Display panel and display device

Abstract

The application discloses a display panel and a display device, and belongs to the technical field of display, which aims to at least improve the problem that the first pixel bears high current density and affects the performance of the display panel in the related art. The display panel comprises a pixel definition layer and a plurality of pixel units on a substrate, the pixel definition layer has a plurality of pixel openings, each pixel unit comprises a plurality of pixels, and each pixel is located in a pixel opening; wherein the plurality of pixels comprise a first pixel and at least two second pixels, the area of the pixel opening corresponding to the first pixel is smaller than the area of the pixel opening corresponding to the second pixel, the second pixel is formed by an organic light-emitting material layer, and the first pixel comprises two organic light-emitting material films and a charge generation layer located between the two organic light-emitting material films.

Description

Technical Field

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

[0002] Organic light-emitting diode (OLED) display panels, with their self-emissive, high-contrast, wide-viewing-angle, and fast-response characteristics, have been widely used in various display terminals such as smartphones, automotive displays, smart wearables, and high-end large-screen displays, becoming one of the mainstream display technologies today.

[0003] In related technologies, due to limitations such as pixel arrangement design, the aperture size of pixels corresponding to different colors cannot be made consistent. In high-brightness display scenarios, to ensure uniform screen brightness, the first pixel with the smaller aperture will bear a higher current density than other pixels. This not only causes a sharp drop in the luminous efficiency of the first pixel, leading to increased power consumption of the display panel, but also accelerates the aging of the organic light-emitting material in the first pixel, thus shortening the lifespan of the display panel and ultimately affecting its performance and product reliability. Summary of the Invention

[0004] This application provides a display panel and display device to at least improve the technical problem in the related art where the performance of the display panel is affected by the high current density of the first pixel.

[0005] To achieve the above objectives, according to a first aspect of this application, a display panel is provided, comprising: Substrate; A pixel definition layer, located on the substrate and having multiple pixel openings; and A plurality of pixel units are located on the substrate, each pixel unit comprising a plurality of pixels, and each pixel being located within a pixel opening; The plurality of pixels includes a first pixel and at least two second pixels. The area of ​​the pixel opening corresponding to the first pixel is smaller than the area of ​​the pixel opening corresponding to the second pixel. The second pixel is formed by a layer of organic light-emitting material. The first pixel includes two layers of organic light-emitting material film and a charge generation layer located between the two layers of organic light-emitting material film.

[0006] In some embodiments, the charge generation layers in two adjacent first pixels are spaced apart from each other.

[0007] In some embodiments, the at least two second pixels include a first color pixel, a second color pixel, and a third color pixel, wherein the light emitted by the first color pixel, the second color pixel, and the third color pixel can be mixed to form white light.

[0008] In some embodiments, the emission color of the first pixel is different from the emission colors of the first color pixel, the second color pixel, and the third color pixel; the first color pixel includes a first organic light-emitting material layer, the second color pixel includes a second organic light-emitting material layer, and the third color pixel includes a third organic light-emitting material layer, wherein the thickness of each of the first organic light-emitting material layer, the second organic light-emitting material layer, and the third organic light-emitting material layer is greater than the thickness of the organic light-emitting material film.

[0009] In some embodiments, the emission color of the first pixel is the same as the emission color of the first color pixel; the first color pixel includes a first organic light-emitting material layer, the thickness of the first organic light-emitting material layer being equal to the thickness of the organic light-emitting material film.

[0010] In some embodiments, the area of ​​the pixel opening corresponding to the first color pixel is larger than the area of ​​the pixel opening corresponding to other pixels in the same pixel unit, the first color pixel and the first pixel are arranged along a first direction, and the second color pixel and the third color pixel are arranged along the first direction.

[0011] In some embodiments, the plurality of pixel openings include a first pixel opening corresponding to the first pixel, a second pixel opening corresponding to the first color pixel, a third pixel opening corresponding to the second color pixel, and a fourth pixel opening corresponding to the third color pixel; along a second direction perpendicular to the first direction, the width of the first pixel opening is equal to the width of the second pixel opening, and the width of the third pixel opening is equal to the width of the fourth pixel opening.

[0012] In some embodiments, the first side of the first pixel opening away from the second pixel opening is flush with the fourth side of the fourth pixel opening away from the third pixel opening, and the second side of the second pixel opening away from the first pixel opening is flush with the third side of the third pixel opening away from the fourth pixel opening.

[0013] In some embodiments, the first color pixel is used to emit blue light.

[0014] According to a second aspect of this application, a display device is provided, including a display panel as described in any embodiment of the first aspect.

[0015] In the display panel of this application embodiment, since the first pixel adopts a stacked structure of a double-layer organic light-emitting material film combined with a charge generation layer, this stacked structure can effectively distribute the carrier injection pressure of the single-layer organic light-emitting material film, thereby reducing the actual current density of the single-layer organic light-emitting material film under high brightness operating conditions, thus suppressing the efficiency roll-off effect of the first pixel and improving the problem of the rapid decay of the luminous efficiency of the first pixel; furthermore, the stacked structure can also effectively improve the current surge resistance of the first pixel and delay the aging and decay rate of the light-emitting material. Therefore, the working stability and service life of the first pixel can be effectively improved, thereby improving the performance and reliability of the display panel. On the other hand, since the second pixel P adopts a single-layer organic light-emitting material layer structure, this simplifies the overall manufacturing process of the display panel, effectively reducing process complexity and production costs; furthermore, this can also avoid the problem of overall driving voltage rise caused by all pixels adopting a stacked structure, thereby avoiding additional power consumption loss, and thus meeting the economic and low power consumption requirements of the display panel.

[0016] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0017] 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 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.

[0018] Figure 1 These are schematic diagrams of the display panel provided in some embodiments of this application; Figure 2 yes Figure 1 Top view of the middle pixel unit; Figure 3 yes Figure 2 A sectional view along the A-A' direction; Figure 4 yes Figure 1 A cross-sectional view of a medium pixel unit; Figure 5 This is a schematic diagram of the structure of a display device provided in some embodiments of this application. Detailed Implementation

[0019] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0020] Some embodiments of this application provide a display panel, such as Figure 1 and Figure 2 As shown, the display panel 100 includes multiple pixel units PU. The pixel units PU are located in the display area to enable the display panel 100 to display images. Each pixel unit PU includes multiple pixels, which may include, for example, pixels with different emission colors to enable color image display.

[0021] like Figure 2 and Figure 3 As shown, the display panel 100 also includes a substrate SUB and a pixel definition layer PDL. The pixel definition layer PDL and the pixel unit PU are both located on the substrate SUB. The pixel definition layer PDL has multiple pixel openings K, and each pixel in each pixel unit PU is located in one pixel opening K.

[0022] The plurality of pixels includes a first pixel P1 and at least two second pixels P2, wherein the area of ​​the pixel opening K corresponding to the first pixel P1 (hereinafter referred to as the first pixel opening K1) is smaller than the area of ​​the pixel opening K corresponding to the second pixel P2. It can be understood that the area of ​​the pixel opening K can refer to the area defined by the edge of the pixel opening K away from the substrate SUB.

[0023] Because the area of ​​the first pixel opening K1 is relatively small, when the display panel 100 displays a bright image, in order to ensure uniform brightness, the current density of the first pixel P1 will be higher than that of the second pixel P2. This will not only cause a sharp drop in the luminous efficiency of the first pixel P1, but also accelerate the aging of the organic light-emitting material in the first pixel, ultimately affecting the performance and reliability of the display panel.

[0024] In this embodiment, the second pixel P2 is formed by an organic light-emitting material layer EML, and the first pixel P1 includes two organic light-emitting material films 10 and a charge generation layer CGL located between the two organic light-emitting material films 10.

[0025] For the display panel 100 provided in this application embodiment, since the first pixel P1 adopts a stacked structure of a double-layer organic light-emitting material film 10 and a charge generation layer CGL, this stacked structure can effectively distribute the carrier injection pressure of the single-layer organic light-emitting material film, thereby reducing the actual current density of the single-layer organic light-emitting material film under high brightness operating conditions, thus suppressing the efficiency roll-off effect of the first pixel P1 and improving the problem of the rapid decay of the luminous efficiency of the first pixel P1; in addition, the stacked structure can also effectively improve the current surge resistance of the first pixel P1 and delay the aging and decay rate of the light-emitting material. Therefore, the working stability and service life of the first pixel P1 can be effectively improved, thereby improving the performance and reliability of the display panel 100. On the other hand, since the second pixel P2 adopts a single-layer organic light-emitting material layer EML, this simplifies the overall manufacturing process of the display panel 100, effectively reducing the process complexity and production cost; in addition, this can also avoid the problem of overall driving voltage rise caused by all pixels adopting a stacked structure, thereby avoiding additional power consumption loss, and thus meeting the economic and low power consumption requirements of the display panel 100.

[0026] In some embodiments, please refer to Figure 3 Each pixel also includes a first electrode ANO and a second electrode CAT disposed opposite to each other. The organic light-emitting material film 10 of the first pixel P1 is located between the corresponding first electrode ANO and the second electrode CAT, and the organic light-emitting material layer EML of the second pixel P2 is located between the corresponding first electrode ANO and the second electrode CAT. The pixel opening K of the pixel definition layer PDL exposes at least a portion of the first electrode ANO, and the exposed portion of the first electrode ANO can provide charge carriers to the corresponding organic light-emitting material film 10 or organic light-emitting material layer EML. The following explanation uses the first electrode ANO as the anode and the second electrode CAT as the cathode as an example to illustrate the light emission of the pixel. The first electrode ANO and the second electrode CAT generate holes and electrons, respectively. The holes and electrons recombine in the corresponding organic light-emitting material film 10 or organic light-emitting material layer EML and are excited to generate photons, thereby realizing the light emission of the pixel.

[0027] The two organic light-emitting material films 10 in the first pixel P1 are a first light-emitting material film 11 and a second light-emitting material film 12, respectively. The charge generation layer CGL is located between the first light-emitting material film 11 and the second light-emitting material film 12. The charge generation layer CGL can generate electrons and holes to cooperate with the first electrode ANO and the second electrode CAT, respectively, so that the first light-emitting material film 11 and the second light-emitting material film 12 emit light.

[0028] In some examples, the charge generation layer CGL includes an N-type charge generation sublayer and a P-type charge generation sublayer. The N-type charge generation sublayer is used to generate electrons to cooperate with the holes generated by the first electrode ANO, causing light to be emitted at the first light-emitting material film 11; the P-type charge generation sublayer is used to generate holes to cooperate with the electrons generated by the second electrode CAT, causing light to be emitted at the second light-emitting material film 12.

[0029] In some embodiments, please continue reading Figure 3 The charge generation layers CGL in two adjacent first pixels P1 are spaced apart from each other.

[0030] The charge generation layer CGL has strong carrier generation and transport capabilities, making it prone to lateral leakage current. This current is laterally transmitted to adjacent first pixels P1. This embodiment addresses this by spacing adjacent charge generation layers CGL, ensuring that the charge generation layers CGL of each first pixel P1 are not interconnected. This effectively cuts off the lateral charge transport path, preventing electrical interference between adjacent first pixels P1 and improving the color purity and display uniformity of the display panel 100. Furthermore, because the first pixel P1 experiences high current density under high brightness conditions, its heat generation is concentrated. If adjacent charge generation layers CGL are connected, heat conduction can easily accumulate, leading to further heat buildup. This embodiment disrupts this heat conduction path by severing the connection between charge generation layers CGL, facilitating zoned heat dissipation for each first pixel P1 and effectively suppressing the aging of the luminescent material of the first pixel P1 caused by heat accumulation.

[0031] In some embodiments, such as Figure 2 and Figure 4 As shown, Figure 4 It shows Figure 2 The cross-sectional structure of the first pixel P1 and three second pixels P2 is shown. Each pixel may further include a first hole transport layer HTL1 and a first electron transport layer ETL1 located between the first electrode ANO and the second electrode CAT. For the first pixel P1, the first hole transport layer HTL1 is disposed between the first electrode ANO and the first light-emitting material film 11, and the first electron transport layer ETL1 is disposed between the second electrode CAT and the second light-emitting material film 12. For the second pixel P2, the first hole transport layer HTL1 is disposed between the first electrode ANO and the organic light-emitting material layer EML, and the first electron transport layer ETL1 is disposed between the second electrode CAT and the organic light-emitting material layer EML.

[0032] In some examples, the second pixel P2 may also include a second electron transport layer ETL2 located between the first luminescent material film 11 and the N-type charge generation sublayer N-CGL, and a second hole transport layer HTL2 located between the second luminescent material film 12 and the P-type charge generation sublayer P-CGL.

[0033] In some examples, the second electrodes (CAT) of each pixel are interconnected to form a single structure. The display panel 100 may also include a refractive index buffer layer (CPL) and a light extraction layer (LIF) arranged sequentially on the side of the second electrode (CAT) facing away from the first electrode (ANO). By adjusting the thickness of the refractive index buffer layer (CPL) and the light extraction layer (LIF), the side-view perspective effect of the display panel 100 can be improved.

[0034] In some embodiments, please continue reading Figure 2 At least two second pixels P2 include a first color pixel P21, a second color pixel P22 and a third color pixel P23, and the light emitted by the first color pixel P21, the second color pixel P22 and the third color pixel P23 can be mixed to form white light.

[0035] As an example, one of the first color pixel P21, the second color pixel P22, and the third color pixel P23 emits red light, while the other two can emit green and blue light, respectively. In other embodiments, one of the first color pixel P21, the second color pixel P22, and the third color pixel P23 can emit cyan light, while the other two emit magenta and yellow light, respectively. Of course, the emitted colors of the first color pixel P21, the second color pixel P22, and the third color pixel P23 can be adjusted as needed, as long as the light emitted by the three pixels can be mixed to form white light.

[0036] In this embodiment, by setting second pixels P2 with different light-emitting colors, and the light emitted by these second pixels P2 can be mixed to form white light, the display panel 100 can display both white and color images, thus improving the user experience.

[0037] In some embodiments, please refer to Figures 2 to 4 The emission color of the first pixel P1 is different from the emission colors of the first color pixel P21, the second color pixel P22, and the third color pixel P23. For example, if the first color pixel P21, the second color pixel P22, and the third color pixel P23 emit blue light, green light, and red light respectively, the first pixel P1 can be used to emit one of the following: white light, cyan light, yellow light, light blue light, or dark red light.

[0038] This configuration allows the use of the first pixel P1 in conjunction with the second pixel P2, thereby enriching the color variety of the display panel 100, expanding the color gamut, and improving the display panel's picture display effect.

[0039] In some examples, the first color pixel P21 includes a first organic light-emitting material layer EML1, the second color pixel P22 includes a second organic light-emitting material layer EML2, and the third color pixel P23 includes a third organic light-emitting material layer EML3. The thickness of each of the first organic light-emitting material layer EML1, the second organic light-emitting material layer EML2, and the third organic light-emitting material layer EML3 is greater than the thickness of the organic light-emitting material film 10. Understandably, the thickness of the organic light-emitting material layer EML or the organic light-emitting material film 10 refers to its dimension along the thickness direction of the display panel 100.

[0040] In this embodiment, by making the organic light-emitting material film 10 relatively thin, the transport path of charge carriers within the organic light-emitting material film 10 can be shortened, reducing the internal resistance of the device and improving the luminous efficiency of the first pixel P1. Furthermore, since the area of ​​the first pixel opening K1 corresponding to the first pixel P1 is small, the cavity length of the microcavity is limited. Making the organic light-emitting material film 10 relatively thin facilitates its adaptation to the microcavity, achieving better optical resonance and alleviating problems such as color shift and viewing angle deterioration caused by microcavity mismatch. On the other hand, by making the thicknesses of the first organic light-emitting material layer EML1, the second organic light-emitting material layer EML2, and the third organic light-emitting material layer EML3 relatively large, it helps to match the organic light-emitting material layers EML with the corresponding microcavities, improving the light extraction efficiency. Moreover, the thicker organic light-emitting material layers EML can also ensure sufficient recombination of charge carriers at the organic light-emitting material layer EML, further improving the light extraction efficiency.

[0041] In some examples, the first color pixel P21 emits blue light, the second color pixel P22 emits green light, and the third color pixel P23 emits red light; the thicknesses of the first organic light-emitting material layer EML1, the second organic light-emitting material layer EML2, and the third organic light-emitting material layer EML3 gradually increase. This allows each organic light-emitting material layer EML to be matched with the corresponding microcavity, improving the light extraction efficiency of each color pixel.

[0042] In some examples, the organic light-emitting material layer (EML) and the organic light-emitting material film 10 respectively include a host material and a dopant. For pixels with different emission colors, the dopant is different from each other, while the host material can be the same or different.

[0043] In other embodiments, the emission color of the first pixel P1 is the same as the emission color of the first color pixel P21. The thickness of the first organic light-emitting material layer EML1 is equal to the thickness of the organic light-emitting material film 10.

[0044] This configuration allows the first organic light-emitting material layer EML1 and the organic light-emitting material film 10 to be fabricated using the same vapor deposition process, thereby reducing the need for debugging the vapor deposition equipment and improving the manufacturing efficiency of the display panel 100.

[0045] In some examples, the first color pixel P21 is used to emit blue light. In this case, the first organic light-emitting material layer EML of the first color pixel P21 has a relatively small thickness, while the thickness of the first organic light-emitting material layer EML1 is equal to the thickness of the organic light-emitting material film 10, thus effectively accommodating the microcavity corresponding to the first pixel P1.

[0046] In some embodiments, please continue reading Figure 2 The area of ​​the pixel opening K corresponding to the first color pixel P21 is greater than the area of ​​the pixel opening K corresponding to other pixels (second color pixel P22, third color pixel P23 and first pixel P1) in the same pixel unit PU. The first color pixel P21 and the first pixel P1 are arranged along the first direction X, and the second color pixel P22 and the third color pixel P23 are arranged along the first direction X.

[0047] In this embodiment, by arranging the first color pixel P21, which occupies the largest area, and the first pixel P1, which occupies the smallest area, on the same side, the spatial arrangement of each pixel in the pixel unit PU can be optimized, the space occupied by the pixel unit PU can be reduced, and thus the pixel density of the display panel 100 can be improved.

[0048] In some examples, the plurality of pixel openings K include a first pixel opening K1 corresponding to a first pixel P1, a second pixel opening K2 corresponding to a first color pixel P21, a third pixel opening K3 corresponding to a second color pixel P22, and a fourth pixel opening K4 corresponding to a third color pixel P23. Along a second direction Y perpendicular to the first direction X, the width of the first pixel opening K1 is equal to the width of the second pixel opening K2, and the width of the third pixel opening K3 is equal to the width of the fourth pixel opening K4.

[0049] This arrangement allows the first color pixel P21 and the first pixel P1 to be arranged side by side, and the second color pixel P22 and the third color pixel P23 to be arranged side by side. This facilitates the optimization of the spatial arrangement of each pixel in the pixel unit PU, further reduces the space occupied by the pixel unit PU, and thus increases the pixel density of the display panel 100.

[0050] In some embodiments, the first side of the first pixel opening K1 away from the second pixel opening K2 is flush with the fourth side of the fourth pixel opening K4 away from the third pixel opening K3, and the second side of the second pixel opening K2 away from the first pixel opening K1 is flush with the third side of the third pixel opening K3 away from the fourth pixel opening K4.

[0051] This configuration allows the outer edge of the pixel unit PU to be rectangular, which is beneficial for the arrangement of multiple pixel units PU in the display panel 100 and improves the display effect of the display panel 100.

[0052] Some embodiments of this application provide a display device, such as... Figure 5 As shown, the display device 200 includes the display panel 100 described in any of the above embodiments.

[0053] Since it includes a display panel 100, the display device 200 has the beneficial effects of the display panel 100 described above, which will not be repeated here.

[0054] In some examples, the display device 200 also includes a protective frame 201 in which the display panel 100 is mounted.

[0055] The display devices in this application include, but are not limited to, mobile phones, personal digital assistants (PDAs), tablet computers, e-books, televisions, access control systems, smart landline phones, control consoles, and other devices with display functions.

[0056] The display device can be any device with display function, such as mobile devices such as mobile phones, tablets, laptops, handheld computers, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), as well as non-mobile devices such as personal computers (PCs), televisions, ATMs, or self-service machines.

[0057] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0058] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0059] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0060] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A display panel, characterized in that, include: Substrate; A pixel definition layer is located on the substrate and has multiple pixel openings; as well as A plurality of pixel units are located on the substrate, each pixel unit comprising a plurality of pixels, and each pixel being located within a pixel opening; The plurality of pixels includes a first pixel and at least two second pixels. The area of ​​the pixel opening corresponding to the first pixel is smaller than the area of ​​the pixel opening corresponding to the second pixel. The second pixel is formed by a layer of organic light-emitting material. The first pixel includes two layers of organic light-emitting material film and a charge generation layer located between the two layers of organic light-emitting material film.

2. The display panel according to claim 1, characterized in that, The charge generation layers in two adjacent first pixels are spaced apart from each other.

3. The display panel according to claim 1, characterized in that, The at least two second pixels include a first color pixel, a second color pixel, and a third color pixel, and the light emitted by the first color pixel, the second color pixel, and the third color pixel can be mixed to form white light.

4. The display panel according to claim 3, characterized in that, The emission color of the first pixel is different from the emission colors of the first color pixel, the second color pixel, and the third color pixel; The first color pixel includes a first organic light-emitting material layer, the second color pixel includes a second organic light-emitting material layer, and the third color pixel includes a third organic light-emitting material layer. The thickness of each of the first organic light-emitting material layer, the second organic light-emitting material layer, and the third organic light-emitting material layer is greater than the thickness of the organic light-emitting material film.

5. The display panel according to claim 3, characterized in that, The emission color of the first pixel is the same as the emission color of the first color pixel; The first color pixel includes a first organic light-emitting material layer, the thickness of which is equal to the thickness of the organic light-emitting material film.

6. The display panel according to any one of claims 3-5, characterized in that, The area of ​​the pixel opening corresponding to the first color pixel is greater than the area of ​​the pixel opening corresponding to other pixels in the same pixel unit. The first color pixel and the first pixel are arranged along the first direction, and the second color pixel and the third color pixel are arranged along the first direction.

7. The display panel according to claim 6, characterized in that, The plurality of pixel openings include a first pixel opening corresponding to the first pixel, a second pixel opening corresponding to the first color pixel, a third pixel opening corresponding to the second color pixel, and a fourth pixel opening corresponding to the third color pixel; Along a second direction perpendicular to the first direction, the width of the first pixel opening is equal to the width of the second pixel opening, and the width of the third pixel opening is equal to the width of the fourth pixel opening.

8. The display panel according to claim 7, characterized in that, The first side of the first pixel opening away from the second pixel opening is flush with the fourth side of the fourth pixel opening away from the third pixel opening, and the second side of the second pixel opening away from the first pixel opening is flush with the third side of the third pixel opening away from the fourth pixel opening.

9. The display panel according to claim 6, characterized in that, The first color pixel is used to emit blue light.

10. A display device, characterized in that, The display panel includes any one of claims 1-9.

Images