Display panel and display device

Abstract

The invention relates to a display panel and a display device, and relates to the technical field of display. The display panel is provided with a plurality of sub-pixels arranged in an array mode, and the sub-pixels comprise the first sub-pixels and the second sub-pixels. The display panel comprises a driving back plate, a pixel layer, a thin film packaging layer and a color film layer which are sequentially arranged in a stacked mode. The light-emitting element of the second sub-pixel is provided with a plurality of organic light-emitting layers which are arranged in a stacked manner; the organic light-emitting layer comprises a second light-emitting layer closest to the thin film packaging layer and a first light-emitting layer far away from the thin film packaging layer; the emergent light of the second sub-pixel at least partially comes from the second light-emitting layer; the thin film packaging layer is provided with thinning grooves which are in one-to-one correspondence with the second sub-pixels. According to the display panel provided by the invention, the optical crosstalk between the adjacent sub-pixels is reduced.

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 a 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 sub-pixels of Micro OLED display devices is more obvious, and 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 life of Micro OLED.

[0003] Dividing the white light emitting layer into two or more light emitting layers and constructing a tandem OLED device can effectively improve important optoelectronic performance indicators such as Micro OLED current efficiency, output brightness, and operating life. Introducing a charge generation layer (CGL) to connect multiple light emitting layers in series to construct a tandem light emitting device can achieve the effect of light superposition. Tandem OLED has the advantages of higher brightness and longer life, but the problem of color crosstalk between pixels has not yet been solved.

[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 the 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, by locally thinning the thin film encapsulation layer in the light-emitting element, thereby increasing the coverage range of the corresponding color film unit to the light output angle of the light-emitting element and reducing crosstalk to adjacent sub-pixels.

[0006] According to one aspect of the present disclosure, there is provided a display panel having a plurality of sub-pixels arranged in an array, wherein the sub-pixels include 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 film layer which are stacked in sequence;

[0008] The pixel layer has a light-emitting element corresponding to each sub-pixel one by one; the light-emitting element of the second sub-pixel has a plurality of organic light-emitting layers stacked in 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 far from the thin-film encapsulation layer; the emitted light of the second sub-pixel at least partially comes from the second light-emitting layer;

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

[0010] The thin film encapsulation layer has thinning grooves corresponding one by one to each of the second sub-pixels, and the orthographic projection of the thinning grooves on the plane where the driving backplane is located covers the orthographic projection of the corresponding light-emitting element of the second sub-pixel 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 emitted light of 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 light-emitting colors of the first light-emitting layer and the second light-emitting layer are the same;

[0015] The light emission wavelength of the second sub-pixel is smaller than the light emission wavelength of 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 which are stacked in sequence; the pixel electrode layer has pixel electrodes corresponding to each sub-pixel one by one;

[0025] The pixel definition layer has pixel openings corresponding to the respective pixel electrodes one by one, and the pixel openings expose a part or the whole 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 respective 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, comprising 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 present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings herein are incorporated into the specification 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 accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

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

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

[0033] Figure 2-2 FIG. 1 is a cross-sectional schematic diagram of a display panel in one embodiment of the present disclosure.

[0034] Figure 3-1 It is a cross-sectional schematic diagram of a light-emitting element in one embodiment of the present disclosure.

[0035] Figure 3-2 FIG. 1 is a schematic diagram of a film layer of a light-emitting element in one embodiment of the present disclosure.

[0036] Figure 4 It is a schematic diagram of a sub-pixel cross-sectional structure in the 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 It is a schematic diagram of the luminescence detection results of the display panel before and after improvement in one embodiment of the present disclosure.

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

[0042] Fig.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 film unit; BEML1, blue first light-emitting layer; BEML2, blue second light-emitting layer; Buff, inorganic buffer layer; CE, cathode; CFL, color film layer; CFU1, first color film unit; CFU2, second color film 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 stacking 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 film 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 a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only 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 relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another 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 an 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 merely 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 at least on one side of the display area AA, for example, the peripheral area BB surrounds the display area AA. In the display area AA, the display panel PNL is provided with sub-pixels for display; in the peripheral area BB, the display panel PNL may not be provided with sub-pixels for display, or the provided sub-pixels 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. Further, 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 only sub-pixels PIX of 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 driving 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 is provided with a light-emitting element LD of a sub-pixel PIX, and the driving backplane DBP is used to drive the light-emitting element LD in the pixel layer PIXL. The driving backplane DBP may drive each light-emitting element LD in an active driving manner or in a passive driving manner.

[0051] In one embodiment of the present disclosure, see Figure 2-1 The driving backplane DBP includes a substrate SBT and a driving layer DRL disposed on one side of the substrate SBT; the pixel layer PIXL is disposed on the side of the driving layer DRL away from the substrate SBT. The driving layer DRL is provided with a pixel driving circuit for driving sub-pixels PIX; each sub-pixel PIX can emit light under the drive of the pixel driving circuit to display a picture.

[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 glass materials such as soda-lime glass, quartz glass, and sapphire glass. In some other embodiments of the present disclosure, the material of the substrate SBT can be polymethyl methacrylate, polyvinyl alcohol, polyvinyl phenol, polyether sulfone, 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 driving layer DRL, any pixel driving circuit may include a thin film transistor TFT and a storage capacitor. Further, the thin film transistor TFT may be selected from a top gate thin film transistor, a bottom gate thin film transistor or a double 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 polycrystalline silicon 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. Exemplarily, in some embodiments, in a pixel driving circuit, some transistors may be N-type transistors and some transistors may be P-type transistors. Again exemplarily, 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 transistor is a low-temperature polysilicon transistor. 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 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 other film layers. Among them, the positional relationship of each film layer can be determined according to the film layer structure of the thin film transistor. Further, the semiconductor layer SCL can be used to form the channel region of the transistor, and when necessary, it can also be formed by conductorization to form part of the wiring or conductive structure. The gate layer can be used to form one or more of the gate layer wirings such as the scanning wiring, the reset control wiring, and the light emitting control wiring, and can also be used to form the gate of the transistor, and can also be used to form part or all of the electrode plates of the storage capacitor. The source-drain metal layer can be used to form source-drain metal layer wirings such as data wiring and driving power supply voltage wiring, and can also be used to form part of the electrode plates of the 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 multilayered, 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, and the passivation layer may be disposed 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 which are stacked in sequence, and the thin film transistor formed in this way is a top-gate thin film transistor.

[0058] It is understandable that the above example of the driving backplane DBP is only one possible way of the driving backplane DBP of the embodiment of the present disclosure. In other embodiments of the present disclosure, the driving backplane DBP can also be other structures, for example, see 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 FIG. 2 , the pixel layer PIXL may include a pixel electrode layer PEL, a light emitting functional layer EFL and a common electrode layer COML stacked in sequence. Among them, the pixel electrode layer PEL has a plurality of pixel electrodes PE in the display area of ​​the display panel; the portion of the light emitting functional layer EFL connected to the pixel electrode 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] Further, the pixel layer PIXL may also include a pixel definition layer PDL located between the pixel electrode layer PEL and the light-emitting function layer EFL. The pixel definition layer PDL has a plurality of through 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 internal 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 function unit EFU), thereby defining the light-emitting area and light-emitting area of ​​the light-emitting element LD. The light-emitting function layer EFL at least covers the pixel electrode PE exposed by the pixel definition layer PDL. The common electrode layer COML may cover the light-emitting function 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 function layer EFL, so that the light-emitting function layer EFL emits light. The portion of the light-emitting function layer EFL located between the pixel electrode PE and the common electrode layer COML may serve as the light-emitting function 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 an anode AE ​​of the light emitting element LD, and the other serves as a cathode CE of the light emitting element.

[0061] In an 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 light-emitting stack structure ELS, or may include multiple stacked light-emitting stack structures ELS. When the light-emitting functional unit EFU includes multiple light-emitting stack structures ELS, a charge generation layer CGL may be provided between two adjacent light-emitting stack structures ELS. Each light-emitting stack 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 comprises an anode AE, a light emitting stack structure ELS and a cathode CE which are stacked in sequence. Any layer of the light emitting stack structure ELS comprises a hole regulating layer, an organic light emitting layer and an electron regulating layer which are stacked in sequence, the hole regulating layer is located on the side of the light emitting layer close to the anode AE, and the electron regulating 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 of the film layers such as the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL, wherein the hole injection layer HIL, the hole transport layer HTL, the electron blocking layer EBL, etc. are stacked in sequence along the direction from the anode AE ​​to the light-emitting layer. It is understood that in some examples, one or more of the film layers such as the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL may be set 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, etc.

[0064] The electron regulating layer may include one or more of the electron injection layer EIL, the electron transport layer ETL, the hole blocking layer HBL and other film layers, wherein the electron injection layer EIL, the electron transport layer ETL, the hole blocking layer HBL and the like are stacked in sequence along the 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 other film layers may be arranged 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 arranged in a stacked manner, etc.

[0065] It is understandable that the type of the 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] Referring to FIG. 2 , the thin film encapsulation layer TFE may be disposed on the surface of the pixel layer PIXL away from the 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 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, wherein 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, and 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 film unit (such as the red color film R-CF or the green color film 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, so that the light emission angle of the blue second light-emitting layer BEML2 becomes larger. For example, Figure 4 The light k shown in the figure can pass through the green color film G-CF directly without passing through the blue color film B-CF. Since the emission wavelength range of the blue second light-emitting layer BEML2 partially overlaps with the light transmission wavelength range of the green color film G-CF, when the blue light sub-pixel is turned on, the adjacent green light sub-pixel will also emit part of the 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, and the sub-pixels PIX include a first sub-pixel PIX1 and a second sub-pixel PIX2. The display panel PNL includes a driving 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 has a multi-layer organic light-emitting layer EML which is stacked; the multi-layer organic light-emitting layer EML includes a second light-emitting layer EML2 which is closest to the thin film encapsulation layer TFE, and a first light-emitting layer EML1 which is far away from the thin film encapsulation layer TFE; the emitted light of the second sub-pixel PIX2 comes at least partially 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 to each second sub-pixel PIX2 one by one, 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 the 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, so that the second color filter unit CFU2 is closer to the second light-emitting layer EML2. In this way, the second color filter unit CFU2 can completely cover the light-emitting angle of the second light-emitting layer EML2, and prevent the light emitted from the second light-emitting layer EML2 from directly emitting through the adjacent first color filter unit CFU1, causing light 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 driving backplane DBP, and after the thin film encapsulation layer TFE is formed or during the process of forming the thin film encapsulation layer TFE, the thin film encapsulation layer TFE is patterned to form a thinning groove TG; and then a color filter layer CFL is formed on the side of the thin film encapsulation layer TFE away from the driving backplane DBP. Exemplarily, the thin film encapsulation layer TFE may include one or more stacked inorganic encapsulation layers; at least one layer of the inorganic encapsulation layer is thinned or penetrated by the thinning groove TG. For example, the thin film encapsulation layer TFE includes 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 can penetrate the third inorganic encapsulation layer and thin the second inorganic encapsulation layer to form a deeper thinning groove TG, so that the light-emitting angle of the second light-emitting layer EML2 completely falls within the coverage range of the second color film 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 plurality of organic light-emitting layers EML stacked together; the plurality of organic light-emitting layers EML include a second light-emitting layer EML2 closest to the thin film encapsulation layer TFE, and a first light-emitting layer EML1 far 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., which are arranged on the side of the first light-emitting layer EML1 far 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 which 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, if 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 avoiding crosstalk between two adjacent pixels.

[0077] In one embodiment of the present disclosure, Figure 7 and Fig. 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 emitted light of the second sub-pixel PIX2 comes from the second light emitting layer EML2; the emitted light of the first sub-pixel PIX1 comes from the first light emitting layer EML1.

[0078] In one example, if 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, thereby 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 to improve the front display panel PNL, having Figure 7The display panel PNL of the exemplary laminated structure is the improved display panel PNL. The luminescence detection is performed on the display panel PNL before and after the improvement. The results are as follows: Figure 8 As shown. Under the 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). It shows that the improved display panel PNL provided by this embodiment can effectively improve the color purity of the monochromatic blue light. After improvement, the CIEy value of the blue light decreases by about 0.02, the purity of the monochromatic blue light color point of the display panel increases, and the color gamut of the display panel increases by about 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 has a smaller noise peak than the monochromatic blue light spectrum of the display panel PNL before improvement. Figure 8 At the position indicated by the arrow in (II), the monochromatic blue light spectrum of the display panel PNL after improvement is more obviously reduced than the monochromatic blue light spectrum of the display panel PNL before improvement. This shows that thinning the thin film encapsulation layer TFE (providing a thinning groove TG) at the position corresponding to the second sub-pixel PIX2 can reduce the interference of the stray peaks at multiple angles and improve the color purity of the monochromatic blue light.

[0081] In another example, Fig. 9As shown, the light-emitting element LD of the second sub-pixel 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 which are stacked in sequence; the light-emitting element LD of the first sub-pixel PIX1 includes an anode AE, a blue first light-emitting layer BEML1, a red / green second light-emitting layer R / GEML2 and a cathode CE which are stacked in sequence. That is, 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 sub-pixel PIX2 includes a red sub-pixel and a green sub-pixel, and the first sub-pixel PIX1 is a blue sub-pixel. By setting a thinning groove TG corresponding to the second sub-pixel PIX2 in the thin film encapsulation layer TFE layer, the formed red color film unit RCFU and the green color film unit GCFU are at least partially located within the thinning groove TG. In this way, when the red sub-pixel emits light, the light emitted by the red / green second light-emitting layer R / GEML2 can be completely within the coverage range of the red color film unit RCFU, avoiding the crosstalk caused by the red / green light to the adjacent color film units. When the green sub-pixel emits light, the light emitted by the red / green second light-emitting layer R / GEML2 can be completely within the coverage of the green color filter unit GCFU, avoiding crosstalk between the red / green light and the adjacent color filter units. Exemplarily, the depth of the thinning groove TG on the thin film encapsulation layer TFE corresponding to the red sub-pixel and the green sub-pixel can be determined according to the light-emitting range of the corresponding red / green second light-emitting layer R / GEML2, and the depth of the thinning groove TG can be the same or different.

[0082] Figure 7 and Fig. 9 The display panel PNL having two layers of organic light-emitting layers EML is exemplarily illustrated. 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 can achieve the anti-reflection effect. For example, Figure 7 As shown, the local thickness of the thin film encapsulation layer TFE is adjusted (for example, a thinning groove TG is provided) so that the optical path between the first light-emitting layer EML1 and the first color film unit CFU1 is one-fourth, five-fourths or nine-fourths 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 film unit RCFU is one-fourth, five-fourths or nine-fourths of the wavelength of the red light emitted by the red / green first light-emitting layer R / GEML1, which can improve 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 film unit CFU2 is one-fourth, five-fourths or nine-fourths 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 blue second 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 blue second light-emitting layer BEML2, which can increase the transmittance of the blue light. In this embodiment, the wavelength of the second light-emitting layer EML2 is short, so 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 path between the first light-emitting layer EML1 and the first color filter unit CFU1 is smaller than the optical path between the second light-emitting layer EML2 and the second color filter unit CFU2. Fig. 9As shown, the local thickness of the thin film encapsulation layer TFE is adjusted (for example, a thinning groove TG is set) so that the optical path between the first light-emitting layer EML1 and the first color film unit CFU1 is one-fourth, five-fourths or nine-fourths 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 film unit BCFU is one-fourth, five-fourths or nine-fourths of the wavelength of the blue light emitted by the blue first light-emitting layer BEML1, which can improve 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 film unit CFU2 is one-fourth, five-fourths or nine-fourths of the wavelength of the light emitted by the second light-emitting layer EML2. For example, for the 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, so as to increase 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 smaller 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 may 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 layer of organic light-emitting layer EML, or can include multiple layers of organic light-emitting layers EML. Fig.10As shown, the light-emitting element LD of the second sub-pixel PIX2 includes two layers of organic light-emitting layers EML, which are respectively a blue first light-emitting layer BEML1 and a blue second light-emitting layer BEML2 stacked in sequence on the side away from the anode AE. The first sub-pixel PIX1 includes a red sub-pixel and a green sub-pixel, the red sub-pixel includes a red light-emitting layer REML, and the light-emitting element LD of the green sub-pixel includes a green light-emitting layer GEML. Due to the limiting effect of the pixel definition layer PDL, the red light-emitting layer REML and the green light-emitting layer GEML avoid the crosstalk caused by the excessive light-emitting angles of the red light and the green light to the adjacent sub-pixels. In this embodiment, by setting a thinning groove TG corresponding to the blue sub-pixel on 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, and the coverage range of the blue color filter unit BCFU to the blue light emitted by the blue second light-emitting layer BEML2 is increased, so as to avoid the blue light directly emitting from the adjacent sub-pixels and causing crosstalk to the blue monochromatic light, thereby improving the color purity of the blue light.

[0088] The present disclosure also provides a display device, which includes the above-mentioned display panel PNL. In this way, the display device has the beneficial effects of the display panel PNL provided in the above-mentioned embodiment, which will not be repeated here. The display device can be a VR (Virtual Reality) head display device, an AR (Augmented Reality) wearable device, MR (Mixed Reality) glasses, etc.

[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 modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are 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 comprising 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 film layer which are stacked in sequence; The pixel layer has a light-emitting element corresponding to each sub-pixel one by one; the light-emitting element of the second sub-pixel has a plurality of organic light-emitting layers stacked in 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 far 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 color filter layer includes first color filter units corresponding to each of the first sub-pixels one by one and second color filter units corresponding to each of the second sub-pixels one by one; The thin film encapsulation layer has thinning grooves corresponding to each of the second sub-pixels one by one, and the orthographic projection of the thinning grooves on the plane where the driving backplane is located covers the orthographic projection of the corresponding light-emitting element of the second sub-pixel on the plane where the driving backplane is located; The orthographic projection of the second color film 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.

2. The display panel according to claim 1, characterized in that: 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 emitted light of the first sub-pixel comes from the first light-emitting layer.

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

4. The display panel according to any one of claims 1 to 3, characterized in that: 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, characterized in that: 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, characterized in that: 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 which are stacked in sequence; the pixel electrode layer has pixel electrodes corresponding to each sub-pixel one by one; The pixel definition layer has pixel openings corresponding to the respective pixel electrodes one by one, and the pixel openings expose a part or the whole 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 respective light emitting elements.

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

10. A display device, characterized in that: A display panel comprising any one of claims 1 to 9.

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