Encapsulation Structure, Display Panel and Display Device

Abstract

The present application discloses a packaging structure, a display panel and a display device, belonging to the technical field of displays. The packaging structure includes: a stacked first inorganic layer and second inorganic layer covering the outside of a light-emitting device. The first inorganic layer is used to adjust the optical path of a first light ray in the light rays emitted from the light-emitting device, so that the first light ray interferes with a second light ray in the light rays emitted from the light-emitting device, improving the light intensity of the light rays emitted after passing through the packaging structure, thereby improving the light extraction efficiency of the light-emitting device.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a packaging structure, a display panel, and a display device. Background Art

[0002] Organic Light-Emitting Diode (OLED) devices have advantages such as a fully solid-state structure, high brightness, full viewing angle, fast response speed, and flexible display, and are widely used in the display industry.

[0003] Since components such as water and oxygen in the air have a great impact on the service life of OLED devices, generally, a packaging structure is required to package the OLED devices to isolate the OLED devices from components such as water and oxygen in the air, thereby extending the service life of the OLED devices. In related technologies, the packaging structure may include: a plurality of packaging film layers coated outside the OLED device, and the plurality of packaging film layers include alternately stacked inorganic layers and organic layers.

[0004] However, when the light emitted by the OLED device passes through the packaging structure, reflection and refraction will occur between the packaging film layers, and there will be a problem of light energy loss during reflection and refraction of the light, resulting in a low light extraction efficiency of the OLED device. Summary of the Invention

[0005] Embodiments of the present application provide a packaging structure, a display panel, and a display device. The problem of low light extraction efficiency of OLED devices in the prior art can be solved, and the technical solutions are as follows:

[0006] In a first aspect, a packaging structure is provided, including:

[0007] Stacked first and second inorganic layers coated outside the light-emitting device, the first inorganic layer is farther from the light-emitting device than the second inorganic layer, the thickness of the first inorganic layer is less than the thickness of the second inorganic layer, and the refractive index of the first inorganic layer is less than the refractive index of the second inorganic layer;

[0008] Wherein, the first inorganic layer is used to adjust the optical path of the first light so that the optical path difference between the optical path of the first light and the optical path of the second light is an integer multiple of the target wavelength, the first light is the light that is emitted from the light-emitting device and is reflected in the packaging structure and then exits the packaging structure, the second light is the light that is emitted from the light-emitting device and is not reflected in the packaging structure and exits the packaging structure, and the wavelengths of the first light and the second light are both the target wavelength.

[0009] Optionally, both the first light and the second light are blue light.

[0010] Optionally, the refractive index of the first inorganic layer ranges from [1.3, 1.7], and the refractive index of the second inorganic layer ranges from [1.6, 1.9].

[0011] Optionally, the thickness of the first inorganic layer ranges from [20, 120] nanometers, and the thickness of the second inorganic layer ranges from [500, 1000] nanometers.

[0012] Optionally, the encapsulation structure further includes: a stacked third inorganic layer and an organic layer coated on the outside of the light-emitting device, the third inorganic layer is closer to the light-emitting device than the organic layer, and both the third inorganic layer and the organic layer are closer to the light-emitting device than the second inorganic layer.

[0013] Optionally, the refractive index of the third inorganic layer is greater than that of the organic layer, and the refractive index of the third inorganic layer is less than that of the second inorganic layer.

[0014] Optionally, the material of the first inorganic layer is silicon oxynitride, the material of the second inorganic layer is silicon nitride, and the material of the third inorganic layer is silicon oxynitride.

[0015] In a second aspect, a display panel is provided, including: a substrate, a light-emitting device located on the substrate, and an encapsulation structure coated on the outside of the light-emitting device, where the encapsulation structure is any of the encapsulation structures in the first aspect.

[0016] Optionally, the display panel further includes: a connection film layer located between the light-emitting device and the encapsulation structure.

[0017] Optionally, the encapsulation structure includes: a third inorganic layer, an organic layer, the second inorganic layer, and the first inorganic layer coated on the outside of the light-emitting device in sequence along the direction away from the substrate, the third inorganic layer is closer to the light-emitting device than the organic layer, and the refractive index of the third inorganic layer is greater than that of the connection film layer.

[0018] Optionally, the light-emitting device is an organic light-emitting diode device.

[0019] In a third aspect, a display device is provided, including: the display panel according to any of the second aspects.

[0020] The beneficial effects brought by the technical solutions provided in the embodiments of the present application are:

[0021] The encapsulation structure includes: a stacked first inorganic layer and second inorganic layer covering the outside of the light-emitting device. The first inorganic layer is used to adjust the optical path of a first light ray among the light rays emitted from the light-emitting device, so that the first light ray interferes with a second light ray among the light rays emitted from the light-emitting device, improving the light intensity of the light ray emitted after passing through the encapsulation structure, thereby improving the light extraction efficiency of the light-emitting device. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 is a schematic structural diagram of an encapsulation structure provided by an embodiment of the present application;

[0024] Figure 2 is the optical path diagram of the light rays emitted from a light-emitting device in Figure 1 the shown encapsulation structure;

[0025] Figure 3 is a schematic structural diagram of another encapsulation structure provided by an embodiment of the present application;

[0026] Figure 4 is a schematic structural diagram of a display panel provided by an embodiment of the present application;

[0027] Figure 5 is a comparison diagram of the relationship curve between the degree of color deviation of the display panel provided by the embodiment of the present application and the viewing angle, and the relationship curve between the degree of color deviation of the display panel in the related art and the viewing angle. Detailed Embodiments

[0028] To make the objectives, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0029] An embodiment of the present application provides an encapsulation structure for encapsulating a light-emitting device, and the light-emitting device can be an OLED device. Please refer to Figure 1 , Figure 1It is a schematic structural diagram of a packaging structure provided by an embodiment of the present application. The packaging structure 100 may include: a stacked first inorganic layer 11 and a second inorganic layer 12 covering the outside of the light-emitting device 200. The first inorganic layer 11 is farther from the light-emitting device 200 than the second inorganic layer 12. The thickness of the first inorganic layer 11 is less than the thickness of the second inorganic layer 12, and the refractive index of the first inorganic layer 11 is less than the refractive index of the second inorganic layer 12.

[0030] In an embodiment of the present application, the first inorganic layer 11 is used to adjust the optical path of the first light ray so that the optical path difference between the optical path of the first light ray and the optical path of the second light ray is an integer multiple of the target wavelength. At this time, the first light ray and the second light ray satisfy the interference condition, and the first light ray and the second light ray can interfere with each other.

[0031] Among them, the first light ray is the light ray that is emitted from the light-emitting device 200 and exits the packaging structure 100 after being reflected inside the packaging structure 100. The second light ray is the light ray that is emitted from the light-emitting device 200 and exits the packaging structure 100 without being reflected inside the packaging structure 100. And the first light ray and the second light ray have the same wavelength, and both of them can be the target wavelength.

[0032] Exemplarily, please refer to Figure 2 , Figure 2 It is an optical path diagram of the light rays emitted by a light-emitting device provided by an embodiment of the present application when transmitted in the Figure 1 shown packaging structure. Among them, the solid arrow represents the first light ray, and the dashed arrow represents the second light ray. The first inorganic layer 11 can adjust the optical path of the first light ray so that the first light ray and the second light ray satisfy the interference condition, and further enable the first light ray and the second light ray to interfere with each other, thereby increasing the light intensity of the light ray exiting after passing through the packaging structure 100.

[0033] In summary, the packaging structure provided by the embodiment of the present application includes: a first inorganic layer and a second inorganic layer covering the outside of the light-emitting device. The first inorganic layer is used to adjust the optical path of the first light ray among the light rays emitted from the light-emitting device, so that the first light ray interferes with the second light ray among the light rays emitted from the light-emitting device, increasing the light intensity of the light ray exiting after passing through the packaging structure, thereby improving the light extraction efficiency of the light-emitting device.

[0034] In an embodiment of the present application, both the first light ray and the second light ray are blue light, and the target wavelength can be the wavelength of blue light. The first light ray and the second light ray belong to the light rays emitted by a light-emitting device for emitting blue light. At this time, the blue light efficiency of the light-emitting device for emitting blue light can be effectively improved through the first inorganic layer 11.

[0035] Exemplarily, the refractive index of the first inorganic layer 11 ranges from [1.3, 1.7], and the refractive index of the second inorganic layer 12 ranges from [1.6, 1.9]. The thickness of the first inorganic layer 11 ranges from [20, 120] nanometers, and the thickness of the second inorganic layer 12 ranges from [500, 1000] nanometers.

[0036] Optionally, please refer to Figure 3 , Figure 3 FIG. Figure 3 is a schematic structural diagram of another encapsulation structure provided by an embodiment of the present application. The encapsulation structure 100 may further include: a stacked third inorganic layer 13 and an organic layer 14 coated on the outside of the light-emitting device 200. The third inorganic layer 13 is closer to the light-emitting device 200 than the organic layer 14, and both the third inorganic layer 13 and the organic layer 14 are closer to the light-emitting device 200 than the second inorganic layer 12. That is, the third inorganic layer 13, the organic layer 14, the second inorganic layer 12, and the first inorganic layer 11 in the encapsulation structure 100 are arranged in sequence in a direction away from the light-emitting device 200.

[0037] In the embodiment of the present application, the refractive index of the third inorganic layer 13 is greater than the refractive index of the organic layer 14, and the refractive index of the third inorganic layer 13 is less than the refractive index of the second inorganic layer 12. In the encapsulation structure 100, the third inorganic layer 13 stacked in sequence in a direction away from the light-emitting device 200 belongs to a high refractive index layer, the organic layer 14 belongs to a low refractive index layer, the second inorganic layer 12 belongs to a high refractive index layer, and the first inorganic layer 11 belongs to a low refractive index layer. That is, the encapsulation structure 100 includes a plurality of high refractive index layers and a plurality of low refractive index layers arranged alternately, which can further improve the light extraction efficiency of the light-emitting device 200.

[0038] Optionally, the material of the first inorganic layer 11 is silicon oxynitride, the material of the second inorganic layer 12 is silicon nitride, and the material of the third inorganic layer 13 is silicon oxynitride.

[0039] Optionally, the wavelength of the first light in the light emitted by the light-emitting device 200 is the same as the wavelength of the second light, and the wavelengths of the first light and the second light may both be the target wavelength. The first inorganic layer 11 is used to adjust the optical path of the first light so that the optical path difference between the optical path of the first light and the optical path of the second light is an integer multiple of the target wavelength. At this time, the first light and the second light satisfy the interference condition, and the first light and the second light can interfere with each other.

[0040] In summary, the encapsulation structure provided by the embodiment of the present application includes: a stacked first inorganic layer and a second inorganic layer coated on the outside of the light-emitting device. The first inorganic layer is used to adjust the optical path of the first light in the light emitted by the light-emitting device, so that the first light interferes with the second light in the light emitted by the light-emitting device, improving the light intensity of the light emitted after passing through the encapsulation structure, thereby improving the light extraction efficiency of the light-emitting device.

[0041] An embodiment of the present application also provides a display panel. Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of a display panel provided by an embodiment of the present application. The display panel may include:

[0042] a substrate 300, a light-emitting device 200 located on the substrate 300, and a packaging structure 100 covering the outside of the light-emitting device 200. The packaging structure 100 may be Figure 1 or Figure 3 the packaging structure 100 shown. Exemplarily, the light-emitting device may be an OLED device.

[0043] Optionally, the display panel may further include: a connection film layer 400 located between the light-emitting device 200 and the packaging structure 100. The connection film layer 400 is used to connect the light-emitting device 200 and the packaging structure 100. The material of the connection film layer 400 may be lithium fluoride. The refractive index of the connection film layer 400 is less than the refractive index of the third inorganic layer 13 in the packaging structure 100.

[0044] In an embodiment of the present application, the substrate 300 has a plurality of pixel regions, and each pixel region has three sub-pixel regions, which are a red sub-pixel region, a green sub-pixel region, and a blue sub-pixel region respectively. The light-emitting device 200 located on the substrate 300 may include: a light-emitting device for emitting red light located in the red sub-pixel region, a light-emitting device for emitting green light located in the green sub-pixel region, and a light-emitting device for emitting blue light located in the blue sub-pixel region.

[0045] In the related art, the luminous efficiency of blue light (also referred to as blue light efficiency) of the OLED device for emitting blue light in the display panel is 130.5 candela per ampere, and only about 20% of the light emitted by the OLED device in the display panel can successfully pass through the packaging structure and be exported, resulting in a low light extraction efficiency of the display panel.

[0046] In an embodiment of the present application, the blue light efficiency of the light-emitting device for emitting blue light can be increased to 137.3 candela per ampere through the first inorganic layer 11 in the packaging structure 100 of the embodiment of the present application, which is a 5% increase compared to the blue light efficiency of the OLED device for emitting blue light in the related art, effectively improving the light extraction efficiency of the light-emitting device for emitting blue light. The red light efficiency of the light-emitting device for emitting red light in the display panel is basically the same as the red light efficiency of the OLED device for emitting red light in the related art, and the green light efficiency of the light-emitting device for emitting green light is basically the same as the green light efficiency of the OLED device for emitting green light in the related art. Therefore, the light extraction efficiency of the display panel can be effectively improved through the packaging structure 100 in the embodiment of the present application.

[0047] Meanwhile, the encapsulation structure 100 in the embodiments of the present application can also reduce the probability of color deviation occurring in the display panel. For example, please refer to Figure 5 , Figure 5 is a relationship curve between the degree of color deviation of the display panel provided in the embodiments of the present application and the viewing angle, and a comparison chart with the relationship curve between the degree of color deviation of the display panel in the related art and the viewing angle. Among them, the solid line represents the relationship curve between the degree of color deviation of the display panel provided in the embodiments of the present application and the viewing angle, and the dashed line represents the relationship curve between the degree of color deviation of the display panel in the related art and the viewing angle.

[0048] The horizontal axis represents the viewing angle, and the unit can be degrees. 0 degrees represents that the viewing direction is perpendicular to the light-emitting surface of the display panel; a positive viewing angle represents viewing the display panel from one side (such as the right side) of the display panel, and the viewing direction forms an acute angle with the light-emitting surface of the display panel; a negative viewing angle represents viewing the display panel from the other side (such as the left side) of the display panel, and the viewing direction forms an acute angle with the light-emitting surface of the display panel. The vertical axis represents the degree of color deviation, and its unit can be JNCD (English: just noticeable color difference).

[0049] According to Figure 4 it can be seen that when the viewing angle is greater than 45 degrees, the degree of color deviation of the display panel provided in the embodiments of the present application is significantly smaller than that of the display panel in the related art. Therefore, the probability of color deviation occurring in the display panel in the embodiments of the present application is relatively low.

[0050] In summary, for the display panel provided in the embodiments of the present application, by adjusting the optical path of the first light in the light emitted from the light-emitting device through the first inorganic layer coated on the outside of the light-emitting device, the first light interferes with the second light in the light emitted from the light-emitting device, improving the light intensity of the light emitted after passing through the encapsulation structure, thereby improving the light extraction efficiency of the light-emitting device, and further improving the light extraction efficiency of the display panel. At the same time, the probability of color deviation occurring in the display panel provided in the embodiments of the present application is relatively low.

[0051] The embodiments of the present application also provide an encapsulation method. This method is used to encapsulate a light-emitting device to form an encapsulation structure outside the light-emitting device. This method may include:

[0052] Form a plurality of encapsulation film layers outside the light-emitting device.

[0053] The multiple encapsulation film layers include: a stacked first inorganic layer and second inorganic layer located on the outermost side, the first inorganic layer is farther from the light-emitting device than the second inorganic layer, the thickness of the first inorganic layer is less than that of the second inorganic layer, and the refractive index of the first inorganic layer is less than that of the second inorganic layer;

[0054] Among them, the first inorganic layer is used to adjust the optical path of the first light ray, so that the first light ray interferes with the second light ray. The first light ray is the light ray that is emitted from the light-emitting device and exits the encapsulation structure after being reflected in the encapsulation structure, and the second light ray is the light ray that is emitted from the light-emitting device and exits the encapsulation structure without being reflected in the encapsulation structure.

[0055] Optionally, a plurality of encapsulation film layers are formed outside the light-emitting device, including: a third inorganic layer, an organic layer, a second inorganic layer, and a first inorganic layer are sequentially formed outside the light-emitting device.

[0056] Exemplarily, the third inorganic layer can be formed outside the light-emitting device by chemical vapor deposition (English: Chemical Vapor Deposition; abbreviation: CVD); then, the organic layer is formed on the third inorganic layer by an inkjet printing process; after that, the second inorganic layer and the first inorganic layer are respectively formed on the organic layer by two CVDs.

[0057] Those skilled in the art can clearly understand that for the sake of convenience and brevity of description, the specific principle of the encapsulation structure formed by the above-described encapsulation method can refer to the corresponding content in the embodiments of the foregoing encapsulation structure, and will not be elaborated herein.

[0058] In summary, the encapsulation method provided by the embodiments of the present application forms a plurality of encapsulation film layers outside the light-emitting device, and the plurality of encapsulation film layers can include a stacked first inorganic layer and second inorganic layer located on the outermost side. The first inorganic layer is used to adjust the optical path of the first light ray in the light rays emitted from the light-emitting device, so that the first light ray interferes with the second light ray in the light rays emitted from the light-emitting device, improving the light intensity of the light rays exiting after passing through the encapsulation structure, thereby improving the light extraction efficiency of the light-emitting device.

[0059] The embodiments of the present application also provide a display device, and the display device may include Figure 4 the display panel shown. The display device may be: an electronic paper, a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, or any product or component with a display function.

[0060] It should be noted that in the drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. Also, it is understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element, or there can be an intermediate layer. Additionally, it is understood that when an element or layer is referred to as being "under" another element or layer, it can be directly under the other element, or there can be more than one intermediate layer or element. Further, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it can be the only layer between the two layers or two elements, or there can be more than one intermediate layer or element. Like reference numerals throughout the specification indicate like elements.

[0061] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless otherwise clearly defined.

[0062] The above are only optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

1. An encapsulation structure, characterized in that, Comprising: A stacked first inorganic layer, second inorganic layer, organic layer, and third inorganic layer coated outside the light-emitting device. The first inorganic layer is farther from the light-emitting device than the second inorganic layer. The third inorganic layer is closer to the light-emitting device than the organic layer, and both the third inorganic layer and the organic layer are closer to the light-emitting device than the second inorganic layer. The thickness of the first inorganic layer is less than that of the second inorganic layer, and the thickness of the first inorganic layer ranges from [20, 120] nanometers, and the thickness of the second inorganic layer ranges from [500, 1000] nanometers. The refractive index of the first inorganic layer is less than that of the second inorganic layer, and the refractive index of the first inorganic layer ranges from [1.3, 1.7], and the refractive index of the second inorganic layer ranges from [1.6, 1.9]. The refractive index of the third inorganic layer is greater than that of the organic layer, and the refractive index of the third inorganic layer is less than that of the second inorganic layer. And the third inorganic layer, which is stacked in sequence in the direction away from the light-emitting device, belongs to a high refractive index layer, the organic layer belongs to a low refractive index layer, the second inorganic layer belongs to a high refractive index layer, and the first inorganic layer belongs to a low refractive index layer, so that the encapsulation structure includes a plurality of high refractive index layers and a plurality of low refractive index layers arranged alternately. Wherein, the first inorganic layer is used to adjust the optical path of the first light so that the optical path difference between the optical path of the first light and the optical path of the second light is an integer multiple of the target wavelength. The first light is the light that is emitted from the light-emitting device and exits the encapsulation structure after being reflected in the encapsulation structure, and the second light is the light that is emitted from the light-emitting device and exits the encapsulation structure without being reflected in the encapsulation structure. And the wavelength of the first light and the wavelength of the second light are both the target wavelength, and both the first light and the second light are blue light.

2. The encapsulation structure according to claim 1, characterized in that, The material of the first inorganic layer is silicon oxynitride, the material of the second inorganic layer is silicon nitride, and the material of the third inorganic layer is silicon oxynitride.

3. A display panel, characterized in that, Comprising: A substrate, a light-emitting device located on the substrate, and an encapsulation structure coated outside the light-emitting device, and the encapsulation structure is the encapsulation structure according to any one of claims 1 to 2.

4. The display panel according to claim 3, characterized in that, The display panel further includes: a connection film layer located between the light-emitting device and the encapsulation structure.

5. The display panel according to claim 4, characterized in that, The encapsulation structure includes: a third inorganic layer, an organic layer, the second inorganic layer, and the first inorganic layer coated outside the light-emitting device in sequence along the direction away from the substrate. The third inorganic layer is closer to the light-emitting device than the organic layer, and the refractive index of the third inorganic layer is greater than that of the connection film layer.

6. The display panel according to claim 5, characterized in that, The light-emitting device is an organic light-emitting diode device.

7. A display device, characterized in that, Comprising: The display panel according to any one of claims 3 to 6.

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