Display panel and display device

Abstract

The embodiment of the present invention discloses a display panel and a display device, wherein the display panel includes a substrate, a light-emitting device layer, a reflective layer and a thin film encapsulation layer, wherein the reflective layer is arranged on a side of the light-emitting device layer away from the substrate, and the thin film encapsulation layer covers a side of the reflective layer away from the substrate, and in a direction away from the substrate, the thin film encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer and a second inorganic encapsulation layer; the reflective layer includes a plurality of patterned microstructures, and the refractive index of the reflective layer is less than the refractive index of the first inorganic encapsulation layer. When the organic encapsulation layer of the thin film encapsulation layer is UV-cured, UV light is prevented from penetrating into the light-emitting device layer to damage the device, causing device failure; in addition, the patterned reflective layer can effectively increase the water and oxygen permeation path, which is conducive to enhancing the encapsulation effect.

Description

Technical Field

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

[0002] The application of thin film encapsulation technology has greatly met the requirements of encapsulation performance of organic light-emitting diode (OLED) devices. At present, the thin film encapsulation layer mostly adopts an inorganic / organic / inorganic multilayer stacking structure. The inorganic layer mainly plays an efficient role in water and oxygen barrier, while the organic layer mainly plays a buffering role, which can cover the particles (particles) that appear in the inorganic layer during preparation, making the surface of the thin film encapsulation layer smoother, thereby making the encapsulation effect better and the thickness of the panel can be further reduced. However, the current organic layer is prepared by a solution method, such as inkjet printing, coating and other technologies. Due to the material, the organic layer needs to be ultraviolet (UV) cured to play the role of encapsulation. However, if UV curing is used, part of the UV light (such as the ultraviolet band part) will penetrate into the OLED light-emitting device, causing damage to the device and causing device failure. Summary of the invention

[0003] Embodiments of the present invention provide a display panel and a display device to solve the technical problem that when an organic layer in a thin film encapsulation layer of an existing display panel is UV-cured, part of the UV light penetrates into an OLED light-emitting device, damaging the device and causing device failure.

[0004] To solve the above problems, the technical solution provided by the present invention is as follows:

[0005] The present invention provides a display panel, comprising:

[0006] substrate;

[0007] A light emitting device layer is arranged on one side of the substrate;

[0008] a reflective layer, disposed on a side of the light-emitting device layer away from the substrate; and

[0009] a thin film encapsulation layer, covering a side of the reflective layer away from the substrate, wherein the thin film encapsulation layer includes at least three encapsulation layers in a direction away from the substrate, and the three encapsulation layers include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked in sequence;

[0010] The reflective layer includes a plurality of patterned microstructures, and the refractive index of the reflective layer is smaller than the refractive index of the first inorganic encapsulation layer.

[0011] According to the display panel provided by the present invention, the first inorganic encapsulation layer and the second inorganic encapsulation layer further include an ultraviolet absorber.

[0012] According to the display panel provided by the present invention, the ultraviolet absorber includes an organic material, the glass transition temperature of the organic material is less than 60 degrees Celsius, and the organic material includes one of a salicylate and a benzophenone organic compound.

[0013] According to the display panel provided by the present invention, the materials of the first inorganic encapsulation layer and the second inorganic encapsulation layer include inorganic metal oxides, and the inorganic metal oxides include any one of calcium oxide, zirconium oxide and zinc oxide.

[0014] According to the display panel provided by the present invention, the thickness of the first inorganic encapsulation layer and the second inorganic encapsulation layer is 0.5 micrometer to 2 micrometers.

[0015] According to the display panel provided by the present invention, the cross-sectional shape of the microstructure includes any one of a semicircle, a triangle, a rectangle and a square.

[0016] According to the display panel provided by the present invention, the material of the reflective layer includes polymethyl methacrylate.

[0017] According to the display panel provided by the present invention, the height of the reflective layer in the thickness direction of the display panel ranges from 0.1 micrometers to 1.5 micrometers.

[0018] According to the display panel provided by the present invention, the refractive index of the reflective layer is in the range of 1 to 1.3.

[0019] The present invention provides a display device, comprising the above-mentioned display panel.

[0020] The beneficial effects of the present invention are as follows: the display panel and the display device provided by the present invention, by arranging a reflective layer on the side of the light-emitting device layer away from the substrate, and the thin-film encapsulation layer is arranged on the side of the reflective layer away from the substrate, the reflective layer includes a plurality of patterned microstructures, and the refractive index of the reflective layer is less than the refractive index of the first inorganic encapsulation layer. When the organic encapsulation layer of the thin-film encapsulation layer is UV-cured, the remaining UV light after curing or the light of a wavelength that does not produce a curing effect is reflected on the surface of the reflective layer and enters the thin-film encapsulation layer again, thereby preventing the UV light from penetrating into the light-emitting device layer to damage the device and causing device failure; in addition, the patterned reflective layer can effectively increase the water and oxygen penetration path, which is beneficial to enhancing the encapsulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a schematic diagram of a cross-sectional structure of a display panel provided by an embodiment of the present invention;

[0023] Figure 2 is a flow chart of a method for preparing a display panel provided by an embodiment of the present invention;

[0024] Figure 3A to Figure 3E It is a schematic diagram of the process structure of a method for preparing a display panel provided by an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 100, display panel; 101, substrate; 102, light-emitting device layer; 103, reflective layer; 1031, microstructure; 104, thin-film encapsulation layer; 1041, first inorganic encapsulation layer; 1042, organic encapsulation layer; 1043, second inorganic encapsulation layer. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention. In the present invention, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the drawings; while "inside" and "outside" refer to the outline of the device.

[0028] The display panel and the display device provided by the present invention are characterized in that a reflective layer is arranged on a side of the light-emitting device layer away from a substrate, and a thin-film encapsulation layer is arranged on a side of the reflective layer away from the substrate, the reflective layer includes a plurality of patterned microstructures, and the refractive index of the reflective layer is less than the refractive index of the first inorganic encapsulation layer. When the organic encapsulation layer of the thin-film encapsulation layer is UV-cured, the remaining UV light after curing or the light of a wavelength that does not produce a curing effect is reflected on the surface of the reflective layer and enters the thin-film encapsulation layer again, thereby preventing the UV light from penetrating into the light-emitting device layer to damage the device and causing device failure. In addition, the patterned reflective layer can effectively increase the water and oxygen penetration path, which is beneficial to enhancing the encapsulation effect.

[0029] In order to better understand the technical solution and technical effects of the present invention, specific embodiments will be described in detail below with reference to the accompanying drawings.

[0030] See also Figure 1 , Figure 1 1 is a schematic diagram of a cross-sectional structure of a display panel provided by an embodiment of the present invention. The embodiment of the present invention provides a display panel 100 , which includes a substrate 101 , a light emitting device layer 102 , a reflective layer 103 and a thin film encapsulation layer 104 .

[0031] According to the driving type, the display panel 100 can be an active matrix organic light emitting diode display panel or a passive matrix organic light emitting diode display panel. It should be noted that, although not shown in the figure, a driving circuit layer for driving the light emitting devices in the light emitting device layer 102 to emit light is also provided between the substrate 101 and the light emitting device layer 102, and the driving circuit layer includes an active matrix driving circuit or a passive matrix driving circuit. In addition, the display panel 100 also includes other functional structures not shown in the figure, such as a pixel definition layer and a touch layer.

[0032] The display panel 100 may be a rigid display panel 100 or a flexible display panel 100. Depending on its type, the substrate 101 of the display panel 100 may be glass, plastic, or a flexible substrate. The flexible substrate may include two flexible substrates and a barrier layer disposed between the two flexible substrates. The materials of the two flexible substrates are independently selected from one of polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyarylate (PAR), polycarbonate (PC), polyetherimide (PEI) and polyether sulfone (PES). The material of the barrier layer may be selected from inorganic materials such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiON) and their laminates, which are used to prevent water vapor from diffusing from the flexible substrate to the drive circuit layer.

[0033] The light-emitting device layer 102 is arranged on one side of the substrate 101, and the light-emitting device layer 102 includes a plurality of light-emitting devices, each of which includes an anode, a hole injection layer and a hole transport layer located on the anode, a light-emitting material layer located on the hole injection layer and the hole transport layer, an electron transport layer and an electron injection layer located on the light-emitting material layer, and a cathode located on the electron transport layer and the electron injection layer, and the reflective layer 103 is located on the side of the cathode away from the substrate 101.

[0034] The thin film encapsulation layer 104 is covered on the side of the reflective layer 103 away from the substrate 101, and is used to encapsulate the light-emitting device layer 102 to prevent external water and oxygen from invading the light-emitting device layer 102 and causing the light-emitting material in the light-emitting material layer to fail. Specifically, in the direction away from the substrate 101, the thin film encapsulation layer 104 includes at least three encapsulation layers, which is a sandwich stacking structure in which an organic encapsulation layer 1042 is sandwiched between two inorganic encapsulation layers. The thin film encapsulation layer 104 can be 3 layers, 5 layers or more layers. In order to clearly explain the technical solution provided by the present invention, the embodiment of the present invention takes the thin film encapsulation layer 104 as a three-layer encapsulation layer as an example for explanation. Specifically, in the direction away from the substrate 101, the three-layer encapsulation layer includes a first inorganic encapsulation layer 1041, an organic encapsulation layer 1042 and a second inorganic encapsulation layer 1043 stacked in sequence.

[0035] Specifically, the materials of the first inorganic encapsulation layer 1041 and the second inorganic encapsulation layer 1043 include inorganic metal oxides. Optionally, the inorganic metal oxides include any one of calcium oxide, zirconium oxide and zinc oxide.

[0036] Furthermore, the first inorganic encapsulation layer 1041 and the second inorganic encapsulation layer 1043 also include an ultraviolet absorber, which is doped in the inorganic metal oxide sol to further absorb UV light in the external ultraviolet band, so that the UV light in the external ultraviolet band is absorbed by the first inorganic encapsulation layer 1041 and the second inorganic encapsulation layer 1043 successively, thereby reducing the damage of the external UV light to the light-emitting device layer 102 and improving the display life of the display panel 100.

[0037] Specifically, the ultraviolet absorber includes an organic material, the glass transition temperature of the organic material is less than 60 degrees Celsius, and the organic material includes one of a salicylate and a benzophenone organic compound. The ultraviolet absorber undergoes molecular crystallization at low temperatures, and the molecular crystallization can form a network cross-linked structure inside the film layer, which is beneficial to extend the water and oxygen permeation path and further improve the encapsulation effect.

[0038] The reflective layer 103 includes a plurality of patterned microstructures 1031, and the refractive index of the reflective layer 103 is smaller than the refractive index of the first inorganic encapsulation layer 1041. When the organic encapsulation layer 1042 of the thin film encapsulation layer 104 is UV-cured, the remaining UV light after curing or the light of a wavelength that does not produce a curing effect is reflected on the surface of the reflective layer 103 and enters the thin film encapsulation layer 104 again, thereby preventing the UV light from penetrating into the light-emitting device layer 102 to damage the device and cause device failure. In addition, the patterned reflective layer 103 can effectively increase the water and oxygen penetration path, which is beneficial to enhancing the encapsulation effect.

[0039] Specifically, the cross-sectional shape of the microstructure 1031 includes any one of a semicircle, a triangle, a rectangle and a square.

[0040] Specifically, the reflective layer 103 is an organic material. Optionally, the organic material includes polymethyl methacrylate.

[0041] In the embodiment of the present invention, the height of the reflective layer 103 in the thickness direction of the display panel 100 is in the range of 0.1 micrometers to 1.5 micrometers.

[0042] Specifically, the plurality of microstructures 1031 are evenly arranged. The present invention has no limitation on the number of the microstructures 1031 , and the number of the microstructures 1031 can be arranged according to actual needs.

[0043] See also Figure 2 and Figure 3A to Figure 3E , Figure 2 is a flow chart of a method for preparing a display panel provided by an embodiment of the present invention, Figure 3A to Figure 3E 1 is a schematic diagram of a process structure of a method for manufacturing a display panel provided by an embodiment of the present invention. The embodiment of the present invention also provides a method for manufacturing a display panel 100, which specifically includes the following steps:

[0044] Step S1: providing a substrate 101;

[0045] Step S2: forming a light emitting device layer 102 on one side of the substrate 101;

[0046] Step S3: forming a reflective layer 103 on a side of the light-emitting device layer 102 away from the substrate 101 , wherein the reflective layer 103 includes a plurality of patterned microstructures 1031 ;

[0047] Step S4: forming a thin film encapsulation layer 104 on a side of the reflective layer 103 away from the substrate 101, wherein the thin film encapsulation layer 104 includes at least three encapsulation layers in a direction away from the substrate 101, and the three encapsulation layers include a first inorganic encapsulation layer 1041, an organic encapsulation layer 1042, and a second inorganic encapsulation layer 1043 which are sequentially stacked; and

[0048] In step S5 , UV light is irradiated on the organic encapsulation layer 1042 at a side of the thin film encapsulation layer 104 away from the substrate 101 to cure the organic encapsulation layer 1042 .

[0049] Specifically, Figure 3A As shown, in the step S1, the substrate 101 may be glass, plastic, or a flexible substrate 101. The flexible substrate 101 may include two flexible substrates and a barrier layer disposed between the two flexible substrates.

[0050] Specifically, Figure 3B As shown, in the step S2, the step of forming the light emitting device layer 102 includes:

[0051] Step S21: forming an anode on one side of the substrate 101;

[0052] Step S22: forming a pixel definition layer on a side of the anode away from the substrate 101, wherein the pixel definition layer includes a plurality of pixel openings;

[0053] Step S23: forming a hole injection layer, a hole transport layer, a light emitting material layer, an electron transport layer and an electron injection layer in the pixel opening; and

[0054] Step S24: forming a cathode on the pixel definition layer and the electron injection layer.

[0055] Specifically, the light emitting material layer can be formed by an inkjet printing process.

[0056] Specifically, Figure 3C As shown, in the step S3, the reflective layer 103 can be formed by a transfer process, specifically including: making a transfer mold, the transfer mold having a plurality of grooves corresponding to the microstructures 1031 one by one and matching in shape; then, filling each groove of the transfer mold with the reflective layer 103 material to form a plurality of microstructures 1031; thereafter, transferring the microstructure 1031 in each groove of the transfer mold to a side surface of the light-emitting device layer 102 away from the substrate 101.

[0057] The refractive index of the reflective layer 103 is smaller than the refractive index of the first inorganic encapsulation layer 1041 . Specifically, the refractive index of the reflective layer 103 is in the range of 1 to 1.3.

[0058] Specifically, the cross-sectional shape of the microstructure 1031 includes any one of a semicircle, a triangle, a rectangle and a square.

[0059] Specifically, the reflective layer 103 is an organic material. Optionally, the organic material includes polymethyl methacrylate.

[0060] Specifically, Figure 3D As shown, in the step S4, the step of forming the thin film encapsulation layer 104 specifically includes:

[0061] Step S41: forming a first inorganic encapsulation layer 1041 on a side of the reflective layer 103 away from the substrate 101;

[0062] Step S42: forming an organic encapsulation layer 1042 on a side of the first inorganic encapsulation layer 1041 away from the substrate 101; and

[0063] Step S43 : forming a second inorganic encapsulation layer 1043 on a side of the organic encapsulation layer 1042 away from the substrate 101 .

[0064] Specifically, in the step S41, the first inorganic encapsulation layer 1041 may be formed by a coating process, and the material of the first inorganic encapsulation layer 1041 includes an inorganic metal oxide, and the inorganic metal oxide includes any one of calcium oxide, zirconium oxide and zinc oxide.

[0065] Furthermore, the first inorganic encapsulation layer 1041 includes an ultraviolet absorber, which is doped in the inorganic metal oxide sol. In the step S5, UV light is required to be used to cure the organic encapsulation layer 1042. The ultraviolet absorber can be used to further absorb UV light in the external ultraviolet band, so that the UV light in the external ultraviolet band is absorbed by the first inorganic encapsulation layer 1041 when passing through it, and the remaining unabsorbed UV light is irradiated to the surface of the microstructure 1031 of the reflective layer 103. After that, the reflected UV light is again incident on the first inorganic encapsulation layer 1041 and absorbed by it, thereby further reducing the amount of external UV light incident on the light-emitting device layer 102, which is beneficial to further reduce the damage of the external UV light to the light-emitting device layer 102, and further improve the display life of the display panel 100.

[0066] Specifically, the ultraviolet absorber includes an organic material, the glass transition temperature of the organic material is less than 60 degrees Celsius, and the organic material includes one of a salicylate and a benzophenone organic compound. The ultraviolet absorber undergoes molecular crystallization at low temperatures, and the molecular crystallization can form a network cross-linked structure inside the film layer, which is beneficial to extend the water and oxygen permeation path and further improve the encapsulation effect.

[0067] Specifically, in S42, the organic encapsulation layer 1042 may be prepared by a solution method, such as inkjet printing or coating. When the organic encapsulation material is formed by inkjet printing or coating, the organic encapsulation material is cured by UV light.

[0068] Specifically, in the step S42 , the preparation process of the second inorganic encapsulation layer 1043 is similar to the preparation process of the first inorganic encapsulation layer 1041 , and the second inorganic encapsulation layer 1043 may also be made of the same type of material as the first inorganic encapsulation layer 1041 .

[0069] Furthermore, the second inorganic encapsulation layer 1043 may also include an ultraviolet absorber, and the material composition of the ultraviolet absorber in the second inorganic encapsulation layer 1043 may be the same as that of the ultraviolet absorber in the first inorganic encapsulation layer 1041. In the step S5, the UV light in the ultraviolet band of the outside world is absorbed by the second inorganic encapsulation layer 1043 and the first inorganic encapsulation layer 1041 when passing through the second inorganic encapsulation layer 1043 and the first inorganic encapsulation layer 1041 successively, and the remaining UV light that is not absorbed is irradiated to the surface of the microstructure 1031 of the reflective layer 103, and then the reflected UV light is again incident on the first inorganic encapsulation layer 1041 and the second inorganic encapsulation layer 1043 and is again absorbed by the two, thereby further reducing the amount of light from the outside UV light incident on the light-emitting device layer 102, which is beneficial to further reduce the damage of the outside UV light to the light-emitting device layer 102, and further improve the display life of the display panel 100.

[0070] S5 , irradiating the organic encapsulation layer 1042 with UV light on a side of the thin film encapsulation layer 104 away from the substrate 101 to cure the organic encapsulation layer 1042 .

[0071] Specifically, Figure 3E As shown, the remaining UV light after curing or the light of a wavelength that does not produce a curing effect is reflected on the surface of the reflective layer 103 and enters the thin film encapsulation layer 104 again, thereby preventing the UV light from penetrating into the light-emitting device layer 102 and damaging the device, thereby causing device failure. In addition, the patterned reflective layer 103 can effectively increase the water and oxygen penetration path, which is beneficial to enhancing the encapsulation effect.

[0072] An embodiment of the present invention further provides a display device, which includes the display panel 100 in the above embodiment. The display device can be a mobile phone, a tablet computer, an e-reader, an electronic display screen, a laptop computer, a mobile phone, an augmented reality (AR) / virtual reality (VR) device, a media player, a wearable device, a digital camera, a car navigation system, etc.

[0073] The beneficial effects are as follows: the display panel and the display device provided by the present invention, by setting a reflective layer on the side of the light-emitting device layer away from the substrate, and the thin-film encapsulation layer is set on the side of the reflective layer away from the substrate, the reflective layer includes a plurality of patterned microstructures, and the refractive index of the reflective layer is less than the refractive index of the first inorganic encapsulation layer. When the organic encapsulation layer of the thin-film encapsulation layer is UV-cured, the remaining UV light after curing or the light of a wavelength that does not produce a curing effect is reflected on the surface of the reflective layer and enters the thin-film encapsulation layer again, thereby preventing the UV light from penetrating into the light-emitting device layer to damage the device and cause device failure; in addition, the patterned reflective layer can effectively increase the water and oxygen penetration path, which is beneficial to enhancing the encapsulation effect.

[0074] In summary, although the present invention has been disclosed as above in terms of preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. A display panel, characterized in that: include: substrate; A light emitting device layer is arranged on one side of the substrate; A reflective layer, disposed on a side of the light-emitting device layer away from the substrate; as well as a thin film encapsulation layer, covering a side of the reflective layer away from the substrate, wherein the thin film encapsulation layer includes at least three encapsulation layers in a direction away from the substrate, and the three encapsulation layers include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer stacked in sequence; Among them, the reflective layer includes a plurality of patterned microstructures, the refractive index of the reflective layer is smaller than the refractive index of the first inorganic packaging layer, the surface of the reflective layer close to the substrate is in direct contact with the surface of the light-emitting device layer away from the substrate, and the surface of the first inorganic packaging layer close to the substrate is in direct contact with the surface of the reflective layer away from the substrate.

2. The display panel according to claim 1, characterized in that: The first inorganic encapsulating layer and the second inorganic encapsulating layer further include an ultraviolet absorber.

3. The display panel according to claim 2, characterized in that: The ultraviolet absorber includes an organic material, the glass transition temperature of the organic material is less than 60 degrees Celsius, and the organic material includes one of salicylic acid esters and benzophenone organic compounds.

4. The display panel according to claim 1, characterized in that: The materials of the first inorganic encapsulation layer and the second inorganic encapsulation layer include inorganic metal oxides, and the inorganic metal oxides include any one of calcium oxide, zirconium oxide, and zinc oxide.

5. The display panel according to claim 1, characterized in that: The thickness of the first inorganic encapsulation layer and the second inorganic encapsulation layer is 0.5 micrometer to 2 micrometers.

6. The display panel according to claim 1, characterized in that: The cross-sectional shape of the microstructure includes any one of a semicircle, a triangle, a rectangle and a square.

7. The display panel according to claim 1, characterized in that: The material of the reflective layer includes polymethyl methacrylate.

8. The display panel according to claim 1, characterized in that: The height of the reflective layer in the thickness direction of the display panel ranges from 0.1 micrometers to 1.5 micrometers.

9. The display panel according to claim 1, characterized in that: The refractive index of the reflective layer is in the range of 1 to 1.

3.

10. A display device, characterized in that: A display panel comprising any one of claims 1 to 9.

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