Display panel and display device

Abstract

The present disclosure relates to a display panel and a display device, and relates to the field of display technology. The display panel has a plurality of sub-pixels arranged in an array, wherein the sub-pixels include a first sub-pixel and a second sub-pixel; the display panel includes a driving backplane, a pixel layer, a thin-film encapsulation layer, and a color filter layer stacked in sequence; the light-emitting element of the second sub-pixel includes a plurality of stacked organic light-emitting layers; the organic light-emitting layers include a second light-emitting layer closest to the thin-film encapsulation layer and a first light-emitting layer away from the thin-film encapsulation layer; the emitted light of the second sub-pixel at least partially comes from the second light-emitting layer; the thin-film encapsulation layer has a thinning groove corresponding to each second sub-pixel. The display panel provided by the present disclosure reduces optical crosstalk between adjacent sub-pixels.

Description

Technical Field

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

[0002] Micro OLED (micro organic light-emitting diode) display devices need to have ultra-high resolution (usually >2000ppi (pixel per inch)) to meet the needs of small size, lightweight and ultra-high definition. In order to achieve such resolution, the pixel size of Micro OLED display devices is usually in the micron level or even nanometer level. The pixels of traditional LCD (display device) and OLED display (100-500ppi) are much larger than those of Micro OLED display devices. Due to the extremely small pixel size, the cross-color problem between the sub-pixels of Micro OLED display devices is more obvious. Due to the limitation of process precision, Micro OLED display devices cannot achieve the red, green and blue side-by-side pixel arrangement similar to large-size OLED display devices. Instead, they use white light emitting elements with RGB (red, green and blue) three-color gel filtering to achieve full-color display, which also limits the efficiency, brightness and lifespan of Micro OLED.

[0003] Splitting the white light-emitting layer into two or more light-emitting layers to create a tandem OLED device can effectively improve key optoelectronic performance indicators of Micro OLEDs, such as current efficiency, output brightness, and operating life. Introducing a charge generation layer (CGL) in series with multiple light-emitting layers to create a tandem OLED device can achieve the effect of superimposed light. Tandem OLEDs offer the advantages of higher brightness and longer lifespan, but they still haven't solved the problem of color crosstalk between pixels.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0005] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned prior art and to provide a display panel and a display device, which increases the coverage range of the corresponding color film unit on the light-emitting element's light-emitting angle by locally thinning the thin-film encapsulation layer in the light-emitting element and reduces crosstalk to adjacent sub-pixels.

[0006] According to one aspect of the present disclosure, a display panel is provided, the display panel having a plurality of sub-pixels arranged in an array, the sub-pixels including a first sub-pixel and a second sub-pixel;

[0007] The display panel includes a driving backplane, a pixel layer, a thin film encapsulation layer and a color filter layer stacked in sequence;

[0008] The pixel layer has a light-emitting element corresponding to each sub-pixel; the light-emitting element of the second sub-pixel has a plurality of stacked organic light-emitting layers; the plurality of organic light-emitting layers includes a second light-emitting layer closest to the thin-film encapsulation layer and a first light-emitting layer farther from the thin-film encapsulation layer; and light emitted from the second sub-pixel is at least partially emitted from the second light-emitting layer.

[0009] The color filter layer includes a first color filter unit corresponding to each of the first sub-pixels one-to-one and a second color filter unit corresponding to each of the second sub-pixels one-to-one;

[0010] The thin film encapsulation layer has a thinning groove corresponding to each second sub-pixel one by one, and the orthographic projection of the thinning groove on the plane where the driving backplane is located covers the orthographic projection of the corresponding second sub-pixel's light-emitting element on the plane where the driving backplane is located; the orthographic projection of the second color film unit on the plane where the driving backplane is located covers the orthographic projection of the corresponding thinning groove on the plane where the driving backplane is located.

[0011] In an exemplary embodiment of the present disclosure, the light-emitting element of the second sub-pixel is the same as the light-emitting element of the first sub-pixel; the light-emitting color of the first light-emitting layer is different from the light-emitting color of the second light-emitting layer;

[0012] The emitted light of the second sub-pixel comes from the second light-emitting layer;

[0013] The light emitted by the first sub-pixel comes from the first light-emitting layer.

[0014] In an exemplary embodiment of the present disclosure, in the light-emitting element of the second sub-pixel, the first light-emitting layer and the second light-emitting layer emit the same light color;

[0015] The wavelength of light emitted by the second sub-pixel is smaller than the wavelength of light emitted by the first sub-pixel.

[0016] In an exemplary embodiment of the present disclosure, the thin film encapsulation layer includes one or more stacked inorganic encapsulation layers;

[0017] At least one of the inorganic encapsulation layers is thinned or penetrated by the thinning groove.

[0018] In an exemplary embodiment of the present disclosure, a charge generation layer is provided between the first light-emitting layer and the second light-emitting layer.

[0019] In an exemplary embodiment of the present disclosure, the wavelength of the light-emitting color of the first light-emitting layer is greater than the wavelength of the light-emitting color of the second light-emitting layer;

[0020] The optical distance between the first light-emitting layer and the first color filter unit is greater than the optical distance between the second light-emitting layer and the second color filter unit.

[0021] In an exemplary embodiment of the present disclosure, the wavelength of the light-emitting color of the first light-emitting layer is smaller than the wavelength of the light-emitting color of the second light-emitting layer;

[0022] The optical distance between the first light-emitting layer and the first color filter unit is shorter than the optical distance between the second light-emitting layer and the second color filter unit.

[0023] In an exemplary embodiment of the present disclosure, the driving backplane is a silicon-based driving substrate;

[0024] The pixel layer includes a pixel electrode layer, a pixel definition layer, a light-emitting function layer and a common electrode layer stacked in sequence; the pixel electrode layer has a pixel electrode corresponding to each sub-pixel one by one;

[0025] The pixel definition layer has pixel openings corresponding to the respective pixel electrodes, and the pixel openings expose a portion or the entire area of ​​the corresponding pixel electrode;

[0026] The light emitting function layer and the common electrode layer cover the pixel electrodes exposed by the pixel definition layer to form various light emitting elements.

[0027] In an exemplary embodiment of the present disclosure, the pixel density of the sub-pixel is not less than 2000 PPI.

[0028] According to another aspect of the present disclosure, a display device is provided, including the above-mentioned display panel.

[0029] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0031] Figure 1 This is a top view of a display panel in one embodiment of the present disclosure.

[0032] Figure 2-1FIG1 is a cross-sectional schematic diagram of a display panel in one embodiment of the present disclosure.

[0033] Figure 2-2 FIG1 is a cross-sectional schematic diagram of a display panel in one embodiment of the present disclosure.

[0034] Figure 3-1 Schematic cross-sectional view of a light-emitting element in one embodiment of the present disclosure.

[0035] Figure 3-2 Schematic diagram of the film layer of a light-emitting element in one embodiment of the present disclosure.

[0036] Figure 4 Schematic diagram of a sub-pixel cross-sectional structure in related art.

[0037] Figure 5 Schematic diagram of a sub-pixel cross-sectional structure in one embodiment of the present disclosure.

[0038] Figure 6 Schematic diagram of a sub-pixel cross-sectional structure in one embodiment of the present disclosure.

[0039] Figure 7 Schematic diagram of a sub-pixel cross-sectional structure in one embodiment of the present disclosure.

[0040] Figure 8 Schematic diagram of luminescence detection results of a display panel before and after improvement in one embodiment of the present disclosure.

[0041] Figure 9 Schematic diagram of a sub-pixel cross-sectional structure in one embodiment of the present disclosure.

[0042] Figure 10 Schematic diagram of a sub-pixel cross-sectional structure in one embodiment of the present disclosure.

[0043] The reference numerals are as follows:

[0044] AA, display area; AE, anode; BB, peripheral area; BCFU, blue color filter unit; BEML1, blue first light-emitting layer; BEML2, blue second light-emitting layer; Buff, inorganic buffer layer; CE, cathode; CFL, color filter layer; CFU1, first color filter unit; CFU2, second color filter unit; CGL, charge generation layer; COML, common electrode layer; CVD1, first inorganic encapsulation layer; CVD2, second inorganic encapsulation layer; DBP, driving backplane; DRL, driving layer; EBL, electron blocking layer; EFL, light-emitting functional layer; EFU, light-emitting functional unit; EIL, electron injection layer; ELS, light-emitting stack structure; EML, organic light-emitting layer; EML1, first light-emitting layer; EML2, second light-emitting layer; EML3, third light-emitting layer; ETL, electron transport layer; GCFU, green color filter unit; GEML, green light-emitting layer; G EML2, green second light-emitting layer; GI, gate insulating layer; GT, gate layer; HBL, hole blocking layer; HIL, hole injection layer; HTL, hole transport layer; IJP, organic encapsulation layer; ILD, interlayer dielectric layer; LD, light-emitting element; PDL, pixel definition layer; PE, pixel electrode; PEL, pixel electrode layer; PIX, sub-pixel; PIX1, first sub-pixel; PIX2, second sub-pixel; PIXL, pixel layer; PLN, planarization layer; PNL, display panel; R / GEML1, red / green first light-emitting layer; R / GEML2, red / green second light-emitting layer; RCFU, red color film unit; REML, red light-emitting layer; REML2, red second light-emitting layer; SBT, substrate; SCL, semiconductor layer; SD, source and drain metal layer; TFE, thin film encapsulation layer; TFT, thin film transistor; TG, thinning groove. DETAILED DESCRIPTION

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent identical or similar structures, and thus their detailed descriptions will be omitted. Furthermore, the figures are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0046] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one illustrated component to another, these terms are used herein for convenience only, such as in accordance with the orientation of the illustrations in the accompanying drawings. It will be understood that if the illustrated device were flipped upside down, the component described as "upper" would become the component "lower." When a structure is referred to as "on" another structure, this may mean that the structure is integrally formed with the other structure, that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via the other structure.

[0047] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second", etc. are used only as labels and are not intended to limit the quantity of their objects.

[0048] The present disclosure provides a display panel PNL. Figure 1 The display panel PNL includes a display area AA and a peripheral area BB located on at least one side of the display area AA. For example, the peripheral area BB surrounds the display area AA. The display panel PNL is provided with subpixels for display in the display area AA. In the peripheral area BB, the display panel PNL may not be provided with subpixels for display, or the provided subpixels are not used for displaying images.

[0049] In an embodiment of the present disclosure, the light-emitting element LD of the sub-pixel in the display panel PNL is a thin-film self-luminous element, such as OLED, PLED, QLED, etc. Furthermore, the sub-pixel PIX located in the display area AA includes sub-pixels PIX of multiple different colors. For example, the sub-pixel PIX may include a red sub-pixel for emitting red light, a green sub-pixel for emitting green light, and a blue sub-pixel for emitting blue light. It is understandable that in other embodiments of the present disclosure, the sub-pixel PIX in the display area AA may also include sub-pixels PIX of only two colors, or may also have sub-pixels PIX of other colors (for example, a yellow sub-pixel for emitting yellow light, a sub-pixel for emitting cyan light, a white sub-pixel for emitting white light, etc.).

[0050] In one embodiment of the present disclosure, see Figure 2-1 and Figure 2-2The display panel PNL may include a driver backplane DBP, a pixel layer PIXL, a thin-film encapsulation layer TFE, and a color filter layer CFL, which are stacked in sequence. The pixel layer PIXL includes light-emitting elements LD for the sub-pixels PIX, and the driver backplane DBP is used to drive the light-emitting elements LD in the pixel layer PIXL. The driver backplane DBP may drive each light-emitting element LD using either an active or passive drive method.

[0051] In one embodiment of the present disclosure, see Figure 2-1 The driver backplane (DBP) includes a base substrate (SBT) and a drive layer (DRL) located on one side of the SBT. The pixel layer (PIXL) is located on the side of the drive layer (DRL) away from the base substrate (SBT). The drive layer (DRL) is equipped with a pixel driver circuit for driving the subpixels (PIX). Each subpixel (PIX) emits light under the drive of the pixel driver circuit to display an image.

[0052] Optionally, the substrate SBT can be a substrate of an inorganic material, or a substrate of an organic material; of course, it can also be a composite substrate formed by stacking a substrate of an inorganic material and a substrate of an organic material. For example, in some embodiments of the present disclosure, the material of the substrate SBT can be a glass material such as soda-lime glass, quartz glass, sapphire glass, etc. In some other embodiments of the present disclosure, the material of the substrate SBT can be polymethyl methacrylate, polyvinyl alcohol, polyvinyl phenol, polyethersulfone, polyimide, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polyethylene naphthalate or a combination thereof. In some other embodiments of the present disclosure, the substrate SBT can also be a flexible substrate, for example, the material of the substrate SBT can include polyimide.

[0053] Optionally, in the drive layer DRL, any pixel drive circuit may include a thin film transistor (TFT) and a storage capacitor. Furthermore, the thin film transistor (TFT) may be selected from a top-gate thin film transistor, a bottom-gate thin film transistor, or a dual-gate thin film transistor. The material of the active layer of the thin film transistor may be an amorphous silicon semiconductor material, a low-temperature polysilicon semiconductor material, a metal oxide semiconductor material, an organic semiconductor material, a carbon nanotube semiconductor material, or other types of semiconductor materials. The thin film transistor may be an N-type thin film transistor or a P-type thin film transistor.

[0054] It is understandable that, among the transistors in the pixel driving circuit, the types of any two transistors may be the same or different. For example, in some embodiments, in a pixel driving circuit, some transistors may be N-type transistors and some transistors may be P-type transistors. Again for example, in other embodiments, in a pixel driving circuit, the material of the active layer of some transistors may be a low-temperature polysilicon semiconductor material, and the material of the active layer of some transistors may be a metal oxide semiconductor material. In some embodiments of the present disclosure, the thin film transistors are low-temperature polysilicon transistors. In some other embodiments of the present disclosure, some thin film transistors are low-temperature polysilicon transistors, and some thin film transistors are metal oxide transistors.

[0055] Optionally, the driving layer DRL may include a semiconductor layer SCL, a gate insulating layer GI, a gate layer GT, an interlayer dielectric layer ILD, a source / drain metal layer SD, a planarization layer PLN, etc. stacked between the substrate SBT and the pixel layer PIXL. Each thin film transistor and storage capacitor may be formed by film layers such as the semiconductor layer SCL, the gate insulating layer GI, the gate layer GT, the interlayer dielectric layer ILD, the source / drain metal layer SD, etc. The positional relationship of each film layer may be determined according to the film layer structure of the thin film transistor. Furthermore, the semiconductor layer SCL may be used to form the channel region of the transistor, and may also be formed into partial wiring or conductive structure by conductorization when necessary. The gate layer may be used to form one or more gate layer wirings such as scan wiring, reset control wiring, and light emission control wiring, may also be used to form the gate of a transistor, and may also be used to form part or all of the electrode plates of a storage capacitor. The source / drain metal layer may be used to form source / drain metal layer wirings such as data wiring and drive power supply voltage wiring, and may also be used to form part of the electrode plates of a storage capacitor. Of course, in other embodiments of the present disclosure, the driving layer DRL may further include other film layers as needed, for example, it may further include a light shielding layer located between the semiconductor layer SCL and the substrate SBT. As needed, any of the above-mentioned film layers such as the semiconductor layer SCL, the gate layer GT, the source / drain metal layer SD, etc. may also be multi-layered. For example, the driving layer DRL may include two different semiconductor layers SCL, or two or three source / drain metal layers SD, or two or three gate layers GT. Accordingly, the insulating film layers in the driving layer DRL (such as the gate insulating layer GI, the interlayer dielectric layer ILD, the planarization layer PLN, etc.) may be adaptively increased or decreased, or new insulating film layers may be added as needed.

[0056] Optionally, the driving layer DRL may further include a passivation layer. The passivation layer may be provided on a surface of the source / drain metal layer SD away from the substrate SBT, so as to protect the source / drain metal layer SD.

[0057] As an example, see Figure 2-1 The driving layer DRL may include an inorganic buffer layer Buff, a semiconductor layer SCL, a gate insulating layer GI, a gate layer GT, an interlayer dielectric layer ILD, a source / drain metal layer SD and a planarization layer PLN stacked in sequence, and the thin film transistor formed in this way is a top-gate thin film transistor.

[0058] It is understood that the above example of the driving backplane DBP is only one possible way of driving the backplane DBP in the embodiment of the present disclosure. In other embodiments of the present disclosure, the driving backplane DBP can also be other structures, such as Figure 2-2 , the driving backplane DBP can also be a silicon-based driving substrate, etc.

[0059] See Figure 2 and Figure 3-1 The light-emitting element LD in the pixel layer PIXL is a thin-film light-emitting element, which may include two stacked electrodes and a light-emitting functional unit EFU sandwiched between the two electrodes. For example, referring to FIG2 , the pixel layer PIXL may include a pixel electrode layer PEL, a light-emitting functional layer EFL, and a common electrode layer COML, which are stacked in sequence. The pixel electrode layer PEL includes multiple pixel electrodes PE in the display area of ​​the display panel; the portion of the light-emitting functional layer EFL connected to the pixel electrodes PE serves as the light-emitting functional unit EFU of the light-emitting element LD; and the common electrode layer COML serves as a common electrode electrically connected to the light-emitting functional units EFU of each light-emitting element LD.

[0060] Furthermore, the pixel layer PIXL may also include a pixel definition layer PDL located between the pixel electrode layer PEL and the light-emitting functional layer EFL. The pixel definition layer PDL has a plurality of through-going pixel openings, and any pixel opening exposes at least a portion of the corresponding pixel electrode PE. In some embodiments, the pixel openings are arranged in a one-to-one correspondence with the pixel electrodes. For example, the pixel definition layer PDL covers the edge of the pixel electrode PE and exposes at least a portion of the inner area of ​​the pixel electrode PE, so that the pixel definition layer PDL can effectively define the actual effective area of ​​the pixel electrode PE (the area directly connected to the light-emitting functional unit EFU), thereby defining the light-emitting region and light-emitting area of ​​the light-emitting element LD. The light-emitting functional layer EFL at least covers the pixel electrode PE exposed by the pixel definition layer PDL. The common electrode layer COML can cover the light-emitting functional layer EFL in the display area. The pixel electrode PE and the common electrode layer COML provide carriers such as electrons and holes to the light-emitting functional layer EFL, so that the light-emitting functional layer EFL emits light. The portion of the light-emitting functional layer EFL located between the pixel electrode PE and the common electrode layer COML can serve as the light-emitting functional unit EFU. The pixel electrode PE, the common electrode layer COML, and the light emitting functional unit EFU form a light emitting element LD, wherein one of the pixel electrode PE and the common electrode layer COML serves as the anode AE ​​of the light emitting element LD, and the other serves as the cathode CE of the light emitting element.

[0061] In one example, the pixel electrode PE serves as the anode AE ​​of the sub-pixel PIX, and the common electrode layer COML serves as the cathode CE of the sub-pixel PIX.

[0062] Optionally, the light emitting functional unit EFU may include a single layer of light emitting stacked structure ELS, or may include a stack of multiple layers of light emitting stacked structure ELS. When the light emitting functional unit EFU includes multiple layers of light emitting stacked structure ELS, a charge generation layer CGL may be provided between two adjacent layers of light emitting stacked structure ELS. Each layer of the light emitting stacked structure ELS is provided with one or more light emitting layers, and the light emitting layer may be any one of an organic light emitting layer or a quantum dot layer, and in particular, may be an organic light emitting layer formed by an evaporation process. Figure 3-2 As shown, the light emitting functional unit EFU has a multi-layered light emitting stack structure ELS ( Figure 3-2 A two-layer light emitting stack structure ELS is exemplified in FIG. Figure 3-2 The light-emitting element LD includes an anode AE, a multi-layered light-emitting stack structure ELS, and a cathode CE, which are stacked in sequence. Each layer of the light-emitting stack structure ELS includes a hole regulation layer, an organic light-emitting layer, and an electron regulation layer, which are stacked in sequence. The hole regulation layer is located on the side of the light-emitting layer close to the anode AE, and the electron regulation layer is located on the side of the light-emitting layer close to the cathode CE.

[0063] The hole regulation layer may include one or more layers of a hole injection layer HIL, a hole transport layer HTL, an electron blocking layer EBL, and the like, wherein the hole injection layer HIL, the hole transport layer HTL, the electron blocking layer EBL, and the like are stacked sequentially in a direction from the anode AE ​​to the light-emitting layer. It will be appreciated that in some examples, one or more of the hole injection layer HIL, the hole transport layer HTL, the electron blocking layer EBL, and the like may be configured as a multi-layer stacked structure. For example, the hole transport layer HTL may include a first hole transport layer and a second hole transport layer stacked together.

[0064] The electron regulation layer may include one or more layers of an electron injection layer (EIL), an electron transport layer (ETL), a hole blocking layer (HBL), and the like, wherein the electron injection layer (EIL), the electron transport layer (ETL), the hole blocking layer (HBL), and the like are stacked sequentially in a direction from the cathode (CE) to the light-emitting layer. It is understood that in some examples, one or more of the electron injection layer (EIL), the electron transport layer (ETL), the hole blocking layer (HBL), and the like may be configured as a multi-layer stacked structure. For example, the electron transport layer (ETL) may include a first electron transport layer and a second electron transport layer stacked in layers.

[0065] It is understandable that the type of light emitting element LD is different, and the material and film layer of the light emitting functional unit EFU are different. For example, the light emitting material in the light emitting functional unit can be an organic light emitting material or a quantum dot light emitting material.

[0066] 2 , the thin film encapsulation layer TFE can be provided on the surface of the pixel layer PIXL away from the base substrate SBT, which may include inorganic encapsulation layers and organic encapsulation layers alternately stacked, or may be a multi-layer inorganic encapsulation layer stacked. The inorganic encapsulation layer can effectively block external moisture and oxygen, and prevent water and oxygen from invading the pixel layer PIXL and causing aging of the material in the pixel layer PIXL. Optionally, the edge of the inorganic encapsulation layer may be located in the peripheral area. The organic encapsulation layer is located between two adjacent inorganic encapsulation layers to achieve planarization and reduce the stress between the inorganic encapsulation layers. Among them, the edge of the organic encapsulation layer may be located between the edge of the display area and the edge of the inorganic encapsulation layer. Exemplarily, the thin film encapsulation layer TFE includes a first inorganic encapsulation layer CVD1, an organic encapsulation layer IJP, and a second inorganic encapsulation layer CVD2 sequentially stacked on the side of the pixel layer PIXL away from the base substrate SBT.

[0067] In the related art, in a stacked silicon-based OLED display panel, the OLED includes at least two light-emitting layers. Figure 4As shown, the light-emitting layer includes a first light-emitting layer EML1 and a second light-emitting layer EML2 stacked in sequence. The first light-emitting layer EML1 is located on the side of the second light-emitting layer EML2 away from the TFE. The first light-emitting layer EML1 is a red / green first light-emitting layer R / GEML1 (or a light-emitting layer emitting yellow light), and the second light-emitting layer EML2 is a blue second light-emitting layer BEML2. Figure 4 In the light transmission direction shown in the figure, the light emission angle of the first light-emitting layer EML1 located in the lower layer becomes smaller due to the limiting effect of the pixel definition layer PDL. The light emitted by the first light-emitting layer EML1 is more convergent, and the light emission angle can be completely covered by the corresponding color filter unit (such as the red color filter R-CF or the green color filter G-CF). However, for the blue second light-emitting layer BEML2 located in the upper layer, the limiting effect of the pixel definition layer PDL is weakened, making the light emission angle of the blue second light-emitting layer BEML2 larger. For example, Figure 4 The light ray k shown in the figure can pass directly through the green color filter G-CF without passing through the blue color filter B-CF. Because the emission wavelength range of the blue second light-emitting layer BEML2 partially overlaps with the transmission wavelength range of the green color filter G-CF, when the blue sub-pixel is illuminated, the adjacent green sub-pixel will also emit some green light due to crosstalk, affecting the color purity of the blue monochromatic light, thereby affecting the color gamut of the display panel and reducing the performance of the display panel.

[0068] In order to solve the above problems, the present disclosure provides a display panel PNL, such as Figure 1 Figure 2 Figure 5 and Figure 6As shown, the display panel has a plurality of sub-pixels PIX arranged in an array, each of which includes a first sub-pixel PIX1 and a second sub-pixel PIX2. The display panel PNL includes a driver backplane DBP, a pixel layer PIXL, a thin-film encapsulation layer TFE, and a color filter layer CFL, which are stacked in sequence. The pixel layer PIXL has a light-emitting element LD corresponding to each sub-pixel PIX. The light-emitting element LD of the second sub-pixel PIX2 comprises a stacked multi-layer organic light-emitting layer EML. The multi-layer organic light-emitting layer EML includes a second light-emitting layer EML2 closest to the thin-film encapsulation layer TFE and a first light-emitting layer EML1 further away from the thin-film encapsulation layer TFE. The light emitted by the second sub-pixel PIX2 at least partially originates from the second light-emitting layer EML2. The color filter layer CFL includes a first color filter unit CFU1 corresponding to each first sub-pixel PIX1 and a second color filter unit CFU2 corresponding to each second sub-pixel PIX2. The thin film encapsulation layer TFE has a thinning groove TG corresponding one to each second sub-pixel PIX2, and the orthographic projection of the thinning groove TG on the plane where the driving backplane DBP is located covers the orthographic projection of the corresponding second sub-pixel PIX2's light-emitting element LD on the plane where the driving backplane DBP is located; the orthographic projection of the second color film unit CFU2 on the plane where the driving backplane DBP is located covers the orthographic projection of the corresponding thinning groove TG on the plane where the driving backplane DBP is located.

[0069] In this embodiment, by providing a thinning groove TG corresponding to each second sub-pixel PIX2, the distance between the second color filter unit CFU2 and the second light-emitting layer EML2 is shortened along the light-emitting direction, bringing the second color filter unit CFU2 closer to the second light-emitting layer EML2. This ensures that the second color filter unit CFU2 fully covers the emission angle of the second light-emitting layer EML2, preventing light emitted from the second light-emitting layer EML2 from directly passing through the adjacent first color filter unit CFU1 and causing optical crosstalk.

[0070] In an example, the opening of the thinning groove TG faces the color filter layer CFL.

[0071] In one example, the thin film encapsulation layer TFE in the second sub-pixel PIX2 is provided with a thinning groove TG so that the local thickness of the thin film encapsulation layer TFE in the second sub-pixel PIX2 is reduced. For example, the distance between the second color filter unit CFU2 and the upper surface of the light-emitting element LD of the second sub-pixel PIX2 (the surface close to the color filter layer CFL) is smaller than the distance between the first color filter unit CFU1 and the upper surface of the light-emitting element LD of the first sub-pixel PIX1.

[0072] In one example, a thin film encapsulation layer (TFE) can be formed on the side of the pixel layer PIXL away from the driver backplane (DBP). After or during the formation of the thin film encapsulation layer (TFE), the thin film encapsulation layer (TFE) can be patterned to form a thinning groove (TG). A color filter layer (CFL) can then be formed on the side of the thin film encapsulation layer (TFE) away from the driver backplane (DBP). Exemplarily, the thin film encapsulation layer (TFE) can include one or more stacked inorganic encapsulation layers; at least one of the inorganic encapsulation layers is thinned or penetrated by the thinning groove (TG). For example, the thin film encapsulation layer (TFE) can include a first inorganic encapsulation layer, a second inorganic encapsulation layer, and a third inorganic encapsulation layer stacked in sequence. The thinning groove (TG) can thin or penetrate the third inorganic encapsulation layer, or it can penetrate the third inorganic encapsulation layer and thin the second inorganic encapsulation layer to form a deeper thinning groove (TG), so that the emission angle of the second light-emitting layer (EML2) falls completely within the coverage range of the second color filter unit (CFU2).

[0073] In one example, the thin film encapsulation layer TFE is composed of multiple stacked inorganic encapsulation layers.

[0074] In some other embodiments, the light-emitting element LD of the second sub-pixel PIX2 has a multi-layer organic light-emitting layer EML arranged in a stacked manner; the multi-layer organic light-emitting layer EML includes a second light-emitting layer EML2 closest to the thin film encapsulation layer TFE, and a first light-emitting layer EML1 away from the thin film encapsulation layer TFE; and may also include a third light-emitting layer EML3, a fourth light-emitting layer EML4, etc. arranged on the side of the first light-emitting layer EML1 away from the thin film encapsulation layer TFE.

[0075] In one embodiment of the present disclosure, the driving backplane DBP is a silicon-based driving substrate; the pixel layer PIXL includes a pixel electrode layer PEL, a pixel definition layer PDL, a light-emitting function layer EFL and a common electrode layer COML that are stacked in sequence; the pixel electrode layer has a pixel electrode PE corresponding to each sub-pixel PIX; the pixel definition layer PDL has a pixel opening corresponding to each pixel electrode PE, and the pixel opening exposes a partial area or the entire area of ​​the corresponding pixel electrode; the light-emitting function layer EFL and the common electrode layer COML cover the pixel electrode PE exposed by the pixel definition layer PDL to form each light-emitting element LD. In this way, the pixel definition layer PDL exposes a larger area or the entire area of ​​the pixel electrode, which can increase the PPI of the display panel PNL when the effective light-emitting area is the same. Exemplarily, the pixel density (PPI) of the display panel PNL is not less than 2000PPI.

[0076] Alternatively, as Figure 2-2As shown, the pixel definition layer PDL is provided with a partition groove between two adjacent light-emitting elements LD. The partition groove is located between the two adjacent light-emitting elements LD. The organic layers and common electrodes of the pixel layer are separated at the partition groove, further preventing crosstalk between the two adjacent pixels.

[0077] In one embodiment of the present disclosure, Figure 7 and Figure 9 As shown, the light emitting element LD of the second sub-pixel PIX2 is the same as the light emitting element LD of the first sub-pixel PIX1; the light emitting color of the first light emitting layer EML1 is different from the light emitting color of the second light emitting layer EML2. The light emitted from the second sub-pixel PIX2 comes from the second light emitting layer EML2; the light emitted from the first sub-pixel PIX1 comes from the first light emitting layer EML1.

[0078] In one example, Figure 7 As shown, the light-emitting element LD of the second sub-pixel PIX2 includes an anode AE, a red / green first light-emitting layer R / GEML1, a blue second light-emitting layer BEML2 and a cathode CE which are stacked in sequence. The light-emitting element LD of the first sub-pixel PIX1 includes an anode AE, a red / green first light-emitting layer R / GEML1, a blue second light-emitting layer BEML2 and a cathode CE which are stacked in sequence. That is to say, in this example, the first light-emitting layer EML1 is a red / green light-emitting layer, and the second light-emitting layer EML2 is a blue light-emitting layer. The second sub-pixel PIX2 is a blue sub-pixel, and the first sub-pixel PIX1 is a red sub-pixel and a green sub-pixel. By providing a thinning groove TG corresponding to the second sub-pixel PIX2 in the thin film encapsulation layer TFE layer, the formed blue color film unit BCFU (second color film unit CFU2) is at least partially located within the thinning groove TG, so that the light emitted by the blue second light-emitting layer BEML2 can be completely within the coverage range of the blue color film unit BCFU, thereby avoiding crosstalk caused by blue light to adjacent color film units. As shown Figure 7 As shown in the figure, the blue color film unit BCFU covers the light emission angle of the blue second light-emitting layer BEML2, and all blue light emitted by the blue second light-emitting layer BEML2 passes through the blue color film unit BCFU. In this way, the wavelength range of the blue light passing through the blue color film unit BCFU does not overlap with the filtering wavelength range of the green color film unit GCFU, avoiding the influence of the green light emitted by the adjacent green color film unit GCFU on the color purity of the blue monochromatic light when displaying blue monochromatic light.

[0079] have Figure 4 The exemplary laminated structure display panel PNL is an improved front display panel PNL having Figure 7The display panel PNL of the exemplary laminated structure is the improved display panel PNL. The luminescence test is performed on the display panel PNL before and after improvement. The results are as follows: Figure 8 As shown. At a normal viewing angle, the color gamut coordinates of the monochromatic blue light of the display panel PNL before improvement are (CIEx, CIEy) = (0.1514, 0.0813); the color gamut coordinates of the monochromatic blue light of the display panel PNL after improvement are (CIEx, CIEy) = (0.1464, 0.0573). This shows that the improved display panel PNL provided by this embodiment can effectively improve the color purity of monochromatic blue light. After improvement, the CIEy value of the blue light decreases by approximately 0.02, the color point purity of the monochromatic blue light of the display panel increases, and the color gamut of the display panel is improved by approximately 8%.

[0080] From a positive perspective, Figure 8 The position indicated by the arrow in (I) shows that the monochromatic blue light spectrum of the display panel PNL after improvement is less than that of the monochromatic blue light spectrum of the display panel PNL before improvement. Figure 8 At the location indicated by the arrow in (II), the monochromatic blue light spectrum of the display panel PNL after improvement shows a more significant reduction in the presence of unwanted peaks compared to the monochromatic blue light spectrum of the display panel PNL before improvement. This demonstrates that thinning the thin-film encapsulation layer TFE (by providing a thinning groove TG) at the location corresponding to the second subpixel PIX2 can reduce the interference of unwanted peaks at multiple angles and improve the color purity of the monochromatic blue light.

[0081] In another example, Figure 9As shown, the light-emitting element LD of the second subpixel PIX2 includes an anode AE, a blue first light-emitting layer BEML1, a red / green second light-emitting layer R / GEML2, and a cathode CE, stacked in sequence. The light-emitting element LD of the first subpixel PIX1 also includes an anode AE, a blue first light-emitting layer BEML1, a red / green second light-emitting layer R / GEML2, and a cathode CE, stacked in sequence. In other words, in this example, the first light-emitting layer EML1 is a blue light-emitting layer, and the second light-emitting layer EML2 is a red / green light-emitting layer. The second subpixel PIX2 includes a red subpixel and a green subpixel, and the first subpixel PIX1 is a blue subpixel. By providing a thinning groove TG corresponding to the second subpixel PIX2 in the thin-film encapsulation layer TFE, the red and green color filter units RCFU and GCFU are at least partially located within the thinning groove TG. This ensures that when the red subpixel emits light, the light emitted by the red / green second light-emitting layer R / GEML2 is completely within the coverage area of ​​the red color filter unit RCFU, preventing crosstalk between the red and green light sources and adjacent color filter units. When the green sub-pixel emits light, the light emitted by the red / green second light-emitting layer R / GEML2 is completely within the coverage area of ​​the green color filter unit GCFU, preventing crosstalk between the red / green light and adjacent color filter units. For example, the depth of the thin-film encapsulation layer TFE corresponding to the red and green sub-pixels can be determined based on the light-emitting range of the corresponding red / green second light-emitting layer R / GEML2. The depth of the thin-film encapsulation layer TG can be the same or different.

[0082] Figure 7 and Figure 9 The display panel PNL is shown as an example having two layers of organic light-emitting layers EML. In other embodiments, more than two layers of organic light-emitting layers EML may be provided. For example, three layers of organic light-emitting layers EML may be provided. If the second light-emitting layer EML2 closest to the thin-film encapsulation layer TFE is a blue second light-emitting layer BEML2, the second sub-pixel PIX2 is a blue sub-pixel, and a thinning groove TG corresponding to the blue sub-pixel is provided on the thin-film encapsulation layer TFE. If the second light-emitting layer EML2 closest to the thin-film encapsulation layer TFE is a red second light-emitting layer REML2, the second sub-pixel PIX2 is a red sub-pixel, and a thinning groove TG corresponding to the red sub-pixel is provided on the thin-film encapsulation layer TFE. If the second light-emitting layer EML2 closest to the thin-film encapsulation layer TFE is a green second light-emitting layer GEML2, the second sub-pixel PIX2 is a green sub-pixel, and a thinning groove TG corresponding to the green sub-pixel is provided on the thin-film encapsulation layer TFE.

[0083] In some embodiments of the present disclosure, the thickness of the film layer between the organic light-emitting layer EML and the color filter layer CFL may be adjusted to improve the light emission effect of the organic light-emitting layer EML and achieve light transmittance enhancement.

[0084] In one embodiment of the present disclosure, the wavelength of the light-emitting color of the first light-emitting layer EML1 is greater than the wavelength of the light-emitting color of the second light-emitting layer EML2; the optical path between the first light-emitting layer EML1 and the first color filter unit CFU1 is greater than the optical path between the second light-emitting layer EML2 and the second color filter unit CFU2. In this embodiment, the thickness of the thin film encapsulation layer TFE can be adjusted so that the first light-emitting layer EML1 and the second light-emitting layer EML2 respectively achieve an anti-reflection effect. For example, Figure 7 As shown, the local thickness of the thin-film encapsulation layer (TFE) can be adjusted (for example, by providing a thinning groove TG) so that the optical path between the first light-emitting layer (EML1) and the first color filter unit (CFU1) is one-quarter, five-quarters, or nine-quarters of the wavelength of the light emitted by the first light-emitting layer (EML1). For example, for a red sub-pixel, the optical path between the red / green first light-emitting layer (R / GEML1) and the red color filter unit (RCFU) is one-quarter, five-quarters, or nine-quarters of the wavelength of the red light emitted by the red / green first light-emitting layer (R / GEML1), thereby improving the transmittance of the red light. Similarly, the local thickness of the thin-film encapsulation layer (TFE) can be adjusted so that the optical path between the second light-emitting layer (EML2) and the second color filter unit (CFU2) is one-quarter, five-quarters, or nine-quarters of the wavelength of the light emitted by the second light-emitting layer (EML2). For example, for a blue sub-pixel, the optical path between the second blue light-emitting layer BEML2 and the blue color filter unit BCFU is one-quarter, five-quarters, or nine-quarters of the wavelength of the blue light emitted by the second blue light-emitting layer BEML2, thereby increasing the transmittance of the blue light. In this embodiment, since the wavelength of the second light-emitting layer EML2 is short, the optical path between the first light-emitting layer EML1 and the first color filter unit CFU1 can be greater than the optical path between the second light-emitting layer EML2 and the second color filter unit CFU2.

[0085] In another embodiment of the present disclosure, the wavelength of the light emitting color of the first light emitting layer EML1 is smaller than the wavelength of the light emitting color of the second light emitting layer EML2; the optical distance between the first light emitting layer EML1 and the first color filter unit CFU1 is smaller than the optical distance between the second light emitting layer EML2 and the second color filter unit CFU2. Figure 9As shown, the local thickness of the thin-film encapsulation layer TFE is adjusted (for example, by providing a thinning groove TG) so that the optical path between the first light-emitting layer EML1 and the first color filter unit CFU1 is one-quarter, five-quarters, or nine-quarters of the wavelength of the light emitted by the first light-emitting layer EML1. For example, for a blue sub-pixel, the optical path between the blue first light-emitting layer BEML1 and the blue color filter unit BCFU is one-quarter, five-quarters, or nine-quarters of the wavelength of the blue light emitted by the blue first light-emitting layer BEML1, thereby improving the transmittance of the blue light. Similarly, the local thickness of the thin-film encapsulation layer TFE can be adjusted so that the optical path between the second light-emitting layer EML2 and the second color filter unit CFU2 is one-quarter, five-quarters, or nine-quarters of the wavelength of the light emitted by the second light-emitting layer EML2. For example, for a green sub-pixel, the optical path between the red / green first light-emitting layer R / GEML1 and the green color filter unit GCFU is one-quarter, five-quarters, or nine-quarters of the wavelength of the green light emitted by the red / green first light-emitting layer R / GEML1, thereby increasing the transmittance of the green light. In this embodiment, the wavelength of the first light-emitting layer EML1 is short, so the optical path between the first light-emitting layer EML1 and the first color filter unit CFU1 can be shorter than the optical path between the second light-emitting layer EML2 and the second color filter unit CFU2.

[0086] In some other embodiments, the thickness of other film layers between the first light-emitting layer EML1 and the first color filter unit CFU1 and between the second light-emitting layer EML2 and the second color filter unit CFU2 can be adjusted to adjust the optical path and achieve an anti-reflection effect.

[0087] In one embodiment of the present disclosure, in the light-emitting element LD of the second sub-pixel PIX2, the light-emitting colors of the first light-emitting layer EML1 and the second light-emitting layer EML2 are the same; the light-emitting wavelength of the second sub-pixel PIX2 is smaller than the light-emitting wavelength of the first sub-pixel PIX1. In this embodiment, the light-emitting element LD of the second sub-pixel PIX2 includes at least two layers of organic light-emitting layers EML, and the light-emitting element LD of the first sub-pixel PIX1 can be a single organic light-emitting layer EML, or can include multiple layers of organic light-emitting layers EML. Figure 10As shown, the light-emitting element LD of the second subpixel PIX2 comprises two organic light-emitting layers (EML): a blue first light-emitting layer BEML1 and a blue second light-emitting layer BEML2, stacked sequentially on the side away from the anode AE. The first subpixel PIX1 includes a red subpixel and a green subpixel. The red subpixel includes a red light-emitting layer REML, and the green subpixel's light-emitting element LD includes a green light-emitting layer GEML. Due to the limiting effect of the pixel definition layer (PDL), the red and green light-emitting layers REML and GEML prevent crosstalk between adjacent subpixels caused by excessively wide emission angles of red and green light. In this embodiment, by providing a thinning groove TG corresponding to the blue subpixel in the thin film encapsulation layer TFE, the distance between the blue color filter unit (BCFU) and the blue second light-emitting layer BEML2 is shortened, increasing the coverage of the blue color filter unit (BCFU) for the blue light emitted by the blue second light-emitting layer BEML2. This prevents blue light from directly emitting from adjacent subpixels and causing crosstalk with the blue monochromatic light, thereby improving the color purity of the blue light.

[0088] The present disclosure also provides a display device comprising the aforementioned display panel PNL. This display device has the beneficial effects of the display panel PNL provided in the aforementioned embodiments, which will not be further described here. The display device may be a VR (Virtual Reality) head-mounted display, an AR (Augmented Reality) wearable device, or MR (Mixed Reality) glasses.

[0089] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. A display panel, characterized in that: A plurality of sub-pixels are arranged in an array, the sub-pixels including a first sub-pixel and a second sub-pixel; The display panel includes a driving backplane, a pixel layer, a thin film encapsulation layer and a color filter layer stacked in sequence; The pixel layer has a light-emitting element corresponding to each sub-pixel; the light-emitting element of the second sub-pixel has a plurality of stacked organic light-emitting layers; the plurality of organic light-emitting layers includes a second light-emitting layer closest to the thin-film encapsulation layer and a first light-emitting layer farther from the thin-film encapsulation layer; and light emitted from the second sub-pixel is at least partially emitted from the second light-emitting layer. The color filter layer includes a first color filter unit corresponding to each of the first sub-pixels one-to-one and a second color filter unit corresponding to each of the second sub-pixels one-to-one; The thin film encapsulation layer has a thinning groove corresponding to each second sub-pixel one by one, and the orthographic projection of the thinning groove on the plane where the driving backplane is located covers the orthographic projection of the light-emitting element of the corresponding second sub-pixel on the plane where the driving backplane is located; The orthographic projection of the second color filter unit on the plane where the driving back plate is located covers the orthographic projection of the corresponding thinning groove on the plane where the driving back plate is located; the second color filter unit is at least partially located in the corresponding thinning groove; The distance between the second color filter unit and the surface of the light emitting element of the second sub-pixel close to the color filter layer is smaller than the distance between the first color filter unit and the surface of the light emitting element of the first sub-pixel close to the color filter layer.

2. The display panel according to claim 1, wherein: The light-emitting element of the second sub-pixel is the same as the light-emitting element of the first sub-pixel; the light-emitting color of the first light-emitting layer is different from the light-emitting color of the second light-emitting layer; The emitted light of the second sub-pixel comes from the second light-emitting layer; The light emitted by the first sub-pixel comes from the first light-emitting layer.

3. The display panel according to claim 1, wherein: In the light-emitting element of the second sub-pixel, the first light-emitting layer and the second light-emitting layer emit the same light color; The wavelength of light emitted by the second sub-pixel is smaller than the wavelength of light emitted by the first sub-pixel.

4. The display panel according to any one of claims 1 to 3, wherein: The thin film encapsulation layer includes one or more stacked inorganic encapsulation layers; At least one of the inorganic encapsulation layers is thinned or penetrated by the thinning groove.

5. The display panel according to any one of claims 1 to 3, wherein: A charge generation layer is provided between the first light-emitting layer and the second light-emitting layer.

6. The display panel according to claim 1 or 2, characterized in that: The wavelength of the light-emitting color of the first light-emitting layer is greater than the wavelength of the light-emitting color of the second light-emitting layer; The optical distance between the first light-emitting layer and the first color filter unit is greater than the optical distance between the second light-emitting layer and the second color filter unit.

7. The display panel according to claim 1 or 2, characterized in that: The wavelength of the light-emitting color of the first light-emitting layer is shorter than the wavelength of the light-emitting color of the second light-emitting layer; The optical distance between the first light-emitting layer and the first color filter unit is shorter than the optical distance between the second light-emitting layer and the second color filter unit.

8. The display panel according to claim 1, wherein: The driving backplane is a silicon-based driving substrate; The pixel layer includes a pixel electrode layer, a pixel definition layer, a light-emitting function layer and a common electrode layer stacked in sequence; the pixel electrode layer has a pixel electrode corresponding to each sub-pixel one by one; The pixel definition layer has pixel openings corresponding to the respective pixel electrodes, and the pixel openings expose a portion or the entire area of ​​the corresponding pixel electrode; The light emitting function layer and the common electrode layer cover the pixel electrodes exposed by the pixel definition layer to form various light emitting elements.

9. The display panel according to claim 1, wherein: The pixel density of the sub-pixel is not less than 2000 PPI.

10. A display device, characterized in that: The display panel comprises the display panel according to any one of claims 1 to 9.

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