Display panel and display device

Abstract

This application discloses a display panel and a display device, belonging to the field of display technology. The display panel includes a substrate and multiple light-emitting units. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. The light-emitting functional layer includes a red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge generation layer, and a blue light-emitting layer. The red, green, and blue light-emitting layers are connected in series, achieving a superposition effect of luminous efficiency. The orthographic projection of the exciton confinement layer onto the substrate overlaps with the orthographic projection of the pixel definition layer onto the substrate. This allows the exciton confinement layer to reduce edge leakage current at the pixel definition layer, thereby improving the display effect of the display panel.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display panel and a display device. Background Technology

[0002] A display panel is a structure that has image display capabilities.

[0003] A display panel includes a substrate and a plurality of light-emitting units located on the substrate. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. The light-emitting functional layer includes a red light-emitting layer, a green light-emitting layer, a charge-generating layer, and a blue light-emitting layer stacked together. The red, green, and blue light-emitting layers are connected in series to achieve the effect of superimposed luminous efficiency.

[0004] However, the aforementioned display panels are prone to leakage problems, resulting in poor display performance. Summary of the Invention

[0005] This application provides a display panel and a display device, the technical solution of which is as follows:

[0006] According to a first aspect of this application, a display panel is provided, the display panel comprising:

[0007] Substrate;

[0008] A pixel definition layer, located on the substrate, the pixel definition layer including a plurality of first openings;

[0009] Multiple light-emitting units are located on the substrate. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. Each light-emitting unit corresponds to a plurality of first openings, and the orthographic projection of the light-emitting unit on the substrate overlaps with the orthographic projection of the corresponding first opening on the substrate.

[0010] The light-emitting functional layer includes a stacked red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge-generating layer, and a blue light-emitting layer. The exciton confinement layer is located between the red and green light-emitting layers. The orthographic projection of the exciton confinement layer on the substrate overlaps with the orthographic projection of the pixel definition layer on the substrate. The exciton confinement layer includes a second opening. The orthographic projection of the second opening of the exciton confinement layer in the light-emitting unit on the substrate overlaps with the orthographic projection of the corresponding first opening on the substrate. Optionally, the red and green light-emitting layers are located on the side of the charge-generating layer closer to the substrate, and the blue light-emitting layer is located on the side of the charge-generating layer away from the substrate. The light emission direction of the light-emitting unit is parallel to the direction of the substrate toward the light-emitting unit.

[0011] Optionally, the charge generation layer includes a first charge generation layer and a second charge generation layer. The first charge generation layer is located on the side of the green light-emitting layer away from the substrate, and the second charge generation layer is located on the side of the first charge generation layer away from the green light-emitting layer. The type of majority carriers in the exciton confinement layer is the same as the type of majority carriers in the first charge generation layer.

[0012] Optionally, the exciton confinement layer includes a first exciton confinement layer and a second exciton confinement layer, wherein the first exciton confinement layer is located on the side of the second exciton confinement layer closer to the red light-emitting layer, and the second exciton confinement layer is located on the side of the first confinement layer closer to the green light-emitting layer;

[0013] The difference between the highest occupied molecular orbital energy level of the first exciton confinement layer and the highest occupied molecular orbital energy level of the red emitting layer is within a first preset range, and the difference between the highest occupied molecular orbital energy level of the second exciton confinement layer and the highest occupied molecular orbital energy level of the green emitting layer is within a second preset range.

[0014] Optionally, the material of the green light-emitting layer includes a first light-emitting host material and a first light-emitting guest material, and the material of the exciton confinement layer includes the first light-emitting host material;

[0015] Alternatively, the material of the exciton confinement layer may include a hole transport material.

[0016] Optionally, the first light-emitting host material includes a P-type light-emitting host material, or the first light-emitting host material includes both a P-type light-emitting host material and an N-type light-emitting host material.

[0017] Optionally, the blue light-emitting layer is located on the side of the charge-generating layer closer to the substrate, and the red and green light-emitting layers are located on the side of the charge-generating layer away from the substrate. The light emission direction of the light-emitting unit is parallel to the direction of the substrate toward the light-emitting unit.

[0018] Optionally, the thickness of the exciton confinement layer ranges from 15 angstroms to 20 angstroms.

[0019] Optionally, the surface of the exciton confinement layer near the green emitting layer and the surface of the exciton confinement layer near the red emitting layer include a plasma surface treatment layer or a doping treatment layer.

[0020] On the other hand, a display device is provided, the display device including a housing and any of the above-described display panels, the display panels being located in the housing.

[0021] The beneficial effects of the technical solutions provided in this application include at least the following:

[0022] A display panel including a substrate and multiple light-emitting units is provided. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. The light-emitting functional layer includes a red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge generation layer, and a blue light-emitting layer. The red, green, and blue light-emitting layers are connected in series, achieving a superposition effect of luminous efficiency. The orthographic projection of the exciton confinement layer onto the substrate overlaps with the orthographic projection of the pixel definition layer onto the substrate. This allows the exciton confinement layer to reduce edge leakage current at the pixel definition layer, thereby improving the display effect of the display panel. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a display panel;

[0025] Figure 2 This is a schematic diagram of the structure of a display panel provided in an embodiment of this application;

[0026] Figure 3 yes Figure 2 Enlarged view of some structures in the provided display panel;

[0027] Figure 4 This is a schematic diagram of another display panel structure provided in an embodiment of this application;

[0028] Figure 5 This is a schematic diagram of another display panel structure provided in an embodiment of this application;

[0029] Figure 6 This is a schematic diagram of another display panel structure provided in an embodiment of this application;

[0030] Figure 7 This is a schematic diagram of another display panel structure provided in an embodiment of this application;

[0031] Figure 8 This is a schematic diagram of another display panel structure provided in an embodiment of this application;

[0032] Figure 9 This is the emission spectrum of this application and related technologies;

[0033] Figure 10This is a graph showing the relationship between the driving voltage and current density of this application and related technologies;

[0034] Figure 11 This is a schematic diagram of another display panel structure provided in an embodiment of this application.

[0035] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0037] Figure 1 This is a schematic diagram of a display panel structure. Please refer to it. Figure 1 The display panel 10 includes a substrate 11 and a plurality of light-emitting units 12 located on the substrate 11. Each light-emitting unit 12 includes a first electrode 121, a light-emitting functional layer 122, and a second electrode 123. The light-emitting functional layer 122 includes a red light-emitting layer A1, a green light-emitting layer A2, a charge-generating layer A3, and a blue light-emitting layer A4, all stacked together. The red, green, and blue light-emitting layers A1 and A2 are connected in series, achieving a cumulative luminous efficiency. However, leakage current is prone to occur at the edges of the light-emitting units 12, resulting in a poor display effect for the display panel 10.

[0038] This application provides a display panel, please refer to... Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of a display panel provided in an embodiment of this application. Figure 3 yes Figure 2 An enlarged view of one of the light-emitting units in the provided display panel 20, which includes a substrate 21.

[0039] Pixel definition layer 23 is located on substrate 21 and includes a plurality of first openings K1.

[0040] Multiple light-emitting units 22 are located on a substrate 21. Each light-emitting unit 22 includes a first electrode 221, a light-emitting functional layer 222, and a second electrode 223. Each light-emitting unit 22 corresponds to a multiple first openings K1, and the orthographic projection of the light-emitting unit 22 on the substrate 21 overlaps with the orthographic projection of the corresponding first opening K1 on the substrate 21.

[0041] The light-emitting functional layer 222 includes a red light-emitting layer A1, an exciton confinement layer A5, a green light-emitting layer A2, a charge generation layer A3, and a blue light-emitting layer A4, all stacked together. The exciton confinement layer A5 is located between the red light-emitting layer A1 and the green light-emitting layer A2. The orthographic projection of the exciton confinement layer A5 onto the substrate 21 overlaps with the orthographic projection of the pixel definition layer 23 onto the substrate 21. The exciton confinement layer A5 includes a second opening, and the orthographic projection of the second opening K2 of the exciton confinement layer A5 in the light-emitting unit 22 onto the substrate 21 overlaps with the orthographic projection of the corresponding first opening K1 onto the substrate 21. It should be noted that... Figure 2 Only three light-emitting units 22 are shown as an example, but the number of light-emitting units 22 is not limited in the embodiments of this application.

[0042] In summary, this application provides a display panel including a substrate and multiple light-emitting units. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. The light-emitting functional layer includes a red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge generation layer, and a blue light-emitting layer. The red, green, and blue light-emitting layers are connected in series, achieving a superposition effect of luminous efficiency. The orthographic projection of the exciton confinement layer onto the substrate overlaps with the orthographic projection of the pixel definition layer onto the substrate. This allows the exciton confinement layer to reduce edge leakage current at the pixel definition layer, thereby improving the display effect of the display panel.

[0043] The display panel provided in this application embodiment can be an Organic Light Emitting Diode (OLED) display panel. For example, the display panel provided in this application embodiment can be a silicon-based OLED display panel. The silicon-based OLED display panel can use a silicon substrate as a base, allowing some circuit structures (such as driver integrated circuits and pixel circuits) to be integrated on the silicon substrate, thereby improving the integration density of the display panel. In addition, the silicon substrate has excellent thermal stability, mechanical strength, and chemical stability, which can effectively improve the stability and reliability of the silicon-based OLED display panel. Simultaneously, the silicon substrate also has good thermal conductivity, which can effectively reduce the temperature of the silicon-based OLED display panel and improve its lifespan. Compared to conventional OLED display panels, silicon-based OLED display panels can also have a denser pixel arrangement, thus achieving higher resolution and detail. These advantages of silicon-based OLED display panels are beneficial for their application in the display fields of Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR).

[0044] Furthermore, the display panel provided in this application embodiment can be a tandem OLED display panel, that is, multiple light-emitting layers are electrically connected in series through an intermediate layer, wherein the intermediate layer may include a charge-generating layer. The multiple light-emitting layers connected in series can emit light together, thereby improving the brightness, luminous efficiency, and lifespan of the tandem OLED display panel. Additionally, the multiple light-emitting layers connected in series can emit light at a lower driving voltage, thus achieving lower power consumption. This application embodiment provides a display panel with a red, green, and blue light-emitting layer connected in series as an example, but the number of light-emitting layers is not limited.

[0045] In this application embodiment, the positions of the red, green, and blue light-emitting layers can vary. In one exemplary embodiment, please refer to... Figure 2 and Figure 3 The red light-emitting layer A1 and the green light-emitting layer A2 are located on the side of the charge-generating layer A3 closer to the substrate 21, while the blue light-emitting layer A4 is located on the side of the charge-generating layer A3 away from the substrate 21. The light emission direction X of the light-emitting unit 22 is parallel to the direction from the substrate 21 toward the light-emitting unit 22. The first electrode 221 and the second electrode 223 cooperate to drive the light-emitting functional layer 222 to emit light. The first electrode 221 can be an anode, and the second electrode 223 can be a cathode. The red light-emitting layer A1, the green light-emitting layer A2, and the blue light-emitting layer A4 can be organic light-emitting layers. The red light-emitting layer A1, the green light-emitting layer A2, and the blue light-emitting layer A4 are connected in series to achieve the effect of emitting white light and to achieve the effect of superimposed luminous efficiency.

[0046] Alternatively, the positions of the red emitting layer A1, green emitting layer A2, and blue emitting layer A4 may also exist in another case; please refer to [reference needed]. Figure 4 , Figure 4 This is a schematic diagram of another display panel structure provided in an embodiment of this application. The blue light-emitting layer A4 is located on the side of the charge-generating layer A3 closest to the substrate 21, while the red light-emitting layer A1 and the green light-emitting layer A2 are located on the side of the charge-generating layer A3 furthest from the substrate 21. The light emission direction X of the light-emitting unit 22 is parallel to the direction from the substrate 21 toward the light-emitting unit 22.

[0047] The display panel provided in this application embodiment may also include other structures; please refer to [reference needed]. Figure 5 , Figure 5This is a schematic diagram of another display panel structure provided in an embodiment of this application. The display panel 20 includes: a substrate 21; a plurality of light-emitting units 22 located on the substrate 21; each light-emitting unit 22 including a first electrode 221, a light-emitting functional layer 222, and a second electrode 223; the light-emitting functional layer 222 including a red light-emitting layer A1, an exciton confinement layer A5, a green light-emitting layer A2, a charge generation layer A3, and a blue light-emitting layer A4 stacked thereon; the exciton confinement layer A5 is located between the red light-emitting layer A1 and the green light-emitting layer A2; the exciton confinement layer A5 includes a portion located in the display area near the edge of the pixel definition layer 23; the display area may include the area corresponding to the first opening K1 of the pixel definition layer 23.

[0048] Between the first electrode 221 and the red light-emitting layer A1, the display panel 20 may further include a hole injection layer HIL, a hole transport layer HTL, and a first electron blocking layer EBL1, which are sequentially stacked along the direction away from the substrate 21. The charge generation layer A3 may further include a first electron transport layer ETL1, a second charge generation layer A32, a first charge generation layer A31, a buffer layer F, and a second electron blocking layer EBL2, which are sequentially stacked along the direction away from the substrate 21. Between the blue light-emitting layer A4 and the second electrode 224, the display panel 20 may further include a second electron transport layer ETL2, a third electron transport layer ETL3, and an electron injection layer EIL, which are sequentially stacked along the direction away from the substrate 21.

[0049] The hole injection layer (HIL) has an energy level that matches the work function of the first electrode 221, allowing it to inject holes from the first electrode 221 into the hole transport layer (HTL). The hole transport layer (HTL) then transports holes from the first electrode 221 to the light-emitting layer. The electron blocking layer (EBL) blocks electrons from the second electrode 223 at the light-emitting layer in the display panel 20, increasing the electron concentration there and thus improving the probability of electron-hole combination, thereby increasing the device's luminous efficiency. The electron transport layer (ETL) transports electrons from the second electrode 223 to the light-emitting layer. The energy level of the electron injection layer (EIL) matches the work function of the second electrode 223, allowing it to inject electrons from the second electrode 223 into the electron transport layer (ETL). Electrons in the second electrode 223 move towards the light-emitting layer in the display panel 20 under the drive of an applied driving voltage. Then, they combine with holes from the first electrode 221 in the light-emitting layer of the display panel 20 to form excitons, thereby enabling the light-emitting layer to emit light.

[0050] This application provides another display panel including a pixel definition layer and a partition structure. Please refer to... Figure 6 , Figure 6 This is a schematic diagram of another display panel structure provided in an embodiment of this application. The display panel 20 further includes a pixel definition layer 23 and a partition structure 24. The pixel definition layer 23 is located on the substrate 21 and can be used to define multiple light-emitting units 22. The partition structure 24 is located on the side of the pixel definition layer 23 away from the substrate 21. Please refer to [reference needed]. Figure 4 In region Q2, which is the area where one side of the pixel definition layer 23 is located, the charge generation layer A3 can be disconnected at the partition structure 24, thereby reducing lateral crosstalk between adjacent light-emitting units 22. Alternatively, the partition structure 24 can be an independent structure from the pixel definition layer 23. The partition structure 24 can also be formed by indenting one side of the pixel definition layer 23 inward by a specified distance L, thus eliminating the need for a separate partition structure 24 and achieving the disconnection of the charge generation layer A3, thereby simplifying the structure.

[0051] In addition, please refer to Figure 6 In region Q3, which is the area on the other side of pixel definition layer 23 without the partition structure 24, there is a leakage path Y between the red emitting layer A1 and the green emitting layer A2. This leakage current flows from the side of charge generation layer A3 to above it, generating stray edge light in region Q3. This stray edge light can be yellow. The height difference on the other side of pixel definition layer 23 without the partition structure 24 allows charge generation layer A3 to have a step, effectively breaking the electric field and reducing stray edge light in region Q3, thus improving the display effect of display panel 20. Furthermore, the height difference on the other side of pixel definition layer 23 without the partition structure 24 also brings the distance between charge generation layer A3 and exciton confinement layer A5 in region Q3 closer.

[0052] Optionally, embodiments of this application can reduce leakage current by controlling the type of majority carriers in the exciton confinement layer. Please refer to [reference needed]. Figure 7 , Figure 7 This is a schematic diagram of another display panel structure provided in an embodiment of this application. The charge generation layer A3 may include a first charge generation layer A31 and a second charge generation layer A32. The first charge generation layer A31 may be located on the side of the green light-emitting layer A2 away from the substrate 21, and the second charge generation layer A32 may be located on the side of the first charge generation layer A31 away from the green light-emitting layer A2. The majority carrier type of the exciton confinement layer A5 may be the same as that of the majority carrier type of the first charge generation layer A31, so that the exciton confinement layer A5 and the first charge generation layer A31 can form a repulsive force due to the same majority carrier type. Please refer to... Figure 6 and Figure 7 , Figure 6In the provided display panel, the charge generation layer A3 may also include a first charge generation layer A31 and a second charge generation layer A32, and the majority carrier type of the exciton confinement layer A5 is the same as that of the majority carrier type of the first charge generation layer A31. Since the charge generation layer A3 and the exciton confinement layer A5 in the Q3 region are close to each other, Figure 6 The repulsive force between the exciton confinement layer A5 and the first charge layer is more pronounced, which effectively reduces the current in the leakage path Y. This means the exciton confinement layer A5 can further reduce edge leakage of the display panel, thereby reducing stray light in the Q3 region and improving the display effect of the display panel 20. Furthermore, because the exciton confinement layer A5 reduces the current in the leakage path Y, more excitons can be confined by the exciton confinement layer A5 to the display area, preventing exciton loss from affecting the light emission brightness of the display panel 20.

[0053] For example, the majority carriers of the first charge generation layer A31 can be electrons, meaning the material of the first charge generation layer A31 can be N-type; the majority carriers of the second charge generation layer A32 can be holes, meaning the material of the second charge generation layer A32 can be P-type; and the electrical properties of the exciton confinement layer A5 are the same as those of the majority carriers of the first charge generation layer A31, meaning the material of the exciton confinement layer A5 can be N-type. The majority carrier types of the first charge generation layer A31, the second charge generation layer A32, and the exciton confinement layer A5 can be adjusted by controlling the type and concentration of the doping material, but this embodiment does not limit this.

[0054] Optionally, the exciton confinement layer may have structures other than the single-layer structure described above. In one exemplary embodiment, the exciton confinement layer may include a first exciton confinement layer and a second exciton confinement layer. Please refer to... Figure 8 , Figure 8 This is a schematic diagram of another display panel structure provided in an embodiment of this application. The display panel 20 includes: a substrate 21; a plurality of light-emitting units 22 located on the substrate 21; each light-emitting unit 22 includes a first electrode 221, a light-emitting functional layer 222, and a second electrode 223; the light-emitting functional layer 222 includes a red light-emitting layer A1, an exciton confinement layer A5, a green light-emitting layer A2, a charge generation layer A3, and a blue light-emitting layer A4 stacked together; the exciton confinement layer A5 is located between the red light-emitting layer A1 and the green light-emitting layer A2.

[0055] The exciton confinement layer A5 includes a first exciton confinement layer A51 and a second exciton confinement layer A52. The first exciton confinement layer A51 is located on the side of the second exciton confinement layer A52 closer to the red emitting layer A1, and the second exciton confinement layer A52 is located on the side of the first confinement layer A51 closer to the green emitting layer A2. The difference between the highest occupied molecular orbital (HOMO) energy level of the first exciton confinement layer A51 and the highest occupied molecular orbital energy level of the red emitting layer A1 is within a first preset range, and the difference between the highest occupied molecular orbital energy level of the second exciton confinement layer A52 and the highest occupied molecular orbital energy level of the green emitting layer A2 is within a second preset range.

[0056] The first preset range and the second preset range can be different or the same. For example, the first preset range and the second preset range are the same and both are less than 0.5 electron volts (eV). This can make the highest occupied molecular orbital energy level of the first exciton confinement layer A51 close to the highest occupied molecular orbital energy level of the red light-emitting layer A1, and the highest occupied molecular orbital energy level of the second exciton confinement layer A52 close to the highest occupied molecular orbital energy level of the green light-emitting layer A2. Thus, the first exciton confinement layer A51 can reduce the transmission barrier with the red light-emitting layer A1, and the second exciton confinement layer A52 can reduce the transmission barrier with the green light-emitting layer A2, thereby improving the luminous efficiency of the display panel 20.

[0057] Optionally, the material of the green luminescent layer A2 includes a first luminescent host material and a first luminescent guest material, and the material of the exciton confinement layer A5 includes the first luminescent host material. The first luminescent host material can serve as a medium for the first luminescent guest material. The first luminescent host material can include luminescent materials with hole transport or electron transport functions, and the first luminescent guest material can include organic fluorescent or phosphorescent materials. The doping ratio of the first luminescent guest material can be adjusted according to different material properties to enhance the lifetime and efficiency of the first luminescent host material. By including the first luminescent host material in the material of the exciton confinement layer A5, the highest occupied molecular orbital energy level of the exciton confinement layer A5 is close to that of the highest occupied molecular orbital energy level of the green luminescent layer A2, thereby reducing the transport barrier between the exciton confinement layer A5 and the green luminescent layer A2.

[0058] Furthermore, since the emission wavelength of red light-emitting materials is longer than that of green and blue light-emitting materials, according to Planck's equation, the energy required to excite red light-emitting materials is less than that required to excite green and blue light-emitting materials. Therefore, the current density required to activate red light-emitting materials is also less than that required to activate green and blue light-emitting materials, which can cause low grayscale display abnormalities in the display panel. By including the first light-emitting host material in the exciton confinement layer A5, the brightness difference between the red light-emitting layer A1 and the green light-emitting layer A2 can be reduced, thereby avoiding low grayscale display abnormalities in the display panel 20.

[0059] Optionally, if the first light-emitting host material includes a P-type light-emitting host material, then the exciton confinement layer A5 also includes a P-type light-emitting host material. Since the highest occupied molecular orbital energy level of the P-type light-emitting host material is close to that of the light-emitting host materials in the red light-emitting layer A1 and the green light-emitting layer A2, the transport barrier between the red light-emitting layer A1 and the green light-emitting layer A2 can be reduced, thereby improving the luminous efficiency of the display panel 20. The P-type light-emitting host material also has a higher lowest unoccupied molecular orbital (LUMO) energy level, making it less likely to accept electrons. Therefore, the exciton confinement layer A5 can reduce electron transport to the red light-emitting layer A1, with more electrons located in the green light-emitting layer A2. This allows the exciton confinement layer A5 to increase the number of excitons formed in the green light-emitting layer A2, improving the luminous efficiency of the green light-emitting layer A2. This reduces the brightness difference between the red light-emitting layer A1 and the green light-emitting layer A2, thereby avoiding low grayscale display abnormalities in the display panel 20.

[0060] Furthermore, the first light-emitting host material may include both P-type and N-type light-emitting host materials. Therefore, the exciton confinement layer A5 may also include both P-type and N-type light-emitting host materials. This allows the exciton confinement layer A5 to reduce the transmission barrier between the red light-emitting layer A1 and the green light-emitting layer A2, thereby improving the luminous efficiency of the display panel 20. Simultaneously, the exciton confinement layer A5 can reduce electron transport to the red light-emitting layer A1, thereby reducing the brightness difference between the red and green light-emitting layers A1 and thus preventing low-grayscale display abnormalities in the display panel 20. This application embodiment does not limit the ratio of P-type and N-type light-emitting host materials. The content of P-type and N-type light-emitting host materials in the exciton confinement layer A5 can be close; for example, the ratio of P-type and N-type light-emitting host materials can be 1:1.

[0061] In the above scheme, the material of the exciton confinement layer A5 is a light-emitting host material. In addition, another scheme exists in this application embodiment where the material of the exciton confinement layer A5 includes a hole transport material. This can increase the transport rate of holes from the first electrode 221 in the exciton confinement layer A5, allowing holes to be transported to the green light-emitting layer A2 more quickly. This results in more holes forming excitons with electrons in the green light-emitting layer A2, thereby improving the luminous efficiency of the green light-emitting layer A2 and reducing the brightness difference between the red light-emitting layer A1 and the green light-emitting layer A2.

[0062] For example, the applicant has compared the photoelectric performance of related technologies with that of this application. The display panel provided by the related technologies does not include an exciton confinement layer, while the display panel provided by this application includes an exciton confinement layer, the material of which comprises a P-type luminescent host material. The applicant has provided a comparison of the relationship between wavelength and luminous intensity between this application and related technologies; please refer to [link / reference]. Figure 9 , Figure 9 This is the emission spectrum of this application and related technologies. Figure 9 The horizontal axis represents wavelength, with units in nanometers. Figure 9 The vertical axis represents the relative luminous intensity, which can be obtained by normalizing the luminous intensity. The relative luminous intensity can reflect the relative magnitude of the luminous intensity of the display panel provided in this application and the display panel provided in related technologies. Figure 9 The current density of the display panel is 40 mA / cm². 2 The test was conducted during operation because the current density of the display panel during actual operation can reach 40mA / cm². 2 In particular, within the wavelength range of 480 nm to 580 nm, the luminous intensity of the display panel provided in this application is greater than that of the display panel provided in related technologies. Therefore, it can be proven that the exciton confinement layer can improve the luminous intensity of the display panel.

[0063] The applicant also provided comparative data on other photoelectric properties of this application and related technologies. Please refer to Table 1, which is a comparison table of photoelectric properties of this application and related technologies.

[0064] Table 1 Comparison of photoelectric performance of this application and related technologies

[0065]

[0066] Table 1 provides comparative data on the light emission brightness of the present application and related technologies. The light emission brightness of the display panel provided in this application is significantly improved compared to that of the display panels provided by related technologies, thus proving that the exciton confinement layer is beneficial to improving the light emission brightness of the display panel. In addition, Table 1 provides comparative data on chromaticity of the present application and related technologies in the first and second directions, where the first and second directions can be parallel to the substrate, and the first direction is perpendicular to the second direction. The chromaticity difference of the display panel provided in this application is small compared to that of the display panels provided by related technologies, thus proving that the exciton confinement layer has a small impact on the chromaticity of the display panel. Table 1 also provides comparative data on the luminous efficiency of the present application and related technologies. The luminous efficiency of the display panel provided in this application is significantly improved compared to that of the display panels provided by related technologies. Calculations show that the luminous efficiency of the display panel provided in this application can be increased by 10% compared to that of the display panels provided by related technologies, thus proving that the exciton confinement layer is beneficial to improving the luminous efficiency of the display panel.

[0067] The applicant also provided a comparison of the relationship between the driving voltage and current density of this application and related technologies; please refer to it. Figure 10 , Figure 10 This is a graph showing the relationship between the driving voltage and current density of this application and related technologies. Figure 10 The horizontal axis represents voltage, measured in volts (V), which reflects the magnitude of the driving voltage of the display panel provided in this application and display panels provided in related technologies. Figure 10 The vertical axis represents the current density, with units of mA / cm². 2 The current density on the display panel is 40 mA / cm². 2 At the same time, the driving voltage of the display panel provided in this application 1 and this application 2 is lower than the driving voltage of the display panel provided in the related technology. Specifically, the driving voltage of the display panel provided in this application 1 is reduced by 1.6V. Therefore, it can be proved that the exciton confinement layer can reduce the driving voltage of the display panel, thereby reducing the power consumption of the display panel.

[0068] Optionally, embodiments of this application can further prevent exciton quenching by increasing the thickness of the exciton confinement layer, thereby avoiding the impact of exciton quenching on the brightness of the display panel and thus reducing the driving voltage. The thickness range of the exciton confinement layer is 15 angstroms to 20 angstroms. For example, the thickness of the exciton confinement layer can be 15 angstroms or 20 angstroms. Figure 10 The relationship between driving voltage and current density of exciton confinement layers with different thicknesses was also compared. The exciton confinement layer used in the display panel provided in application 1 has a thickness of 15 angstroms, while the exciton confinement layer used in the display panel provided in application 2 has a thickness of 20 angstroms. Figure 10It can be seen that the driving voltage of the display panel provided in this application 2 is lower than that of the display panel provided in this application 1. Therefore, it can be proven that by increasing the thickness of the exciton confinement layer, the driving voltage of the display panel can be reduced, thereby reducing the power consumption of the display panel.

[0069] Optionally, the surfaces of the exciton confinement layer near the green emitting layer and near the red emitting layer include a plasma surface treatment layer or a doping treatment layer. Please refer to [reference needed]. Figure 11 , Figure 11 This is a schematic diagram of another display panel structure provided in an embodiment of this application. The display panel 20 includes: a substrate 21; a plurality of light-emitting units 22 located on the substrate 21; each light-emitting unit 22 includes a first electrode 221, a light-emitting functional layer 222, and a second electrode 223; the light-emitting functional layer 222 includes a red light-emitting layer A1, an exciton confinement layer A5, a green light-emitting layer A2, a charge generation layer A3, and a blue light-emitting layer A4 disposed along the stack; the exciton confinement layer A5 is located between the red light-emitting layer A1 and the green light-emitting layer A2.

[0070] Figure 11 In the illustrated display panel, the surface of the exciton confinement layer A5 near the green emitting layer A2 includes a doping layer A54, and the surface of the exciton confinement layer A5 near the red emitting layer A1 includes a plasma surface treatment layer A53. The positions of the plasma surface treatment layer A53 and the doping layer A54 can also be different. For example, both the surface of the exciton confinement layer A5 near the green emitting layer A2 and the surface of the exciton confinement layer A5 near the red emitting layer A1 may include the plasma surface treatment layer A53, or both the surface of the exciton confinement layer A5 near the green emitting layer A2 and the surface of the exciton confinement layer A5 near the red emitting layer A1 may include the doping layer A54. This embodiment of the application does not limit this to any particular configuration.

[0071] The plasma surface treatment layer A53 can be obtained by plasma surface treatment of the exciton confinement layer A5. The ions and free radicals generated by the plasma can chemically and physically react with impurities and contaminants on the surface of the exciton confinement layer A5, forming volatile substances or being blown away, thus effectively cleaning the surface of the exciton confinement layer A5. The high-energy ions and free radicals generated by the plasma can also change the chemical composition and structure of the exciton confinement layer A5, thereby increasing its work function. The work function is the minimum energy required to move an electron from the interior of a solid to its surface. A higher work function makes it less likely for electrons to leave the solid, thus increasing the hole transport rate of the exciton confinement layer A5. For example, the plasma surface treatment layer A53 can be obtained by treating the surface of the exciton confinement layer A5 with oxygen plasma.

[0072] The doped layer A54 can be obtained by doping the exciton confinement layer A5. Doping increases the carrier concentration in the exciton confinement layer A5, thereby improving hole mobility and ultimately increasing the hole transport rate of the exciton confinement layer A5. Specifically, the doped layer A54 can be doped using thermal diffusion or ion implantation. Thermal diffusion uses high temperatures to drive impurities into the structure of the doped layer A54 material; ion implantation uses high-temperature ion bombardment of impurities, causing atomic-level high-energy collisions between the impurities and the material of the doped layer A54, thus allowing the impurities to enter the structure of the doped layer A54 material. For example, the doped layer A54 can be obtained by doping the exciton confinement layer A5 with strontium fluoride.

[0073] In summary, this application provides a display panel including a substrate and multiple light-emitting units. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. The light-emitting functional layer includes a red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge generation layer, and a blue light-emitting layer. The red, green, and blue light-emitting layers are connected in series, achieving a superposition effect of luminous efficiency. The orthographic projection of the exciton confinement layer onto the substrate overlaps with the orthographic projection of the pixel definition layer onto the substrate. This allows the exciton confinement layer to reduce leakage current at the edge of the pixel definition layer in the display panel, thereby improving the display effect.

[0074] On the other hand, this application also provides a display device, which includes a housing and any of the display panels provided in the above embodiments, wherein the display panel may be located within the housing. This display device can be various devices including display functions, such as monitors, televisions, vertical advertising displays, digital signage devices, mobile phones, and various smart wearable devices.

[0075] Since the display device includes the display panel provided in the above embodiments, the display device can also have a similar effect, that is, it can improve the brightness and lifespan of the display device.

[0076] In summary, this application provides a display panel including a substrate and multiple light-emitting units. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. The light-emitting functional layer includes a red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge generation layer, and a blue light-emitting layer. The red, green, and blue light-emitting layers are connected in series, achieving a superposition effect of luminous efficiency. The orthographic projection of the exciton confinement layer onto the substrate overlaps with the orthographic projection of the pixel definition layer onto the substrate. This allows the exciton confinement layer to reduce edge leakage current at the pixel definition layer, thereby improving the display effect of the display panel.

[0077] It should be noted that the dimensions of layers and regions may be exaggerated in the accompanying drawings for clarity. Furthermore, it is understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element, or there may be intermediate layers. Additionally, it is understood that when an element or layer is referred to as being "below" another element or layer, it can be directly below the other element, or there may be more than one intermediate layer or element. Furthermore, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it can be the only layer between the two layers or two elements, or there may be more than one intermediate layer or element. Similar reference numerals throughout indicate similar elements.

[0078] In this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0079] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A display panel, characterized in that, The display panel includes: Substrate; A pixel definition layer, located on the substrate, the pixel definition layer including a plurality of first openings; Multiple light-emitting units are located on the substrate. Each light-emitting unit includes a first electrode, a light-emitting functional layer, and a second electrode. Each light-emitting unit corresponds to a plurality of first openings, and the orthographic projection of the light-emitting unit on the substrate overlaps with the orthographic projection of the corresponding first opening on the substrate. The light-emitting functional layer includes a stacked red light-emitting layer, an exciton confinement layer, a green light-emitting layer, a charge generation layer, and a blue light-emitting layer. The exciton confinement layer is located between the red light-emitting layer and the green light-emitting layer. The orthographic projection of the exciton confinement layer on the substrate overlaps with the orthographic projection of the pixel definition layer on the substrate. The exciton confinement layer includes a second opening. The orthographic projection of the second opening of the exciton confinement layer in the light-emitting unit on the substrate overlaps with the orthographic projection of the corresponding first opening on the substrate. The surfaces of the exciton confinement layer near the green emitting layer and near the red emitting layer include a plasma surface treatment layer or a doping treatment layer.

2. The display panel according to claim 1, characterized in that, The red and green light-emitting layers are located on the side of the charge-generating layer closer to the substrate, and the blue light-emitting layer is located on the side of the charge-generating layer away from the substrate. The light emission direction of the light-emitting unit is parallel to the direction of the substrate toward the light-emitting unit.

3. The display panel according to claim 2, characterized in that, The charge generation layer includes a first charge generation layer and a second charge generation layer. The first charge generation layer is located on the side of the green light-emitting layer away from the substrate, and the second charge generation layer is located on the side of the first charge generation layer away from the green light-emitting layer. The majority carriers of the exciton confinement layer are of the same type as the majority carriers of the first charge generation layer.

4. The display panel according to claim 1, characterized in that, The exciton confinement layer includes a first exciton confinement layer and a second exciton confinement layer. The first exciton confinement layer is located on the side of the second exciton confinement layer closer to the red light-emitting layer, and the second exciton confinement layer is located on the side of the first exciton confinement layer closer to the green light-emitting layer. The difference between the highest occupied molecular orbital energy level of the first exciton confinement layer and the highest occupied molecular orbital energy level of the red emitting layer is within a first preset range, and the difference between the highest occupied molecular orbital energy level of the second exciton confinement layer and the highest occupied molecular orbital energy level of the green emitting layer is within a second preset range.

5. The display panel according to claim 2, characterized in that, The material of the green light-emitting layer includes a first light-emitting host material and a first light-emitting object material, and the material of the exciton confinement layer includes the first light-emitting host material; Alternatively, the material of the exciton confinement layer may include a hole transport material.

6. The display panel according to claim 5, characterized in that, The first light-emitting host material includes a P-type light-emitting host material, or the first light-emitting host material includes both a P-type light-emitting host material and an N-type light-emitting host material.

7. The display panel according to claim 1, characterized in that, The blue light-emitting layer is located on the side of the charge-generating layer closer to the substrate, and the red and green light-emitting layers are located on the side of the charge-generating layer away from the substrate. The light emission direction of the light-emitting unit is parallel to the direction of the substrate toward the light-emitting unit.

8. The display panel according to any one of claims 1 to 7, characterized in that, The thickness of the exciton confinement layer ranges from 15 angstroms to 20 angstroms.

9. A display device, characterized in that, The display device includes a housing and a display panel as described in any one of claims 1 to 8, wherein the display panel is located within the housing.

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