Display panel and display device
By introducing a charge accumulation layer into the target color subpixels of the OLED display panel, the color shift phenomenon was solved, capacitance uniformity and brightness uniformity were achieved, and the display effect was optimized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING VISIONOX TECHNOLOGY CO LTD
- Filing Date
- 2022-12-07
- Publication Date
- 2026-06-19
AI Technical Summary
OLED display panels exhibit color shift when switching images, affecting display quality.
A charge accumulation layer corresponding to the charge transport layer is introduced into the target color sub-pixel. The molecular orbital energy levels of the charge accumulation layer are set to be opposite to those of the charge transport layer, with a difference of less than 0.3 eV, in order to prevent some charge from accumulating at the interface and improve capacitance uniformity.
By increasing the capacitance of the target color subpixels, the brightness of the first frame is uniformized, the color shift phenomenon of the display panel is optimized, and the display quality is improved.
Smart Images
Figure CN115867084B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of display technology, specifically to a display panel and a display device. Background Technology
[0002] Organic light-emitting display (OLED) is a highly promising display technology. OLED display panels not only possess excellent display performance, but also feature self-illumination, simple structure, ultra-thinness, fast response speed, wide viewing angle, low power consumption, and the ability to achieve flexible displays. They are hailed as "dream displays" and have gained favor with major display manufacturers, becoming a mainstay in the display technology field.
[0003] However, current OLED display panels exhibit color shift when switching images, affecting display quality. Therefore, optimizing color shift in display panels has become an urgent problem to be solved. Summary of the Invention
[0004] To address the aforementioned technical problems, this application is proposed. Embodiments of this application provide a display panel and a display device.
[0005] In a first aspect, one embodiment of this application provides a display panel, the display panel including: a plurality of sub-pixels, the plurality of sub-pixels including a target color sub-pixel and other color sub-pixels besides the target color sub-pixel; the sub-pixels include a light-emitting layer and a charge transport layer stacked thereon, the target color sub-pixel further including a charge accumulation layer corresponding to the charge transport layer, the charge accumulation layer being stacked between the light-emitting layer and the charge transport layer, the charge transported by the charge accumulation layer having an electrical polarity opposite to that of the charge transport layer, and the molecular orbital energy level of the charge accumulation layer being configured such that the charge transported by the charge transport layer accumulates at the interface between the charge transport layer and the charge accumulation layer, compared to the molecular orbital energy level of the charge transport layer.
[0006] In conjunction with the first aspect, in some implementations of the first aspect, the absolute value of the difference between the molecular orbital energy levels of the charge accumulation layer and the molecular orbital energy levels of the charge transport layer is less than or equal to 0.3 eV; preferably, the absolute value of the difference between the molecular orbital energy levels of the charge accumulation layer and the molecular orbital energy levels of the charge transport layer is less than or equal to 0.2 eV.
[0007] In conjunction with the first aspect, in some implementations of the first aspect, the charge transport layer includes an electron transport layer, the charge accumulation layer includes an electron accumulation layer, the molecular orbital energy level includes the highest occupied molecular orbital energy level, the material of the electron accumulation layer is a material with hole transport characteristics, and the absolute value of the highest occupied molecular orbital energy level of the electron accumulation layer is greater than the absolute value of the highest occupied molecular orbital energy level of the electron transport layer; preferably, the absolute value of the difference between the highest occupied molecular orbital energy level of the electron accumulation layer and the highest occupied molecular orbital energy level of the electron transport layer is less than or equal to 0.3 eV.
[0008] In conjunction with the first aspect, in some implementations of the first aspect, the display panel further includes: an electron injection layer, which is stacked on the side of the electron transport layer away from the light-emitting layer, wherein the absolute value of the highest occupied molecular orbital energy level of the electron injection layer is greater than or equal to the absolute value of the highest occupied molecular orbital energy level of the electron transport layer; preferably, it further includes: a hole blocking layer, which is stacked between the light-emitting layer and the electron accumulation layer, wherein the absolute value of the highest occupied molecular orbital energy level of the hole blocking layer is greater than the absolute value of the highest occupied molecular orbital energy level of the electron accumulation layer.
[0009] In conjunction with the first aspect, in some implementations of the first aspect, the material having hole transport properties includes at least one of carbazole compounds, derivatives having a triarylamine structure, triazine, or other electron-deficient nitrogen heterocyclic substituted derivatives.
[0010] In conjunction with the first aspect, in some implementations of the first aspect, the charge transport layer includes a hole transport layer, the charge accumulation layer includes a hole accumulation layer, the molecular orbital energy level includes the lowest unoccupied molecular orbital energy level, the material of the hole accumulation layer is a material with electron transport properties, and the absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer is less than the absolute value of the lowest unoccupied molecular orbital energy level of the hole transport layer; preferably, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the hole accumulation layer and the lowest unoccupied molecular orbital energy level of the hole transport layer is less than or equal to 0.3 eV.
[0011] In conjunction with the first aspect, in some implementations of the first aspect, the display panel further includes: a hole injection layer, which is stacked on the side of the hole transport layer away from the light-emitting layer, wherein the absolute value of the lowest unoccupied molecular orbital energy level of the hole injection layer is less than or equal to the absolute value of the lowest unoccupied molecular orbital energy level of the hole transport layer; preferably, it further includes: an electron blocking layer, which is stacked between the light-emitting layer and the hole accumulation layer, wherein the absolute value of the lowest unoccupied molecular orbital energy level of the electron blocking layer is less than the absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer.
[0012] In conjunction with the first aspect, in some implementations of the first aspect, the material having electron transport properties comprises at least an imidazopyrimidine derivative and / or a triphenylene derivative.
[0013] In conjunction with the first aspect, in some implementations of the first aspect, the thickness of the charge accumulation layer is less than or equal to 30 angstroms.
[0014] Secondly, one embodiment of this application provides a display device, which includes a display panel as mentioned in any of the above embodiments.
[0015] The display panel provided in this application includes: a plurality of sub-pixels, including a target color sub-pixel and other color sub-pixels besides the target color sub-pixel; each sub-pixel includes a light-emitting layer and a charge transport layer stacked together, and the target color sub-pixel also includes a charge accumulation layer corresponding to the charge transport layer. The charge accumulation layer is stacked between the light-emitting layer and the charge transport layer, and the charge transferred by the charge accumulation layer has the opposite charge polarity to that transferred by the charge transport layer. Furthermore, compared to the molecular orbital energy levels of the charge transport layer, the molecular orbital energy levels of the charge accumulation layer are configured to allow the charge transferred by the charge transport layer to accumulate at the interface between the charge transport layer and the charge accumulation layer. Therefore, some of the charge from the charge transport layer can be effectively blocked by the charge accumulation layer, thereby accumulating charge at the interface between the charge transport layer and the charge accumulation layer, thus increasing the capacitance of the target color sub-pixel. This makes the capacitance of the target color sub-pixel and the capacitance of the other color sub-pixels more uniform, thereby making the first-frame brightness of the target color sub-pixel and the first-frame brightness of the other color sub-pixels more uniform, thus optimizing the color shift phenomenon of the display panel. Attached Figure Description
[0016] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.
[0017] Figure 1 The diagram shown is a structural schematic of a display panel provided in an embodiment of this application.
[0018] Figure 2 The diagram shown is a schematic diagram of the energy levels of a target color sub-pixel provided in an embodiment of this application.
[0019] Figure 3 The diagram shown is a schematic diagram of the energy levels of a target color sub-pixel provided in another embodiment of this application.
[0020] Figure 4 The diagram shown is a schematic diagram of the energy levels of a target color sub-pixel provided in another embodiment of this application.
[0021] Figure 5 The diagram shown is a schematic diagram of the energy levels of a target color sub-pixel provided in another embodiment of this application.
[0022] Figure 6 The diagram shown is a schematic diagram of the energy levels of a target color sub-pixel provided in another embodiment of this application.
[0023] Figure 7 The diagram shown is a schematic diagram of the energy levels of a target color sub-pixel provided in another embodiment of this application.
[0024] Figure 8 The diagram shown is a comparison of capacitance before and after optimization of color shift phenomenon according to an embodiment of this application.
[0025] Figure 9 The diagram shown is a schematic diagram of the structure of a display device provided in an embodiment of this application.
[0026] Reference numerals: Display panel 110; Target color sub-pixel C1; First color sub-pixel C2; Second color sub-pixel C3; Emitting layer L; Electron transport layer A1; Electron accumulation layer A2; Hole blocking layer A3; Electron injection layer A4; Hole transport layer B1; Hole accumulation layer B2; Electron blocking layer B3; Hole injection layer B4; Optimized capacitance curve M; Unoptimized capacitance curve N; Display device 100. Detailed Implementation
[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0028] Furthermore, to better illustrate this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In some instances, methods and means well-known to those skilled in the art have not been described in detail in order to highlight the main points of this application.
[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0030] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0031] When OLED display panels switch images, especially from a black image to a white image, color shift occurs at the moment of image switching due to differences in the initial brightness of the sub-pixels. Through in-depth research, the inventors discovered that the cause of this color shift is related to the capacitance of each sub-pixel. When transitioning from a black state to a bright state, the difference in capacitance among the sub-pixels leads to a difference in the initial brightness of the first frame, thus causing the color shift.
[0032] Figure 1 The diagram shown is a structural schematic of a display panel provided in one embodiment of this application. Figure 1 As shown in the embodiment of this application, the display panel 110 includes a plurality of sub-pixels, which include a target color sub-pixel C1 and other color sub-pixels besides the target color sub-pixel C1. For example, the other color sub-pixels may be a first color sub-pixel C2 and a second color sub-pixel C3.
[0033] Taking the display panel 110 being biased towards the target color when switching displayed images as an example, the method of increasing the capacitance of the target color sub-pixel C1 according to the embodiments of this application is explained in detail. Specifically, the display panel 110 being biased towards the target color means that the first frame brightness of the target color sub-pixel C1 is greater than the first frame brightness of other color sub-pixels besides the target color sub-pixel C1. By increasing the capacitance of the target color sub-pixel C1, the first frame brightness of the target color sub-pixel C1 is reduced within a certain first frame on-time.
[0034] The sub-pixel includes a light-emitting layer and a charge transport layer stacked together. The target color sub-pixel C1 also includes a charge accumulation layer corresponding to the charge transport layer. The charge accumulation layer is stacked between the light-emitting layer and the charge transport layer. The charge transferred by the charge accumulation layer has the opposite charge to that transferred by the charge transport layer. Moreover, compared to the molecular orbital energy levels of the charge transport layer, the molecular orbital energy levels of the charge accumulation layer are set to allow the charge transferred by the charge transport layer to accumulate at the interface between the charge transport layer and the charge accumulation layer. Therefore, some of the charge from the charge transport layer can be effectively blocked by the charge accumulation layer, thereby accumulating charge at the interface between the charge transport layer and the charge accumulation layer. This increases the capacitance of the target color sub-pixel C1, making the capacitance of the target color sub-pixel C1 and the capacitance of other color sub-pixels more uniform. Consequently, the first-frame brightness of the target color sub-pixel C1 and the first-frame brightness of other color sub-pixels are more uniform, thus optimizing the color shift phenomenon of the display panel 110.
[0035] It should be noted that the charge accumulation layer corresponding to the charge transport layer refers to the charge accumulation layer corresponding to the electron transport layer if the charge transport layer is an electron transport layer, and the charge accumulation layer corresponding to the hole transport layer if the charge transport layer is a hole transport layer.
[0036] Figure 2 The diagram shown is a schematic representation of the energy levels of a target color sub-pixel according to an embodiment of this application. In this application... Figure 1 This application extends from the embodiments shown. Figure 2 The illustrated embodiment will be described in detail below. Figure 2 The illustrated embodiments and Figure 1 The differences between the embodiments shown are not repeated here, and the similarities are not repeated here.
[0037] like Figure 2 As shown, the charge transport layer includes an electron transport layer A1, the charge accumulation layer includes an electron accumulation layer A2, and the molecular orbital energy level includes the highest occupied molecular orbital (HOMO) energy level. The absolute value of the HOMO energy level of the electron accumulation layer A2 is greater than the absolute value of the HOMO energy level of the electron transport layer A1. Figure 2 The downward arrows indicate the coordinate axis where the highest occupied molecular orbital energy level is located.
[0038] The material of the electron accumulation layer A2 is a material with hole transport properties, which includes at least one of carbazole compounds, derivatives with a triarylamine structure, triazine or other electron-deficient nitrogen heterocyclic substituted derivatives.
[0039] Electron accumulation layer A2 has hole transport properties but not electron transport properties. Therefore, electron accumulation layer A2 can block electrons from electron transport layer A1. Meanwhile, electron accumulation layer A2 and electron transport layer A1 can be stacked adjacent to each other. Other films can be disposed between electron accumulation layer A2 and light-emitting layer L, or electron accumulation layer A2 and light-emitting layer L can be stacked adjacent to each other; this application does not further limit this.
[0040] At the same time, such as Figure 2 As shown, the absolute value of the highest occupied molecular orbital energy level in electron accumulation layer A2 is greater than that in electron transport layer A1. Therefore, electron accumulation layer A2 can effectively block electrons from electron transport layer A1, accumulating electrons at the interface between electron transport layer A1 and electron accumulation layer A2, thereby increasing the capacitance of the target color sub-pixel C1. It is important to note that electron accumulation layer A2 only blocks a portion of electrons; simultaneously, it still transports another portion of electrons to the emitting layer L.
[0041] The absolute value of the difference between the molecular orbital energy levels of the charge accumulation layer and the charge transport layer is less than or equal to 0.3 eV; preferably, the absolute value of the difference is less than or equal to 0.2 eV. Specifically, in this embodiment, the absolute value of the difference between the highest occupied molecular orbital energy level of the electron accumulation layer A2 and the highest occupied molecular orbital energy level of the electron transport layer A1 can be set to be less than or equal to 0.3 eV. Preferably, the absolute value of the difference is less than or equal to 0.2 eV. In this case, the electron accumulation layer A2 can effectively block some electrons from the electron transport layer A1, while simultaneously allowing a suitable amount of electrons to be transported to the luminescent layer L, thereby ensuring the electron-hole recombination rate of the luminescent layer L and thus ensuring the luminous efficiency of the luminescent layer L. For example, the absolute value of the above difference can be 0.1 eV or 0.2 eV. Preferably, the absolute value of the above difference is 0.2 eV. In addition, in some embodiments, the thickness of the electron accumulation layer A2 is less than or equal to 30 angstroms.
[0042] Figure 3 The diagram shown is a schematic representation of the energy levels of a target color sub-pixel according to another embodiment of this application. In this application... Figure 2 This application extends from the embodiments shown. Figure 3 The illustrated embodiment will be described in detail below. Figure 3 The illustrated embodiments and Figure 2 The differences between the embodiments shown are not repeated here, and the similarities are not repeated here.
[0043] like Figure 3 As shown, the display panel 110 provided in this application embodiment further includes: a hole blocking layer A3, which is stacked between the light-emitting layer L and the electron accumulation layer A2, and the absolute value of the highest occupied molecular orbital energy level of the hole blocking layer A3 is greater than the absolute value of the highest occupied molecular orbital energy level of the electron accumulation layer A2.
[0044] Hole blocking layer A3 blocks holes from the anode at the interface between the light-emitting layer L and hole blocking layer A3, increasing the hole concentration in the light-emitting layer L and preventing holes from entering the electron accumulation layer A2 and combining with electrons, thus affecting the luminous efficiency of the light-emitting layer L.
[0045] Figure 4 The diagram shown is a schematic representation of the energy levels of a target color sub-pixel according to another embodiment of this application. In this application... Figure 3 This application extends from the embodiments shown. Figure 4 The illustrated embodiment will be described in detail below. Figure 4 The illustrated embodiments and Figure 3 The differences between the embodiments shown are not repeated here, and the similarities are not repeated here.
[0046] like Figure 4 As shown, the display panel 110 provided in this embodiment further includes an electron injection layer A4, which is stacked on the side of the electron transport layer A1 away from the light-emitting layer L. The absolute value of the highest occupied molecular orbital energy level of the electron injection layer A4 is greater than or equal to the absolute value of the highest occupied molecular orbital energy level of the electron transport layer A1. Therefore, the electron injection layer A4 enables electrons from the cathode to be smoothly injected into the electron transport layer A1 even at a lower driving voltage, thus improving electron utilization.
[0047] Figure 5 The diagram shown is a schematic representation of the energy levels of a target color sub-pixel according to another embodiment of this application. In this application... Figure 1 This application extends from the embodiments shown. Figure 5 The illustrated embodiment will be described in detail below. Figure 5 The illustrated embodiments and Figure 1 The differences between the embodiments shown are not repeated here, and the similarities are not repeated here.
[0048] like Figure 5 As shown, the charge transport layer includes a hole transport layer B1, the charge accumulation layer includes a hole accumulation layer B2, and the molecular orbital energy level includes the lowest unoccupied molecular orbital (LUMO). The absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2 is less than the absolute value of the lowest unoccupied molecular orbital energy level of the hole transport layer B1. Figure 5 The downward arrows indicate the coordinate axis containing the lowest unoccupied molecular orbital energy level.
[0049] The hole accumulation layer B2 is made of a material with electron transport properties, which includes at least an imidazopyrimidine derivative and / or a triphenylene structure derivative.
[0050] Hole accumulation layer B2 has electron transport properties but not hole transport properties. Therefore, hole accumulation layer B2 can block holes from hole transport layer B1. Meanwhile, hole accumulation layer B2 and hole transport layer B1 can be stacked adjacent to each other. Other film layers can be disposed between hole accumulation layer B2 and light-emitting layer L, or hole accumulation layer B2 and light-emitting layer L can be stacked adjacent to each other; this embodiment does not further limit this.
[0051] At the same time, such as Figure 5As shown, the absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2 is smaller than that of the lowest unoccupied molecular orbital energy level of the hole transport layer B1. Therefore, the hole accumulation layer B2 can effectively block holes from the hole transport layer B1, accumulating holes at the interface between the hole transport layer B1 and the hole accumulation layer B2, thereby increasing the capacitance of the target color sub-pixel C1. It should be noted that the hole accumulation layer B2 only blocks some holes; simultaneously, it still transports another portion of holes to the emissive layer L.
[0052] Specifically, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2 and the lowest unoccupied molecular orbital energy level of the hole transport layer B1 can be set to be less than or equal to 0.3 eV. Preferably, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2 and the lowest unoccupied molecular orbital energy level of the hole transport layer B1 is less than or equal to 0.2 eV. In this case, the hole accumulation layer B2 can effectively block some holes from the hole transport layer B1, while allowing an appropriate amount of holes to be transported to the light-emitting layer L, so as to ensure the electron-hole recombination rate of the light-emitting layer L, and thus ensure the luminous efficiency of the light-emitting layer L. For example, the absolute value of the above difference can be 0.1 eV or 0.2 eV. Preferably, the absolute value of the above difference is 0.2 eV. In addition, in some embodiments, the thickness of the hole accumulation layer B2 is less than or equal to 30 angstroms.
[0053] In some embodiments, combinations can be made Figure 2 The illustrated embodiments and Figure 5 The embodiment shown in the figure has an electron accumulation layer A2 stacked between the electron transport layer A1 and the light-emitting layer L, and a hole accumulation layer B2 stacked between the hole transport layer B1 and the light-emitting layer L, thereby further improving the capacitance of the target color sub-pixel C1.
[0054] Figure 6 The diagram shown is a schematic representation of the energy levels of a target color sub-pixel according to another embodiment of this application. In this application... Figure 5 This application extends from the embodiments shown. Figure 6 The illustrated embodiment will be described in detail below. Figure 6 The illustrated embodiments and Figure 5 The differences between the embodiments shown are not repeated here, and the similarities are not repeated here.
[0055] like Figure 6 As shown, the display panel 110 provided in this embodiment of the application further includes: an electron blocking layer B3, which is stacked between the light-emitting layer L and the hole accumulation layer B2, wherein the absolute value of the lowest unoccupied molecular orbital energy level of the electron blocking layer B3 is less than the absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2.
[0056] The electron blocking layer B3 blocks electrons from the cathode at the interface between the light-emitting layer L and the electron blocking layer B3, increasing the electron concentration in the light-emitting layer L and preventing electrons from entering the hole accumulation layer B2 and combining with holes, thus affecting the luminous efficiency of the light-emitting layer L.
[0057] Figure 7 The diagram shown is a schematic representation of the energy levels of a target color sub-pixel according to another embodiment of this application. In this application... Figure 6 This application extends from the embodiments shown. Figure 7 The illustrated embodiment will be described in detail below. Figure 7 The illustrated embodiments and Figure 6 The differences between the embodiments shown are not repeated here, and the similarities are not repeated here.
[0058] like Figure 7 As shown, the display panel 110 provided in this embodiment further includes a hole injection layer B4, which is stacked on the side of the hole transport layer B1 away from the light-emitting layer L. The absolute value of the lowest unoccupied molecular orbital energy level of the hole injection layer B4 is less than or equal to the absolute value of the lowest unoccupied molecular orbital energy level of the hole transport layer B1. Therefore, the hole injection layer B4 enables holes from the anode to be smoothly injected into the hole transport layer B1 even at a lower driving voltage, thereby improving the utilization rate of holes.
[0059] Additionally, it should be noted that the display panel provided in this application increases the capacitance of the target color sub-pixels when driven at lower voltages. Simultaneously, because the thickness of the charge accumulation layer and the difference in molecular orbital energy levels are limited, the charge transport barrier continuously decreases as the voltage and the amount of accumulated charge increase, thus not affecting the driving voltage when displaying higher brightness.
[0060] Specifically, the initial power-on voltage of a display panel is typically 2 to 2.8 volts. Taking the target color sub-pixel C1 as the red sub-pixel as an example, the combination... Figure 2 The illustrated embodiments and Figure 5 The illustrated embodiment involves stacking an electron accumulation layer A2 between the electron transport layer A1 and the light-emitting layer L, and also stacking a hole accumulation layer B2 between the hole transport layer B1 and the light-emitting layer L. The highest occupied molecular orbital energy level of the electron transport layer A1 is -6 eV, and the highest occupied molecular orbital energy level of the electron accumulation layer A2 is -6.20 eV. The lowest unoccupied molecular orbital energy level of the hole transport layer B1 is -2.30 eV, and the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2 is -2.10 eV. Based on the above experimental conditions, the following results were obtained: Figure 8 The experimental results are shown below. Figure 8As shown, the optimized capacitance curve M and the unoptimized capacitance curve N are compared. Cp represents capacitance in farads (F). For the capacitance corresponding to the above voltage range, the optimized capacitance is significantly larger than the unoptimized capacitance (i.e., in the prior art).
[0061] Furthermore, taking the target color sub-pixel C1 as the red sub-pixel as an example, the first frame start-up voltage of the display panel was set to 2.3 volts, the device frequency to 5 kHz, and the capacitance of the red sub-pixel before optimization to 3.0E-10 farads. The experimental results are shown in Table 1. As shown in Table 1, based on... Figure 2 In the illustrated embodiment, an electron accumulation layer A2 is stacked only between the electron transport layer A1 and the light-emitting layer L. Under experimental conditions where the highest occupied molecular orbital energy level of the electron transport layer A1 is -6 eV and the highest occupied molecular orbital energy levels of the electron accumulation layer A2 are -6.13 eV, -6.20 eV, and -6.27 eV, it can be seen that the optimized capacitance is greater than the unoptimized capacitance. Furthermore, the optimized capacitance is maximized when the absolute value of the difference between the highest occupied molecular orbital energy level of the electron accumulation layer A2 and the highest occupied molecular orbital energy level of the electron transport layer A1 is 0.2 eV.
[0062] It should be noted that the above experimental conditions used three display panels with different highest occupied molecular orbital energy levels in the electron accumulation layer A2. Specifically, the highest occupied molecular orbital energy level in the electron transport layer A1 of these three display panels is -6 eV, while the highest occupied molecular orbital energy levels in the electron accumulation layer A2 of these panels are -6.13 eV, -6.20 eV, and -6.27 eV, respectively.
[0063] As shown in Table 1, based on Figure 5 In the illustrated embodiment, a hole accumulation layer B2 is stacked only between the hole transport layer B1 and the light-emitting layer L. Under experimental conditions where the lowest unoccupied molecular orbital energy level of the hole transport layer B1 is -2.30 eV and the lowest unoccupied molecular orbital energy levels of the hole accumulation layer B2 are -2.20 eV, -2.10 eV, and -2.0 eV, it can be seen that the optimized capacitance is greater than the unoptimized capacitance. Furthermore, the optimized capacitance is maximized when the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the hole accumulation layer B2 and the lowest unoccupied molecular orbital energy level of the hole transport layer B1 is 0.2 eV.
[0064] It should be noted that the above experimental conditions used three display panels with different lowest unoccupied molecular orbital energy levels in the hole accumulation layer B2. Specifically, the lowest unoccupied molecular orbital energy level of the hole transport layer B1 in these three display panels is -2.30 eV, and the lowest unoccupied molecular orbital energy levels of the hole accumulation layer B2 in these panels are -2.20 eV, -2.10 eV, and -2.0 eV, respectively.
[0065] Therefore, by Figure 8 As shown in Table 1, the display panel provided in this application increases the capacitance of the target color sub-pixel, thereby making the capacitance of the target color sub-pixel and the capacitance of other color sub-pixels more uniform, thus making the first frame brightness of the target color sub-pixel and the first frame brightness of other color sub-pixels more uniform, and optimizing the color shift phenomenon of the display panel.
[0066] Table 1
[0067]
[0068] Figure 9 The diagram shown is a structural schematic of a display device provided in an embodiment of this application. Figure 9 As shown, one embodiment of this application also provides a display device 100. It is understood that the display panel 110 can be applied to the display device 100, which can be, for example, any product or component with display functionality such as a mobile terminal, tablet computer, computer monitor, television, wearable device, or information kiosks. The display device 100 includes the display panel 110 as in any embodiment of this application, and its technical principles and effects are similar, so they will not be described again here.
[0069] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.
[0070] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.
[0071] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.
[0072] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.
[0073] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.
Claims
1. A display panel, characterized in that, include: The system comprises multiple sub-pixels, including a target color sub-pixel and other color sub-pixels besides the target color sub-pixel. The first-frame brightness of the target color sub-pixel is greater than that of the other color sub-pixels. Each sub-pixel includes a stacked emitting layer and a charge transport layer. The target color sub-pixel also includes a charge accumulation layer corresponding to the charge transport layer, which is stacked between the emitting layer and the charge transport layer. The charge transferred by the charge accumulation layer has an opposite charge polarity to that transferred by the charge transport layer. Compared to the molecular orbital energy level of the charge transport layer, the molecular orbital energy level of the charge accumulation layer is configured to accumulate the charge transferred by the charge transport layer at the interface between the charge transport layer and the charge accumulation layer. The absolute value of the difference between the molecular orbital energy level of the charge accumulation layer and the molecular orbital energy level of the charge transport layer is less than or equal to 0.3 eV, thereby increasing the capacitance of the target color sub-pixel and making the capacitance of the target color sub-pixel and the other color sub-pixels uniform within a certain first-frame illumination time.
2. The display panel of claim 1, wherein, The absolute value of the difference between the molecular orbital energy levels of the charge accumulation layer and the molecular orbital energy levels of the charge transport layer is less than or equal to 0.2 electron volts.
3. The display panel of claim 1 or 2, wherein, The charge transport layer includes an electron transport layer, the charge accumulation layer includes an electron accumulation layer, the molecular orbital energy level includes a highest occupied molecular orbital energy level, the material of the electron accumulation layer is a material with hole transport characteristics, and the absolute value of the highest occupied molecular orbital energy level of the electron accumulation layer is greater than the absolute value of the highest occupied molecular orbital energy level of the electron transport layer.
4. The display panel of claim 3, wherein, The absolute value of the difference between the highest occupied molecular orbital energy level of the electron accumulation layer and the highest occupied molecular orbital energy level of the electron transport layer is less than or equal to 0.3 electron volts.
5. The display panel of claim 3, wherein, Also includes: An electron injection layer is stacked on the side of the electron transport layer away from the light-emitting layer, and the absolute value of the highest occupied molecular orbital energy level of the electron injection layer is greater than or equal to the absolute value of the highest occupied molecular orbital energy level of the electron transport layer.
6. The display panel of claim 5, wherein, Also includes: A hole blocking layer is stacked between the light-emitting layer and the electron accumulation layer, wherein the absolute value of the highest occupied molecular orbital energy level of the hole blocking layer is greater than the absolute value of the highest occupied molecular orbital energy level of the electron accumulation layer.
7. The display panel of claim 3, wherein, The material with hole transport properties includes at least one of carbazole compounds, derivatives having a triarylamine structure, triazine, or other electron-deficient nitrogen heterocyclic substituted derivatives.
8. The display panel of claim 1 or 2, wherein, The charge transport layer includes a hole transport layer, the charge accumulation layer includes a hole accumulation layer, the molecular orbital energy level includes a lowest unoccupied molecular orbital energy level, the material of the hole accumulation layer is a material with electron transport properties, and the absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer is less than the absolute value of the lowest unoccupied molecular orbital energy level of the hole transport layer.
9. The display panel of claim 8, wherein, The absolute value of the difference between the lowest unoccupied molecular orbital energy level of the hole accumulation layer and the lowest unoccupied molecular orbital energy level of the hole transport layer is less than or equal to 0.3 electron volts.
10. The display panel of claim 8, wherein, Also includes: A hole injection layer is stacked on the side of the hole transport layer away from the light-emitting layer, wherein the absolute value of the lowest unoccupied molecular orbital energy level of the hole injection layer is less than or equal to the absolute value of the lowest unoccupied molecular orbital energy level of the hole transport layer.
11. The display panel of claim 10, wherein, Also includes: An electron blocking layer is stacked between the light-emitting layer and the hole accumulation layer, wherein the absolute value of the lowest unoccupied molecular orbital energy level of the electron blocking layer is less than the absolute value of the lowest unoccupied molecular orbital energy level of the hole accumulation layer.
12. The display panel of claim 10, wherein, The material having electron transport properties comprises at least an imidazopyrimidine derivative and / or a triphenylene derivative.
13. The display panel of claim 1 or 2, wherein, The thickness of the charge accumulation layer is less than or equal to 30 angstroms.
14. A display device comprising: Includes the display panel as described in any one of claims 1 to 13 above.