Organic electroluminescence device and display panel

Abstract

The application provides an organic electroluminescent device and a display panel, and belongs to the technical field of display. The organic electroluminescent device provided by the application comprises a first electrode, a second electrode and a light-emitting layer located between the first electrode and the second electrode, and an optical structure located on the side of the first electrode away from the light-emitting layer; wherein the reflectivity of the optical structure to the light emitted by the organic electroluminescent device is greater than the reflectivity to other light; and the material of the optical structure comprises at least one of nitrogen, oxygen and fluorine. The organic electroluminescent device provided by the application can make the organic electroluminescent device have sufficient transmittance, and can improve the light extraction efficiency of the organic electroluminescent device.

Description

Technical Field

[0001] This invention belongs to the field of display technology, specifically relating to an organic electroluminescent device and a display panel. Background Technology

[0002] In some application scenarios, the transmittance requirements of light-emitting devices in different areas of the display panel are different. For example, in display panels that use under-display cameras, the display effect and the imaging effect of the camera area are the two most important indicators of the display panel. This mainly depends on the transmittance of the anode of the light-emitting device in the camera area. Improving the transmittance of the anode is an effective way to improve the transmittance of the entire film layer in the camera area.

[0003] However, if the transmittance of the anode is too high, it will lead to a decrease in the reflectance of the anode. According to the light-emitting principle of light-emitting devices, when the reflectance of the anode is low, the microcavity effect of the light-emitting device will decrease significantly, resulting in a significant decrease in the light output of the light-emitting device. This will cause obvious display differences between the camera area and other display areas, and the display effect will be poor. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art, and to provide an organic electroluminescent device that can have sufficient transmittance and improve the light extraction efficiency of the organic electroluminescent device.

[0005] Firstly, the technical solution adopted to solve the technical problem of this invention is an organic electroluminescent device, comprising:

[0006] A first electrode, a second electrode, and a light-emitting layer located between them, and an optical structure located on the side of the first electrode opposite to the light-emitting layer; wherein,

[0007] The optical structure has a reflectivity for light emitted by the organic electroluminescent device that is greater than its reflectivity for other types of light; the material of the optical structure includes at least one of nitrogen, oxygen, and fluorine.

[0008] The organic electroluminescent device provided by the present invention has an optical structure on the side of the first electrode away from the light-emitting layer. The optical structure can reflect only the light emitted by the light-emitting layer and transmit light of other wavelengths. Therefore, while ensuring the transmittance of the organic electroluminescent device, the reflectivity of the first electrode to the light emitted by the light-emitting layer can be increased, thereby ensuring the light extraction efficiency of the organic electroluminescent device.

[0009] Preferably, both the first electrode and the second electrode are made of metal oxide.

[0010] Preferably, the optical structure includes multiple layers of first optical film and multiple layers of second optical film, wherein the first optical film and the second optical film are stacked and alternately arranged; wherein,

[0011] The refractive index of the first optical film is greater than that of the second optical film.

[0012] Preferably, at least some of the first optical film layers in the multilayer first optical film layer are made of different materials; and / or, at least some of the second optical film layers in the multilayer second optical film layer are made of different materials.

[0013] Preferably, the material of the first optical film layer includes at least one of silicon nitride, aluminum oxide, and titanium dioxide; and the material of the second optical film layer includes at least one of silicon oxide, barium fluoride, and calcium fluoride.

[0014] Preferably, the thickness of the first optical film layer is different from the thickness of the second optical film layer.

[0015] Preferably, the organic electroluminescent device includes a red organic electroluminescent device, a green organic electroluminescent device, and a blue organic electroluminescent device;

[0016] In the optical structure of the red organic electroluminescent device, the thickness of the first optical film layer is greater than the thickness of the second optical film layer;

[0017] In the optical structure of the green organic electroluminescent device, the thickness of the first optical film layer is greater than the thickness of the second optical film layer;

[0018] In the optical structure of the blue organic electroluminescent device, the thickness of the first optical film layer is less than the thickness of the second optical film layer.

[0019] Preferably, the first electrode at least covers the optical structure.

[0020] Preferably, the optical structure includes 6-8 first optical film layers and 6-8 second optical film layers;

[0021] The first optical film layer is made of silicon nitride; the second optical film layer is made of silicon dioxide.

[0022] The thickness of the first optical film is 40 nanometers; the thickness of the second optical film is 5 nanometers.

[0023] Preferably, the organic electroluminescent device is a red organic electroluminescent device, and the optical structure is disposed on the side of the first electrode of the red organic electroluminescent device opposite to the light-emitting layer.

[0024] Preferably, the optical structure includes 5-7 first optical film layers and 5-7 second optical film layers;

[0025] The first optical film layer is made of silicon nitride; the second optical film layer is made of silicon dioxide.

[0026] The thickness of the first optical film is 35 nanometers; the thickness of the second optical film is 10 nanometers.

[0027] Preferably, the organic electroluminescent device is a green organic electroluminescent device, and the optical structure is disposed on the side of the first electrode of the green organic electroluminescent device opposite to the light-emitting layer.

[0028] Preferably, the optical structure includes 3-5 first optical film layers and 3-5 second optical film layers;

[0029] The first optical film layer is made of silicon nitride; the second optical film layer is made of silicon dioxide.

[0030] The thickness of the first optical film is 20 nanometers; the thickness of the second optical film is 45 nanometers.

[0031] Preferably, the organic electroluminescent device is a blue organic electroluminescent device, and the optical structure is disposed on the side of the first electrode of the blue organic electroluminescent device opposite to the light-emitting layer.

[0032] In a second aspect, the present invention also provides a display panel comprising a plurality of the aforementioned organic electroluminescent devices.

[0033] Preferably, the display panel includes a display area, and at least a portion of the display area is a mounting area; the organic electroluminescent device is a transparent device and is mounted in the mounting area.

[0034] Preferably, the display panel further includes a substrate on which a plurality of the organic electroluminescent devices are arranged;

[0035] The plurality of organic electroluminescent devices include organic electroluminescent devices emitting multiple colors; wherein,

[0036] The thickness of the optical structure and the thickness of the first electrode of the organic electroluminescent devices with different emission colors are different; and the sum of the thickness of the optical structure and the thickness of the first electrode of each organic electroluminescent device is the same. Attached Figure Description

[0037] Figure 1 A schematic diagram of the structure of an embodiment of the organic electroluminescent device provided in this disclosure;

[0038] Figure 2 A schematic diagram of one embodiment of the optical structure of the organic electroluminescent device provided in this disclosure;

[0039] Figure 3 An exemplary pixel layout diagram for a display panel using an organic electroluminescent device provided in the embodiments of this disclosure;

[0040] Figure 4 For along Figure 3 A cross-sectional view cut along the CD direction;

[0041] Figure 5 for Figure 4 Schematic diagram of the structure of the first electrode of organic electroluminescent devices of various colors;

[0042] Figure 6 A schematic diagram showing the positions of the first electrode, optical structure, and light-emitting layer of an organic electroluminescent device provided in an embodiment of this disclosure;

[0043] Figure 7 A reflectance curve of an organic electroluminescent device provided in an embodiment of this disclosure;

[0044] Figure 8 A transmittance curve of an organic electroluminescent device provided in an embodiment of this disclosure;

[0045] Figure 9 This is a schematic diagram of the area of ​​a display panel provided in an embodiment of this disclosure. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0048] Firstly, see [the following] Figure 1 This disclosure provides an organic electroluminescent device, including a first electrode 1, a second electrode 2, and a light-emitting layer 3 located between the first electrode 1 and the second electrode 2. It also includes an optical structure 4 located on the side of the first electrode 1 facing away from the light-emitting layer 3. The optical structure 4 has a higher reflectivity for light emitted by the organic electroluminescent device than for other types of light. That is, only when light emitted from the light-emitting layer 3 of the organic electroluminescent device shines on the optical structure 4 is a large amount of light reflected by the optical structure 4; other types of light have lower reflectivity when shining on the optical structure 4, exhibiting a transmission effect. Therefore, while ensuring the transmittance of the organic electroluminescent device, the reflectivity of light emitted from the light-emitting layer 3 by the first electrode 1 can be increased. Thus, if the organic electroluminescent device is applied to a display panel, the light extraction efficiency of the organic electroluminescent device can be guaranteed.

[0049] It should be noted that the aforementioned "other light" specifically refers to light with wavelengths outside the wavelength range of the light emitted by the light-emitting layer 3. For example, if the light-emitting layer 3 emits red light with a wavelength of 650 nanometers, then "other light" refers to light with wavelengths less than or greater than 650 nanometers.

[0050] It should be noted that one of the first electrode 1 and the second electrode 2 mentioned above is the anode and the other is the cathode. This is not a limitation. For ease of explanation, the following explanation will use the first electrode 1 as the anode and the second electrode 2 as the cathode as an example.

[0051] In some examples, to enable optical structure 4 to reflect only the light emitted by light-emitting layer 3 while transmitting light of other wavelengths, two optical films with different refractive indices can be superimposed to filter light of a specific wavelength. See specifically... Figure 1 , Figure 2 The optical structure 4 may include multiple layers of first optical film 41 and multiple layers of second optical film 42. The first optical film 41 and the second optical film 42 are stacked and alternately arranged, and the refractive index of the first optical film 41 is greater than the refractive index of the second optical film 42. That is, the first optical film 41 is a high refractive index film compared to the second optical film 42, and the second optical film 42 is a low refractive index film compared to the first optical film 41. The optical structure 4 is composed of alternating stacks of high refractive index film and low refractive index film, i.e., it has periodic refraction. The optical structure 4 can filter the wavelength of light incident upon it, making the reflectivity of light in a specific wavelength band much greater than its transmittance, and making the transmittance of light in wavelength bands other than the specific wavelength band much greater than its refractive index.

[0052] In some examples, anode 1 and cathode 2 can be made of various materials, such as metal oxide materials, and can be transparent metal oxide materials. Specifically, the metal oxide materials used for anode 1 and cathode 2 can be indium tin oxide or indium zinc oxide, without limitation.

[0053] It should be noted that, depending on the wavelength of the light to be reflected, in the optical structure 4, the film layer closest to the light-emitting layer 3 can be either the first optical film layer 41 or the second optical film layer 42, and the film layer furthest from the light-emitting layer 3 can be either the first optical film layer 41 or the second optical film layer 42, without any limitation.

[0054] In some examples, the material of optical structure 4 includes at least one of nitrogen, oxygen, and fluorine. Specifically, the material of the first optical film layer 41 can include a variety of materials, such as at least one of silicon nitride (SiN), aluminum oxide (Al2O3), and titanium dioxide (TiO2); correspondingly, the material of the second optical film layer 42 can also include a variety of materials, such as at least one of silicon oxide (SiO2), barium fluoride (BaF), and calcium fluoride (CaF). Of course, the first optical film layer 41 can also be made of other materials, and the second optical film layer 42 can also be made of other materials, as long as the refractive index of the material of the first optical film layer 41 is greater than the refractive index of the material of the second optical film layer 42, which is not limited here.

[0055] It should be noted that the material of optical structure 4 includes at least one of nitrogen, oxygen, and fluorine, specifically meaning that the chemical elements in the material of optical structure 4 include at least one of nitrogen, oxygen, and fluorine.

[0056] In some examples, the materials of each first optical film layer 41 in the optical structure 4 can be the same or different. For example, each first optical film layer 41 can be made of SiN; or, some of the first optical film layers 41 can be made of SiN, and the remaining parts can be made of TiO2. Correspondingly, the materials of each second optical film layer can be the same or different. For example, each second optical film layer 42 can be made of SiO2; or, some of the second optical film layers 42 can be made of SiO2, and the remaining parts can be made of CaF, without limitation.

[0057] In some examples, the thickness of the first optical film layer 41 in the optical structure 4 can be different from or the same as the thickness of the second optical film layer 42, specifically set according to the required optical thickness of the first optical film layer 41 and the required optical thickness of the second optical film layer 42. It should be noted that the optical thickness of an optical film layer is equal to the product of its refractive index and its physical thickness.

[0058] In some examples, the optical structure 4 of the organic electroluminescent device is designed according to the wavelength of the light emitted by the light-emitting layer 3 of the organic electroluminescent device. The first optical film layer 41 and the second optical film layer 42 of various materials and thicknesses can be stacked alternately to filter and reflect the light emitted by the light-emitting layer 3.

[0059] Specifically, organic electroluminescent devices can include organic electroluminescent devices that emit light in various colors, such as red organic electroluminescent devices, green organic electroluminescent devices, and blue organic electroluminescent devices.

[0060] In the optical structure 4 of the red organic light-emitting device, the first optical film layer 41 can be made of SiN, and the second optical film layer 42 can be made of SiO2. Specifically, the thickness of the first optical film layer 41 made of SiN can be greater than the thickness of the second optical film layer 42 made of SiO2. For example, the thickness of the first optical film layer 41 can be 40 nanometers, and the thickness of the second optical film layer 42 can be 5 nanometers. Furthermore, the optical structure 4 can include any number of first optical film layers 41 and second optical film layers 42. For example, it can include 6 to 8 layers of first optical film layers 41 and 6 to 8 layers of second optical film layers 42, and the first optical film layers 41 and second optical film layers 42 are stacked alternately. The optical structure 4 with the above structure is disposed on the side of the anode 1 of the red organic light-emitting device away from the light-emitting layer 3 (specifically the red light-emitting layer). It can have the maximum reflectivity in the red light band (approximately 650 nanometers) and a low reflectivity for other light bands, thus reflecting red light while transmitting light of other bands.

[0061] Furthermore, in the optical structure 4 of the green organic light-emitting device, the material of the first optical film layer 41 can be SiN, and the material of the second optical film layer 42 can be SiO2. Specifically, the thickness of the first optical film layer 41 made of SiN can be greater than the thickness of the second optical film layer 42 made of SiO2. For example, the thickness of the first optical film layer 41 can be 35 nanometers, and the thickness of the second optical film layer 42 can be 10 nanometers. Moreover, the optical structure 4 can include any number of first optical film layers 41 and second optical film layers 42. For example, it can include 5 to 7 layers of first optical film layers 41 and 5 to 7 layers of second optical film layers 42, with the first optical film layers 41 and second optical film layers 42 stacked alternately. The optical structure 4 with the above structure is disposed on the side of the anode 1 of the green organic light-emitting device away from the light-emitting layer 3 (specifically, the green light-emitting layer). It can have the highest reflectivity in the green light band (approximately 550 nanometers) and a lower reflectivity for other light bands, thus reflecting green light while transmitting light of other bands.

[0062] Furthermore, in the optical structure 4 of the blue organic light-emitting device, the material of the first optical film layer 41 can be SiN, and the material of the second optical film layer 42 can be SiO2. Specifically, the thickness of the first optical film layer 41 made of SiN can be less than the thickness of the second optical film layer 42 made of SiO2. For example, the thickness of the first optical film layer 41 can be 20 nanometers, and the thickness of the second optical film layer 42 can be 45 nanometers. Moreover, the optical structure 4 can include any number of first optical film layers 41 and second optical film layers 42. For example, it can include 3 to 5 layers of first optical film layers 41 and 3 to 5 layers of second optical film layers 42, with the first optical film layers 41 and second optical film layers 42 stacked alternately. The optical structure 4 with the above structure is disposed on the side of the anode 1 of the blue organic light-emitting device away from the light-emitting layer 3 (specifically the blue light-emitting layer). It can have the highest reflectivity in the green light band (approximately 405 nanometers) and a lower reflectivity for other light bands, thus reflecting green light while transmitting light of other bands.

[0063] In some instances, the thickness of anode 1 can be set arbitrarily, for example, it can be approximately 80 angstroms.

[0064] Of course, the specific structure of optical structure 4 is not limited to the above, and can be set according to the wavelength of the light emitted by light-emitting layer 3.

[0065] It should be noted that an organic electroluminescent device of a certain color refers to the light emitted by the light-emitting layer 3 of the organic electroluminescent device being of that color. For example, a red organic electroluminescent device refers to the light emitted by its light-emitting layer 3 being red light.

[0066] Based on the above, it can be understood that the film thickness of the optical structure 4 may be different for organic electroluminescent devices of different colors. If organic electroluminescent devices of different colors are applied to a display panel, uneven film thickness may lead to color deviation. Therefore, in the organic electroluminescent devices provided in this embodiment, the sum of the thicknesses of the anode 1 and the optical structure 2 of organic electroluminescent devices of different colors can be the same.

[0067] Specifically, see Figures 3-5 ,in Figure 4 For Figure 3The cross-sectional view along the CD direction is shown below. Taking the application of multiple organic light-emitting devices (OLEDs) in a display panel as an example, the multiple OLEDs may include a red OLED R, a green OLED, the green OLED including a first green OLED G1 and a second green OLED G2, and a blue OLED B. The red OLED R includes an anode 1, a cathode 2, and a red light-emitting layer 3a disposed between them. A first optical structure 4a is disposed below the anode 1, and the first optical structure 4a reflects only red light. The green OLED (e.g., the second green OLED G2) includes an anode 1, a cathode 2, and a green light-emitting layer 3b disposed between them. A second optical structure 4b is disposed below the anode 1, and the second optical structure 4b reflects only green light. The blue OLED B includes an anode 1, a cathode 2, and a blue light-emitting layer 3c disposed between them. A third optical structure 4c is disposed below the anode 1, and the third optical structure 4c reflects only blue light.

[0068] Further, see Figure 5 , Figure 5 The diagrams, from top to bottom, show the anode 1 and optical structures (including the first to third optical structures) of the red organic light-emitting device R, the second green organic light-emitting device G2, and the blue organic light-emitting device B. Assuming the thickness d1a of the first optical structure 4a is greater than the thickness d1b of the second optical structure 4b, and the thickness d1b of the second optical structure 4b is greater than the thickness d1c of the third optical structure 4c, then correspondingly, the thickness d2a of the portion of the anode 1 of the red organic light-emitting device R covering the first optical structure 4a is less than the thickness d2b of the portion of the anode 1 of the second green organic light-emitting device G2 covering the second optical structure 4b, and the thickness d2b of the portion of the anode 1 of the second green organic light-emitting device G2 covering the second optical structure 4b is less than the thickness d2c of the portion of the anode 1 of the blue organic light-emitting device B covering the third optical structure 4c. However, the sum of the thicknesses d3a of the anode 1 of the red organic light-emitting device R and the first optical structure 4a, d3b of the anode 1 of the second green organic light-emitting device G2 and the second optical structure 4b, and d3c of the anode 1 of the blue organic light-emitting device B and the third optical structure 4c are equal, i.e., d3a = d3b = d3c. In other words, the thickness of the anode 1 covering the optical structure 3 is adjusted according to the change in the thickness of the optical structure 4 of the organic light-emitting device, so that the sum of the thicknesses of the optical structure 3 and the anode 1 of each color organic light-emitting device is the same. Therefore, if organic light-emitting devices of different colors are applied to the display panel, the distance from the surface of the anode 1 of each color near the light-emitting layer 3 to the substrate is the same, the film thickness is uniform, and the problem of color deviation can be avoided.

[0069] See in some examples Figure 6 , Figure 6 This diagram illustrates an exemplary arrangement of pixels of organic electroluminescent devices of various colors on a display panel. To show the relative positions of the anode 1, the opening area of ​​the light-emitting layer 3, and the optical structure 4, solid lines indicate the position of the anode 1 relative to the opening area of ​​the light-emitting layer 3, and dense dashed lines indicate the position of the optical structure 4 relative to the opening area of ​​the light-emitting layer 3. It can be seen that the anode 1 of the organic electroluminescent device at least covers the optical structure 4, and the optical structure 4 at least covers the opening area of ​​the light-emitting layer 3.

[0070] See Figure 7 , Figure 8 , Figure 7 The reflectance curves are simulated using the organic electroluminescent devices provided in this embodiment, namely red organic electroluminescent device R, green organic electroluminescent device G, and blue organic electroluminescent device B. Figure 8 The transmittance curves for simulations using the organic electroluminescent devices provided in this embodiment—a red organic electroluminescent device R, a green organic electroluminescent device G, and a blue organic electroluminescent device B—show that the red organic electroluminescent device R has extremely high reflectivity and extremely low transmittance in the red light band, while exhibiting extremely low reflectivity and extremely high transmittance for light outside the red light band. Similarly, the green organic electroluminescent device G has extremely high reflectivity and extremely low transmittance in the green light band, while exhibiting extremely low reflectivity and extremely high transmittance for light outside the green light band. The blue organic electroluminescent device B has extremely high reflectivity and extremely low transmittance in the blue light band, while exhibiting extremely low reflectivity and extremely high transmittance for light outside the blue light band. This verifies that the organic electroluminescent devices provided in this embodiment can effectively reflect the light emitted from the light-emitting layer 3 while transmitting other light.

[0071] Secondly, see Figure 3 , Figure 4 This disclosure also provides a display panel, including a substrate 01 and a plurality of organic electroluminescent devices (including R, G1, G2, and B) disposed on the substrate 01. The plurality of organic electroluminescent devices can be arranged in an array on the substrate 01, wherein the anode 1 is closer to the substrate 01 than the cathode 2. The plurality of organic electroluminescent devices can include organic electroluminescent devices of various colors, and organic electroluminescent devices of different colors can be disposed on the substrate 01 in various arrangements, for example, using... Figure 3For example, an organic light-emitting device includes a red organic light-emitting device R, a green organic light-emitting device, and the green organic light-emitting device includes a first green organic light-emitting device G1 and a second green organic light-emitting device G2, and a blue organic light-emitting device B. The red organic light-emitting device R, the green organic light-emitting device, and the blue organic light-emitting device B are arranged sequentially along a first direction X. The green organic light-emitting device is disposed between the red organic light-emitting device R and the blue organic light-emitting device B, and the first green organic light-emitting device G1 and the second green organic light-emitting device G2 are arranged along a second direction Y. A red organic light-emitting device R, a green organic light-emitting device, and a blue organic light-emitting device B constitute a repeating unit 100. The repeating unit 100 is arranged along the first direction X on the substrate O1, and the first direction X is perpendicular to the second direction Y. Of course, the organic light-emitting devices can also be arranged in other ways, which are not limited here.

[0072] See Figure 4 Specifically, in the display panel provided in this embodiment, a driving circuit is further provided between the substrate 01 and the organic electroluminescent device. The driving circuit includes multiple transistors. Taking the layer structure of transistor T1 as an example, the display panel may also include a buffer layer 02, an active layer A1, a gate insulating layer 03, a gate G1, a first insulating layer 04, a source S1 and a drain D1, and a planarization layer 05 sequentially disposed on the substrate 01. The active layer A1, the gate G1, the source S1 and the drain D1 form a transistor T1, and the gate S1 and the drain D1 are disposed on the same layer. They are connected to the active layer A1 through vias disposed in the gate insulating layer 03 and the first insulating layer 04. The planarization layer 05 has vias, and the anode 1 of the organic electroluminescent device is electrically connected to the transistor T1 through a connecting electrode 001 extending along the via. An optical structure 4 may be disposed on the side of the anode 1 of the organic electroluminescent device away from the light-emitting layer 3. Since the anode 1 needs to be connected to the transistor T1 through the connecting electrode 001, in order to avoid the connecting electrode 001 from contacting the optical structure 4, the orthogonal projection of the connecting electrode 001 on the substrate 01, that is, the orthogonal projection of the via in the planarization layer 05 on the substrate 01, does not overlap with the orthogonal projection of the optical structure 4 on the substrate 01.

[0073] Optionally, the display panel may further include a pixel defining layer 06, which has multiple openings. An organic light-emitting device (OLED) is disposed in one of the openings. The anode 1, light-emitting layer 3, cathode 2, and optical structure 4 of the OLED, together with the inner wall of the opening of the pixel defining layer 06, can form a microcavity structure. Light from the light-emitting layer 3 illuminates the optical structure 4 under the anode 1. The optical structure 4 acts as a reflective electrode, reflecting the light from the light-emitting layer 3 to ensure the light extraction efficiency of the microcavity structure. Light other than that from the light-emitting layer 3 is transmitted through the optical structure 4. (See also...) Figure 6 In an organic electroluminescent device, the orthographic projection of the optical structure 4 onto the substrate 01 is in the orthographic projection of the anode 1 onto the substrate 01, and the orthographic projection of the portion of the light-emitting layer 3 within the opening region onto the substrate 01 is in the orthographic projection of the optical structure 4 onto the substrate 01.

[0074] In some examples, the display panel may include a display area S1 and a peripheral area S2 surrounding the display area S1, and at least a portion of the display area S1 is a mounting area S11. Various organic electroluminescent devices are distributed in the display area S1. The organic electroluminescent devices provided in this embodiment are transparent devices, and these devices can be disposed in the mounting area S11. Other areas of the display area S1 may contain opaque organic electroluminescent devices. If some devices, such as a camera, are disposed in the mounting area S11 and on the side of the substrate 01 opposite to the organic electroluminescent devices, then when the camera captures images of the organic electroluminescent devices in the mounting area of ​​the display panel, the transparent organic electroluminescent devices provided in this embodiment have sufficient transmittance to ensure effective image capture. When the display panel is displaying images, the optical structure 4 of the organic electroluminescent devices provided in this embodiment can reflect the light emitted by the light-emitting layer 3, ensuring that the organic electroluminescent devices have sufficient light emission, maintaining or minimizing the difference in luminance with the organic electroluminescent devices in other areas of the display area S1, thus ensuring good display quality.

[0075] See in some examples Figure 4 , Figure 5 The multiple organic electroluminescent devices include organic electroluminescent devices with various emission colors. Among them, the thickness of the optical structure 4 and the thickness of the anode 1 of the organic electroluminescent devices with different emission colors are different, and the sum of the thickness of the optical structure 4 and the thickness of the anode 1 of each organic electroluminescent device is the same.

[0076] For example, multiple organic light-emitting devices may include a red organic light-emitting device R, a green organic light-emitting device, the green organic light-emitting device including a first green organic light-emitting device G1 and a second green organic light-emitting device G2, and a blue organic light-emitting device B. The red organic light-emitting device R includes an anode 1, a cathode 2, and a red light-emitting layer 3a disposed between the two. A first optical structure 4a is disposed below the anode 1, and the first optical structure 4a reflects only red light. The green organic light-emitting device (e.g., the second green organic light-emitting device G2) includes an anode 1, a cathode 2, and a green light-emitting layer 3b disposed between the two. A second optical structure 4b is disposed below the anode 1, and the second optical structure 4b reflects only green light. The blue organic light-emitting device B includes an anode 1, a cathode 2, and a blue light-emitting layer 3c disposed between the two. A third optical structure 4c is disposed below the anode 1, and the third optical structure 4c reflects only blue light.

[0077] Specifically, assuming the thickness d1a of the first optical structure 4a > the thickness d1b of the second optical structure 4b > the thickness d1c of the third optical structure 4c, then correspondingly, the thickness d2a of the portion of the anode 1 of the red organic light-emitting device R covering the first optical structure 4a is less than the thickness d2b of the portion of the anode 1 of the second green organic light-emitting device G2 covering the second optical structure 4b and the thickness d2c of the portion of the anode 1 of the blue organic light-emitting device B covering the third optical structure 4c. However, the sum of the thicknesses d3a of the anode 1 of the red organic light-emitting device R and the first optical structure 4a, d3b of the anode 1 of the second green organic light-emitting device G2 and the second optical structure 4b, and d3c of the anode 1 of the blue organic light-emitting device B and the third optical structure 4c are equal, i.e., d3a = d3b = d3c. In other words, the thickness of the anode 1 covering the optical structure 3 is adjusted according to the change in the thickness of the optical structure 4 of the organic light-emitting device, so that the sum of the thicknesses of the optical structure 3 and the anode 1 of each color organic light-emitting device is the same. Therefore, if organic light-emitting devices of different colors are applied to the display panel, the distance from the surface of the anode 1 of each color near the light-emitting layer 3 to the substrate is the same, the film thickness is uniform, and the problem of color deviation can be avoided.

[0078] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A display panel, characterized by, Includes multiple organic electroluminescent devices; The display panel includes a display area, and at least a portion of the display area is a mounting area; the organic electroluminescent device is a transparent device and is disposed in the mounting area; The organic electroluminescent device includes: a first electrode, a second electrode, and a light-emitting layer located between the two, as well as an optical structure located on the side of the first electrode opposite to the light-emitting layer; wherein, The optical structure has a higher reflectivity for light emitted by the organic electroluminescent device than for other types of light; the material of the optical structure includes at least one of nitrogen, oxygen, and fluorine. The organic electroluminescent device includes a red organic electroluminescent device, a green organic electroluminescent device, and a blue organic electroluminescent device; the thickness of the optical structure and the thickness of the first electrode of the organic electroluminescent device with different emission colors are different; and the sum of the thickness of the optical structure and the thickness of the first electrode of the red organic electroluminescent device, the green organic electroluminescent device, and the blue organic electroluminescent device is the same.

2. The display panel of claim 1, wherein, Both the first electrode and the second electrode are made of metal oxide.

3. The display panel of claim 1, wherein, The optical structure includes multiple layers of first optical film and multiple layers of second optical film, wherein the first optical film and the second optical film are stacked and alternately arranged; wherein... The refractive index of the first optical film is greater than that of the second optical film.

4. The display panel of claim 3, wherein, The materials of at least some of the first optical films in the multilayer first optical film layer are different; and / or, the materials of at least some of the second optical films in the multilayer second optical film layer are different.

5. The display panel of claim 3, wherein, The material of the first optical film layer includes at least one of silicon nitride, aluminum oxide, and titanium dioxide; the material of the second optical film layer includes at least one of silicon oxide, barium fluoride, and calcium fluoride.

6. The display panel of claim 3, wherein, The thickness of the first optical film layer is different from the thickness of the second optical film layer.

7. The display panel of claim 6, wherein, In the optical structure of the red organic electroluminescent device, the thickness of the first optical film layer is greater than the thickness of the second optical film layer; In the optical structure of the green organic electroluminescent device, the thickness of the first optical film layer is greater than the thickness of the second optical film layer; In the optical structure of the blue organic electroluminescent device, the thickness of the first optical film layer is less than the thickness of the second optical film layer.

8. The display panel of any of claims 1-7, wherein, The first electrode at least covers the optical structure.

9. The display panel according to any one of claims 3-7, characterized in that, The optical structure includes 6-8 first optical film layers and 6-8 second optical film layers; The first optical film layer is made of silicon nitride; the second optical film layer is made of silicon dioxide. The thickness of the first optical film is 40 nanometers; the thickness of the second optical film is 5 nanometers.

10. The display panel according to any one of claims 3-7, characterized in that, The optical structure includes 5-7 first optical film layers and 5-7 second optical film layers; The first optical film layer is made of silicon nitride; the second optical film layer is made of silicon dioxide. The thickness of the first optical film is 35 nanometers; the thickness of the second optical film is 10 nanometers.

11. The display panel according to any one of claims 3-7, characterized in that, The optical structure includes 3-5 first optical film layers and 3-5 second optical film layers; The first optical film layer is made of silicon nitride; the second optical film layer is made of silicon dioxide. The thickness of the first optical film is 20 nanometers; the thickness of the second optical film is 45 nanometers.

12. The display panel according to claim 1, characterized in that, The display panel also includes a substrate on which a plurality of organic electroluminescent devices are arranged.

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