Display panel and display device

Abstract

The present application provides a display panel and a display device. The display panel includes a plurality of pixel units, each pixel unit includes a plurality of sub-pixels, and the plurality of sub-pixels are divided into a first type of sub-pixels and a second type of sub-pixels. The brightness life of the first type of sub-pixels is shorter than the brightness life of the second type of sub-pixels. Each sub-pixel includes a cathode, an anode, and a light-emitting layer and a carrier transport layer located between the cathode and the anode. In addition, the carrier mobility of the carrier transport layer of the first type of sub-pixel is different from the carrier mobility of the carrier transport layer of the second type of sub-pixel. By adjusting the carrier mobility, the brightness difference between sub-pixels of different types can be reduced, and the problem of display color cast can be improved.

Description

Technical Field

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

[0002] Organic Light-Emitting Display (OLED) is an active light-emitting display device. Due to its advantages such as simple preparation process, low cost, and easy color display, large-screen display, and flexible display, it is expected to become the next generation of mainstream flat-panel display technology. Currently, OLEDs generally use different colors as base colors and adjust the color mixing ratio of different color combinations to produce true color and ultimately achieve display. However, due to the differences in brightness lifespan between different colors, especially in high-brightness mode, the brightness lifespan gap between different colors will increase. Therefore, after a period of display, color cast problems will occur. Summary of the Invention

[0003] A first aspect of the present application provides a display panel. The display panel includes a plurality of pixel units, each pixel unit includes a plurality of sub-pixels, and the plurality of sub-pixels are divided into a first type of sub-pixels and a second type of sub-pixels. The luminance lifetime of the first type of sub-pixels is shorter than the luminance lifetime of the second type of sub-pixels. Each sub-pixel includes a cathode, an anode, and a light-emitting layer and a carrier transport layer located between the cathode and the anode. The carrier mobility of the carrier transport layer of the first type of sub-pixels is different from the carrier mobility of the carrier transport layer of the second type of sub-pixels.

[0004] In the above scheme, the carrier mobility in the carrier transport layer corresponding to the first type sub-pixel and the second sub-pixel with different brightness lifetimes is designed to be different, and the size of the carrier recombination area of ​​the first type sub-pixel / second sub-pixel in the corresponding light-emitting layer is adjusted, thereby reducing the difference between the brightness lifetime of the first type sub-pixel and the brightness lifetime of the second sub-pixel, and improving the problem of display color cast.

[0005] In combination with the first aspect, in some embodiments, the carrier transport layer includes an electron transport layer located between the cathode and the light-emitting layer, and the electron mobility of the electron transport layer of the first type of sub-pixel is less than the mobility of the electron transport layer of the second type of sub-pixel.

[0006] In the above solution, the electron mobility of the electron transport layer of the first type of sub-pixel is lower than that of the second type of sub-pixel, which improves the brightness lifetime of the first type of sub-pixel with a short brightness lifetime, thereby improving the display color cast problem of the display panel.

[0007] In conjunction with the first aspect, in some embodiments, the electron transport layer of the first sub-pixel type and the electron transport layer of the second sub-pixel type both include a first film layer. The electron transport layer of the first sub-pixel type also includes a second film layer, wherein the electron mobility of the second film layer is less than that of the first film layer and the second film layer is located between the first film layer and the light-emitting layer of the first sub-pixel type. Furthermore, the first sub-pixel type includes multiple sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel type that emits light of a larger wavelength has a thicker thickness.

[0008] In the above scheme, a second film layer with low electron mobility is set only between the first film layer of the electron transport layer and the light-emitting layer of the first type of sub-pixel with low brightness lifetime. This increases the carrier recombination area of ​​the light-emitting layer of the first type of sub-pixel, allowing more electrons and holes to recombine to produce more excitons, thereby improving the brightness lifetime of the first type of sub-pixel.

[0009] In conjunction with the first aspect, in some embodiments, the electron transport layer of the first sub-pixel and the electron transport layer of the second sub-pixel both include a first film layer, and the electron transport layer of the second sub-pixel further includes a second film layer, wherein the second film layer has an electron mobility greater than that of the first film layer and is located between the first film layer and the light-emitting layer of the second sub-pixel. Furthermore, the second sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the thickness of the second film layer is smaller for sub-pixels emitting light of a larger wavelength.

[0010] In the above scheme, by setting a second film layer with high electron mobility in the second type of sub-pixels, the carrier recombination area in the light-emitting layer of the second type of sub-pixels is reduced, thereby reducing the brightness life of the second type of sub-pixels, and finally reducing the difference in brightness life between the first type of sub-pixels and the second type of sub-pixels, thereby improving the problem of display color cast.

[0011] In conjunction with the first aspect, in some embodiments, the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, the second film layer having an electron mobility lower than that of the first film layer and being located between the first film layer and the light-emitting layer of the first type of sub-pixel and the second type of sub-pixel, respectively, and the thickness of the second film layer of the first type of sub-pixel is greater than the thickness of the second film layer of the second type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel with a larger wavelength is thicker; and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel with a larger wavelength is thicker.

[0012] In the above solution, by adjusting the brightness lifetimes of all sub-pixels within a pixel, the differences in brightness lifetimes of sub-pixels of different colors can be balanced, thereby more effectively improving the problem of display color cast.

[0013] In combination with the first aspect, in some embodiments, when the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, the total thickness of the first film layer and the second film layer between different sub-pixels is equal, and the thickness of the second film layer of the first type of sub-pixel is greater than the thickness of the second film layer of the second type of sub-pixel.

[0014] In the above solution, the thickness of the first and second film layers is designed to be between the first and second sub-pixels. This not only significantly improves the brightness lifespan of the first sub-pixels by allowing more electrons from the first sub-pixels to enter the light-emitting layer at a slower rate, resulting in more electron-hole recombination, but also shortens the difference in brightness lifespan between the first and second sub-pixels. Furthermore, the arrangement of the first and second film layers facilitates the production and processing of display panels, saving production costs.

[0015] In conjunction with the first aspect, in some embodiments, the electron transport layer of the first type of sub-pixel is made of a substrate layer doped with a second type of material, the substrate layer being composed of the first type of material, and the electron transport layer of the second type of sub-pixel is made of the first type of material. The second type of material is doped on the side of the substrate layer of the first type of sub-pixel facing the light-emitting layer, and the electron mobility of the second type of material is less than that of the first type of material. Furthermore, the first type of sub-pixel includes multiple sub-pixels emitting light of different wavelengths, and the doping concentration of the second type of material increases in sub-pixels emitting light of a larger wavelength.

[0016] In the above solution, doping reduces the electron mobility of the electron transport layer corresponding to the first-type pixel, increases the size of the carrier recombination zone, improves the brightness lifetime of the first-type sub-pixels, reduces the brightness difference between the first-type sub-pixels and the second-type sub-pixels, and improves the display color cast problem. Furthermore, the doping method is simple and easy to implement, saving production costs. Furthermore, doping all sub-pixels included in the first-type sub-pixels further effectively alleviates the display color cast problem.

[0017] In conjunction with the first aspect, in some embodiments, the electron transport layer of the first type of sub-pixel is made of the first type of material, and the electron transport layer of the second type of sub-pixel is made of a substrate layer doped with the second type of material, the substrate layer being made of the first type of material, and the second type of material is doped on the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer, wherein the electron mobility of the second type of material is greater than that of the first type of material. Furthermore, the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the second type of material decreases in sub-pixels emitting light of a larger wavelength.

[0018] In the above solution, the electron transport layer of the second-type sub-pixel is doped with a second-type material with high electron mobility, reducing the brightness lifetime of the second-type sub-pixel. Furthermore, by doping with different concentrations of the second-type material based on the wavelength of light emitted by all sub-pixels in the second-type sub-pixel, the brightness lifetime of all sub-pixels in the second-type sub-pixel is reasonably reduced, more effectively alleviating the problem of display color cast.

[0019] In conjunction with the first aspect, in some embodiments, the material of the electron transport layer of the first type of sub-pixel and the material of the electron transport layer of the second type of sub-pixel are both substrate layers doped with the second type of material, the substrate layers being composed of the first type of material, and the substrate layers of the first type of sub-pixel and the second type of sub-pixel facing the light-emitting layer are doped with the second type of material, the electron mobility of the second type of material is less than that of the first type of material, and the doping concentration of the second type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration of the second type of material in the substrate layer of the second type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the second type of material is greater in sub-pixels emitting light of a greater wavelength; and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the second type of material is greater in sub-pixels emitting light of a greater wavelength.

[0020] In the above solution, the electron transport layers of both the first and second sub-pixels are doped with varying concentrations of a second material with low electron mobility, thereby improving the brightness lifespan of the first sub-pixels and addressing the issue of display color cast. Furthermore, all sub-pixels are doped, and the concentration of the doped second material is adjusted based on the wavelengths of light emitted by the sub-pixels, further effectively addressing the issue of display color cast.

[0021] In combination with the first aspect, in some embodiments, the carrier transport layer includes a hole transport layer, which is located between the anode and the light-emitting layer, and the hole mobility of the hole transport layer of the first type of sub-pixel is greater than the hole mobility of the hole transport layer of the second type of sub-pixel.

[0022] In the above scheme, the hole mobility of the hole transport layer of the first type of sub-pixel is limited to be greater than the hole mobility of the hole transport layer of the second type of sub-pixel, thereby improving the carrier recombination efficiency of the first type of sub-pixel, generating more excitons, and thereby improving the brightness life of the first type of sub-pixel.

[0023] In conjunction with the first aspect, in some embodiments, the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer. The hole transport layer of the first type of sub-pixel also includes a fourth film layer. The fourth film layer has a hole mobility greater than that of the third film layer and is located between the third film layer and the light-emitting layer of the first type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths. The fourth film layer has a greater thickness for sub-pixels emitting light of a larger wavelength.

[0024] In the above solution, the composite film design of the hole transport layer corresponding to the first type of sub-pixels increases the size of the carrier recombination area in the light-emitting layer, thereby improving the brightness and lifespan of the first type of sub-pixels. Furthermore, the thickness of the fourth film layer is designed for all sub-pixels in the first type according to the wavelength of the emitted light, further effectively improving the display color cast problem.

[0025] In conjunction with the first aspect, in some embodiments, the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer, and the hole transport layer of the second type of sub-pixel further includes a fourth film layer, wherein the hole mobility of the fourth film layer is less than that of the third film layer and the fourth film layer is located between the third film layer and the light-emitting layer of the second type of sub-pixel. Furthermore, the second type of sub-pixel includes multiple sub-pixels emitting light of different wavelengths, and the thickness of the fourth film layer is smaller for sub-pixels emitting light of a larger wavelength.

[0026] In the above scheme, the fourth film layer with low hole mobility set in the second type of sub-pixels allows holes to enter the light-emitting layer at a slow speed, and also reduces the number of holes entering the light-emitting layer of the second type of sub-pixels per unit time, reduces the size of the carrier recombination zone, and thus reduces the brightness life of the second type of sub-pixels.

[0027] In conjunction with the first aspect, in some embodiments, the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer, the hole mobility of the fourth film layer being greater than that of the third film layer, and the fourth film layer being located between the third film layer and the light-emitting layers of the first type of sub-pixel and the second type of sub-pixel, respectively, and the thickness of the fourth film layer of the first type of sub-pixel being greater than the thickness of the fourth film layer of the second type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the thickness of the fourth film layer is greater for sub-pixels that emit light of a larger wavelength, and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the thickness of the fourth film layer is greater for sub-pixels that emit light of a larger wavelength.

[0028] In the above solution, the design of the hole transport layer corresponding to the first and second sub-pixels not only reduces the difference in brightness lifetime between the two, improving the luminous efficiency of the display panel, but also facilitates production and saves costs. Furthermore, the thin film design of some pixels can further effectively improve the problem of display color cast.

[0029] In combination with the first aspect, when the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer, the total thickness of the third film layer and the fourth film layer between different sub-pixels is equal, and the thickness of the fourth film layer of the first type of sub-pixel is greater than the thickness of the fourth film layer of the second type of sub-pixel.

[0030] In the above solution, more holes enter the first type of sub-pixels at a fast speed, thereby improving the brightness life of the first type of sub-pixels and simplifying the processing technology of the hole injection layer to facilitate production.

[0031] In conjunction with the first aspect, in some embodiments, the hole transport layer of the first type of sub-pixel is made of a substrate layer doped with a fourth type of material, the substrate layer being made of the third type of material. The hole transport layer of the second type of sub-pixel is made of the third type of material. The fourth type of material is doped on the side of the substrate layer of the first type of sub-pixel facing the light-emitting layer, and the hole mobility of the fourth type of material is greater than that of the third type of material. Furthermore, the first type of sub-pixel includes multiple sub-pixels emitting light of different wavelengths, and the doping concentration of the fourth type of material is greater in sub-pixels emitting light of a larger wavelength.

[0032] In the above solution, the doping process is simple, which helps to save production costs. Furthermore, doping sub-pixels with different brightness lifetimes with different concentrations is more conducive to improving the difference in brightness lifetime between different sub-pixels, thereby effectively improving the problem of display color cast.

[0033] In conjunction with the first aspect, in some embodiments, the hole transport layer of the first type of sub-pixel is made of the third type of material, and the hole transport layer of the second type of sub-pixel is made of a substrate layer doped with a fourth type of material, the substrate layer being made of the third type of material. The fourth type of material is doped on the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer, and the hole mobility of the fourth type of material is lower than that of the third type of material. Furthermore, the second type of sub-pixel includes multiple sub-pixels emitting light of different wavelengths, and the doping concentration of the fourth type of material is lower in sub-pixels emitting light of a larger wavelength.

[0034] In the above solution, by reducing the brightness lifetime of the second type of sub-pixels through doping, the brightness difference between the first and second types of sub-pixels is reduced, thereby improving the display color cast problem. Furthermore, the brightness lifetime of the second type of sub-pixels is reasonably reduced, which is further conducive to improving the display color cast problem.

[0035] In conjunction with the first aspect, in some embodiments, the material of the hole transport layer of the first type of sub-pixel and the material of the hole transport layer of the second type of sub-pixel are both substrate layers doped with a fourth type of material, the substrate layers being composed of a third type of material. The fourth type of material is doped on the side of the substrate layer of the first type of sub-pixel and the substrate layer of the second type of sub-pixel facing the light-emitting layer, respectively. The hole mobility of the fourth type of material is greater than the hole mobility of the third type of material, and the doping concentration of the fourth type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration of the fourth type of material in the substrate layer of the second type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the fourth type of material is greater in sub-pixels with larger wavelengths of emitted light; and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the fourth type of material is greater in sub-pixels with larger wavelengths of emitted light.

[0036] In the above solution, by doping sub-pixels with different brightness lifetimes with different concentrations of the fourth material, it is beneficial to efficiently reduce the brightness difference between all sub-pixels and effectively improve the problem of display color cast.

[0037] A second aspect of the present application provides a display device, which includes any one of the display panels provided in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to an embodiment of the present application.

[0039] Figure 2 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to an embodiment of the present application.

[0040] Figure 3 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to an embodiment of the present application.

[0041] Figure 4 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0042] Figure 5 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0043] Figure 6 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0044] Figure 7 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0045] Figure 8 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0046] Figure 9 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to an embodiment of the present application.

[0047] Figure 10 This is a schematic diagram of the structure of a pixel of a display panel according to another embodiment of the present application.

[0048] Figure 11 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0049] Figure 12 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application.

[0050] Figure 13 FIG. 1 is a schematic structural diagram of a pixel of a display panel according to another embodiment of the present application. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0052] Due to material limitations, the brightness lifespans of sub-pixels of different colors in a display panel are inconsistent. After the lighting time reaches its limit, some sub-pixels of certain colors reach the end of their lifespans, gradually decreasing in brightness and failing to display properly. This ultimately results in areas of abnormal display on the display panel. Therefore, adjusting the brightness lifespans of sub-pixels of different colors can alleviate display anomalies, such as color cast, on display panels.

[0053] An embodiment of the present application provides a display panel that improves the problem of display color cast by making the mobility of carriers corresponding to sub-pixels with brightness differences different, thereby changing the size of the carrier recombination zone corresponding to the sub-pixels with brightness differences.

[0054] like Figure 1 As shown, the display panel includes multiple pixel units, each pixel unit includes multiple sub-pixels, and the multiple sub-pixels are divided into a first type of sub-pixels and a second type of sub-pixels. The brightness lifespan of the first type of sub-pixels is shorter than the brightness lifespan of the second type of sub-pixels. Each sub-pixel includes a cathode 1, an anode 2, and a light-emitting layer 3 and a carrier transport layer 4 located between the cathode 1 and the anode 2. The carrier transport layer is located between the light-emitting layer and the anode or between the light-emitting layer and the cathode. The carrier mobility of the carrier transport layer of the first type of sub-pixel is different from the carrier mobility of the carrier transport layer of the second type of sub-pixel.

[0055] Based on the luminescence mechanism of sub-pixels: Driven by voltage, carriers, namely holes at the anode and electrons at the cathode, migrate to the light-emitting layer to recombine and produce excitons, which emit light. The area where excitons are produced becomes the carrier recombination zone. It can be seen that changing the size of the recombination zone will affect the luminescence brightness of the sub-pixel, thereby directly affecting the brightness lifespan of the sub-pixel. The size of the recombination zone is related to the carrier transport capacity. Different carriers with faster transport will pass through the light-emitting layer and reach other functional film layers such as the carrier blocking layer or the counter electrode, causing quenching. Therefore, adjusting the carrier transport capacity corresponding to different sub-pixels can adjust the brightness lifespan of different sub-pixels, thereby alleviating display anomalies such as the occurrence of color cast.

[0056] Specifically, if Figure 2 As shown, each pixel unit includes three sub-pixels, namely sub-pixel R, sub-pixel G and sub-pixel B, where sub-pixel B is a first-type sub-pixel, and sub-pixel R and sub-pixel G are second-type sub-pixels. The carrier transport layer includes a hole transport layer and an electron transport layer. Sub-pixel R includes a cathode 1, an anode 2, a light-emitting layer (referred to as R-EML) located between the cathode 1 and the anode 2, a hole transport layer 42 (referred to as R-HTL) located between the light-emitting layer 3 and the anode 2, and an electron transport layer 41 (referred to as R-ETL) located between the light-emitting layer 3 and the cathode 1. Sub-pixel G includes a cathode 1, an anode 2, a light-emitting layer 3 (referred to as G-EML) located between the cathode 1 and the anode 2, a hole transport layer 42 (referred to as G-HTL) located between the light-emitting layer 3 and the anode 2, and an electron transport layer 41 (referred to as G-ETL) located between the light-emitting layer 3 and the cathode 1. Subpixel B includes a cathode 1, an anode 2, a light-emitting layer 3 (B-EML) located between cathode 1 and anode 2, a hole transport layer 42 (B-HTL) located between the light-emitting layer 3 and anode 2, and an electron transport layer 41 (B-ETL) located between the light-emitting layer 3 and cathode 1. Based on the luminance lifetimes of the three different RGB subpixels, the carrier mobility corresponding to the B-EML in the subpixel B with the lowest brightness is made different from the carrier mobility corresponding to the R-EML in subpixel R and the carrier mobility corresponding to the G-EML in subpixel G. This increases the luminance lifetime of the subpixel B with the lowest brightness, reduces the brightness difference between subpixels of different colors, and improves the color cast problem that occurs in the display panel due to the different luminance lifetimes of subpixels of different colors.

[0057] It should be understood that the first type of sub-pixels and / or the second type of sub-pixels represent two types of sub-pixels with a similar brightness lifetime, and do not only include sub-pixels of a single color. For example, the first type of sub-pixels may include sub-pixels that emit blue light (referred to as "B"), and the second type of sub-pixels may include sub-pixels that emit green light (referred to as "G") and / or sub-pixels that emit red light (referred to as "R"), and the brightness lifetime of sub-pixels BG and / or sub-pixels BR are both shorter than that of sub-pixels BB. Similarly, the first type of sub-pixels may not only include sub-pixels of one color, such as sub-pixel B, but may also include at least one sub-pixel of another color, such as sub-pixel G. At the same time, the number and color of sub-pixels contained in each pixel unit are not limited to the above. Figure 2 The solution described in the above may also include other design solutions, such as each pixel including multiple sub-pixels arranged in RGBG. The design can be made according to the actual requirements of the display panel.

[0058] In a display panel, charge carriers include holes and electrons. Therefore, by changing the hole mobility, electron mobility, or both, the difference in brightness lifetime between sub-pixels of different colors can be modified, thereby improving the color cast problem that may occur in the display panel. The following describes in detail different schemes for changing electron mobility to achieve different electron mobilities in the electron transport layer of sub-pixels of different colors.

[0059] Considering that electron mobility is greater than hole mobility in the same light-emitting layer, in order to increase the number of electrons and holes injected into the light-emitting layer that recombine, the electron mobility can be reduced so that when holes reach the light-emitting layer, more electrons can still migrate within the light-emitting layer and do not pass through the light-emitting layer. In some embodiments, the carrier transport layer includes an electron transport layer located between the cathode and the light-emitting layer, and the electron mobility of the electron transport layer of the first type of sub-pixel is less than the mobility of the electron transport layer of the second type of sub-pixel.

[0060] By limiting the electron mobility of the electron transport layer of the first type of sub-pixel to be lower than that of the second type of sub-pixel, the carrier recombination zone in the light-emitting layer corresponding to the first type of sub-pixel is increased, meaning that more electrons and holes recombine to produce excitons. This increase in the number of excitons increases the brightness lifetime of the first type of sub-pixel, thereby reducing the difference in brightness lifetime between the first type of sub-pixel and the second type of sub-pixel, thereby alleviating the color cast problem of the display panel.

[0061] Specifically, if Figure 2As shown in the figure, in the RBG three-color pixel, sub-pixel B is a first-type sub-pixel, and sub-pixels R and G are second-type sub-pixels. The corresponding electron mobility of B-ETL is smaller than that of R-ETL and G-ETL. This increases the carrier recombination zone of sub-pixel B, which has the shortest luminance lifetime, thereby increasing the lifetime of sub-pixel B and reducing the brightness difference between sub-pixel B, sub-pixels R, and sub-pixels G.

[0062] Of course, the RGB sub-pixels can be reclassified according to the brightness lifespan between sub-pixels with different brightness. Figure 2 As shown in the figure, in an RBG three-color pixel, sub-pixels B and G are first-type sub-pixels, and sub-pixel R is second-type sub-pixel. The electron mobility of the B-ETL and R-ETL is lower than that of the G-ETL. This also increases the brightness lifetime of relatively small sub-pixels, shortening the difference in brightness lifetime between them and the sub-pixel with the longest brightness lifetime, thus alleviating the problem of display color cast.

[0063] There are various ways to achieve a lower electron mobility of the electron transport layer of a first-type sub-pixel than that of a second-type sub-pixel within the same pixel. These include reducing the electron mobility of the electron transport layer of the first-type sub-pixel and / or increasing the electron mobility of the electron transport layer of the second-type sub-pixel. The following details the design of the electron transport layer for the first-type sub-pixel and / or the second-type sub-pixel.

[0064] In some embodiments, the electron transport layer of the first sub-pixel and the electron transport layer of the second sub-pixel both include a first film layer. The electron transport layer of the first sub-pixel also includes a second film layer, wherein the electron mobility of the second film layer is less than that of the first film layer and the second film layer is located between the first film layer and the light-emitting layer of the first sub-pixel. Furthermore, the first sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the thickness of the second film layer is greater for sub-pixels that emit light of a larger wavelength.

[0065] Only the electron transport layer of the first-type sub-pixels with a short brightness lifetime is configured as a composite film layer. The film layer with low electron mobility is composited onto the side of the original first film layer facing the light-emitting layer. This allows the electrons in the first-type pixels to enter the light-emitting layer at a slower rate than the electrons in the second-type pixels and to be transported longitudinally within the light-emitting layer at a slower rate. This not only increases the carrier recombination area but also reduces the number of electrons passing through the light-emitting layer of the first-type sub-pixels per unit time, allowing more electrons to recombine with holes to produce more excitons, thereby improving the brightness lifetime of the first-type sub-pixels. Furthermore, the thickness of the second film layer added to the first-type sub-pixels is designed according to the wavelength of the emitted light, further improving the brightness difference between all sub-pixels of the display panel and more effectively addressing the problem of display color cast.

[0066] like Figure 3 As shown, in an RBG three-color pixel, sub-pixel B is a first-type sub-pixel, and sub-pixels R and G are second-type sub-pixels. The electron transport layers corresponding to the three sub-pixels R, B, and G all include a first film layer 411, and a second film layer 412 with lower electron mobility is provided between the B-ETL layer and the B-EML. The first film layer 411 with high electron mobility is located between the cathode 1 and the B-EML, and the second film layer 412 with low electron mobility is located between the first film layer 411 and the B-EML. In the film structure near or adjacent to the B-EML, the electron mobility changes from high to low, causing electrons to enter the B-EML at a slower rate. This causes the carrier recombination zone of the B-EML to shift from the outer edge of the B-EML near the cathode 1 to the anode 2 and become larger. Even if the recombination zone moves toward the center of the B-EML, this improves the carrier recombination efficiency, thereby increasing the brightness life of sub-pixel B.

[0067] The categories of RGB sub-pixels can also be reclassified according to the size relationship of brightness life. Specifically, Figure 4 As shown in FIG1 , sub-pixel B and sub-pixel G are first-type sub-pixels, and sub-pixel R is second-type sub-pixel. Then, a second film layer 412 with low electron mobility is set between the first film layer 411 of the B-ETL layer and the G-ETL layer and the light-emitting layer (B-EML and G-EML), respectively. By reducing the electron mobility of sub-pixel B and sub-pixel G, the brightness life of sub-pixel B and sub-pixel G is improved, and the brightness difference between RGB pixels is reduced. At the same time, considering that the brightness life of sub-pixel B is shorter than that of sub-pixel G, the thickness D of the second film layer 412 of sub-pixel B with a larger wavelength of emitted light is 0.1mm. B2 The thickness D of the second film layer 412 of the sub-pixel G having a smaller wavelength than the emitted light is greater than G2 , that is, D B2 >D G2 , reducing the difference in brightness lifetime between sub-pixels that emit light of different colors within the first type of sub-pixels, thereby further reducing the difference in brightness lifetime between different sub-pixels within the same pixel, further alleviating the problem of display color cast.

[0068] In addition to increasing the brightness lifespan of the first type of sub-pixels, reducing the brightness lifespan of the second type of sub-pixels can also reduce the brightness difference between the first type of sub-pixels and the second type of sub-pixels. In other embodiments, the electron transport layer of the first type of sub-pixels and the electron transport layer of the second type of sub-pixels both include a first film layer, and the electron transport layer of the second type of sub-pixels also includes a second film layer, the electron mobility of the second film layer is greater than the electron mobility of the first film layer, and is located between the first film layer and the light-emitting layer of the second type of sub-pixels. Furthermore, the second type of sub-pixels include multiple sub-pixels that emit light of different wavelengths, and the thickness of the second film layer of the sub-pixels with larger wavelengths of emitted light is smaller.

[0069] Between the first film layer of the electron transport layer corresponding to the second type of sub-pixel and its light-emitting layer, an electron transport layer, namely the second film layer, with an electron mobility greater than that of the first film layer is added. Without affecting the electron mobility of the first type of sub-pixel, the average electron mobility of electrons corresponding to the second type of sub-pixel entering the transport layer is increased, so that more electrons pass through the light-emitting layer without participating in carrier recombination. Therefore, the carrier recombination area in the light-emitting layer of the second type of sub-pixel is reduced, and the total amount of exciton recombination in the light-emitting layer of the second type of sub-pixel is also reduced, thereby reducing the brightness life of the second type of sub-pixel, and finally reducing the difference in brightness life between the first type of sub-pixel and the second type of sub-pixel, thereby improving the problem of display color cast.

[0070] According to the brightness lifespan of different sub-pixels, the three RGB sub-pixels are divided into two categories of sub-pixels, which include two classification schemes, as follows.

[0071] In the first solution, if Figure 5 As shown, sub-pixels B and G are classified as first-category sub-pixels, and sub-pixel R is classified as second-category sub-pixels. A second film layer 412 with high electron mobility is provided between the first film layer 411 of the R-ETL and the R-EML, but not between the first film layer 411 of the G-ETL and the G-EML, and between the first film layer 411 of the B-ETL and the G-BML. This increases the electron mobility of sub-pixel R, reduces the number of electrons that reside in sub-pixel R per unit time, and increases the speed of electron movement in the R-EML layer, reducing the carrier recombination zone and shortening the brightness life of sub-pixel R.

[0072] In the second option, if Figure 6As shown, in the RGB pixel, sub-pixel B is a first type of sub-pixel, sub-pixel R and sub-pixel G are second type of sub-pixels, and the electron transport layers of the three sub-pixels all include a first film layer 411. The electron transport layers of sub-pixel R and sub-pixel G are also provided with a second film layer 412 with high electron mobility located between the R-EML and the first film layer 411 and the G-EML and the first film layer 411. The speed of electron migration of sub-pixels R and sub-pixel G is improved, and the brightness life of sub-pixels R and sub-pixel G is reduced. Although the R-ETL includes the first film layer 411 and the second film layer 412, and the G-ETL also includes the first film layer 411 and the second film layer 412, considering that the brightness life of sub-pixel R is greater than that of sub-pixel G, in order to further reduce the difference in brightness life of all sub-pixels in the pixel, the second film layer 412 corresponding to sub-pixel R and sub-pixel G is set to different film thicknesses. The wavelength of light emitted by sub-pixel G is large, so the thickness D of the second film layer of sub-pixel G is large. G2 smaller than the thickness D of the second film layer of the sub-pixel R R2 That is, the thickness of the second film layer 412 set for the sub-pixel G with a short brightness lifetime is small. Compared with the sub-pixel R, fewer electrons are accelerated, and the lifetime of the sub-pixel G is reduced less than that of the sub-pixel R, which is more conducive to balancing the difference in brightness lifetimes between sub-pixels with different brightness lifetimes, and further improving the problem of display color cast.

[0073] To more effectively improve the display color cast problem, in other embodiments, the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, wherein the electron mobility of the second film layer is less than that of the first film layer and the second type of sub-pixel is located between the first film layer and the light-emitting layer of the first type of sub-pixel and the second type of sub-pixel, respectively; the thickness of the second film layer of the first type of sub-pixel is greater than the thickness of the second film layer of the second type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel with a larger wavelength is thicker; and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel with a larger wavelength is thicker.

[0074] In the above scheme, the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel are both designed with a second film layer with low electron mobility, so that more electrons in the first type of sub-pixel enter the light-emitting layer at a slow speed, making the carrier recombination area larger, and more electrons participate in the recombination to produce excitons, thereby improving the brightness life of the first type of sub-pixel. In addition, the electron transport layers of different sub-pixels are limited by the same film layer structure, which is convenient for production and saves costs. Furthermore, the thickness of the second film layer set between the sub-pixels of different luminous colors contained in the same type of sub-pixels is different according to the wavelength of the light emitted between the sub-pixels, reducing the difference in brightness life of sub-pixels of different colors in the same type of sub-pixels, which is a more refined design, thereby more evenly reducing the difference in brightness life of different sub-pixels in the pixel, thereby more effectively alleviating the problem of display color cast.

[0075] Specifically, if Figure 7 As shown, the first type of sub-pixel includes sub-pixel B, and the second type of sub-pixel includes sub-pixel R and sub-pixel G. The electron transport layers corresponding to the sub-pixels of different colors all include a first film layer 411 and a second film layer 412 with low electron mobility. In addition, according to the arrangement of the wavelengths of the light emitted by the sub-pixels R, G, and B, that is, R<G<B, the thickness D of the second film layer 412 corresponding to the sub-pixel B with the largest wavelength of the emitted light is B2 The thickness D of the second film layer 412 corresponding to the sub-pixel R with the largest wavelength and the smallest emitted light is R2 This design adjusts the brightness lifetime of all sub-pixels within a pixel, balancing the brightness lifetime differences between sub-pixels of different colors and effectively improving the display color cast problem.

[0076] In order to save production processes, in some embodiments, when the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, the total thickness of the first film layer and the second film layer between different sub-pixels is equal, and the thickness of the second film layer of the first type of sub-pixel is greater than the thickness of the second film layer of the second type of sub-pixel.

[0077] Specifically, if Figure 7 As shown, the electron transport layer 41 corresponding to the three sub-pixels R, G and B respectively includes a first film layer 411 and a second film layer 412 with low electron mobility. The materials of the first film layer 411 and the second film layer 412 of different sub-pixels are equal, and the sum of their thicknesses is the same, that is, D R1 +D R2 =D G1 +D G2 =D B1 +D B2The thickness of the different film layers of the electron transport layer 41 corresponding to the sub-pixel R, sub-pixel G and sub-pixel B is related to their own brightness lifespan. The sub-film layer with higher mobility corresponding to the sub-pixel with greater brightness lifespan is thicker, and the sub-film layer with lower mobility corresponding to the sub-pixel is thinner, that is, D B1 <D G1 <D R1 , D B2 >D G2 >D R2 According to the display requirements of the display panel, it can be calculated that:

[0078] D B1 =π / 2*D EBL , D B2 =πN / 2*D EBL +D BML

[0079] Among them, N, K: Hole Only Device (HOD) and Electron Only Device (EOD) modulation coefficients, N is the refractive index, K is the extinction coefficient, both of which change with the material and thickness of the electron transport layer, D EBL : thickness of the electron group monolayer, D BML : The thickness of the blue light-emitting layer. This calculation method is also applicable to the calculation of the thickness of the corresponding electron transport layer in the red and green sub-pixels.

[0080] In addition to adding a composite film layer to change the electron mobility of the electron transport layer of the first type of sub-pixel / or the second type of sub-pixel, in other embodiments, doping can also be considered to reduce the brightness lifespan between the first type of sub-pixel and the second type of sub-pixel. The specific solution is as follows.

[0081] In the first solution, the material of the electron transport layer of the first type of sub-pixel is a substrate layer doped with a second type of material, the substrate layer is composed of the first type of material, and the material of the electron transport layer of the second type of sub-pixel is the first type of material. The second type of material is doped on the side of the substrate layer of the first type of sub-pixel facing the light-emitting layer, and the electron mobility of the second type of material is less than that of the first type of material. Specifically, Figure 2 As shown, the second type of material with low electron mobility is doped only on one side of the B-ETL of sub-pixel B located at the B-EML, thereby increasing the brightness life of sub-pixel B.

[0082] Furthermore, the first type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the sub-pixel with a larger wavelength of emitted light has a larger doping concentration of the second type of material. Specifically, Figure 2As shown, the second type of material is doped at a first concentration on the side of the B-ETL located on the B-EML of sub-pixel B, and at a second concentration on the side of the G-ETL located on the G-EML of sub-pixel G. Because the wavelength of light emitted by sub-pixel B is greater than that of light emitted by sub-pixel G, the first concentration is greater than the second concentration. Simultaneously doping all sub-pixels in the first type of sub-image with different concentrations reduces differences in brightness and lifetime among sub-pixels in the first type of sub-image, further improving the problem of displayed color cast.

[0083] In the first solution, the electron mobility of the electron transport layer corresponding to the first type of pixel is reduced by doping, so that the electrons corresponding to the first type of pixel enter its light-emitting layer at a slow speed, increasing the size of the carrier recombination zone, allowing more electrons and holes to recombine, thereby improving the brightness lifespan of the first type of sub-pixels, reducing the brightness difference between the first type of sub-pixels and the second type of sub-pixels, and improving the problem of display color cast. In addition, the doping method is simple and easy to implement, saving production costs. Furthermore, doping all sub-pixels contained in the first type of sub-pixels can evenly improve the brightness lifespan difference between the first type of sub-pixels and the second type of sub-pixels, more effectively alleviating the problem of display color cast.

[0084] In the second solution, the material of the electron transport layer of the first type of sub-pixel is the first type of material, and the material of the electron transport layer of the second type of sub-pixel is a substrate layer doped with the second type of material. The substrate layer is composed of the first type of material, and the second type of material is doped on the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer. The electron mobility of the second type of material is greater than that of the first type of material. For example, Figure 2 As shown, only the second type of material with large electron mobility is doped on one side of the R-ETL of R located on the R-EML, which reduces the brightness lifetime of R.

[0085] Furthermore, the second type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the sub-pixel with a larger wavelength of emitted light has a lower doping concentration of the second type of material. Specifically, Figure 2 As shown, the second type of material is doped with a first concentration on one side of the R-ETL of sub-pixel R located at the R-EML, and the second type of material is doped with a second concentration on one side of the G-ETL of sub-pixel G located at the G-EML. Since the wavelength of light emitted by sub-pixel G is greater than the wavelength of light emitted by sub-pixel R, the second concentration is less than the first concentration.

[0086] In the second solution, the electron transport layer of the second-type sub-pixel is doped with a second-type material with high electron mobility, reducing the brightness lifetime of the second-type sub-pixels. Furthermore, by doping with different concentrations of the second-type material based on the wavelength of light emitted by all sub-pixels in the second-type sub-pixel, the brightness lifetime of all sub-pixels in the second-type sub-pixel can be reasonably reduced, further reducing the brightness lifetime difference between the first-type and second-type sub-pixels, and more effectively alleviating the problem of display color cast.

[0087] In a third embodiment, in some embodiments, the material of the electron transport layer of the first sub-pixel and the material of the electron transport layer of the second sub-pixel are both substrate layers doped with the second material. The substrate layers are composed of the first material, and the substrate layers of the first sub-pixel and the second sub-pixel are doped with the second material on the side facing the light-emitting layer. The electron mobility of the second material is less than that of the first material, and the doping concentration of the second material in the substrate layer of the first sub-pixel is greater than the doping concentration of the second material in the substrate layer of the second sub-pixel. Furthermore, the first sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the second material in the sub-pixel with a larger wavelength is greater; and / or the second sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the doping concentration of the second material in the sub-pixel with a larger wavelength is greater.

[0088] Specifically, if Figure 2 As shown, the second type material is doped with a first concentration on the side of the R-ETL located on the R-EML of sub-pixel R, the second type material is doped with a second concentration on the side of the G-ETL located on the G-EML of sub-pixel G, and the second type material is doped with a third concentration on the side of the B-ETL located on the B-EML of sub-pixel B. Because the wavelength of light emitted by sub-pixel B is greater than the wavelength of light emitted by sub-pixel G, and the wavelength of light emitted by sub-pixel G is greater than the wavelength of light emitted by sub-pixel R, the third concentration is greater than the second concentration, and the second concentration is greater than the first concentration.

[0089] In the third solution, the electron transport layers of both the first and second sub-pixels are doped with a second material with low electron mobility. However, the doping concentration of the first sub-pixels is greater than that of the second sub-pixels. This causes the electrons in the first sub-pixels to enter the light-emitting layer more slowly, thereby improving the brightness lifetime of the first sub-pixels and alleviating the color cast problem. Furthermore, all sub-pixels are doped, and the concentration of the doped second material is adjusted based on the different wavelengths of light emitted by the sub-pixels. This more effectively reduces the differences in brightness lifetime among all sub-pixels and more effectively improves the color cast problem.

[0090] Taking into account the size of the recombination area of ​​carriers in the light-emitting layer corresponding to the first type of sub-pixel and / or the second sub-pixel, holes are also included. In some embodiments, the carrier transport layer includes a hole transport layer, which is located between the anode and the light-emitting layer, and the hole mobility of the hole transport layer of the first type of sub-pixel is greater than the hole mobility of the hole transport layer of the second type of sub-pixel. By limiting the hole mobility of the hole transport layer of the first type of sub-pixel to be greater than the hole mobility of the hole transport layer of the second type of sub-pixel, the holes corresponding to the first type of sub-pixel can enter the light-emitting layer of the first type of sub-pixel more quickly to recombine with electrons, thereby improving the carrier recombination efficiency of the first type of sub-pixel and generating more excitons, thereby improving the brightness life of the first type of sub-pixel.

[0091] Specifically, if Figure 2 As shown in the figure, the hole mobility of B-HTL is greater than that of R-HTL and G-HTL. This increases the carrier recombination area of ​​sub-pixel B, improves the lifetime of sub-pixel B, and reduces the brightness difference between sub-pixel B and sub-pixels R and G.

[0092] Regarding the design of the hole transport layer of the first type of sub-pixel and / or the hole transport layer of the second type of sub-pixel, from the perspective of saving production costs and improving the performance of the display panel, the specific design scheme for the hole transport layer is as follows.

[0093] In some embodiments, the hole transport layer of the first sub-pixel and the hole transport layer of the second sub-pixel both include a third film layer. The hole transport layer of the first sub-pixel also includes a fourth film layer. The fourth film layer has a hole mobility greater than that of the third film layer and is located between the third film layer and the light-emitting layer of the first sub-pixel. Furthermore, the first sub-pixel includes multiple sub-pixels emitting light of different wavelengths. The thickness of the fourth film layer is greater for sub-pixels emitting light of a larger wavelength.

[0094] The design of the composite film layer for the hole transport layer corresponding to the first-type sub-pixels allows holes to enter the light-emitting layer of the first-type sub-pixels at a rapid rate, increasing the size of the carrier recombination area in the light-emitting layer and improving the brightness lifespan of the first-type sub-pixels. Furthermore, the design of the fourth film layer for all sub-pixels in the first-type sub-pixels is based on the wavelength of the emitted light, that is, the brightness lifespan. This can more evenly improve the brightness lifespan difference between all sub-pixels in the first-type sub-pixels and those in the second-type sub-pixels, more effectively improving the display color cast problem.

[0095] Specifically, such as Figure 8As shown, in an RBG three-color pixel, subpixel B is a first-type subpixel, while subpixels R and G are second-type subpixels. The corresponding hole transport layers for both RBG and RGB include a third film layer 421, and a fourth film layer 422 with higher hole mobility is located between the B-HTL layer and the B-EML. The third film layer 421, with low hole mobility, is located between the anode 2 and the B-EML, while the fourth film layer 422, with high hole mobility, is located between the third film layer 421 and the B-EML. In the film layer structure near or adjacent to the B-EML, the hole mobility increases from low to high, allowing holes to enter the B-EML at a faster rate. This shifts the carrier recombination zone of the B-EML from the outer edge of the B-EML near the cathode toward the anode, increasing its size. This shifts the recombination zone toward the center of the B-EML, improving the carrier recombination efficiency of subpixel B and thereby increasing the brightness lifespan of subpixel B.

[0096] In order to further improve the brightness difference between RGB sub-pixels and improve the problem of display color cast, such as Figure 9 As shown, the sub-pixels B and G, which have lower brightness lifetimes than the largest, are regarded as the second type of sub-pixels. A fourth film layer 422 is provided between the third film layer 421 and the B-EML of the sub-pixel B, and a fourth film layer 422 is provided between the third film layer 421 and the G-EML of the sub-pixel G. The thickness D of the fourth film layer 422 of the sub-pixel B is B4 Greater than the thickness D of the fourth film layer 422 of the sub-pixel G G4 The difference between the brightness lifespan of sub-pixels B and G and the sub-pixel R with the maximum brightness lifespan is reduced, which more effectively improves the problem of display color cast.

[0097] In some embodiments, the hole transport layer of the first sub-pixel and the hole transport layer of the second sub-pixel both include a third film layer. The hole transport layer of the second sub-pixel also includes a fourth film layer. The fourth film layer has a hole mobility lower than that of the third film layer and is located between the third film layer and the light-emitting layer of the second sub-pixel. Furthermore, the second sub-pixel includes multiple sub-pixels emitting light of different wavelengths. Sub-pixels emitting light of a larger wavelength have a smaller thickness of the fourth film layer.

[0098] The fourth film layer with low hole mobility set in the second type of sub-pixels allows holes to enter the light-emitting layer at a slow speed, and also reduces the number of holes entering the light-emitting layer of the second type of sub-pixels per unit time, reduces the size of the carrier recombination zone, and also reduces the efficiency of carrier recombination, that is, reduces the generation of excitons, thereby reducing the brightness life of the second type of sub-pixels.

[0099] When specifically introducing RGB pixels as an example, including Figure 10 and Figure 11 There are two situations.

[0100] In the first case, if Figure 10 As shown, sub-pixels B and G are classified as first-category sub-pixels, and sub-pixel R is classified as second-category sub-pixel. A fourth film layer 422 with low hole mobility is provided only between the third film layer 421 of the R-HTL and the R-EML. Compared to other sub-pixels, the hole mobility of sub-pixel R is reduced, resulting in a smaller number of holes remaining in sub-pixel R per unit time. Furthermore, the holes move more slowly in the R-EML layer, reducing the carrier recombination zone and shortening the brightness lifespan of sub-pixel R.

[0101] In the second case, if Figure 11 As shown, not only the hole transport layer of sub-pixel R is designed, but also the G-HTL layer of sub-pixel G is designed. That is, a fourth film layer 422 with a lower hole mobility is set between the third film layer 421 and the G-EML of sub-pixel G. In this way, the hole migration rate of sub-pixels R and G is reduced, thereby reducing the brightness life of sub-pixels R and G. In order to further reduce the difference in brightness life of all sub-pixels in a pixel, the wavelength of the emitted light is greater than the thickness D of the fourth film layer of sub-pixel G. G4 Less than the thickness D of the fourth film layer of the sub-pixel R R4 Therefore, compared with sub-pixel R, the speed of hole migration slows down, and the life of sub-pixel G is reduced less than that of sub-pixel R, which is more conducive to balancing the difference in brightness life between sub-pixels with different brightness life, and more effectively improving the problem of display color cast.

[0102] In some embodiments, the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer, the hole mobility of the fourth film layer being greater than that of the third film layer, and the fourth film layer being located between the third film layer and the light-emitting layers of the first and second type of sub-pixels, respectively. Furthermore, the thickness of the fourth film layer of the first type of sub-pixel is greater than that of the second type of sub-pixel. Furthermore, the first type of sub-pixel includes multiple sub-pixels emitting light of different wavelengths, and the thickness of the fourth film layer is greater for sub-pixels emitting light of greater wavelengths; and / or the second type of sub-pixel includes multiple sub-pixels emitting light of different wavelengths, and the thickness of the fourth film layer is greater for sub-pixels emitting light of greater wavelengths.

[0103] In the above solution, the design of the hole transport layer corresponding to the first and second sub-pixels not only reduces the difference in brightness lifetime between the two, improving the luminous efficiency of the display panel, but also facilitates production and saves costs. Furthermore, the thin film design of some pixels can further effectively improve the problem of display color cast.

[0104] Specifically, if Figure 12As shown, in an RGB pixel, the first type of sub-pixel includes sub-pixel B, and the second type of sub-pixel includes sub-pixel R and sub-pixel G. The hole transport layer corresponding to the sub-pixels of different colors all includes a third film layer and a fourth film layer with low hole mobility. Furthermore, according to the arrangement of the wavelengths of light emitted by sub-pixels R, G, and B, that is, R<G<B, the fourth film layer corresponding to sub-pixel B, which emits the largest wavelength of light, has the greatest thickness, and the fourth film layer corresponding to sub-pixel R, which emits the smallest wavelength of light, has the smallest thickness. This design adjusts the brightness lifetime of all sub-pixels within the pixel, which helps to balance the brightness lifetime differences between sub-pixels of different colors and effectively improves the problem of display color cast.

[0105] In order to more effectively improve the color cast problem of the display panel while reducing the lifespan or brightness of the display panel, in some embodiments, when the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer, the total thickness of the third film layer and the fourth film layer between different sub-pixels is equal, and the thickness of the fourth film layer of the first type of sub-pixel is greater than the thickness of the fourth film layer of the second type of sub-pixel. More holes enter the first type of sub-pixel at a faster speed, thereby improving the brightness lifespan of the first type of sub-pixel and simplifying the processing of the hole injection layer, facilitating production.

[0106] Specifically, if Figure 12 As shown, the electron transport layers corresponding to the three sub-pixels R, G and B all include a third film layer and a fourth film layer, and the thickness of the third film layer and the total thickness of the fourth film layer corresponding to different sub-pixels are equal, that is, D R3 +D R4 =D G3 +D G4 =D B3 +D B4 , but the thickness of the same film layer is different between sub-pixels. The thickness of the different film layers of the electron transport layer 41 corresponding to sub-pixel R, sub-pixel G and sub-pixel B is related to their own brightness lifespan. The sub-pixel with a larger brightness lifespan has a thicker sub-film layer with a higher mobility, and the corresponding sub-film layer with a lower mobility is thinner, that is, D B3 <D G3 <D R3 , D B4 >D G4 >D R4 , D B3 is the thickness of the third film layer of sub-pixel B, D B4 is the thickness of the fourth film layer of sub-pixel B, D G3 is the thickness of the third film layer of sub-pixel G, D G4 is the thickness of the fourth film layer of sub-pixel G, D R3 is the thickness of the third film layer of sub-pixel R, DR4 is the thickness of the fourth film layer of the sub-pixel R. According to the display requirements of the display panel, it can be calculated as follows:

[0107] D B3 =π / 2*D EBL , D B4 =πN / 2*D EBL +D BML

[0108] Among them, N, K: Hole Only Device (HOD) and Electron Only Device (EOD) modulation coefficients, N is the refractive index, K is the extinction coefficient, both of which change with the material and thickness of the electron transport layer, D EBL : thickness of the electron group monolayer, D BML : The thickness of the blue light-emitting layer. This calculation method is also applicable to the calculation of the thickness of the hole transport layer in the red and green sub-pixels.

[0109] Regarding the design of the hole transport layer, in addition to adding sub-film layers with different hole mobilities, doping can also be used to increase the hole mobility of the first type of sub-pixels or reduce the hole mobility of the second type of sub-pixels. The specific solution is as follows.

[0110] In some embodiments, the hole transport layer of the first type of sub-pixel is made of a base material layer doped with a fourth type of material, the base material layer is made of a third type of material, the hole transport layer of the second type of sub-pixel is made of a third type of material, the base material layer of the first type of sub-pixel is doped with the fourth type of material on the side facing the light-emitting layer, and the hole mobility of the fourth type of material is greater than that of the third type of material. Specifically, Figure 2 As shown, the fourth type of material with high hole mobility is doped only on the B-HTL side of sub-pixel B, which is located on the B-EML. This improves the mobility of holes entering the B-EML layer, increases the size of the carrier recombination zone, and improves the lifespan of sub-pixel B.

[0111] Furthermore, the first type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the sub-pixel with a larger wavelength of emitted light has a greater doping concentration of the fourth type of material. Specifically, Figure 2 As shown, the B-HTL of subpixel B, located on the side of the B-EML, is doped with the fourth material at a first concentration, while the G-HTL of subpixel G, located on the side of the G-EML, is doped with the fourth material at a second concentration. Because the wavelength of light emitted by subpixel B is greater than that of light emitted by subpixel G, the first concentration is greater than the second concentration. This reduces the brightness difference between all subpixels and effectively improves the problem of display color cast.

[0112] In other embodiments, the hole transport layer of the first type of sub-pixel is made of the third type of material, and the hole transport layer of the second type of sub-pixel is made of a substrate layer doped with a fourth type of material. The substrate layer is made of the third type of material, and the fourth type of material is doped on the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer. The hole mobility of the fourth type of material is lower than that of the third type of material. For example, Figure 2 As shown, only the fourth type of material with low hole mobility is doped on one side of the R-HTL of the sub-pixel R located on the R-EML, which reduces the brightness life of the sub-pixel R.

[0113] Furthermore, the second type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the sub-pixel with a larger wavelength of emitted light has a lower doping concentration of the fourth type of material. Specifically, Figure 2 As shown, the fourth material is doped with a first concentration on the side of the R-HTL of the sub-pixel R located at the R-EML, and the fourth material is doped with a second concentration on the side of the G-HTL of the sub-pixel G located at the G-EML. Since the wavelength of the light emitted by the sub-pixel G is greater than the wavelength of the light emitted by the sub-pixel R, the second concentration is less than the first concentration. Except for the sub-pixel B with the smallest brightness lifetime, the brightness lifetime of other sub-pixels is reduced, which more effectively reduces the difference in brightness lifetime between all sub-pixels, thereby effectively improving the problem of display color cast.

[0114] In other embodiments, the material of the hole transport layer of the first type of sub-pixel and the material of the hole transport layer of the second type of sub-pixel are both substrate layers doped with the fourth type of material, the substrate layer is composed of the third type of material, and the fourth type of material is doped on the side of the substrate layer of the first type of sub-pixel and the substrate layer of the second type of sub-pixel facing the light-emitting layer, respectively. The hole mobility of the fourth type of material is greater than the hole mobility of the third type of material, and the doping concentration of the fourth type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration in the substrate layer of the second type of sub-pixel; preferably, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the sub-pixel with a larger wavelength of the emitted light has a larger doping concentration of the fourth type of material; and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the sub-pixel with a larger wavelength of the emitted light has a larger doping concentration of the fourth type of material.

[0115] Specifically, if Figure 2As shown, the R-HTL of subpixel R, located on the R-EML side, is doped with a first concentration of the fourth material; the G-HTL of subpixel G, located on the G-EML side, is doped with a second concentration of the fourth material; and the B-HTL of subpixel B, located on the B-EML side, is doped with a third concentration of the fourth material. Because the wavelength of light emitted by subpixel B is greater than that of subpixel G, and the wavelength of light emitted by subpixel G is greater than that of subpixel R, the third concentration is greater than the second concentration, and the second concentration is greater than the first concentration. This uniformly improves the brightness lifetime of different subpixels, more effectively reducing the difference in brightness lifetime across all subpixels and effectively improving the display color cast.

[0116] It should be understood that the specific types and specific doping concentrations of the second type of material doped with the electron transport layer and the fourth type of material doped with the hole transport layer, as well as the differences in doping between different sub-pixels, can all be designed according to the functional requirements of the display panel, such as doping the electron transport layers of different sub-pixels with different concentrations of the same second type of material, or doping the hole transport layers of different sub-pixels with different types of fourth type materials at the same concentration. The display panel may also include other functional layer structures, such as a hole injection layer between the anode and the hole transport layer, an electron blocking layer between the hole transport layer and the light-emitting layer, an electron injection layer between the cathode and the electron transport layer, and a hole blocking layer between the electron transport layer and the light-emitting layer. The display panel adopts a multi-layer structure to make it easier for the carriers of the anode and cathode to be injected into the organic functional film, thereby improving the luminous efficiency of the display panel.

[0117] In addition to improving the electron transport layer and hole transport layer of the sub-pixel separately, it is also possible to Figure 13 As shown, the design of the electron transport layer and the hole transport layer are improved at the same time. The specific scheme has been described in detail above and will not be repeated here. It should be understood that the scheme of improving both the electron transport layer and the hole transport layer of the sub-pixel is not limited to Figure 13 The solution in , can also be used to improve a certain film layer of the electron transport layer and the hole transport layer. The specific improvement solution will not be described here.

[0118] This embodiment further provides a display device. The display device includes any one of the display panels provided in the first aspect. The display device is any product or component with a display function, such as a mobile phone, tablet computer, television, navigation system, or in-vehicle application.

[0119] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A display panel, characterized in that: include: a plurality of pixel units, each of the pixel units including a plurality of sub-pixels, the plurality of sub-pixels being divided into a first type of sub-pixels and a second type of sub-pixels, each of the sub-pixels including a cathode, an anode, a light-emitting layer and a carrier transport layer located between the cathode and the anode, the carrier transport layer including an electron transport layer located between the cathode and the light-emitting layer, wherein the electron mobility of the electron transport layer of the first type of sub-pixel is less than the mobility of the electron transport layer of the second type of sub-pixel, so as to increase the carrier recombination zone in the light-emitting layer corresponding to the first type of sub-pixel; and The electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer, and the electron transport layer of the first type of sub-pixel further includes a second film layer, the electron mobility of the second film layer is smaller than the electron mobility of the first film layer, and the second film layer is located between the first film layer and the light-emitting layer of the first type of sub-pixel; or The electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer, and the electron transport layer of the second type of sub-pixel further includes a second film layer, the electron mobility of the second film layer is greater than the electron mobility of the first film layer, and the second film layer is located between the first film layer and the light-emitting layer of the second type of sub-pixel; or The electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, the electron mobility of the second film layer is less than the electron mobility of the first film layer, and the second film layer is respectively located between the first film layer and the light-emitting layer of the first type of sub-pixel and the second type of sub-pixel, and the thickness of the second film layer of the first type of sub-pixel is greater than the thickness of the second film layer of the second type of sub-pixel.

2. The display panel according to claim 1, wherein: In the case where both the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel include a first film layer, and the electron transport layer of the first type of sub-pixel further includes a second film layer, and the electron mobility of the second film layer is less than the electron mobility of the first film layer, the first type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the thickness of the second film layer is greater for sub-pixels emitting light of a larger wavelength; In the case where both the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel include a first film layer, and the electron transport layer of the second type of sub-pixel further includes a second film layer, and the electron mobility of the second film layer is greater than the electron mobility of the first film layer, the second type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the thickness of the second film layer is smaller for sub-pixels emitting light of a larger wavelength; When the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, and the electron mobility of the second film layer is less than that of the first film layer, the first type of sub-pixel includes a plurality of sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel with a larger wavelength of emitted light is thicker; and / or the second type of sub-pixel includes a plurality of sub-pixels that emit light of different wavelengths, and the second film layer of the sub-pixel with a larger wavelength of emitted light is thicker.

3. The display panel according to claim 2, wherein: In the case where the electron transport layer of the first type of sub-pixel and the electron transport layer of the second type of sub-pixel both include a first film layer and a second film layer, the total thickness of the first film layer and the second film layer between different sub-pixels is equal, and the thickness of the second film layer of the first type of sub-pixel is greater than the thickness of the second film layer of the second type of sub-pixel.

4. The display panel according to claim 1, wherein: The material of the electron transport layer of the first type of sub-pixel is a substrate layer doped with a second type of material, the substrate layer is composed of the first type of material, the material of the electron transport layer of the second type of sub-pixel is the first type of material, the second type of material is doped on the side of the substrate layer of the first type of sub-pixel facing the light-emitting layer, and the electron mobility of the second type of material is lower than that of the first type of material; or The material of the electron transport layer of the first type of sub-pixel is the first type of material, and the material of the electron transport layer of the second type of sub-pixel is a substrate layer doped with the second type of material, the substrate layer is composed of the first type of material, and the second type of material is doped on the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer, and the electron mobility of the second type of material is greater than the electron mobility of the first type of material; or The material of the electron transport layer of the first type of sub-pixel and the material of the electron transport layer of the second type of sub-pixel are both substrate layers doped with the second type of material, the substrate layer is composed of the first type of material, and the second type of material is doped on the side of the substrate layer of the first type of sub-pixel and the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer respectively, the electron mobility of the second type of material is less than the electron mobility of the first type of material, and the doping concentration of the second type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration in the substrate layer of the second type of sub-pixel.

5. The display panel according to claim 4, wherein: In the case where the material of the electron transport layer of the first-type sub-pixel is a substrate layer doped with a second-type material, the substrate layer is composed of the first-type material, and the material of the electron transport layer of the second-type sub-pixel is the first-type material, the second-type material is doped on the side of the substrate layer of the first-type sub-pixel facing the light-emitting layer, and the electron mobility of the second-type material is lower than that of the first-type material, the first-type sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the sub-pixel emitting light of a larger wavelength has a greater doping concentration of the second-type material; In the case where the material of the electron transport layer of the first-type sub-pixel is the first-type material, and the material of the electron transport layer of the second-type sub-pixel is a substrate layer doped with the second-type material, the substrate layer is composed of the first-type material, the second-type material is doped on the side of the substrate layer of the second-type sub-pixel facing the light-emitting layer, and the electron mobility of the second-type material is greater than the electron mobility of the first-type material, the second-type sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the doping concentration of the second-type material in the sub-pixel emitting light of a larger wavelength is lower; In the case where the material of the electron transport layer of the first type of sub-pixel and the material of the electron transport layer of the first type of sub-pixel are both substrate layers doped with the second type of material, the substrate layers are composed of the first type of material, and the second type of material is doped on the side of the substrate layer of the first type of sub-pixel and the substrate layer of the second type of sub-pixel facing the light-emitting layer, the electron mobility of the second type of material is less than the electron mobility of the first type of material, and the doping concentration of the second type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration in the substrate layer of the second type of sub-pixel, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the sub-pixel with a larger wavelength of the emitted light has a larger doping concentration of the second type of material, and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the sub-pixel with a larger wavelength of the emitted light has a larger doping concentration of the second type of material.

6. The display panel according to any one of claims 1 to 5, characterized in that: The carrier transport layer includes a hole transport layer located between the anode and the light-emitting layer, and the hole mobility of the hole transport layer of the first type of sub-pixel is greater than the hole mobility of the hole transport layer of the second type of sub-pixel.

7. The display panel according to claim 6, wherein: The hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer, and the hole transport layer of the first type of sub-pixel further includes a fourth film layer, the hole mobility of the fourth film layer is greater than the hole mobility of the third film layer, and the fourth film layer is located between the third film layer and the light-emitting layer of the first type of sub-pixel; or The hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer, and the hole transport layer of the second type of sub-pixel further includes a fourth film layer, the hole mobility of the fourth film layer is lower than the hole mobility of the third film layer, and the fourth film layer is located between the third film layer and the light-emitting layer of the second type of sub-pixel; or The hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer. The hole mobility of the fourth film layer is greater than the hole mobility of the third film layer, and the fourth film layer is located between the third film layer and the light-emitting layers of the first type of sub-pixel and the second type of sub-pixel, respectively. The thickness of the fourth film layer of the first type of sub-pixel is greater than the thickness of the fourth film layer of the second type of sub-pixel.

8. The display panel according to claim 7, wherein: In the case where both the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel include a third film layer, and the hole transport layer of the first type of sub-pixel further includes a fourth film layer, and the hole mobility of the fourth film layer is greater than the hole mobility of the third film layer, the first type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the thickness of the fourth film layer is greater for sub-pixels emitting light of a larger wavelength; In the case where both the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel include a third film layer, and the hole transport layer of the second type of sub-pixel further includes a fourth film layer, and the hole mobility of the fourth film layer is less than the hole mobility of the third film layer, the second type of sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the thickness of the fourth film layer is smaller for sub-pixels emitting light of a larger wavelength; When the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer, the hole mobility of the fourth film layer is greater than the hole mobility of the third film layer, and the fourth film layer is respectively located between the third film layer and the light-emitting layers of the first type of sub-pixel and the second type of sub-pixel, and the thickness of the fourth film layer of the first type of sub-pixel is greater than the thickness of the fourth film layer of the second type of sub-pixel, the first type of sub-pixel includes a plurality of sub-pixels that emit light of different wavelengths, and the thickness of the fourth film layer of the sub-pixel with a larger wavelength of the emitted light is larger, and / or the second type of sub-pixel includes a plurality of sub-pixels that emit light of different wavelengths, and the thickness of the fourth film layer of the sub-pixel with a larger wavelength of the emitted light is larger.

9. The display panel according to claim 8, wherein: In the case where the hole transport layer of the first type of sub-pixel and the hole transport layer of the second type of sub-pixel both include a third film layer and a fourth film layer, the total thickness of the third film layer and the fourth film layer between different sub-pixels is equal, and the thickness of the fourth film layer of the first type of sub-pixel is greater than the thickness of the fourth film layer of the second type of sub-pixel.

10. The display panel according to claim 4, wherein: The hole transport layer of the first type of sub-pixel is made of a substrate layer doped with a fourth type of material, the substrate layer being made of a third type of material; the hole transport layer of the second type of sub-pixel is made of a third type of material, the fourth type of material being doped on a side of the substrate layer of the first type of sub-pixel facing the light-emitting layer, and the hole mobility of the fourth type of material being greater than that of the third type of material; or The hole transport layer of the first sub-pixel is made of the third material, and the hole transport layer of the second sub-pixel is made of a substrate layer doped with a fourth material, wherein the substrate layer is made of the third material, and the fourth material is doped on the side of the substrate layer of the second sub-pixel facing the light-emitting layer, and the hole mobility of the fourth material is lower than that of the third material; or The material of the hole transport layer of the first type of sub-pixel and the material of the hole transport layer of the second type of sub-pixel are both substrate layers doped with the fourth type of material, the substrate layer is composed of the third type of material, and the fourth type of material is doped on the side of the substrate layer of the first type of sub-pixel and the side of the substrate layer of the second type of sub-pixel facing the light-emitting layer respectively, the hole mobility of the fourth type of material is greater than the hole mobility of the third type of material, and the doping concentration of the fourth type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration in the substrate layer of the second type of sub-pixel.

11. The display panel according to claim 10, wherein: In the case where the hole transport layer of the first-type sub-pixel is made of a base layer doped with a fourth-type material, the base layer is made of a third-type material, and the hole transport layer of the second-type sub-pixel is made of a third-type material, the fourth-type material is doped on the side of the base layer of the first-type sub-pixel facing the light-emitting layer, and the hole mobility of the fourth-type material is greater than the hole mobility of the third-type material, the first-type sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the sub-pixels emitting light of a larger wavelength have a greater doping concentration of the fourth-type material; In the case where the hole transport layer of the first-type sub-pixel is made of the third-type material, the hole transport layer of the second-type sub-pixel is made of a base material layer doped with a fourth-type material, the base material layer is made of the third-type material, the base material layer of the second-type sub-pixel is doped with the fourth-type material on a side facing the light-emitting layer, and the hole mobility of the fourth-type material is lower than that of the third-type material, the second-type sub-pixel includes a plurality of sub-pixels emitting light of different wavelengths, and the doping concentration of the fourth-type material is lower for sub-pixels emitting light of a larger wavelength. In the case where the material of the hole transport layer of the first type of sub-pixel and the material of the hole transport layer of the second type of sub-pixel are both substrate layers doped with the fourth type of material, the substrate layers are composed of the third type of material, and the fourth type of material is doped on the side of the substrate layer of the first type of sub-pixel and the substrate layer of the second type of sub-pixel facing the light-emitting layer, the hole mobility of the fourth type of material is greater than the hole mobility of the third type of material, and the doping concentration of the fourth type of material in the substrate layer of the first type of sub-pixel is greater than the doping concentration in the substrate layer of the second type of sub-pixel, the first type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the sub-pixel with a larger wavelength of the emitted light has a larger doping concentration of the fourth type of material; and / or the second type of sub-pixel includes multiple sub-pixels that emit light of different wavelengths, and the sub-pixel with a larger wavelength of the emitted light has a larger doping concentration of the fourth type of material.

12. A display device, characterized in that: A display panel comprising any one of claims 1 to 11.

Images