Display panel, preparation method thereof and display device

Abstract

The embodiment of the invention provides a display panel, a preparation method thereof and a display device. The display panel comprises a substrate, a plurality of light-emitting units arranged at intervals and a first packaging layer. The light-emitting units are located on the same side of the substrate, and each light-emitting unit comprises a first electrode, a light-emitting material layer and a second electrode which are sequentially stacked on the substrate; the adjacent second electrodes are arranged at intervals; the first packaging layer is located on the side, away from the substrate, of the second electrode, the first packaging layer comprises a plurality of packaging structures arranged at intervals, and each packaging structure covers one second electrode; the packaging structure comprises an inorganic packaging layer, the inorganic packaging layer covers the surface, away from the substrate, of the corresponding second electrode, the inorganic packaging layer is made of SiNx-H, and the atomic percent of hydrogen in the inorganic packaging layer is smaller than or equal to 20%. The failure of the display panel caused by water vapor invasion can be prevented, and the external quantum efficiency of the display panel is improved.

Description

Technical Field

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

[0002] When cracks appear or peeling occurs on the encapsulation layer above the light-emitting element in the display panel, the light-emitting element is easily corroded by external water vapor, which may easily cause the display panel to fail. Summary of the invention

[0003] An embodiment of the present application provides a display panel, including:

[0004] substrate;

[0005] A plurality of light-emitting units arranged at intervals are located on one side of the substrate; the light-emitting units include a first electrode, a light-emitting material layer and a second electrode sequentially stacked on the substrate; the second electrodes are arranged at intervals adjacent to each other;

[0006] A first packaging layer is located on a side of the second electrode away from the substrate, the first packaging layer includes a plurality of packaging structures arranged at intervals, each of the packaging structures covers one of the second electrodes; the packaging structure includes an inorganic packaging layer, the inorganic packaging layer covers the surface of the corresponding second electrode away from the substrate, and the material of the inorganic packaging layer is SiN x -H, the atomic percentage of hydrogen in the inorganic encapsulation layer is less than or equal to 20%.

[0007] In some embodiments, a surface of each second electrode away from the substrate is a rough surface, and the rough surface has a plurality of pits.

[0008] In some embodiments, the encapsulation structure further includes a barrier layer, the barrier layer is disposed on a side of the inorganic encapsulation layer away from the substrate, and a material of the barrier layer includes metal oxide.

[0009] In some embodiments, the material of the barrier layer includes at least one of aluminum oxide and titanium oxide.

[0010] In some embodiments, the packaging structure also includes a barrier layer, which is arranged on a side of the inorganic packaging layer away from the substrate; in a direction away from the substrate, the barrier layer includes a first sub-barrier layer and a second sub-barrier layer arranged alternately, and the refractive index of the first sub-barrier layer is less than the refractive index of the second sub-barrier layer.

[0011] In some embodiments, the refractive index of the first sub-blocking layer is 1.4-1.6, and the refractive index of the second sub-blocking layer is 2.4-2.8.

[0012] In some embodiments, a material of the first sub-barrier layer includes aluminum oxide, and a material of the second sub-barrier layer includes titanium oxide.

[0013] In some embodiments, the encapsulation structure further includes a barrier layer, the barrier layer is disposed on a side of the inorganic encapsulation layer away from the substrate, and the material of the barrier layer includes organic silicon.

[0014] In some embodiments, the packaging structure further includes a barrier layer, the barrier layer is disposed on a side of the inorganic packaging layer away from the substrate, and the material of the barrier layer includes silicon carbon nitride.

[0015] In some embodiments, the orthographic projection of each inorganic packaging layer on the substrate covers the orthographic projection of the corresponding second electrode on the substrate, and the area of ​​the orthographic projection of the inorganic packaging layer on the substrate is larger than the area of ​​the orthographic projection of the corresponding second electrode on the substrate.

[0016] In some embodiments, the display panel also includes a second encapsulation layer located on the side of the first encapsulation layer away from the substrate, the second encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked in sequence in a direction away from the substrate, and the first inorganic encapsulation layer covers each of the encapsulation structures.

[0017] The present application also provides a display device, comprising the display panel as described above.

[0018] The present application also provides a method for preparing a display panel, comprising:

[0019] A plurality of light-emitting units and a packaging structure located on a side of each light-emitting unit away from the substrate are formed on the substrate; the light-emitting unit comprises a first electrode, a light-emitting material layer and a second electrode stacked in sequence on the substrate; adjacent second electrodes are arranged at intervals; each packaging structure covers one second electrode; each packaging structure comprises an inorganic packaging layer, the inorganic packaging layer covers the surface of the corresponding second electrode away from the substrate, and the material of the inorganic packaging layer is SiN x -H, the atomic percentage of hydrogen in the inorganic encapsulation layer is less than or equal to 20%.

[0020] In some embodiments, the steps of forming the light emitting unit include:

[0021] forming a first electrode, a light-emitting material layer, and a second electrode in sequence on the substrate;

[0022] A hydrogen plasma treatment is performed on a surface of the second electrode which is away from the substrate.

[0023] In some embodiments, each of the encapsulation structures further comprises a barrier layer located on a side of the inorganic encapsulation layer away from the substrate, wherein the barrier layer comprises metal oxide, organic silicon or silicon carbon nitride; and the steps of forming the encapsulation structure comprise:

[0024] forming an inorganic encapsulation film layer on a side of the second electrode away from the substrate;

[0025] forming a barrier film layer on a side of the inorganic encapsulation film layer away from the substrate; the inorganic encapsulation film layer and the barrier film layer are both continuous film layers;

[0026] The inorganic packaging film layer and the barrier film layer are etched to obtain a plurality of inorganic packaging layers arranged at intervals and a plurality of barrier layers arranged at intervals.

[0027] In some embodiments, the display panel further comprises a pixel defining layer located on the substrate, the pixel defining layer comprises a plurality of pixel openings, and the light emitting material layer and the second electrode of each light emitting unit are at least partially located in the pixel opening;

[0028] Before forming the encapsulation structure on the side of the light-emitting unit away from the substrate, the method for preparing the display panel further includes: forming an inorganic protective layer, wherein the inorganic protective layer is at least partially located on the side of the pixel defining layer away from the substrate;

[0029] In the step of performing hydrogen plasma treatment on the surface of the second electrode away from the substrate, plasma treatment is simultaneously performed on at least a portion of the surface of the inorganic protective layer away from the substrate.

[0030] The beneficial effects of this application include:

[0031] In this embodiment, the material of the inorganic encapsulation layer is SiN x -H, that is, the material of the inorganic encapsulation layer can be silicon nitride with less hydrogen content or no hydrogen, which can be obtained by dehydrogenating silicon nitride. Therefore, while ensuring that the inorganic encapsulation layer blocks water vapor corrosion, it can prevent excessive hydrogen in the inorganic encapsulation layer from diffusing into the second electrode and affecting the conductivity of the second electrode, thereby improving the external quantum efficiency of the display panel.

[0032] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0034] Figure 1Shown is a schematic diagram of an exemplary top view structure of a display panel;

[0035] Figures 2 to 4 Zhongwei Figure 1 Schematic diagram of different sections obtained by cutting along the section line PP;

[0036] Figure 5a to Figure 5n Shown is a schematic structural diagram of each step of a method for preparing a display panel provided by an exemplary embodiment of the present application.

[0037] In the figure: 10-substrate; 20-driving circuit layer; 31-pixel defining layer; 311-pixel opening; 311a-first pixel opening; 311b-second pixel opening; 311c-third pixel opening; 32-inorganic protective layer; 33-light-emitting unit; 331-first electrode; 332-light-emitting material layer; 333-second electrode; 33a-first light-emitting unit; 33b-second light-emitting unit; 33c-third light-emitting unit; 40-package Structure; 40a-first packaging structure; 40b-first packaging structure; 40c-first packaging structure; 41-inorganic packaging layer; 41'-inorganic packaging film layer; 42-barrier layer; 42'-barrier film layer; 421-first sub-barrier layer; 422-second sub-barrier layer; 43-packaging protection layer; 50-second packaging layer; 51-first inorganic packaging layer; 52-organic packaging layer; 53-second inorganic packaging layer; 61 / 62 / 63-mask layer. DETAILED DESCRIPTION

[0038] Hereinafter, the present application will be described more fully with reference to the accompanying drawings, in which embodiments are shown.

[0039] It should be noted that when an A element such as a layer, a film, or a region is referred to as being "on the side of the B element away from the C element", it means that the A element may be directly on the surface of the side of the B element away from the C element, or an intermediate layer, intermediate region, or intermediate element may exist between the B element and the A element. When an A element such as a layer, a film, or a region is referred to as being "between the B element and the C element", it means that only the A element exists between the B element and the C element, or an intermediate layer, intermediate region, or intermediate element may exist between the A element and the B element, or between the A element and the C element.

[0040] Although terms such as "first", "second", etc. can be used to describe various components, such components are not limited by the above terms. These terms are only used to distinguish one component from another component, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more. In the absence of conflict, the features in the following embodiments of the present application can complement or combine with each other.

[0041] In the accompanying drawings, the symbols "x", "y" and "z" are used to indicate directions, and the x, y and z directions are not limited to three mutually perpendicular directions of a rectangular coordinate system, and can be interpreted in a broader sense. For example, the x, y and z directions may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. Exemplarily, x is used to indicate a first direction, y is used to indicate a second direction perpendicular to the first direction, and z is used to indicate a third direction perpendicular to the first direction and the second direction. The first direction x, the second direction y and the third direction z may correspond to the horizontal direction, the vertical direction and the thickness direction of the display panel, respectively.

[0042] In the accompanying drawings, the size and thickness of the elements may be exaggerated for better understanding, clarity and ease of description. However, the present application is not limited to the size and thickness shown in the accompanying drawings. In the accompanying drawings, the thickness of layers, films, panels, regions and other elements may be exaggerated for clarity. Example embodiments are shown in the accompanying drawings, wherein the same reference numerals represent the same elements.

[0043] In the preparation process of OLED display panels, impurities may exist on the cathode surface of the light-emitting element, resulting in weak adhesion between the light-emitting element and the encapsulation layer, which in turn leads to poor encapsulation performance and easy failure of the display panel.

[0044] The present application provides a display panel and a method for manufacturing the same, and a display device, aiming to solve or improve the above technical problems.

[0045] Figure 1 FIG. 1 is a schematic diagram of an exemplary top view of a display panel. Figure 1 As shown, the display panel may include a display area AA and a non-display area NA located at least on one side of the display area AA. Figure 1 In the embodiment shown, the non-display area NA surrounds the display area AA. The display panel is provided with a plurality of pixels PX arranged in an array in the display area AA to display an image. The pixel PX may include a plurality of sub-pixels, for example, a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3, in combination with Figures 2 to 4As shown in any of the figures, the sub-pixel includes a light-emitting unit 33 and a pixel circuit (not shown in the figure) connected to the light-emitting unit 33, the first sub-pixel PX1 includes a first light-emitting unit 33aa, the second sub-pixel PX2 includes a second light-emitting unit 33bb, and the third sub-pixel PX3 includes a third light-emitting unit 33cc. The first light-emitting unit 33aa, the second light-emitting unit 33bb, and the third light-emitting unit 33cc have different light-emitting colors. In an example, the first light-emitting unit 33aa can emit red light, the second light-emitting unit 33bb can emit blue light, and the third light-emitting unit 33cc can emit green light.

[0046] like Figures 2 to 4 As shown in any of the accompanying drawings, Figures 2 to 4 Zhongwei Figure 1 Schematic diagram of different cross-sections obtained by cutting along the section line PP. Figures 2 to 4 As shown, the display panel includes a substrate 10, a plurality of light-emitting units 33 arranged at intervals, and a first encapsulation layer. Each light-emitting unit 33 is located on the same side of the substrate 10, and the light-emitting unit 33 includes a first electrode 331, a light-emitting material layer 332, and a second electrode 333 stacked in sequence on the substrate 10; adjacent second electrodes 333 are arranged at intervals; the first encapsulation layer is located on the side of the second electrode 333 away from the substrate 10, and the first encapsulation layer includes a plurality of encapsulation structures 40 arranged at intervals, each encapsulation structure 40 covers a second electrode 333; the encapsulation structure 40 includes an inorganic encapsulation layer 41, and the inorganic encapsulation layer 41 covers the surface of the corresponding second electrode 333 away from the substrate 10, and the material of the inorganic encapsulation layer 41 is SiN x -H, the atomic percentage of hydrogen in the inorganic encapsulation layer 41 is less than or equal to 20%.

[0047] In this embodiment, the material of the inorganic encapsulation layer 41 is SiN x -H, that is, the material of the inorganic encapsulation layer 41 can be silicon nitride with a hydrogen content of less than 20% or no hydrogen, which can be obtained by dehydrogenating the hydrogen-containing silicon nitride. Therefore, while ensuring that the inorganic encapsulation layer 41 blocks water vapor corrosion, it can prevent excessive hydrogen in the inorganic encapsulation layer 41 from diffusing into the second electrode 333 to affect the conductivity of the second electrode 333, thereby improving the external quantum efficiency of the display panel.

[0048] In some embodiments, the atomic percentage of hydrogen in the inorganic encapsulation layer 41 may be 20%, 15%, 10%, 5%, 2%, 1% or 0.

[0049] In some embodiments, the substrate 10 may be a flexible substrate or a rigid substrate. The material of the flexible substrate may include one or more of polyimide, polyethylene terephthalate, polycarbonate, and organic resin materials, and the rigid substrate may include any one of a glass substrate, a quartz substrate, and a sapphire substrate.

[0050] In some embodiments, one of the first electrode 331 and the second electrode 333 is an anode, and the other is a cathode. In one example, the first electrode 331 is an anode, and the second electrode 333 is a cathode.

[0051] In some embodiments, when the second electrode 333 is a cathode, the second electrode 333 may be a single layer or a multilayer. The second strip electrode may be a metal, a transparent conductive oxide, or a stacked structure thereof. In some examples, the second electrode 333 may be a magnesium-silver alloy. In other examples, the second electrode 333 may include a magnesium-silver alloy layer and a transparent conductive layer stacked in sequence in the direction of the substrate 10, and the transparent conductive layer may be ITO (indium tin oxide) or IZO (indium zinc oxide).

[0052] In some embodiments, Figure 2 As shown, the display panel further includes a driving circuit layer 20 located between the substrate 10 and the light-emitting unit 33. The driving circuit layer 20 includes a plurality of pixel circuits (not shown in the figure), and the pixel circuits are used to drive the light-emitting unit 33. The pixel circuits and the light-emitting units 33 may correspond one to one, and each pixel circuit is used to drive the corresponding light-emitting unit 33.

[0053] In some embodiments, Figure 2 As shown, the display panel also includes a pixel defining layer 31; the pixel defining layer 31 is located on the side of the first electrode 331 away from the substrate 10; the pixel defining layer 31 is provided with a plurality of pixel openings 311, each pixel opening 311 corresponds to a light-emitting unit 33; each pixel opening 311 exposes at least part of the surface of its corresponding first electrode 331; the light-emitting material layer 332 and the second electrode 333 of each light-emitting unit 33 are at least partly located in the corresponding pixel opening 311.

[0054] In some embodiments, Figure 2 As shown, the display panel also includes an inorganic protective layer 32, which partially covers the side of the pixel defining layer 31 away from the substrate 10. The side of each pixel opening 311 is covered by the inorganic protective layer 32 and is located between the light-emitting material layer 332 of the sub-pixel and the side of the pixel opening 311.

[0055] In some embodiments, the material of the inorganic encapsulation layer 41 is silicon nitride hydrogen, and the atomic percentage of hydrogen is less than or equal to 20%; or the material of the inorganic encapsulation layer 41 is silicon nitride. In this embodiment, the content of hydrogen in silicon nitride hydrogen is small, so while ensuring that the inorganic encapsulation layer 41 blocks water vapor erosion, it can prevent excessive hydrogen in the inorganic encapsulation layer 41 from diffusing into the second electrode 333 and affecting the conductivity of the second electrode 333. In some embodiments, the material of the inorganic encapsulation layer 41 is silicon nitride hydrogen, and the atomic percentage of hydrogen can be 20%, 15%, 10%, 5%, 2% or 1%. In other embodiments, the material of the inorganic encapsulation layer 41 is silicon nitride.

[0056] In some embodiments, a surface of each second electrode 333 away from the substrate 10 is a rough surface, and the rough surface has a plurality of pits (not shown in the figure).

[0057] In this embodiment, since the second electrode 333 has a pit on the side away from the substrate 10, the contact area between the second electrode 333 and the inorganic encapsulation layer 41 can be increased, that is, the adhesion area between the second electrode 333 and the inorganic encapsulation layer 41 can be increased to further increase the adhesion between the second electrode 333 and the inorganic encapsulation layer 41. At least part of the inorganic encapsulation layer 41 can be filled in the pit and interlocked with the pit, which can also further increase the adhesion effect between the inorganic encapsulation layer 41 and the second electrode 333, improve the adhesion between the encapsulation layer and the side of the second electrode 333 away from the substrate 10, and improve the packaging reliability. In the process step of forming a plurality of pits on the surface of the second electrode 333, impurities on the surface of the second electrode 333 can be removed, which also helps to improve the packaging reliability. It can be seen that the display panel provided in the embodiment of the present application can improve the packaging performance, prevent water vapor intrusion from causing the display panel to fail, and improve the external quantum efficiency of the display panel.

[0058] In some embodiments, the pits on the surface of the second electrode 333 can be formed by bombarding the surface of the second electrode 333 away from the substrate 10 with hydrogen plasma. Further, it has been verified by experiments that after the second electrode 333 is treated with hydrogen plasma and packaged, the external quantum efficiency of the light-emitting unit 33 is significantly improved, which helps to improve the performance of the display panel and extend the service life of the display panel.

[0059] An exemplary embodiment of the present application performs red light tests on different display panels, and the results are shown in Table 1. Among them, J@3V is the current density passing through the display panel when a voltage of 3 volts is applied to the display panel, L@3V is the brightness of the display panel when a voltage of 3 volts is applied to the display panel, and EQE-max is the maximum external quantum efficiency of the display panel. The units of the current density and brightness of each display panel in Table 1 are the same. GB (base) corresponds to a display panel in the related art in which the second electrode 333 is not subjected to hydrogen plasma treatment and the inorganic encapsulation layer 41 is silicon nitride hydrogen (the atomic percentage of hydrogen is 50%), Air corresponds to a display panel in which the second electrode 333 is subjected to hydrogen plasma (H-Plasma) treatment for 30 seconds and is not provided with an inorganic encapsulation layer 41, Air+TFE (30s) corresponds to a display panel in which the second electrode 333 is subjected to hydrogen plasma treatment for 30 seconds and the inorganic encapsulation layer 41 is silicon nitride hydrogen (the atomic percentage of hydrogen is 0-20%), Air+TFE (90s) corresponds to a display panel in which the second electrode 333 is subjected to hydrogen plasma treatment for 90 seconds and the inorganic encapsulation layer 41 is silicon nitride hydrogen (the atomic percentage of hydrogen is 0-20%); Air+TFE (180s) corresponds to a display panel in which the second electrode 333 is subjected to hydrogen plasma treatment for 180 seconds and the inorganic encapsulation layer 41 is silicon nitride hydrogen (the atomic percentage of hydrogen is 0-20%). It can be seen from Table 1 that when the cathode is treated with hydrogen plasma and the light-emitting unit is encapsulated with silicon nitride with a low hydrogen content as the inorganic encapsulation layer 41, the external quantum efficiency of the display panel is significantly improved; and the longer the cathode is treated with hydrogen plasma, the greater the current density, brightness and maximum external quantum efficiency of the display panel.

[0060] Table 1

[0061] Display Panel J@3V L@3V EQE-max GB(base) 65.8 14100 19.8％ Air 7.1 1300 15.9％ Air+TFE(30s) 13 3200 17.5％ Air+TFE(90s) 68.1 14950 20.4％ Air+TFE(180s) 66.5 15500 19.7％

[0062] In some embodiments, Figure 2 As shown, the packaging structure 40 further includes a barrier layer 42 , and the barrier layer 42 is disposed on a side of the inorganic packaging layer 41 away from the substrate 10 .

[0063] In one embodiment, the material of the barrier layer 42 includes metal oxide. In some embodiments, the material of the barrier layer 42 is metal oxide. The metal oxide can be formed on the side of the inorganic encapsulation layer 41 away from the substrate 10 by atomic layer deposition (ALD), which can make the barrier layer 42 denser and have better adhesion to the inorganic encapsulation layer 41, reduce the risk of peeling from the adjacent film layer, and help improve the encapsulation effect.

[0064] In some embodiments, the material of the barrier layer 42 includes at least one of aluminum oxide and titanium oxide. In some examples, the material of the barrier layer 42 may be aluminum oxide. In other examples, the material of the barrier layer 42 may be titanium oxide. In yet other examples, the material of the barrier layer 42 may be a mixture of aluminum oxide and titanium oxide.

[0065] In some embodiments, Figure 3 As shown, the barrier layer 42 is arranged on the side of the inorganic encapsulation layer 41 away from the substrate 10; in the direction away from the substrate 10, the barrier layer 42 includes a first sub-barrier layer 421 and a second sub-barrier layer 422 arranged alternately, and the refractive index of the first sub-barrier layer 421 is less than the refractive index of the second sub-barrier layer 422.

[0066] In this embodiment, the first sub-blocking layer 421 and the second sub-blocking layer 422 with different refractive indices and arranged alternately can form a DBR (Distributed Bragg Reflector). A resonant cavity is formed by two relatively arranged DBRs, so that light of a specific wavelength can be reflected back and forth and enhanced in the resonant cavity, and only light of a specific wavelength is emitted at a specific angle. In this way, the wavelength of the emitted light can be accurately controlled, the emission angle distribution of the emitted light can be adjusted, and the directional emission of the emitted light of the display panel can be achieved.

[0067] In some embodiments, the refractive index of the first sub-blocking layer 421 is 1.4-1.6, and the refractive index of the second sub-blocking layer 422 is 2.4-2.8. In some examples, the refractive index of the first sub-blocking layer 421 may be 1.4, 1.45, 1.5, 1.55, or 1.6. The refractive index of the second sub-blocking layer 422 may be 2.4, 2.5, 2.6, 2.7, or 2.8.

[0068] In some examples, the material of the first sub-blocking layer 421 may be aluminum oxide, wherein the refractive index of aluminum oxide is 1.53. The material of the second sub-blocking layer 422 may be titanium oxide, wherein the refractive index of titanium oxide is 2.7. It should be noted that in this embodiment, the first sub-blocking layer 421 and the second sub-blocking layer 422 can not only form a DBR, but also form an Al-O-Ti bond, thereby enhancing the adhesion and stability of the film layer, and further enhancing the reliability of the display panel.

[0069] In one embodiment, the barrier layer 42 may include 6 sub-barrier layers with different thicknesses, specifically including a first sub-barrier layer, a second sub-barrier layer, a first sub-barrier layer, a second sub-barrier layer, a first sub-barrier layer, and a second sub-barrier layer stacked in sequence. In some embodiments, in a direction away from the substrate 10, the thicknesses of the 6 sub-barrier layers of the barrier layer 42 may be 129.58 nm, 142.38 nm, 73.56 nm, 50.18 nm, 97.47 nm, and 105.26 nm, respectively.

[0070] In some embodiments, in combination Figure 2 As shown, the material of the barrier layer 42 includes organic silicon. Organic silicon has both the high barrier property of the inorganic layer and the high toughness of the organic layer, and has good water and oxygen barrier performance even at a relatively thin thickness.

[0071] In some embodiments, in combination Figure 2 As shown, the material of the barrier layer 42 includes silicon carbon nitride. Silicon carbon nitride has a good flattening effect when forming a thin film, so it can fill the holes that may be formed on the inorganic encapsulation layer 41 or cover the impurity particles remaining on the surface, which is beneficial to improve the adhesion between the barrier layer 42 and the inorganic encapsulation layer 41, so as to further improve the encapsulation performance. Furthermore, when the inorganic encapsulation layer 41 is silicon hydrogen nitride, silicon carbon nitride can form hydrogen bonds with the inorganic encapsulation layer 41, can form physical adsorption, have a higher surface mobility, and have a stronger adhesion.

[0072] In some embodiments, Figure 4 As shown, the encapsulation structure 40 further includes an encapsulation protection layer 43, which is located on the side of the barrier layer 42 away from the substrate 10 to further enhance the water vapor barrier performance of the light emitting unit 33. In some examples, the material of the encapsulation protection layer 43 can be silicon nitride.

[0073] In some embodiments, the orthographic projection of each inorganic encapsulation layer 41 on the substrate 10 covers the orthographic projection of the corresponding second electrode 333 on the substrate 10, and the area of ​​the orthographic projection of the inorganic encapsulation layer 41 on the substrate 10 is larger than the area of ​​the orthographic projection of the corresponding second electrode 333 on the substrate 10. That is, each inorganic encapsulation layer 41 covers the edge of the corresponding second electrode 333 to prevent the second electrode 333 from being exposed, causing water vapor to invade the light-emitting material layer 332 along the gap between the second electrode 333 and the inorganic protective layer 32, causing the light-emitting material layer 332 to be corroded by water vapor and fail.

[0074] In some embodiments, the display panel further includes a second encapsulation layer 50 located on a side of the first encapsulation layer away from the substrate 10, and the second encapsulation layer 50 includes a first inorganic encapsulation layer 51, an organic encapsulation layer 52, and a second inorganic encapsulation layer 53 stacked in sequence in a direction away from the substrate 10, and the first inorganic encapsulation layer 51 covers each encapsulation structure 40. The first inorganic encapsulation layer 51, the organic encapsulation layer 52, and the second inorganic encapsulation layer 53 are all continuous film layers, and their orthographic projections on the substrate 10 cover the orthographic projections of all encapsulation structures 40 on the substrate 10. In some embodiments, the material of the first inorganic encapsulation layer 51 and the second inorganic encapsulation layer 53 may be silicon nitride; the organic encapsulation layer 52 may be formed by an inkjet printing process.

[0075] Based on the same inventive concept, the present application also provides a display device, including a display panel and a housing as in the aforementioned embodiment, wherein the display panel is embedded in the housing. It should be noted that the display device may be any device that displays images, whether in motion (e.g., video) or fixed (e.g., still images), and whether text or images. For example, the display device may include a portable electronic device (such as a mobile phone, a smart phone, a tablet personal computer (PC), a mobile communication terminal, an electronic notebook, an electronic book, a portable multimedia player, a navigation device, and an ultra-mobile PC, as well as a television, a notebook computer, a monitor, an advertising panel, and an Internet of Things device. The display device may also be used in wearable devices such as smart watches, watch phones, and glasses-type displays. The display device may also be used as a dashboard of a vehicle, a central information display (CID) of a central fascia or dashboard of a vehicle, an interior mirror display that replaces a side mirror of a vehicle, and a display arranged or set on the rear side of a front seat to be used as an entertainment device for rear seat passengers of a vehicle.

[0076] Based on the same inventive concept, the present application also provides a method for preparing a display panel, comprising the following steps:

[0077] Step 100: Figure 5c to Figure 5n As shown, a plurality of light-emitting units 33 and a packaging structure 40 located on a side of each light-emitting unit 33 away from the substrate 10 are formed on the substrate 10; the light-emitting unit 33 includes a first electrode 331, a light-emitting material layer 332 and a second electrode 333 sequentially stacked on the substrate 10; adjacent second electrodes 333 are arranged at intervals; each packaging structure 40 covers a second electrode 333; each packaging structure 40 includes an inorganic packaging layer 41, the inorganic packaging layer 41 covers the surface of the corresponding second electrode 333 away from the substrate 10, and the material of the inorganic packaging layer is SiN x -H, the atomic percentage of hydrogen in the inorganic encapsulation layer is less than or equal to 20%.

[0078] In this embodiment, since the inorganic encapsulation layer material has a low hydrogen content, it can ensure that the inorganic encapsulation layer 41 blocks water vapor erosion while preventing excessive hydrogen in the inorganic encapsulation layer 41 from diffusing into the second electrode 333 to affect the conductivity of the second electrode 333, thereby improving the external quantum efficiency of the display panel.

[0079] In some embodiments, hydrogen-containing silicon nitride may be subjected to a hydrogen reduction treatment to obtain silicon nitride having a hydrogen atomic percentage of less than or equal to 20%.

[0080] In some embodiments, the steps of forming the light emitting unit include:

[0081] like Figure 5c As shown, a first electrode, a light-emitting material layer and a second electrode are sequentially formed on the substrate; Figure 5d As shown, a surface of the second electrode 333 away from the substrate 10 is treated with hydrogen plasma.

[0082] In step 200 of the present embodiment, by performing hydrogen plasma treatment on the side of the second electrode 333 away from the substrate 10, on the one hand, impurity particles that may be attached to the surface of the second electrode 333 can be removed, and at the same time, by bombarding the surface of the second electrode 333 away from the substrate 10 with hydrogen plasma, a plurality of pits can be formed on the surface of the second electrode 333 away from the substrate 10, so as to increase the contact area between the surface of the second electrode 333 away from the substrate 10 and the inorganic packaging layer 41, thereby improving the adhesion effect between the second electrode 333 and the packaging structure 40, preventing the packaging structure 40 from separating from the second electrode 333, and thereby improving the packaging performance.

[0083] In some embodiments, each packaging structure 40 further includes a barrier layer 42 located on a side of the inorganic packaging layer 41 away from the substrate 10, and the barrier layer 42 includes metal oxide, organic silicon or silicon carbon nitride; the steps of forming the packaging structure 40 in step 300 include:

[0084] Step 310: Figure 5e As shown, an inorganic encapsulation film layer 41 ′ is formed on a side of the second electrode 333 away from the substrate 10 ;

[0085] Step 320: Figure 5f As shown, a barrier film layer 42' is formed on the side of the inorganic packaging film layer 41' away from the substrate 10; the inorganic packaging film layer 41' and the barrier film layer 42' are both continuous film layers;

[0086] Step 330: Figure 5g to Figure 5h As shown, the inorganic encapsulation film layer 41' and the barrier film layer 42' are etched to obtain a plurality of inorganic encapsulation layers 41 arranged at intervals and a plurality of barrier layers 42 arranged at intervals. Figure 5hFIG. 4 exemplarily shows a cross-sectional structure of one of the package structures 40 .

[0087] In the present embodiment, a barrier layer 42 is provided to further improve the sealing of each spaced-apart light-emitting unit 33, and as in the aforementioned embodiment, the additional barrier layer 42 in the present embodiment includes metal oxide, organic silicon or silicon carbon nitride; the adhesion between the barrier layer 42 and the inorganic encapsulation layer 41 can be increased, thereby further improving the sealing of the display panel and improving the problem of display panel failure.

[0088] In some embodiments, Figure 5a As shown, before forming the light-emitting unit, the preparation method further includes: forming a driving circuit layer 20. After forming the first electrode 331, the preparation method further includes: forming a pixel defining layer 31 located on a side of the first electrode 331 away from the substrate 10, the pixel defining layer 31 is provided with a plurality of pixel openings 311, and each pixel opening 311 exposes at least a portion of the surface of a first electrode 331. The light-emitting material layer 332 and the second electrode 333 of each light-emitting unit 33 are at least partially located in the pixel opening 311.

[0089] In one embodiment, the pixel opening 311 is formed after the pixel defining layer is formed and before the light emitting material layer 332 and the second electrode 333 are formed. Figure 5b As shown, the method for preparing the display panel further includes: forming an inorganic protective layer 32, wherein the inorganic protective layer 32 is at least partially located on a side of the pixel defining layer 31 away from the substrate 10. The inorganic protective layer 32 partially covers the side of each pixel opening 311, and is partially located on a side of the pixel defining layer 31 away from the substrate 10.

[0090] In one embodiment, in the step of performing hydrogen plasma treatment on the surface of the second electrode 333 away from the substrate 10, at least a portion of the surface of the inorganic protective layer 32 away from the substrate 10 is simultaneously subjected to plasma treatment. Specifically, the surface of the inorganic protective layer 32 located on the side of the pixel defining layer 31 away from the substrate 10 is subjected to plasma treatment. In this way, the impurity particles on the surface of the inorganic protective layer 32 away from the substrate 10 can be removed and pits can be formed on the surface, which helps to increase the contact area between the inorganic protective layer 32 and the second encapsulation layer 50 when the second encapsulation layer 50 is subsequently formed, thereby increasing the adhesion between the inorganic protective layer 32 and the second encapsulation layer 50, thereby further improving the encapsulation sealing of the display panel and reducing the risk of peeling between film layers.

[0091] In one embodiment, the display panel includes N light-emitting units 33, the N light-emitting units 33 include M first light-emitting units 33a, X second light-emitting units 33b, and Y third light-emitting units 33c, and the light-emitting colors of the first light-emitting unit 33a, the second light-emitting unit 33b, and the third light-emitting unit 33c are different; the pixel defining layer 31 includes N pixel openings 311, the N pixel openings 311 include M first pixel openings 311a corresponding to the first light-emitting unit 33a, X second pixel openings 311b corresponding to the second light-emitting unit 33b, and Y third pixel openings 311c corresponding to the third light-emitting unit 33c; combined Figure 2 As shown, the encapsulation structure 40 includes a first encapsulation structure 40a corresponding to the first light-emitting unit 33a, a second encapsulation structure 40b corresponding to the second light-emitting unit 33b, and a third encapsulation structure 40c corresponding to the third light-emitting unit 33c. Wherein, N=M+X+Y, N, M, X and Y are all positive integers. The formation process of the light-emitting unit 33 and the encapsulation structure 40 is as follows:

[0092] First, if Figure 5d As shown, N first light emitting units 33 a are formed, and each first light emitting unit 33 a is located in the pixel opening 311 .

[0093] Then, if Figure 5e and Figure 5f As shown, a first packaging structure film layer is formed, and the first packaging structure film layer includes an inorganic packaging film layer 41 ′ and a barrier film layer 42 ′; the inorganic packaging film layer 41 ′ and the barrier film layer 42 ′ are both continuous film layers, and their orthographic projections on the substrate 10 cover the orthographic projections of all pixel openings 311 on the substrate 10 .

[0094] like Figure 5f As shown, the first pixel opening 311a, the second pixel opening 311b and the third pixel opening 311c are respectively formed with a light-emitting material layer 332 and a second electrode 333; the inorganic encapsulation film layer 41' and the barrier film layer 42' are both continuous film layers. After the first encapsulation structure film layer is formed, a mask layer 61 is formed on the side of the first encapsulation structure film layer away from the substrate, and the orthographic projection of the mask layer 61 on the substrate 10 covers the orthographic projection of the second electrode in the first pixel opening 311a on the substrate 10, and has no overlap with the orthographic projection of the second electrode in the second pixel opening 311b and the third pixel opening 311c on the substrate 10. In some embodiments, the material of the mask layer 61 can be photoresist.

[0095] Then, if Figure 5g to Figure 5hAs shown, the first packaging structure film layer is patterned, and the light-emitting material layer 332 and the second electrode 333 located in the second pixel opening 311b and the third pixel opening 311c are removed to obtain the first light-emitting unit 33a located in the first pixel opening 311a, the first packaging structure 40a, and the first electrode 331 of the second light-emitting unit 33b and the third light-emitting unit 33c.

[0096] Through this step, we can obtain Figure 5h The structure shown. Figure 5g to Figure 5h As shown, the light emitting material layer 332 and the second electrode 333 in the second pixel opening 311 b and the third pixel opening 311 c are removed, and the first encapsulation structure film layer forms a first encapsulation structure 40 a .

[0097] In this step, the patterning of the packaging structure film layer and the removal of the light emitting material layer 332 and the second electrode 333 in the second pixel opening 311b and the third pixel opening 311c can be performed in the same RIE (Reactive Ion Etching) process step. In this step, a mask layer 61 is used to protect the area that does not need to be etched.

[0098] Then, if Figure 5i As shown, a light-emitting material layer 332 and N second electrodes 333 of N second light-emitting units 33b are formed, a light-emitting material layer 332 and a second electrode 333 are respectively formed on the side of each first packaging structure 40 away from the substrate 10, and a light-emitting material layer 332 and a second electrode 333 are respectively formed in each second pixel opening 311b and each third pixel opening 311c.

[0099] Subsequently, a second packaging structure film layer is formed, which includes an inorganic packaging film layer 41 ′ and a barrier film layer 42 ′. The inorganic packaging film layer 41 ′ and the barrier film layer 42 ′ are both continuous film layers, and their orthographic projections on the substrate 10 cover the orthographic projections of all pixel openings 311 on the substrate 10 .

[0100] Through this step, we can obtain Figure 5i The structure shown. Figure 5i As shown, the second pixel opening 311b and the third pixel opening 311c are respectively formed with a light-emitting material layer 332 and a second electrode 333, and a light-emitting material layer 332 and a second electrode 333 are formed on the side of the first packaging structure 40 away from the substrate 10; the inorganic packaging film layer 41' and the barrier film layer 42' are both continuous film layers covering each second electrode 333 formed in the previous step.

[0101] Then, if Figure 5j and Figure 5kAs shown, the second encapsulation structure film layer is patterned, and the light-emitting material layer 332 and the second electrode 333 located in the third pixel opening 311c, and the light-emitting material layer 332 and the second electrode 333 located on the side of each first encapsulation structure 40 away from the substrate 10 are removed, so as to obtain the second light-emitting unit 33b located in the second pixel opening 311b, the second encapsulation structure 40b, and the first electrode 331 of the third light-emitting unit 33c. After the second encapsulation structure film layer is formed, a mask layer 62 is formed on the side of the second encapsulation structure film layer away from the substrate, and the orthographic projection of the mask layer 62 on the substrate 10 covers the orthographic projection of the second electrode in the second pixel opening 311b on the substrate 10, and has no overlap with the orthographic projection of the second electrode in the first encapsulation structure 40a and the third pixel opening 311c on the substrate 10. In some embodiments, the material of the mask layer 62 may be photoresist.

[0102] In this step, the patterning of the packaging structure film layer, the removal of the light emitting material layer 332 and the second electrode 333 can be performed in the same RIE process step. In this step, a mask layer 62 can be used to protect the area that does not need to be etched.

[0103] Then, if Figure 5l As shown, a light-emitting material layer 332 and N second electrodes 333 of N third light-emitting units 33c are formed, a light-emitting material layer 332 and a second electrode 333 are respectively formed on the side of each first packaging structure 40a and each second packaging structure 40b away from the substrate 10, and a light-emitting material layer 332 and a second electrode 333 are respectively formed in each third pixel opening 311c.

[0104] Subsequently, a third packaging structure film layer is formed, which includes an inorganic packaging film layer 41 ′ and a barrier film layer 42 ′. The inorganic packaging film layer 41 ′ and the barrier film layer 42 ′ are both continuous film layers, and their orthographic projections on the substrate 10 cover the orthographic projections of all pixel openings 311 on the substrate 10 .

[0105] Then, if Figure 5m and Figure 5n As shown, the third packaging structure film layer is patterned, and the light-emitting material layer 332 and the second electrode 333 located on the side of each first packaging structure 40a and each second packaging structure 40b away from the substrate 10 are removed to obtain a third light-emitting unit 33c and a third packaging structure 40c located in the third pixel opening 311c.

[0106] After forming the third encapsulation structure film layer, a mask layer 63 is formed on the side of the third encapsulation structure film layer away from the substrate, and the orthographic projection of the mask layer 63 on the substrate 10 covers the orthographic projection of the second electrode in the third pixel opening 311c on the substrate 10, and has no overlap with the orthographic projections of the first encapsulation structure 40a and the second encapsulation structure 40b on the substrate 10. The patterning of the third encapsulation structure film layer can be performed by RIE process, and the mask layer 63 can be used to protect the area that does not need to be etched during the etching process. In some embodiments, the material of the mask layer 63 can be photoresist.

[0107] The embodiments of the display panel and the embodiments of the method for manufacturing the display panel provided in the embodiments of the present application belong to the same inventive concept, and the descriptions of the relevant details and beneficial effects can be referred to each other and will not be repeated here.

[0108] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for the purpose of limitation. The description of features or aspects within each embodiment should generally be considered as other similar features or aspects that can be used in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope defined by the claims and their equivalents.

Claims

1. A display panel, characterized in that: include: substrate; A plurality of light-emitting units arranged at intervals are located on one side of the substrate; the light-emitting units include a first electrode, a light-emitting material layer and a second electrode sequentially stacked on the substrate; the second electrodes are arranged at intervals adjacent to each other; A first packaging layer is located on a side of the second electrode away from the substrate, the first packaging layer includes a plurality of packaging structures arranged at intervals, each of the packaging structures covers one of the second electrodes; the packaging structure includes an inorganic packaging layer, the inorganic packaging layer covers the surface of the corresponding second electrode away from the substrate, and the material of the inorganic packaging layer is SiN x -H, the atomic percentage of hydrogen in the inorganic encapsulation layer is less than or equal to 20%.

2. The display panel according to claim 1, characterized in that: A surface of each second electrode away from the substrate is a rough surface, and the rough surface has a plurality of pits.

3. The display panel according to claim 1, characterized in that: The packaging structure further includes a barrier layer, which is disposed on a side of the inorganic packaging layer away from the substrate, and the material of the barrier layer includes metal oxide.

4. The display panel according to claim 3, characterized in that: The material of the barrier layer includes at least one of aluminum oxide and titanium oxide.

5. The display panel according to claim 1, characterized in that: The encapsulation structure also includes a barrier layer, which is arranged on a side of the inorganic encapsulation layer away from the substrate; in a direction away from the substrate, the barrier layer includes a first sub-barrier layer and a second sub-barrier layer arranged alternately, and the refractive index of the first sub-barrier layer is smaller than the refractive index of the second sub-barrier layer.

6. The display panel according to claim 5, characterized in that: The refractive index of the first sub-barrier layer is 1.4-1.6, and the refractive index of the second sub-barrier layer is 2.4-2.

8.

7. The display panel according to claim 5, characterized in that: The material of the first sub-barrier layer includes aluminum oxide, and the material of the second sub-barrier layer includes titanium oxide.

8. The display panel according to claim 1, characterized in that: The packaging structure further includes a barrier layer, which is disposed on a side of the inorganic packaging layer away from the substrate, and the material of the barrier layer includes organic silicon.

9. The display panel according to claim 1, characterized in that: The packaging structure further includes a barrier layer, which is disposed on a side of the inorganic packaging layer away from the substrate, and a material of the barrier layer includes silicon carbon nitride.

10. The display panel according to claim 1, characterized in that: The orthographic projection of each inorganic encapsulation layer on the substrate covers the orthographic projection of the corresponding second electrode on the substrate, and the orthographic projection area of ​​the inorganic encapsulation layer on the substrate is larger than the orthographic projection area of ​​the corresponding second electrode on the substrate.

11. The display panel according to any one of claims 1 to 10, characterized in that: The display panel also includes a second encapsulation layer located on a side of the first encapsulation layer away from the substrate, the second encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer stacked in sequence in a direction away from the substrate, and the first inorganic encapsulation layer covers each of the encapsulation structures.

12. A display device, characterized in that: It comprises the display panel as claimed in any one of claims 1 to 11.

13. A method for preparing a display panel, characterized in that: include: A plurality of light-emitting units and a packaging structure located on a side of each light-emitting unit away from the substrate are formed on the substrate; the light-emitting unit comprises a first electrode, a light-emitting material layer and a second electrode stacked in sequence on the substrate; adjacent second electrodes are arranged at intervals; each packaging structure covers one second electrode; each packaging structure comprises an inorganic packaging layer, the inorganic packaging layer covers the surface of the corresponding second electrode away from the substrate, and the material of the inorganic packaging layer is SiN x -H, the atomic percentage of hydrogen in the inorganic encapsulation layer is less than or equal to 20%.

14. The method for preparing a display panel according to claim 13, characterized in that: The steps of forming the light emitting unit include: forming a first electrode, a light-emitting material layer, and a second electrode in sequence on the substrate; A hydrogen plasma treatment is performed on a surface of the second electrode which is away from the substrate.

15. The method for preparing a display panel according to claim 14, characterized in that: Each of the encapsulation structures further comprises a barrier layer located on a side of the inorganic encapsulation layer away from the substrate, wherein the barrier layer comprises metal oxide, organic silicon or silicon carbon nitride; the steps of forming the encapsulation structure comprise: forming an inorganic encapsulation film layer on a side of the second electrode away from the substrate; forming a barrier film layer on a side of the inorganic encapsulation film layer away from the substrate; the inorganic encapsulation film layer and the barrier film layer are both continuous film layers; The inorganic packaging film layer and the barrier film layer are etched to obtain a plurality of inorganic packaging layers arranged at intervals and a plurality of barrier layers arranged at intervals.

16. The method for preparing a display panel according to claim 14, characterized in that: The display panel further comprises a pixel defining layer located on the substrate, the pixel defining layer comprising a plurality of pixel openings, and the light emitting material layer and the second electrode of each light emitting unit are at least partially located in the pixel openings; Before forming the encapsulation structure on the side of the light-emitting unit away from the substrate, the method for preparing the display panel further includes: forming an inorganic protective layer, wherein the inorganic protective layer is at least partially located on the side of the pixel defining layer away from the substrate; In the step of performing hydrogen plasma treatment on the surface of the second electrode away from the substrate, plasma treatment is simultaneously performed on at least a portion of the surface of the inorganic protective layer away from the substrate.

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