Patent Publication Number: US-2023165108-A1

Title: Display panel and display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present disclosure is a national phase application under 35 U.S.C. § 371 of International Application No. PCT/CN2021/073142 filed Jan. 21, 2021, the contents of which being incorporated by reference in their entirety herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the technical field of display and, in particular, to a display panel and a display device. 
     BACKGROUND 
     Organic Light Emitting Diode (OLED) display panels have various advantages, such as high color gamut, thinness, and flexibility, and they are widely used in the display field. However, in the related art, the OLED display panel has a relatively low transmittance and is generally yellowish, so that an image obtained by a camera provided under the OLED display panel tends to have an abnormal color. 
     It should be noted that the information disclosed in the above “Background” section is merely intended to reinforce understanding of the background technology of the present disclosure, accordingly the Background may include information that does not constitute the prior art as already known by an ordinary person skilled in the art. 
     SUMMARY 
     An objective of the present disclosure is to overcome the above-mentioned shortcomings in the related art. Thus, the present disclosure provides a display panel and a display device, improving the accuracy of a sensing result of a photosensitive assembly. 
     According to an aspect of the present disclosure, a display panel is provided. The display panel has a first display area and at least one second display area at a side of the first display area. A transmittance of the second display area is greater than a transmittance of the first display area. 
     The display panel includes a base substrate, a driving circuit layer and a pixel light-emitting layer which are sequentially laminated. 
     The base substrate includes at least one organic material layer. The at least one organic material layer is provided with a first groove, and the first groove at least partially overlaps with the second display area. A thickness of a part of the at least one organic material layer close to the first groove gradually decreases from the first display area to the second display area. 
     In an exemplary embodiment of the present disclosure, a slope angle of the at least one organic material layer is 10 degrees to 60 degrees at a position close to the first groove. 
     In an exemplary embodiment of the present disclosure, in the direction from the first display area to the second display area, a width of an orthographic projection of the at least one organic material layer close to a side wall of the first groove on the base substrate is not more than 30 microns. 
     In an exemplary embodiment of the present disclosure, an orthographic projection of the first groove on the base substrate covers the second display area. 
     In an exemplary embodiment of the present disclosure, the base substrate includes a first organic material layer, a first barrier layer and a second organic material layer which are sequentially laminated, and the driving circuit layer is arranged at a side of the second organic material layer away from the first organic material layer; and 
     the first groove is arranged at a side of the second organic material layer away from the first organic material layer. 
     In an exemplary embodiment of the present disclosure, the first groove penetrates through the second organic material layer and exposes a part of the first barrier layer. 
     In an exemplary embodiment of the present disclosure, the base substrate includes a first organic material layer, a first barrier layer and a second organic material layer which are sequentially laminated, and the driving circuit layer is arranged at a side of the second organic material layer away from the first organic material layer; and 
     the first organic material layer is provided with the first groove at a side close to the driving circuit layer. 
     In an exemplary embodiment of the present disclosure, the first groove penetrates through the first organic material layer. 
     In an exemplary embodiment of the present disclosure, the first barrier layer has a hollowed-out hole exposing the first groove; an edge of the hollowed-out hole substantially coincides with an edge of the first groove close to an opening of the first barrier layer. 
     In an exemplary embodiment of the present disclosure, a transmittance of the second organic material layer is greater than that of the first organic material layer. 
     In an exemplary embodiment of the present disclosure, a size of a notch of the first groove is larger than a size of a bottom of the first groove. 
     In an exemplary embodiment of the present disclosure, the display panel further includes a first filling material layer, the first filling material layer is located between the base substrate and the driving circuit layer and located in the first groove; and 
     a transmittance of the first filling material layer is greater than a transmittance of the first organic material layer. 
     In an exemplary embodiment of the present disclosure, the base substrate includes a first organic material layer, a first barrier layer and a second organic material layer which are sequentially laminated, and the driving circuit layer is arranged at a side of the second organic material layer away from the first organic material layer; and 
     the first organic material layer is provided with the first groove at a side away from the driving circuit layer. 
     In an exemplary embodiment of the present disclosure, the display panel further includes a second filling material layer embedded in the first groove; and 
     a transmittance of the second filling material layer is greater than a transmittance of the first organic material layer. 
     In an exemplary embodiment of the present disclosure, the base substrate includes a first organic material layer, a first barrier layer and a second organic material layer which are sequentially laminated, and the driving circuit layer is arranged at a side of the second organic material layer away from the first organic material layer; the first groove is arranged in the second organic material layer; and 
     the first organic material layer is also provided with a second groove at a side thereof away from the driving circuit layer, and an orthographic projection of the second groove on the base substrate covers the second display area. 
     In an exemplary embodiment of the present disclosure, a slope angle of the first organic material layer is 80 degrees to 90 degrees at a position close to the second groove. 
     In an exemplary embodiment of the present disclosure, the display panel further includes a third filling material layer embedded in the second groove; a transmittance of the third filling material layer is greater than a transmittance of the first organic material layer. 
     In an exemplary embodiment of the present disclosure, the display panel further includes a back film layer located at a side of the base substrate away from the driving circuit layer; the back film layer is provided with an opening, and the second display area is located in an orthographic projection of the opening on the base substrate. 
     In an exemplary embodiment of the present disclosure, the display panel further includes a second barrier layer and a buffer layer which are sequentially laminated between the base substrate and the driving circuit layer, the buffer layer is located at a side of the second barrier layer away from the base substrate; and 
     the display panel may further include a planarization layer located between the pixel light-emitting layer and the driving circuit layer. 
     In an exemplary embodiment of the present disclosure, the display panel further includes a touch layer and an anti-drop layer which are sequentially laminated at a side of the pixel light-emitting layer away from the base substrate, the anti-drop layer includes a black matrix layer and a color film layer. 
     According to another aspect of the present disclosure, a display device is provided. The display device includes the display panel as described above and at least one photosensitive assembly, and the photosensitive assembly is located at a side of the display panel close to the substrate and directly faces the second display area. 
     It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description serve to explain the principles of the present disclosure. Understandably, the drawings in the following description are only intended to illustrate some embodiments of the present disclosure, and for those ordinarily skilled in the art, other drawings can be obtained according to these drawings without paying creative efforts. 
         FIG.  1    is a top structural schematic view of a display panel in an embodiment of the present disclosure. 
         FIG.  2    is a top structural schematic view of a display panel in an embodiment of the present disclosure. 
         FIG.  3    is a partially sectional structural schematic view of a display panel in an embodiment of the present disclosure. 
         FIG.  4    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  5    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  6    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  7    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  8    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  9    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  10    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  11    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  12    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  13    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  14    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  15    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  16    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  17    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  18    is a structural schematic view of a supporting substrate having a protruding layer in an embodiment of the present disclosure. 
         FIG.  19    is a structural schematic view of a supporting substrate having a protruding layer in an embodiment of the present disclosure. 
         FIG.  20    is a structural schematic view of preparing a base substrate on a supporting substrate in an embodiment of the present disclosure. 
         FIG.  21    is a structural schematic view of the substrate after peeling off a supporting substrate in an embodiment of the present disclosure. 
         FIG.  22    is a structural schematic view of the substrate after peeling off a supporting substrate in an embodiment of the present disclosure. 
         FIG.  23    is a structural schematic view of preparing a base substrate on a supporting substrate in an embodiment of the present disclosure. 
         FIG.  24    is a structural schematic view of a base substrate after peeling off a supporting substrate in an embodiment of the present disclosure. 
         FIG.  25    is a structural schematic view of a base substrate after peeling off a supporting substrate in an embodiment of the present disclosure. 
         FIG.  26    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
         FIG.  27    is a partially sectional structural schematic view of a display device in an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments will now be described more fully by reference to the accompanying drawings. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the examples set forth herein; rather, the embodiments are provided so that the present disclosure will be thorough and complete, and the conception of exemplary embodiments will be fully conveyed to those skilled in the art. The same reference signs in the drawings denote the same or similar structures and detailed description thereof will be omitted. In addition, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. 
     The wordings “a”, “a”, “the”, “said”, and “at least one” are used to indicate the presence of one or more elements/components/etc. The terms “include”, “comprise”, and “have” are used to express an open-ended inclusive meaning and mean that there may be other elements/components/etc. besides the listed elements/components/etc. The terms “first”, “second”, and “third” are only used as marks, and not as a limit to the number of their objects. 
     Reference numbers used in the drawings are as follows:  100 —back film layer;  110 —adhesion layer;  101 —opening;  200 —base substrate;  210 —organic material layer;  211 —first organic material layer;  212 —first barrier layer;  213 —second organic material layer;  201 —anti-reflection groove;  202 —hollowed-out hole;  203 —thinning groove;  300 —driving circuit layer;  301 —transistor;  310 —semiconductor layer;  320 —gate insulating layer;  330 —gate layer;  340 —interlayer dielectric layer;  350 —source-drain metal layer;  400 —pixel light-emitting layer;  410 —pixel electrode layer;  420 —pixel definition layer;  430 —support column layer;  440 —organic light-emitting functional layer;  450 —common electrode layer;  500 —thin film encapsulation layer;  510 —first inorganic encapsulation layer;  520 —organic encapsulation layer;  530 —second inorganic encapsulation layer;  600 —touch function layer;  700 —anti-drop layer;  801 —cover plate;  802 —optical adhesive layer;  803 —second barrier layer;  804 —buffer layer;  805 —planarization layer;  806 —first filling material layer;  807 —second filling material layer;  808 —third filling material layer;  901 —photosensitive assembly;  902 —supporting substrate;  903 —protruding layer; A—peripheral area; B—display area; C—first display area; and D—second display area. 
     In the related art, the OLED display panel may include a base substrate, a driving circuit layer, and a pixel light-emitting layer which are sequentially laminated. The driving circuit layer is provided with pixel driving circuits, and each of the pixel driving circuits is configured to drive a corresponding one of pixels in the pixel light-emitting layer. In order to improve the flexibility of the display panel, the base substrate may have an organic material, such as a polyimide material. However, in order to effectively support film layers on the display panel, the base substrate needs to have a certain mechanical strength, so that a variety of additives are often added to the organic material of the base substrate, and these additives tends to decrease an absorbance of the base substrate and have different absorptivities for different wavelengths of light. For example, in the related art, the polyimide material as the base substrate tends to have high absorbance and especially, have high absorbance for blue light, which enables the display panel to have high yellow coefficient. 
     The present disclosure provides a display panel. Referring to  FIGS.  1  and  2   , the display panel has a first display area C and at least one second display area D at a side of the first display area C. A transmittance of the second display area D is greater than a transmittance of the first display area C. 
     Referring to  FIGS.  4  to  17   , the display panel includes a base substrate  200 , a driving circuit layer  300 , and a pixel light-emitting layer  400  which are sequentially laminated. The base substrate  200  includes at least one organic material layer  210 , the at least one organic material layer  210  is provided with an anti-reflection groove  201  (i.e., a groove for increasing light transmission), and the anti-reflection groove  201  at least partially overlaps with the second display area D. A thickness of a part of at least one organic material layer  210  close to the anti-reflection groove  201  gradually decreases in a direction from the first display area C to the second display area D. 
     In the present disclosure, the display panel has the second display area D with higher transmittance, and the second display area D may be used for a photosensitive assembly  901  to sense light on a light extraction side of the display panel. In other words, in the display device applying the display panel, the photosensitive assembly  901  may be arranged on a back surface of the display panel and directly face the second display area D. The transmittance of the second display area D is high, thereby improving the accuracy of a sensing result of the photosensitive assembly  901 , for example, the accuracy of an image collected by a camera. 
     The base substrate  200  of the display panel is provided with the anti-reflection groove  201  at least partially overlapping with the second display area D, so that the anti-reflection groove  201  may reduce an absorption of the light transmitted from the second display area D by the base substrate  200 , and further improve the transmittance of the display panel in the second display area D. The thickness of the part of the at least one organic material layer  210  of the base substrate  200  close to the anti-reflection groove  201  gradually decreases in the direction from the first display area C to the second display area D, so that a side wall of the anti-reflection groove  201  is not perpendicular to a plane where the base substrate  200  is located, avoiding adverse effects on the driving circuit layer  300  and the pixel light-emitting layer  400  due to the perpendicular arrangement of the side wall of the anti-reflection groove  201 , and ensuring a display quality of the display panel. 
     Thereinafter, the structure, principle, and effect of the display panel of the present disclosure will be further explained and described with reference to the accompanying drawings. 
     The present disclosure provides a display panel. Referring to  FIG.  3   , the display panel includes a base substrate  200 , a driving circuit layer  300  and a pixel light-emitting layer  400  which are sequentially laminated. The driving circuit layer  300  may be formed with a plurality of pixel driving circuits, and the pixel light-emitting layer  400  may be formed with a plurality of organic light emitting diodes as sub-pixels. Each of the pixel driving circuits is configured to drive a corresponding sub-pixel. 
     In the driving circuit layer  300 , any one of pixel driving circuits may include a thin film transistor  301  and a storage capacitor. The thin film transistor may be a top gate type thin film transistor, a bottom gate type thin film transistor or a double gate type thin film transistor. A material of the active layer of the thin film transistor may be amorphous silicon semiconductor material, low-temperature polysilicon semiconductor material, metal oxide semiconductor material, organic 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. In an embodiment of the present disclosure, the thin film transistor  301  is a low-temperature polysilicon transistor. 
     The driving circuit layer  300  may include a semiconductor layer  310 , a gate insulating layer  320 , a gate layer  330 , an interlayer dielectric layer  340 , a source-drain metal layer  350  and the like laminated between the base substrate  200  and the pixel light-emitting layer  400 . Each of the thin film transistors  301  and the storage capacitor may be formed by the semiconductor layer  310 , the gate insulating layer  320 , the gate layer  330 , the interlayer dielectric layer  340 , the source-drain metal layer  350  or the like. A positional relationship of the film layers may be determined according to the film layer structure of the thin film transistor  301 . For example, in an embodiment of the present disclosure, the driving circuit layer  300  may include the semiconductor layer  310 , the gate insulating layer  320 , the gate layer  330 , the interlayer dielectric layer  340 , and the source-drain metal layer  350 , which are sequentially laminated, so that the formed thin film transistor  301  is in a top gate type. For another example, in another embodiment of the present disclosure, the driving circuit layer may include the gate layer, the gate insulating layer, the semiconductor layer, the interlayer dielectric layer and the source-drain metal layer which are sequentially laminated, and the formed thin film transistor is in a bottom gate type. The driving circuit layer may also has a double gate layer structure, that is, the gate layer may include a first gate layer and a second gate layer, the gate insulating layer may include a first gate insulating layer for isolating the semiconductor layer from the first gate layer and a second gate insulating layer for isolating the first gate layer from the second gate layer. For example, in an embodiment of the present disclosure, the driving circuit layer may include the semiconductor layer, the first gate insulating layer, the first gate layer, the second gate insulating layer, the second gate layer, the interlayer dielectric layer and the source-drain metal layer which are sequentially laminated at a side of the base substrate. 
     In an embodiment of the present disclosure, referring to  FIG.  26   , a transistor may not be provided in the second display area D in order to reduce the influence of the pixel driving circuit on the transmittance. The pixel driving circuits of the sub-pixels located in the second display area D may be arranged in the first display area C. In other embodiments of the present disclosure, referring to  FIG.  16   , a transistor may also be provided in the second display area D. The density of pixel driving circuits in the second display area D may be the same as that in the first display area C or lower than that in the first display area C. 
     Optionally, the driving circuit layer  300  may further include a passivation layer, and the passivation layer may be arranged on a surface of the source-drain metal layer  350  away from the base substrate  200  to protect the source-drain metal layer  350 . 
     Optionally, the display panel may also include a buffer material layer between the base substrate  200  and the driving circuit layer  300 , and the semiconductor layer  310 , the gate layer  330 , and the like are located at a side of the buffer material layer away from the base substrate  200 . The buffer material layer may be made of an inorganic insulating material such as silicon oxide and silicon nitride. The buffer material layer may be a layer of the inorganic material layer or a multilayer laminated inorganic material layer. For example, in an embodiment of the present disclosure, referring to  FIG.  3   , the buffer material layer may include a second barrier layer  803  at a side close to the base substrate  200  and a buffer layer  804  at a side of the second barrier layer  803  away from the base substrate  200 . The second barrier layer  803  is configured to block permeation of ions and other components in the base substrate  200  into the driving circuit layer  300 , so that the driving circuit layer  300  may maintain stable performance. The buffer layer  804  may improve a bonding force between the driving circuit layer  300  and the base substrate  200  and provide a stable environment for the driving circuit layer  300 . 
     Referring to  FIG.  3   , the pixel light-emitting layer  400  may be arranged at a side of the driving circuit layer  300  away from the base substrate  200 , and may include a pixel electrode layer  410 , a pixel definition layer  420 , a support column layer  430 , an organic light-emitting functional layer  440  and a common electrode layer  450  which are sequentially laminated. The pixel electrode layer  410  has a plurality of pixel electrodes in the display area B of the display panel. The pixel definition layer  420  has a plurality of pixel openings in the display area B, which are penetrated through the display area and arranged corresponding to a plurality of pixel electrodes one-to-one, and any one of the pixel openings exposes at least part of the corresponding pixel electrode. The support column layer  430  includes a plurality of support columns in the display area B, and the support columns are located on a surface of the pixel definition layer  420  away from the base substrate  200 , so as to support a Fine Metal Mask (FMM) in an evaporation process. The light-emitting functional layer  440  at least covers the pixel electrode exposed by the pixel definition layer  420 . The organic light-emitting functional layer  440  may include an organic electroluminescent material layer, and may include one or more of a hole injection layer, a hole transport layer, an electron barrier layer, a hole barrier layer, an electron transport layer, and an electron injection layer. The film layers of the organic light-emitting functional layer  440  may be prepared by the evaporation process, and a fine metal mask or an open mask may be used to define a pattern of each of the film layers during evaporation. The common electrode layer  450  may cover the organic light-emitting functional layer  440  in the display area B. In this way, the pixel electrode, the common electrode layer  450  and the organic light-emitting functional layer  440  between the pixel electrode and the common electrode layer  450  form organic light-emitting diodes, and any one of the organic light-emitting diodes may be used as a sub-pixel of the display panel. 
     In some embodiments, the pixel light-emitting layer  400  may further include a light extraction layer located at a side of the common electrode layer  450  away from the base substrate  200  to enhance the light extraction efficiency of the organic light-emitting diode. 
     In an embodiment of the present disclosure, in the second display area D, both the pixel electrode and the common electrode are transparent electrodes to improve the transmittance of the second display area D. In other embodiments of the present disclosure, the pixel electrode of the second display area D may also have a reflective layer to ensure a luminance of the display panel in the second display area D. 
     Optionally, referring to  FIG.  3   , the display panel may further include a planarization layer  805  located between the driving circuit layer  300  and the pixel light-emitting layer  400 , and the planarization layer  805  may provide a planarization surface for the pixel electrode. Optionally, the planarization layer  805  may be made of an organic material. 
     Optionally, referring to  FIG.  3   , the display panel may further include a thin film encapsulation layer  500 . The thin film encapsulation layer  500  is arranged on a surface of the pixel light-emitting layer  400  away from the base substrate  200 , and may include an inorganic encapsulation layer and an organic encapsulation layer  520  alternately laminated. The inorganic encapsulation layer may effectively block the external moisture and oxygen, and avoid the material degradation caused by invasion of moisture and oxygen into the organic light-emitting functional layer  440 . Optionally, an edge of the inorganic encapsulation layer may be located in the peripheral area A. The organic encapsulation layer  520  is located between two adjacent inorganic encapsulation layers in order to realize planarization and reduce the stress between the inorganic encapsulation layers. An edge of the organic encapsulation layer  520  is located between the display area B and the edge of the inorganic encapsulation layer. Exemplarily, referring to  FIG.  3   , the thin film encapsulation layer  500  includes a first inorganic encapsulation layer  510 , an organic encapsulation layer  520  and a second inorganic encapsulation layer  530  which are sequentially laminated at a side of the pixel light-emitting layer  400  away from the base substrate  200 . 
     Optionally, referring to  FIG.  3   , the display panel may further include an anti-drop layer  700 , and the anti-drop layer  700  may be arranged at a side of the thin film encapsulation layer  500  away from the pixel light-emitting layer  400  to reduce the reflection of the ambient light by the display panel, thereby reducing the influence of the ambient light on the display effect. In an embodiment of the present disclosure, referring to  FIG.  27   , the anti-drop layer  700  may include a color film layer  701  and a black matrix layer  702  which are laminated, thereby reducing the interference of ambient light and avoiding reducing the transmittance of the display panel. In another embodiment of the present disclosure, the anti-drop layer  700  may be a polarizer, for example, a patterned coated circular polarizer. 
     In an embodiment of the present disclosure, the anti-drop layer  700  may not cover the second display area D to improve the transmittance of the second display area D. In other words, the anti-drop layer  700  may not be provided in the second display area D. In other embodiments of the present disclosure, referring to  FIG.  17   , the second display area D may also have an anti-drop layer  700  to improve the display effect of the second display area D. Optionally, when the anti-drop layer  700  is provided in the second display area D, the anti-drop layer  700  may also have a hollowed-out design in the second display area D. The anti-drop layer  700  only covers a part of the second display area D and exposes a part thereof, so as to achieve a balance between improving the transmittance of the second display area D and improving the display effect of the second display area D. 
     Optionally, referring to  FIG.  3   , the display panel may further include a touch function layer  600 , and the touch function layer  600  is arranged at a side of the film packaging layer  500  away from the base substrate  200  for realizing the touch operation of the display panel. In an embodiment of the present disclosure, the touch function layer  600  may be arranged between the thin film encapsulation layer  500  and the anti-drop layer  700 . 
     Optionally, referring to  FIG.  3   , the display panel may further include a back film layer  100 , and the back film layer  100  may be arranged at a side of the base substrate  200  away from the pixel light-emitting layer  400  for supporting the display panel. Further, the back film layer  100  may be connected with the base substrate  200  by the adhesion layer  110 . 
     Optionally, referring to  FIG.  3   , the display panel may further include a cover plate  801 , and the cover plate  801  may be located at an outermost side of the light extraction side of the display panel to protect the display panel. The cover plate  801  may be an inorganic light-transmitting material, such as glass. The cover plate  801  may also be a light-transmitting organic material. Optionally, the cover plate  801  may be attached to other film layer of the display panel through an optical adhesive layer  802 , for example, to a side of the anti-drop layer  700  of the display panel away from the base substrate  200 . 
       FIGS.  1  and  2    are top views of a display panel. Referring to  FIGS.  1  and  2   , the display panel may include a display area B and a peripheral area A around the display area B. The display area B may include a first display area C and at least one second display area D at a side of the first display area C. In both the first display area C and the second display area D, the pixel light-emitting layer  400  may be provided with pixels, so that both the first display area C and the second display area D can realize normal image display. 
       FIGS.  4  to  17    are sectional schematic views of a display device using the display panel at a position close to the second display area D. The display device includes at least one photosensitive assembly  901 . The photosensitive assembly  901  may correspond to the second display area D in a one-to-one correspondence, and the photosensitive assembly  901  may directly face the corresponding second display area D, so as to receive the light transmitted from the second display area D. Referring to  FIGS.  4  to  17   , the photosensitive assembly  901  may have a photosensitive area for sensing light, and an orthographic projection of the photosensitive area on the base substrate  200  may be located in the second display area D. The photosensitive assembly  901  may be one or more light sensors, for example, a camera, an optical fingerprint identification chip, or the like. In some embodiments, the photosensitive assembly  901  may be a camera, for example, a CCD (Charge Coupled Device) camera. Thus, the display device may realize the under-screen camera and increase the screen-to-body ratio of the display device. 
     Optionally, referring to  FIGS.  1  and  2   , the second display area D may be embedded in the first display area C, that is, the first display area C surrounds around the second display area D. When a plurality of second display areas D are provided, the second display areas D may be dispersedly distributed or arranged adjacent to each other. 
     Optionally, any one of the second display areas D may be shaped as a circle, a square, a diamond, a regular hexagon, or another shape. In an embodiment of the present disclosure, the second display area D may be shaped as a circle. 
     One or more second display areas D may be provided to meet the arrangement of the photosensitive assembly  901 . In an embodiment of the present disclosure, one second display area D is provided. In this way, the display device may be provided with an under-screen photosensitive assembly  901 , for example, an under-screen camera or an under-screen optical fingerprint identification chip. In another embodiment of the present disclosure, a plurality of second display areas D may be provided. In this way, the display device may be provided with a plurality of photosensitive assemblies  901 , and any two of the photosensitive assemblies  901  may be the same or different. 
     For example, referring to  FIG.  2   , three second display areas D are provided and arranged adjacent to each other. In this way, the display device may be provided with different photosensitive assemblies  901  corresponding to the three second display areas D one-to-one, for example, three different photosensitive assemblies  901  such as an imaging camera, a deep camera and an infrared camera are provided. 
     Optionally, the anti-reflection grooves  201  are arranged to correspond to second display areas D one-to-one, and any one of the second display areas D at least partially overlaps with a corresponding anti-reflection groove  201 . Further, the second display area D is located in the corresponding anti-reflection groove  201 , that is, an orthographic projection of the anti-reflection groove  201  on the base substrate  200  covers the corresponding second display area D, thereby avoiding that a change of a thickness of the organic material layer  210  of the base substrate  200  enables a change of the transmittance at different positions in the second display area D. In other embodiments of the present disclosure, the number of anti-reflection grooves  201  may be less than the number of second display areas D, so that one of the anti-reflection grooves  201  may at least partially overlap with a plurality of second display areas D. 
     In the present disclosure, the anti-reflection groove  201  has two annular edges which are oppositely arranged, and a size of one of the edges is larger than a size of the other edge. The orthographic projection of the anti-reflection groove  201  on the base substrate  200  refers to an orthographic projection of a smaller edge of the anti-reflection groove  201  on the base substrate  200 , that is, an orthographic projection of a bottom of the anti-reflection groove  201  on the base substrate  200 . When the anti-reflection groove  201  penetrates through at least one organic material layer  210 , a smaller open end of the anti-reflection groove  201  may serve as the bottom of the anti-reflection groove  201 , and a larger open end of the anti-reflection groove  201  may serve as a notch of the anti-reflection groove  201 . When the notch of the anti-reflection groove  201  is located at a side of the bottom away from the base substrate  200 , the anti-reflection groove  201  is an anti-reflection groove  201  that opens toward the light extraction side of the display panel, that is, a first anti-reflection groove  201 . When the notch of the anti-reflection groove  201  is located at a side of the bottom close to the base substrate  200 , the anti-reflection groove  201  is the anti-reflection groove  201  that opens towards a back surface of the display panel, that is, a second anti-reflection groove  201 . 
     Optionally, the second display area D is completely located in the anti-reflection groove  201 , that is, the second display area D is completely located in the orthographic projection of the anti-reflection groove  201  on the base substrate  200 . 
     Optionally, referring to  FIGS.  4  to  17   , a slope angle of at least one organic material layer  210  is 10 degrees to 60 degrees at a position close to the anti-reflection groove  201 . In other words, an included angle between a side wall of the anti-reflection groove  201  and a plane where the display panel is located may range from 10 degrees to 60 degrees, and the side wall of the anti-reflection groove  201  is a surface of the organic material layer  210  connecting the bottom and the notch of the anti-reflection groove  201 . In this way, a slope of the anti-reflection groove  201  is relatively gentle, which can avoid each of conductive structures in the driving circuit layer  300  and the pixel light-emitting layer  400  from having a larger climbing angle at the side wall of the anti-reflection groove  201 , and further avoid the driving circuit layer  300  and the pixel light-emitting layer  400  from having poor broken wires. Alternatively, the slope angle of the organic material layer  210  is in a range of 23 degrees to 33 degrees. For example, in an embodiment of the present disclosure, the slope angle of the organic material layer  210  is 28.23 degrees. 
     Optionally, in the direction from the first display area C to the second display area D, a width of an orthographic projection of at least one organic material layer  210  close to the side wall of the anti-reflection groove  201  on the base substrate  200  may not be greater than 30 microns. In other words, a width of the orthographic projection of the side wall of the anti-reflection groove  201  on the base substrate  200  may not be greater than 30 microns. At the side wall of the anti-reflection groove  201 , it is difficult to ensure the uniformity of the semiconductor layer  310  in the driving circuit layer  300 , and thus it is not appropriate to arrange the transistor  301  in the driving circuit layer  300  at this position. By reducing the width of the orthographic projection of the side wall of the anti-reflection groove  201  on the base substrate  200 , it is possible to provide more sufficient space for arranging transistors. 
     Optionally, referring to  FIGS.  4  to  17   , in the base substrate  200 , at least one organic material layer  210  may include a first organic material layer  211  and a second organic material layer  213 , and a first barrier layer  212  may be sandwiched between the first organic material layer  211  and the second organic material layer  213 . The driving circuit layer  300  is arranged at a side of the second organic material layer  213  away from the first organic material layer  211 . 
     In some embodiments, the first organic material layer  211  and the second organic material layer  213  may be made of materials that may meet the mechanical performance requirements of the base substrate  200 , for example, some yellowish polyimide materials may be used. The first barrier layer  212  may shield the first organic material layer  211  to prevent additives, ions, and the like in the first organic material layer  211  from permeating into the driving circuit layer  300 . The first barrier layer  212  may also be configured to balance a stress between the first organic material layer  211  and the second organic material layer  213 . In the display panel provided by the present disclosure, the organic material layer  210  of the base substrate  200  is provided with the anti-reflection groove  201 , which realizes the thinning of the organic material layer  210  of the base substrate  200 . Therefore, the transmittance of the display panel of the present disclosure in the second display area D is enhanced. Also, since the organic material layer  210  in the base substrate  200  is thinned, an absorbance difference of the display panel in the second display area D for different wavelength bands is reduced, and a yellow light coefficient of the display panel in the second display area D may be reduced. In this way, the accuracy of light detection by the photosensitive assembly  901  may be improved, for example, the entire image collected by the camera may be prevented from yellowing. In addition, the base substrate  200  may only be provided with the anti-reflection groove  201  at or close to the second display area D, and the size of the second display area D is often relatively small, and therefore, the mechanical properties of the base substrate  200  will not be greatly affected. 
     In other embodiments, the first organic material layer  211  may be made of a material that may meet the mechanical performance requirements of the base substrate  200 , for example, some yellowish polyimide materials may be used. The first barrier layer  212  may shield the first organic material layer  211  to prevent additives, ions, and the like in the first organic material layer  211  from permeating into the driving circuit layer  300 . The second organic material layer  213  may be made of a material with high transmittance, such as colorless and transparent polyimide material, so that the transmittance of the second organic material layer  213  is greater than that of the first organic material layer  211 , thereby improving the transmittance of the display panel. 
     Alternatively, a thickness of each of the first organic material layer  211  and the second organic material layer  213  may be in a range of 3 microns to 20 microns. Optionally, the thickness of each of the first organic material layer  211  and the second organic material layer  213  may be in a range of 5 microns to 15 microns to meet the performance requirements of the display panel on the base substrate  200 . 
     Optionally, the thickness of the second organic material layer  213  may not be less than the thickness of the first organic material layer  211 . Further, the thickness of the second organic material layer  213  may be 1 to 4 times the thickness of the first organic material layer  211 . 
     For example, in an embodiment of the present disclosure, the thickness of the first organic material layer  211  is 5 microns, and the thickness of the second organic material layer  213  is 5 microns. For another example, in another embodiment of the present disclosure, the thickness of the first organic material layer  211  is 5 microns, and the thickness of the second organic material layer  213  is 10 microns. For another example, in another embodiment of the present disclosure, the thickness of the first organic material layer  211  is 5 microns and the thickness of the second organic material layer  213  is 15 microns. 
     In some embodiments, referring to  FIG.  4   , the anti-reflection groove  201  may be arranged at a side of the second organic material layer  213  away from the first organic material layer  211 . In other words, the second organic material layer  213  may be partially thinned to form the anti-reflection groove  201 . In this way, the thickness of the organic material of the base substrate  200  in the second display area D may be reduced, and then the transmittance of the display panel in the second display area D may be improved. 
     Alternatively, a depth of the anti-reflection groove  201  may be 0.5-1 times the thickness of the second organic material layer  213 . Further, the depth of the anti-reflection groove  201  may be 0.8 to 1 times the thickness of the second organic material layer  213 . In the present disclosure, the depth of the anti-reflection groove  201  refers to an interval between a plane where the notch of the anti-reflection groove  201  is located and a plane where the bottom of the anti-reflection groove  201  is located. 
     For example, referring to  FIG.  5   , the anti-reflection groove  201  may penetrate through the second organic material layer  213  and expose a part of the first barrier layer  212 . In other words, the second organic material layer  213  may be provided with a via hole exposing the first barrier layer  212 , and the via hole may serve as the anti-reflection groove  201  provided on the base substrate  200 . That is, the depth of the anti-reflection groove  201  is equal to the thickness of the second organic material layer  213 , thereby greatly thinning the organic material layer  210  of the base substrate  200 , and improving the transmittance of the display panel in the second display area D. 
     Optionally, in this embodiment, the anti-reflection groove  201  may be a first anti-reflection groove. That is, the size of the notch of the anti-reflection groove  201  is larger than the size of the bottom of the anti-reflection groove  201 , thereby ensuring that the materials of the driving circuit and the pixel light-emitting layer  400  may sequentially cover the anti-reflection groove  201 , and avoiding breakage at the anti-reflection groove  201 . The anti-reflection groove  201  is also convenient for preparation, for example, by photolithography or exposure development. 
     Optionally, referring to  FIG.  14   , when the anti-reflection groove  201  is arranged in the second organic material layer  213 , a thinning groove  203  may also be provided at a side of the first organic material layer  211  away from the driving circuit layer  300 , and an orthographic projection of the thinning groove  203  on the base substrate  200  covers the second display area D, so as to further reduce the transmittance of the display panel in the second display area D. In an embodiment of the present disclosure, the slope angle of the first organic material layer is 80 degrees to 90 degrees at a position close to the thinning groove. 
     Optionally, the thinning groove may be formed by the following methods: referring to  FIGS.  18  and  19   , a supporting substrate  902  with a protruding layer  903  corresponding to the thinning groove  203  may be provided first; and then, referring to  FIG.  20   , the base substrate and the film layers above the base substrate may be sequentially formed. Then, referring to  FIG.  21   , the supporting substrate  902  may be peeled off and the protruding layer  903  may be simultaneously peeled off, and the peeling off of the protruding layer  903  enables the back surface of the base substrate to be formed with a thinning groove  203 . Alternatively, the supporting substrate  902  may be a glass substrate. Optionally, the protruding layer  903  may be made of an inorganic material. 
     For example, referring to  FIG.  18   , the supporting substrate  902  may be a glass substrate, and the glass substrate is patterned to form a protruding layer  903  on the surface of the glass substrate. For another example, referring to  FIG.  19   , a light-transmitting material layer may be formed on the surface of the supporting substrate  902 , and the light-transmitting material layer may be made of an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride and metal oxide. Then, the light-transmitting material layer is patterned to form the protruding layer  903 . Further, the protruding layer  903  has a certain transmittance in an ultraviolet band for laser peeling. 
     For another example, the surface of the protruding layer may also be provided with a sacrificial layer, for example, a sacrificial layer made of an inorganic material such as silicon nitride and silicon oxide. When the protruding layer is peeled off, a mechanical peeling method may also be used for peeling off. In this embodiment, the protruding layer may include an opaque material, for example, it may be a metal film layer. 
     Optionally, the protruding layer  903  may be made of a material with high transmittance, and its transmittance is greater than that of the first organic material layer  211 . In this way, referring to  FIGS.  22  and  15   , the protruding layer  903  may not be peeled off, so that the protruding layer  903  may be embedded in the first organic material layer  211  of the base substrate  200  to act as a third filling material layer  808  filled in the thinning groove  203 . In other words, the display panel may further include a third filling material layer  808  embedded in the thinning groove  203 . A transmittance of the third filling material layer  808  is greater than that of the first organic material layer  211 . In an embodiment of the present disclosure, the third filling material layer  808  is a colorless and transparent organic material, such as a colorless and transparent polyimide material. 
     In other embodiments, referring to  FIG.  6   , the first organic material layer  211  is provided with an anti-reflection groove  201  at a side close to the driving circuit layer  300 . In this way, the base substrate  200  of the present disclosure may achieve thinning of the first organic material layer  211  in the second display area D, thereby improving the transmittance of the display panel in the second display area D. 
     Optionally, in this embodiment, the anti-reflection groove  201  may be the first anti-reflection groove, that is, the size of the notch is larger than the size of the bottom, thereby ensuring that the materials of the driving circuit layer and the pixel light-emitting layer may sequentially cover the anti-reflection groove  201 , and avoiding breakage at the anti-reflection groove  201 . The anti-reflection groove  201  is also convenient for preparation, for example, by photolithography or exposure development. 
     Optionally, in an embodiment, referring to  FIGS.  6  and  7   , the first barrier layer  212  and the second organic material layer  213  may sequentially cover the anti-reflection groove  201  on the first organic material layer  211 . In another embodiment, referring to  FIG.  8   , the first barrier layer  212  may have a hollowed-out hole  202  exposing the anti-reflection groove  201 . An edge of the hollowed-out hole  202  coincides with an edge of the notch of the anti-reflection groove  201  close to the first barrier layer  212 . In this way, the first organic material layer  211  may be patterned using the first barrier layer  212  as a mask to form the required anti-reflection groove  201 . 
     Optionally, the second organic material layer  213  may be made of a high transparent organic material, such as colorless and transparent polyimide material, so that the transmittance of the second organic material layer  213  is greater than the transmittance of the first organic material layer  211 , thereby further improving the transmittance of the second display area D. 
     Alternatively, the depth of the anti-reflection groove  201  may be 0.5-1 times the thickness of the first organic material layer  211 . Further, the depth of the anti-reflection groove  201  may be 0.8 to 1 times the thickness of the first organic material layer  211 . 
     For example, referring to  FIGS.  7  and  8   , the anti-reflection groove  201  penetrates through the first organic material layer  211 . In other words, the depth of the anti-reflection groove  201  is one time the thickness of the first organic material layer  211 . 
     In other embodiments, referring to  FIGS.  9  and  10   , the display panel further includes a first filling material layer  806 , and the first filling material layer  806  is located between the base substrate  200  and the driving circuit layer  300  and in the anti-reflection groove  201 . A transmittance of the first filling material layer  806  is greater than the transmittance of the first organic material layer  211 . In this way, the first filling material layer  806  may fill up the surface of the base substrate  200  and provide a relatively flat surface for the driving circuit layer  300 . 
     Optionally, the first filler material layer  806  is made of an organic material to improve the flexibility of the display panel and enhance the performance of the base substrate  200 . Further, the first filling material layer  806  may be made of a colorless and transparent polyimide material. 
     Optionally, the first filling material layer  806  may be arranged in the first anti-reflection groove. 
     In other embodiments, referring to  FIG.  11   , the first organic material layer  211  is provided with an anti-reflection groove  201  at a side away from the driving circuit layer  300 . In other words, the anti-reflection groove  201  is arranged in the first organic material layer  211  and the notch is located on the surface of the first organic material away from the driving circuit layer  300 . In this way, the first organic material layer  211  may be thinned without affecting the flatness of the surface of the base substrate  200  at a side close to the base substrate  200 . 
     Optionally, the anti-reflection groove  201  is the second anti-reflection groove, that is, the size of the notch of the anti-reflection groove  201  is larger than the size of the bottom, which can facilitate the preparation of the anti-reflection groove  201 . 
     In a manufacturing method, referring to  FIG.  23   , a supporting substrate  902  having a protruding layer  903  corresponding to the anti-reflection groove  201  may be provided first, and then various film layers such as a base substrate and the like may be sequentially formed. Then, referring to  FIG.  24   , the supporting substrate  902  may be peeled off and the protruding layer  903  may be peeled off simultaneously, and the peeling of the protruding layer  903  enables the back surface of the base substrate  200  to form the anti-reflection groove  201 . 
     Alternatively, the supporting substrate  902  may be a glass substrate. Optionally, the protruding layer  903  may be made of an inorganic material. 
     For example, the glass substrate may be patterned to form the protruding layer  903  on the surface of the glass substrate. For another example, a light-transmitting material layer may be formed on the surface of the glass substrate. The light-transmitting material layer may be made of an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride or metal oxide. Then, the light-transmitting material layer is patterned to form the protruding layer  903 . Further, the protruding layer  903  has a certain transmittance in the ultraviolet band for laser peeling. For another example, the surface of the protruding layer  903  may also be provided with a sacrificial layer, for example, a sacrificial layer made of inorganic materials such as silicon nitride and silicon oxide. When the protruding layer  903  is peeled off, it may also be peeled off by mechanical peeling. In this embodiment, a material of the protruding layer  903  may include an opaque material, for example, the protruding layer may be a metal film layer. 
     In another embodiment of the present disclosure, the protruding layer  903  may be made of a material with a high transmittance, and has a transmittance greater than that of the first organic material layer  211 . In this way, referring to  FIGS.  25  and  13   , the protruding layer  903  may not be peeled off, so that the protruding layer  903  may be embedded in the first organic material layer  211  of the base substrate  200  to act as the second filling material layer  807  filled in the anti-reflection groove  201 . In other words, the display panel may further include a second filling material layer  807  embedded in the anti-reflection groove  201 . The transmittance of the second filling material layer  807  is greater than that of the first organic material layer  211 . 
     Alternatively, the depth of the anti-reflection groove  201  may be 0.5-1 times the thickness of the first organic material layer  211 . Further, the depth of the anti-reflection groove  201  may be 0.8-1 times the thickness of the first organic material layer  211 . For example, referring to  FIG.  12   , the anti-reflection groove  201  penetrates through the first organic material layer  211 . In other words, the depth of the anti-reflection groove  201  is one time the thickness of the first organic material layer  211 . 
     Optionally, referring to  FIGS.  4  to  17   , the back film layer  100  is located at a side of the base substrate  200  away from the driving circuit layer  300 . The back film layer  100  is provided with an opening  101 , and the second display area D is located in the orthographic projection of the opening  101  on the base substrate  200 . Further, the back film layer  100  may be connected with the base substrate  200  through the adhesion layer  110 , and the adhesion layer  110  also does not cover the second display area D. 
     The embodiment of the present disclosure also provides a display device, which includes the display panel described in any one of the above display panel embodiments. The display device may be a smart phone screen, a smart watch screen or another type of display device. Since the display device has the display panel described in any one of the above display panel embodiments, it has the same beneficial effects, and the present disclosure will not be repeated herein. 
     In an embodiment of the present disclosure, referring to  FIGS.  4  to  17   , the display device includes a display panel and at least one photosensitive assembly  901 , and the photosensitive assembly  901  is located at a side of the display panel close to the base substrate  200  and directly faces the second display area D. 
     Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed here. This application is intended to cover any variations, uses, or adaptations of the disclosure following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art. It is intended that the specification and embodiments be considered as exemplary only, with a true scope and spirit of the present disclosure being indicated by the following claims.