Display panel and display device

Abstract

The invention provides a display panel and a display device. The display panel comprises a substrate; the planarization layer is located on the substrate, a first groove is formed in the side, away from the substrate, of the planarization layer in the first direction, and the first direction is the direction perpendicular to the plane where the substrate is located; a pixel unit including an anode, a pixel definition layer, and a common layer on the anode and the pixel definition layer, the common layer including a first light emitting stack, a charge production layer, and a second light emitting stack; and the cathode is positioned on the common layer, and the cathode is electrically connected with the end part of the charge generation layer along the second direction. According to the display panel, the cathode is electrically connected with the charge generation layer, so that current mainly passes through the single light-emitting element when the display panel is in a low-brightness state, the brightness of the display panel in the low-brightness state is improved, and the brightness attenuation speed of the display panel is slowed down.

Description

Technical Field

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

[0002] Organic light-emitting diode (OLED) display technology has been widely used due to its excellent light-emitting performance. Due to the characteristics of OLED devices themselves, in the low-brightness state, the attenuation rate of OLED devices is higher than that in the constant-brightness state, resulting in yellowing of the display panel in the low brightness, which affects the display effect of the display panel. Therefore, a solution to improve the too-fast brightness attenuation of OLED devices is needed. Summary of the Invention

[0003] This application provides a display panel and a display device. The display panel provided by this application can effectively slow down the speed of brightness attenuation of the display panel.

[0004] In a first aspect, a display panel is provided. The display panel includes: a substrate; a planarization layer located on the substrate, and a first groove is provided on a side of the planarization layer away from the substrate along a first direction, where the first direction is a direction perpendicular to the plane where the substrate is located; a pixel unit, where the pixel unit includes: an anode located on the planarization layer; a pixel definition layer that is disposed on the planarization layer and surrounds the anode, and a projection of the pixel definition layer on the substrate does not overlap with the first groove; a common layer located on the anode and the pixel definition layer, where the common layer includes a first light-emitting stack, a charge generation layer, and a second light-emitting stack that are stacked along the first direction; and a cathode located on the common layer, where an end of the cathode along a second direction is electrically connected to an end of the charge generation layer along the second direction, the second direction is the direction of the plane where the substrate is located, and the first direction is perpendicular to the second direction.

[0005] Based on the above technical solution, since the charge generation layer and the cathode are overlapped, in the low-brightness state of the display panel, the current mainly passes through the second light-emitting stack, improving the brightness of the second light-emitting stack and slowing down the speed of brightness attenuation of the display panel.

[0006] In combination with the first aspect, in some implementation manners of the first aspect, an included angle between a first side wall of the pixel definition layer on a side away from the anode along the second direction and a second side wall of the first groove on a side close to the pixel definition layer is greater than 180 degrees.

[0007] Based on the above technical solution, when the angle between the pixel definition layer and the first groove is greater than 180 degrees, during the deposition and forming process of the pixel unit, the cathode and the charge generation layer are more likely to overlap, improving the reliability of the forming process of the display panel.

[0008] Combined with the first aspect, in some implementation manners of the first aspect, the size of the pixel definition layer in the first direction is less than or equal to 1.5 micrometers.

[0009] Based on the above technical solution, when the thickness of the pixel definition layer is thin enough, the included angle between the side wall of the pixel definition layer and the second direction is larger, which is more conducive to the overlap of the cathode and the charge generation layer during the deposition and forming process of the pixel unit, further improving the reliability of the forming process of the display panel.

[0010] Combined with the first aspect, in some implementation manners of the first aspect, it further includes: an inorganic isolation layer, the inorganic isolation layer is located between the pixel unit and the planarization layer, and the projection of the inorganic isolation layer on the substrate falls into the first groove.

[0011] Based on the above technical solution, by introducing the inorganic isolation layer, the pixel unit is separated from the planarization layer, and the projection of the inorganic isolation layer falls into the first groove, so that when the pixel unit is deposited and formed, the charge generation layer and the cathode can naturally overlap on the inorganic isolation layer, which is beneficial to improving the reliability of the forming process of the display panel.

[0012] Combined with the first aspect, in some implementation manners of the first aspect, the pixel unit includes a red pixel unit, and the length of the projection of the inorganic isolation layer falling into the first groove in the first direction is greater than or equal to 2 micrometers and less than or equal to 4 micrometers.

[0013] Based on the above technical solution, since the attenuation rate of the red pixel unit is relatively fast, when the length of the projection of the inorganic isolation layer in the first groove in the first direction is relatively long, the overlapping area of the cathode and the charge generation layer increases, which is beneficial to the current passing through the overlapping position of the cathode and the charge generation layer, increasing the current passing through the second light-emitting stack, and further slowing down the attenuation rate of the red pixel unit.

[0014] Combined with the first aspect, in some implementation manners of the first aspect, the pixel unit includes a green pixel unit, and the length of the projection of the inorganic isolation layer falling into the first groove in the first direction is greater than or equal to 1 micrometer and less than or equal to 2 micrometers.

[0015] Based on the above technical solution, since the attenuation rate of the green pixel units is slow, when the length of the projection of the inorganic isolation layer in the first groove along the first direction is short, the cathode and the charge generation layer can also overlap on the inorganic isolation layer, enabling the current to pass through the overlapping position of the cathode and the charge generation layer, increasing the current passing through the second light-emitting stack, and slowing down the attenuation rate of the green pixel units.

[0016] In a second aspect, a display device is provided, and the display device includes: a display panel as described in the first aspect and any one of its implementation manners. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1a is a schematic diagram of the brightness test of the red pixel units in a display panel;

[0018] Figure 1b is a schematic diagram of the brightness test of the green pixel units in a display panel;

[0019] Figure 1c is a schematic diagram of the brightness test of the blue pixel units in a display panel;

[0020] Figure 2 is a top view schematic diagram of a display panel provided by an embodiment of the present application;

[0021] Figure 3 is Figure 2 a cross-sectional view of the display panel shown in along the AA direction;

[0022] Figure 4 is Figure 3 a cross-sectional view of the display panel shown in along the BB direction;

[0023] Figure 5 is a circuit schematic diagram in the display panel provided by an embodiment of the present application;

[0024] Figure 6 is a circuit schematic diagram in the display panel provided by an embodiment of the present application;

[0025] Figure 7 is a top view schematic diagram of another display panel provided by an embodiment of the present application;

[0026] Figure 8 is Figure 7 a cross-sectional view of the display panel shown in along the CC direction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Hereinafter, the technical solutions in the present application will be described with reference to the drawings.

[0028] Aspects, embodiments, or features of the embodiments of the present application will be presented around a system including multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in connection with the accompanying drawings. In addition, combinations of these solutions may also be used.

[0029] In addition, in the embodiments of the present application, words such as "exemplary" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" in the embodiments of the present application should not be construed as being more preferred or more advantageous than other embodiments or design solutions. Rather, the use of the word "exemplary" is intended to present concepts in a specific manner.

[0030] The business scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. As is known to those of ordinary skill in the art, with the evolution of technology and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0031] Reference to "one embodiment" or "some embodiments" etc. described in this specification means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0032] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: including the case where A exists alone, the case where A and B exist simultaneously, and the case where B exists alone, where A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item)" or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural item(s). For example, at least one (item) of a, b, or c may represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, c may be single or multiple.

[0033] In the description of the embodiments of the present application, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "vertical", "horizontal", etc. is defined with respect to the orientation or position where the components in the drawings are schematically placed. It should be understood that these directional terms are relative concepts, which are used for relative description and clarification, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. It can change accordingly with the change of the orientation where the components in the drawings are placed. Therefore, it should not be construed as a limitation to the present application.

[0034] In the embodiments of the present application, the same reference numeral is used to represent the same component or the same part. For the same parts in the embodiments of the present application, only one of the parts or components may be labeled with a reference numeral in the drawings. It should be understood that the reference numerals are also applicable to other identical parts or components. In addition, the various parts in the drawings are not drawn to scale, and the sizes and dimensions of the parts shown in the drawings are only exemplary and should not be construed as a limitation to the present application.

[0035] The following introduces the technical content related to the embodiments of the present application.

[0036] Organic light-emitting diode (OLED) display technology is a self-luminous display technology based on organic semiconductor materials, and its core lies in achieving electroluminescence through carrier injection and recombination. An OLED display device is composed of multiple functional structures, and each layer plays a specific role in the light-emitting process.

[0037] In an OLED display device, the substrate serves as the physical support of the device and is usually made of glass or flexible materials. The anode can be made of a transparent conductive material, such as indium tin oxide (ITO), which is responsible for injecting holes. Its high light transmittance ensures that the light from the light-emitting layer can be output outward. The cathode can be made of metal materials such as aluminum and magnesium-silver alloy and is used for injecting electrons. In some designs, a transparent anode can be used to achieve bidirectional light emission.

[0038] The organic functional layer can include a hole injection layer, a hole transport layer, an electron transport layer, or a light-emitting layer. The hole injection layer can be used to modify the surface of the anode and improve the hole injection efficiency. The hole transport layer can be used to transport holes to the light-emitting layer. The electron transport layer can be used to transfer electrons to the light-emitting layer. Electrons and holes recombine at the light-emitting layer to form excitons, which excite organic molecules to emit light. Different light-emitting materials determine different light-emitting colors, such as red, green, and blue.

[0039] The light-emitting process of an OLED display device can be divided into the following steps: carrier injection, carrier transport, exciton formation and recombination, and light radiation. Carrier injection refers to the injection of holes from the anode and electrons from the cathode under the drive of an electric field. Carrier transport refers to the migration of holes through the hole transport layer and electrons through the electron transport layer to the light-emitting layer. Exciton formation and recombination refer to the combination of electrons and holes in the light-emitting layer to form high-energy excitons. Light radiation refers to the release of energy when excitons decay, emitting light in the form of photons. The color of the light is determined by the energy level difference of the light-emitting layer material, and the brightness is proportional to the injection current intensity.

[0040] In recent years, due to the advantages of self-luminescence characteristics, ultra-high contrast, fast response, wide viewing angle, and high color gamut of OELD display technology, its application scope has been expanding day by day and has also been widely used in the field of vehicle-mounted displays. However, users have high requirements for the service life of OLED display devices. In application scenarios at normal temperature or high temperature, when the OLED display device works in a low-brightness state, the light-emitting decay rates of red pixels and green pixels are much higher than those in the constant-brightness state, which will cause the display effect of the OLED display device to turn yellow in the low-brightness state, seriously affecting the display image quality of the OLED display device.

[0041] Figure 1a It is a schematic diagram of the brightness test of a red pixel unit in a display panel. Figure 1b It is a schematic diagram of the brightness test of a green pixel unit in a display panel. Figure 1c It is a schematic diagram of the brightness test of a blue pixel unit in a display panel.

[0042] Figure 1a 、 Figure 1b and Figure 1c represent the change trends of the brightness of three different color light-emitting pixels with the test time. As Figure 1a shown, when the red pixel is lit at a brightness of 100 nit, the change in the light-emitting brightness before and after the test is not significant, while when it is lit at a brightness of 1 nit, the light-emitting brightness after the test drops to 90% of that before the test; as Figure 1b shown, when the green pixel is lit at a brightness of 100 nit, the change in the light-emitting brightness before and after the test is not significant, while when it is lit at a brightness of 1 nit, the light-emitting brightness after the test drops to 93% of that before the test; as Figure 1c shown, when the blue pixel is lit at a brightness of 100 nit or 1 nit, the change in the light-emitting brightness before and after the test is not significant, both being about 98% of that before the test.

[0043] In view of this, a solution that can improve the too-fast brightness decay of OLED devices is needed.

[0044] Embodiments of the present application provide a display panel and a display device, which can effectively alleviate the brightness attenuation rate of the display panel and improve the display effect of the display panel.

[0045] Figure 2 It is a top view schematic diagram of a display panel provided by an embodiment of the present application. Figure 3 is Figure 2 a cross-sectional view of the display panel shown in along the AA direction.

[0046] Combined with Figure 2 and Figure 3 , the display panel 100 may include a substrate 110, a planarization layer 120, and pixel units 200 that are stacked.

[0047] Among them, the planarization layer 120 is located on the substrate 110, and a first groove 121 is provided on one side of the planarization layer 120 away from the substrate 110 along the first direction.

[0048] The pixel unit 200 includes an anode 210, a pixel definition layer 240, a common layer 230, and a cathode 220. Among them, the anode 210 is located on the planarization layer 120; the pixel definition layer 240 is disposed around the anode 210 on the planarization layer 120, and the projection of the pixel definition layer 240 on the substrate 110 does not overlap with the first groove 121; the common layer 230 is located on the anode 210 and the pixel definition layer 240, and the common layer 230 includes a first light-emitting stack 231, a charge generation layer 232, and a second light-emitting stack 233 that are stacked along the first direction; the cathode 220 is located on the common layer 230, and the end of the cathode 220 along the second direction is electrically connected to the end of the charge generation layer 232 along the second direction.

[0049] The second direction is the direction of the plane where the display panel 100 is located, the first direction is perpendicular to the second direction, and the first direction can also be referred to as the thickness direction of the display panel 100. The first direction is the direction shown by the Z axis in the figure, and the second direction is the direction shown by the Y axis in the figure.

[0050] The substrate 110 may be a thin-film transistor (TFT) substrate 110. The TFT substrate 110 may include a base and TFTs disposed on the base. The TFTs may include an active layer, a source electrode, a drain electrode, a gate insulating layer, and a gate electrode. The materials of the active layer of the TFT include, but are not limited to: low temperature poly-silicon (LTPS), oxides, amorphous silicon (a-Si), low temperature polycrystalline oxide (LTPO), and organic materials, etc. The base, as the supporting structure of the display panel 100, the planarization layer 120, the anode 210, the pixel definition layer 240, the common layer 230, the cathode 220, etc. can all be carried on the base.

[0051] In some possible implementation manners, the base may be a rigid base. Exemplarily, the base may be any one of a glass base, a quartz base, or a ceramic base. For example, the glass base may be composed of soda-lime glass and / or borosilicate glass. These types of bases may have good mechanical strength and good thermal stability.

[0052] In some possible implementation manners, the base may be a flexible base. Exemplarily, the base may be composed of a polymer material. For example, the polymer material here may include one or more of the following: polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate (PEN), or cyclo olefin copolymer (COC), etc. These polymer materials may have good optical properties and mechanical properties, enabling the base to be bent and deformed, and further enabling the display panel 100 to meet the usage requirements of foldable electronic devices (such as foldable mobile phones).

[0053] In some possible implementation manners, the base may also be jointly composed of the inorganic materials constituting the rigid base and the polymer materials constituting the flexible base as described above, and the present application does not limit this.

[0054] Exemplarily, the base may have a multi-layer structure. For example, the base may include a first synthetic resin layer, a multi-layer or single-layer inorganic layer, and a second synthetic resin layer disposed on the multi-layer or single-layer inorganic layer. Each of the first synthetic resin layer and the second synthetic resin layer may contain a polyimide resin.

[0055] The planarization layer 120 is located on the substrate 110, and the planarization layer 120 is mainly used to form a flat surface on the surface of the substrate 110. The material of the planarization layer 120 can be: organic polymers such as polyimide, silicone, polyamide, acrylic acid, etc.

[0056] The first groove 121 on the planarization layer 120 can increase the lateral transmission speed of OLED material molecules in the common layer 230 and improve the crosstalk problem of the tandem OLED.

[0057] The display panel 100 can be a tandem structure (i.e., Tandem OLED) including multiple light-emitting devices OLED (such as dual-device OLED), and the common layer 230 can include a first light-emitting stack 231, a charge generation layer 232, and a second light-emitting stack 233 stacked along the first direction.

[0058] Figure 4 Yes Figure 3 The cross-sectional view of the shown display panel along the BB direction.

[0059] As Figure 4 As shown, the first light-emitting stack 231 can include a first hole control layer 2311, a first light-emitting layer 2313, and a first electron control layer 2312 stacked along the first direction. Among them, the first hole control layer 2311 can include at least one of a first hole injection layer and a first hole transport layer, and the first hole transport layer can include at least one of a first hole buffer layer and a first electron blocking layer. The first electron control layer 2312 can include at least one of a first electron transport layer and a first electron injection layer, and the first electron control layer 2312 can also include a first hole blocking layer.

[0060] The second light-emitting stack 233 can include a second hole control layer 2331, a second light-emitting layer 2333, and a second electron control layer 2332 stacked along the first direction. Among them, the second hole control layer 2331 can include at least one of a second hole injection layer and a second hole transport layer. The second electron control layer 2332 can include at least one of a second electron injection layer and a second electron transport layer. The descriptions of the first hole control layer 2311 and the first electron control layer 2312 can equally apply to the descriptions of the second hole control layer 2331 and the second electron control layer 2332.

[0061] In some examples, the light emitted from the first light-emitting stack 231 and the second light-emitting stack 233 may have the same wavelength. For example, the light emitted from the first light-emitting stack 231 and the second light-emitting stack 233 may be red light, green light, or blue light. In other examples, the wavelength ranges of the light emitted from the first light-emitting stack 231 and the second light-emitting stack 233 may be different from each other. For example, at least one of the first light-emitting stack 231 and the second light-emitting stack 233 may emit blue light, and the other of the first light-emitting stack 231 and the second light-emitting stack 233 may emit green light, so that the light-emitting element including the first light-emitting stack 231 and the second light-emitting stack 233 can emit white light.

[0062] The charge generation layer 232 may be disposed between the first light-emitting stack 231 and the second light-emitting stack 233. When a voltage is applied to the charge generation layer 232, charges (electrons and holes) can be generated by forming a complex through a redox reaction. In addition, the charge generation layer 232 can supply the generated charges to each of the first light-emitting stack 231 and the second light-emitting stack 233. The charge generation layer 232 can double the efficiency of the current generated by each of the first light-emitting stack 231 and the second light-emitting stack 233 and plays a role in controlling the balance of charges between the first light-emitting stack 231 and the second light-emitting stack 233.

[0063] Still as Figure 2 and Figure 3 shown, the pixel unit A may be a red pixel unit 200 or a green pixel unit 200, and the pixel unit B may be a blue pixel unit 200.

[0064] Figure 5 and Figure 6 are schematic circuit diagrams in the display panel 100 provided by the embodiments of the present application.

[0065] As Figure 5 shown, it may be a schematic circuit diagram at the pixel unit B. At the pixel unit B, the anode 210, the first light-emitting stack 231, the charge generation layer 232, the second light-emitting stack 233, and the cathode 220 are in a series relationship in sequence. Whether tested in a low-brightness state or a high-brightness state, the current in the circuit passes through one circuit.

[0066] As Figure 6As shown, it can be a schematic circuit diagram at pixel unit A. Since the end of the cathode 220 along the second direction is electrically connected to the end of the charge generation layer 232 along the second direction, the charge generation layer 232 and the second light-emitting stack 233 are in a parallel relationship in the circuit. Therefore, there are two circuits at pixel unit A. The first circuit is that current flows from the anode 210 to the first light-emitting stack 231, then to the second light-emitting stack 233, and finally to the cathode 220. The second circuit is that current flows from the anode 210 to the charge generation layer 232, then to the second light-emitting stack 233, and finally to the cathode 220.

[0067] Before testing the display panel 100, since the resistances of the first light-emitting stack 231 and the second light-emitting stack 233 are small, the current mainly passes through the first circuit. At this time, the display panel 100 is a series OLED device.

[0068] Under the test of the high-brightness state, the first circuit still dominates. At this time, the display panel 100 is a series OLED device; while under the test of the low-brightness state, the resistances of the first light-emitting stack 231 and the second light-emitting stack 233 increase, and the direction of the current will tend from the first circuit to the second circuit. In the second circuit, it can be considered that the charge generation layer 232 shorts the first light-emitting stack 231, so that in the second circuit, the voltage division obtained by the second light-emitting stack 233 becomes larger, the output current becomes more, and the brightness of the second light-emitting stack 233 is increased. At this time, most of the current passes through the second light-emitting stack 233. At this time, the display panel 100 is equivalent to a single OLED device, and the brightness is increased.

[0069] Among them, the low-brightness state can refer to a brightness less than 100 nit, and the high-brightness state can refer to a brightness greater than or equal to 100 nit.

[0070] Based on the above technical solution, in the low-brightness state, the current output by the second light-emitting stack 233 becomes more, increasing the brightness of the display panel 100 and improving the problem that the OLED device decays too fast in the low-brightness state.

[0071] In some possible implementation manners, the angle between the first sidewall 240a of the pixel definition layer 240 on the side away from the anode 210 along the second direction and the second sidewall 121a of the first groove 121 on the side close to the pixel definition layer 240 is greater than 180 degrees.

[0072] It can be understood that the cross-section of the pixel definition layer 240 along the second direction can be regarded as a trapezoid, and the cross-section of the first groove 121 along the second direction can also be regarded as a trapezoid.

[0073] It can be understood that when the angle between the first sidewall 240a and the second sidewall 121a is less than 180 degrees, it is difficult for the charge generation layer 232 and the cathode 220 to be fully overlapped during the deposition process. When the angle between the first sidewall 240a and the second sidewall 121a is greater than 180 degrees, the charge generation layer 232 and the cathode 220 can be effectively overlapped.

[0074] Based on the above technical solution, when the angle between the pixel definition layer and the first groove is greater than 180 degrees, during the deposition and forming process of the pixel unit, the cathode and the charge generation layer are more likely to be overlapped, improving the reliability of the forming process of the display panel.

[0075] In some possible implementation manners, the size of the pixel definition layer 240 in the first direction is less than or equal to 1.5 micrometers, that is to say, the thickness of the pixel definition layer 240 is less than or equal to 1.5 micrometers.

[0076] It should be noted that the thickness of the pixel definition layer 240 affects the angle between the first sidewall 240a and the second direction. The thinner the thickness of the pixel definition layer 240, the larger the angle between the first sidewall 240a and the second direction under the same exposure time.

[0077] Based on the above technical solution, when the thickness of the pixel definition layer is thin enough, the angle between the sidewall of the pixel definition layer and the second direction is larger, which is more beneficial to the overlap of the cathode and the charge generation layer during the deposition and forming process of the pixel unit, further improving the reliability of the forming process of the display panel.

[0078] On the other hand, during the process of forming the pixel definition layer 240 by exposure, the longer the irradiation time of the ultraviolet lamp, the larger the angle between the first sidewall 240a and the second direction.

[0079] It should be noted that the angle between the second sidewall 121a of the first groove 121 in the planarization layer 120 and the second direction is mainly affected by the etching process. For example, when etching the first groove 121 in an oxygen environment, the larger the oxygen etching amount, the larger the angle between the second sidewall 121a and the second direction, that is, the larger the angle between the first sidewall 240a and the second sidewall 121a.

[0080] Figure 7 It is a top view schematic diagram of a display panel 100 provided by an embodiment of the present application. Figure 8 is Figure 7 a cross-sectional view of the display panel 100 shown in

[0081] and Figure 2Compared with the display panel 100 shown, the display panel 100 further includes an inorganic isolation layer 250, which is located between the pixel unit 200 and the planarization layer 120, and the projection of the inorganic isolation layer 250 on the substrate 110 falls within the first groove 121.

[0082] In Figure 8 the display panel 100 shown, the relevant characteristics of the substrate 110, the planarization layer 120, the pixel unit 200, the common layer 230, and the cathode 220 can be referred to the description of Figure 2 and Figure 3 . For the sake of brevity, they will not be elaborated here.

[0083] Among them, the pixel unit C can be a red pixel unit 200, the pixel unit A can be a green pixel unit 200, and the pixel unit B can be a blue pixel unit 200.

[0084] The inorganic isolation layer 250 is located on the planarization layer 120, and the material of the inorganic isolation layer 250 can be an inorganic material such as silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, or indium tin oxide.

[0085] When the inorganic isolation layer 250 is provided in the display panel 100, since the projection of the inorganic isolation layer 250 on the substrate 110 falls within the first groove 121, it is equivalent to separating the pixel unit 200 from the planarization layer 120. During the deposition of the pixel unit 200 on the inorganic isolation layer 250, the cathode 220 and the charge generation layer 232 can be electrically connected on the inorganic isolation layer 250. Even if the angle between the first sidewall 240a and the second sidewall 121a is less than 180 degrees, the cathode 220 and the charge generation layer 232 can be overlapped on the inorganic isolation layer 250.

[0086] In some possible implementation manners, the pixel unit 200 includes a red pixel unit 200, and the length of the projection of the inorganic isolation layer 250 along the first direction in the first groove 121 is greater than or equal to 2 micrometers and less than or equal to 4 micrometers.

[0087] As Figure 8 shown, the length of the projection of the inorganic isolation layer 250 along the first direction in the first groove 121 can be represented by d1, and d1 satisfies the condition: 2 micrometers ≤ d1 ≤ 4 micrometers.

[0088] The pixel unit C can be a red pixel unit 200. Combining Figure 1a and Figure 1bIt can be seen that in the test of the display panel 100, the brightness of the red pixels decays faster than that of the green pixels after the test, that is, the low gray-scale brightness of the red pixels deteriorates more than that of the green pixels. Therefore, when the pixel unit 200 is a red pixel unit 200, the length of the projection of the inorganic isolation layer 250 in the first groove 121 along the first direction can be relatively long.

[0089] When the length of d1 is long, it can increase the overlapping area of the charge generation layer 232 and the cathode 220 on the inorganic isolation layer 250, which is beneficial to increasing the effective overlapping area of the charge generation layer 232 and the cathode 220, and the current can pass through here more easily. Combining Figure 6 with the circuit schematic diagram shown, after the overlapping area of the charge generation layer 232 and the cathode 220 increases, it can improve the voltage division of the second light-emitting stack 233, which is more beneficial to improving the brightness of the OLED device.

[0090] In some possible implementation manners, the pixel unit 200 includes a green pixel unit 200, and the length of the projection of the inorganic isolation layer 250 in the first groove 121 along the first direction is greater than or equal to 1 μm and less than or equal to 2 μm.

[0091] As Figure 8 shown, the length of the projection of the inorganic isolation layer 250 in the first groove 121 along the first direction can be represented by d2, and d2 satisfies the condition: 1 μm ≤ d2 ≤ 2 μm.

[0092] Combining Figure 1b with, when the pixel unit 200 is a green pixel unit 200, since the brightness decay rate of the green pixel unit 200 is relatively slow. Therefore, when the pixel unit 200 is a green pixel unit 200, the length of the projection of the inorganic isolation layer 250 in the first groove 121 along the first direction can be relatively short.

[0093] Combining Figure 1c with, when the pixel unit 200 is a blue pixel unit 200, when the blue pixel unit 200 is tested at high brightness and low brightness respectively, the brightness of the blue pixel unit 200 changes little before and after the test. Therefore, when the pixel unit 200 is a blue pixel unit 200, the length of the projection of the inorganic isolation layer 250 in the first groove 121 along the first direction can be 0, that is, the blue pixel unit 200 can always remain in the state of the series OLED device.

[0094] An embodiment of the present application further provides a display device, and the display device includes the display panel described in any of the above embodiments.

[0095] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0096] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0097] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0098] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0099] In addition, the functional units in each embodiment of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0100] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs.

[0101] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A display panel, characterized in that, The display panel includes: a substrate; a planarization layer located on the substrate, a first groove is provided on a side of the planarization layer away from the substrate along a first direction, and the first direction is a direction perpendicular to the plane where the substrate is located; a pixel unit, the pixel unit includes: an anode located on the planarization layer; a pixel definition layer, the pixel definition layer is disposed around the anode on the planarization layer, and a projection of the pixel definition layer on the substrate does not overlap with the first groove; a common layer located on the anode and the pixel definition layer, the common layer includes a first light-emitting stack, a charge generation layer, and a second light-emitting stack stacked along the first direction; a cathode, the cathode is located on the common layer, an end of the cathode along a second direction is electrically connected to an end of the charge generation layer along the second direction, the second direction is the direction of the plane where the substrate is located, and the first direction is perpendicular to the second direction.

2. The display panel according to claim 1, wherein an angle between a first sidewall of the pixel definition layer on a side away from the anode along the second direction and a second sidewall of the first groove on a side close to the pixel definition layer is greater than 180 degrees.

3. The display panel according to claim 1 or 2, wherein a dimension of the pixel definition layer along the first direction is less than or equal to 1.5 micrometers.

4. The display panel according to any one of claims 1-3, characterized in that, It further includes: an inorganic isolation layer, the inorganic isolation layer is located between the pixel unit and the planarization layer, and a projection of the inorganic isolation layer on the substrate falls into the first groove.

5. The display panel according to claim 4, wherein the pixel unit includes a red pixel unit, and a length of a projection of the inorganic isolation layer falling into the first groove along the first direction is greater than or equal to 2 micrometers and less than or equal to 4 micrometers.

6. The display panel according to claim 4, wherein the pixel unit includes a green pixel unit, and a length of a projection of the inorganic isolation layer falling into the first groove along the first direction is greater than or equal to 1 micrometer and less than or equal to 2 micrometers.

7. A display device, characterized in that, The display device includes: the display panel according to any one of claims 1-6.

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