] Embodiment 1 and Embodiment 2 further illustrate that the display panel of the embodiment of the present application has a relatively high aperture ratio.

[0141] In a third aspect, the present invention provides a display device, comprising the display panel of the first aspect. It is understandable that the display device has all the features and advantages of the above display panel, which will not be elaborated here. In short, the display device has high quality and yield rate and good display effect.

[0142] The display device is a product with an image display function. For example, the display device may be: a display, a television, a billboard, a digital photo frame, a laser printer with a display function, a telephone, a mobile phone, a personal digital assistant (PDA), a digital camera, a camcorder, a viewfinder, a navigator, a vehicle, a large-area wall, a home appliance, an information query device (such as business query equipment of e-government, banks, hospitals, power and other departments), a monitor, etc. The display device may also be a microdisplay or a product containing a microdisplay. The product containing a microdisplay may be a smart watch, a smart bracelet, a helmet display, a stereo display mirror, and any of AR devices (such as AR glasses), VR devices (such as VR glasses), etc. For example, a microdisplay may be a display with a display size ranging from about 0.2 inches to about 2.5 inches, but is not limited thereto. It can be understood that the microdisplay may also be a display with a smaller display size, such as a display size less than or equal to 0.2 inches.

[0143] It should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used above to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the panel or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0144] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A display panel, characterized in that: include: A pixel definition layer, the pixel definition layer having a plurality of pixel openings and a spacing region between two adjacent pixel openings, the spacing region comprising a heat shrink material; an anode layer, the anode layer comprising a corrugated portion, the corrugated portion being located within the pixel opening; A light-emitting layer, wherein the light-emitting layer is disposed in a conformal lamination manner on one side of the folded portion; Under the effect of heat shrinkage of the spacer in a direction parallel to the anode layer, the wrinkled portion and the light-emitting layer can extend and expand in a direction parallel to the anode layer.

2. The display panel according to claim 1, characterized in that: The pixel definition layer includes a main body material, and the heat shrink material is doped in the main body material.

3. The display panel according to claim 2, characterized in that: The heat shrinkable material includes polyethylene, ethylene-vinyl acetate copolymer, aluminum hydroxide and red phosphorus; Preferably, the mass ratio of the polyethylene, the ethylene-vinyl acetate copolymer, the aluminum hydroxide and the red phosphorus is 20:80:40:

10.

4. The display panel according to claim 1, characterized in that: The thermal shrinkage deformation range of the spacer area is 10%-30% of the initial volume.

5. The display panel according to any one of claims 1 to 4, characterized in that: The anode layer includes a main layer and at least a thin film layer stacked on the main layer and located inside the pixel opening, the thin film layer includes an organic conductive polymer layer, and the wrinkled portion is formed by increasing the surface roughness of the organic conductive polymer layer through heat treatment.

6. The display panel according to claim 5, characterized in that: The film layer also includes a graphene layer, the graphene layer is stacked on the main layer, the organic conductive polymer layer is stacked on the side of the graphene layer away from the main layer, and the wrinkled portion is formed by increasing the surface roughness of the organic conductive polymer layer and the graphene layer through heat treatment.

7. The display panel according to claim 5, characterized in that: The area of ​​the anode layer located in the pixel opening is in a continuous wavy shape, and the area of ​​the anode layer in a continuous wavy shape is configured as the fold portion; Preferably, the region of the anode layer located within the pixel opening includes a plurality of periodically changing crests and troughs.

8. The display panel according to claim 5, characterized in that: The roughness of the wrinkled portion is 100nm-400nm.

9. A method for preparing a display panel according to any one of claims 1 to 8, characterized in that: The specific steps include: forming the pixel definition layer, wherein the pixel definition layer comprises a plurality of pixel openings and a spacer region between two adjacent pixel openings, wherein the spacer region comprises a heat shrink material; forming the anode layer, wherein the anode layer comprises a corrugated portion, and the corrugated portion is located in each of the pixel openings; forming the light-emitting layer, wherein the light-emitting layer is disposed in a conformal lamination manner on one side of the folded portion; The spacer is heated, and under the effect of heat shrinkage of the spacer, the wrinkled portion and the light-emitting layer can extend and expand along a direction parallel to the anode layer.

10. The preparation method according to claim 9, characterized in that: The pixel definition layer further includes a main body material, and the pixel definition layer is formed by: The heat shrink material is doped into the main material to form the pixel definition layer.

11. The preparation method according to claim 9, characterized in that: The anode layer includes a main body layer and at least a thin film layer stacked on the main body layer and located inside the pixel opening, wherein the thin film layer includes an organic conductive polymer layer and a graphene layer, and the anode layer is formed, including: forming the main body layer; The organic conductive polymer layer and the graphene layer are laminated and then heat treated to increase the surface roughness, and then formed in the area of ​​the main layer located inside the pixel opening to obtain the wrinkled portion.

12. A display device, characterized in that A display panel comprising any one of claims 1 to 8.

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