Patent Publication Number: US-2022231255-A1

Title: Substrate and preparation method thereof, display panel and preparation method thereof, and display device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation application of U.S. patent application Ser. No. 16/765,984 filed on May 21, 2020 which is the National Stage of PCT/CN2019/123336 filed on Dec. 5, 2019, which claims priority under 35 U.S.C. § 119 of Chinese Application No. 201811496810.5 filed on Dec. 7, 2018, the disclosure of which is incorporated by reference. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present disclosure relate to a substrate and a preparation method thereof, a display panel and a preparation method thereof, and a display device. 
     BACKGROUND 
     A display panel may include an array substrate and an opposed substrate which is opposite to the array substrate and is used for packaging and protection. The array substrate includes a plurality of pixel units for display and functional structures such as a driving circuit for driving the pixel units to emit light and the like. The opposed substrate is bonded with the array substrate by a sealant so as to provide packaging and protection for the pixel units and the functional structures such as the driving circuit and the like on the array substrate. 
     SUMMARY 
     At least one embodiment of the present disclosure provides a substrate comprising a display region and a peripheral region positioned in a periphery of the display region and used for sealing, the substrate comprises: a base substrate; an insulating layer, arranged on a side of the base substrate and positioned in the display region and the peripheral region for sealing; and a plurality of pixel units, positioned on the insulating layer corresponding to the display region, and in the peripheral region, at least one groove is disposed on a side of the insulating layer which faces away from the base substrate, a side of the groove which is away from the base substrate is open, and a depth direction of the groove is perpendicular to the base substrate. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, the peripheral region for sealing is a sealant set region, and each of the plurality of pixel units includes: a light-emitting element layer which is arranged on a side of the insulating layer which faces away from the base substrate and includes a light-emitting layer. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, an extending direction of the groove is parallel to a plane where the base substrate is positioned, and on a plane perpendicular to the base substrate, a longitudinal cross-section of the groove is of a regular trapezoid or inverted trapezoid shape. 
     For example, the substrate provided by at least one embodiment of the present disclosure further comprises: a pixel definition layer positioned on the insulating layer corresponding to the display region and includes a plurality of pixel openings for defining the plurality of pixel units, the light-emitting layer at least covering the plurality of pixel openings, and an extending direction of the groove is identical with an extending direction of the pixel opening. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, a shape and a size of an end of the groove away from the base substrate are identical with shapes and sizes of ends of the plurality of pixel openings away from the base substrate; or the shape of the end of the groove away from the base substrate is identical with the shapes of the ends of the plurality of pixel openings away from the base substrate, the size of the end of the groove away from the base substrate is greater than sizes of the ends of the plurality of pixel openings away from the base substrate. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, the insulating layer includes a plurality of grooves in the peripheral region, extending directions of the plurality of grooves are identical, the plurality of grooves are arranged into a plurality of rows and a plurality of columns in the periphery of the display region, a row direction of the grooves is identical with a row direction of the plurality of pixel openings, and a column direction of the grooves is identical with a column direction of the pixel openings, a shape of an end of the groove away from the base substrate is identical with shapes of ends of the plurality of pixel openings away from the base substrate, sizes of the ends of the plurality of grooves away from the base substrate are equal to sizes of the ends of the plurality of pixel openings away from the base substrate, or the sizes of the ends of at least one portion of the plurality of grooves away from the base substrate are greater than the sizes of the ends of the plurality of pixel openings away from the base substrate. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, the sizes of the ends of the plurality of grooves away from the base substrate are equal to the sizes of the ends of the plurality of pixel openings away from the base substrate, the shapes of the plurality of grooves are identical and the sizes of the plurality of grooves are identical, a pitch of the grooves in the row direction is identical with a pitch of the pixel openings in the row direction and/or a pitch of the grooves in the column direction is identical with that of the pixel openings in the column direction. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, the plurality of grooves are divided into two groups according to different lengths, a width of each of the plurality of grooves is equal to a width of the pixel opening, the length of a groove in one group of the two groups is equal to a sum of pitches of the plurality of pixel openings along the column direction, the grooves in the one group of the two groups are arranged on both sides of the display region along the row direction of the pixel opening, the length of a groove in other group of the two groups is equal to or greater than a length of each of the plurality of pixel openings, the grooves in the other group are arranged on both sides of the display region in the column direction, and a pitch of the plurality of grooves along the row direction are identical with the pitch of the plurality of pixel openings along the row direction. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, a surface of the insulating layer which is positioned in the peripheral region has lyophobicity. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, at least one portion of the light-emitting layer is positioned in the groove. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, the insulating layer includes: a first sub insulating layer, having a first groove portion; and a second sub insulating layer, laminated on the first sub insulating layer and having an opening communicating with the first groove portion, and the first groove portion and the opening constitutes the groove. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, a longitudinal cross-section of the first groove portion is of a regular trapezoid shape, and a longitudinal cross-section of the opening is of an inverted trapezoid or rectangle shape. 
     For example, in the substrate provided by at least one embodiment of the present disclosure, a material of the first sub insulating layer includes a negative photoresist material, and a material of the second sub insulating layer includes a positive photoresist material or an inorganic material. 
     For example, the substrate provided by at least one embodiment of the present disclosure further comprises a driving circuit positioned on the base substrate in the display region and configured to drive the plurality of pixel units, and the insulating layer covers the driving circuit. 
     At least one embodiment of the present disclosure provides a display panel, the display panel comprises: the substrate as mentioned above; an opposed substrate, arranged to be opposite to the substrate; and a sealant, disposed between the substrate and the opposed substrate, and the sealant covers the groove and bonds the opposed substrate with the substrate. 
     At least one embodiment of the present disclosure provides a preparation method of a substrate, the substrate includes a display region and a peripheral region which is positioned in a periphery of the display region and used for sealing, the preparation method comprises: providing a base substrate; forming an insulating layer in the display region and the peripheral region and on a side of the base substrate; and forming at least one groove in the peripheral region and on a side of the insulating layer faces away from the base substrate, a side of the groove away from the base substrate being open, a depth direction of the groove being perpendicular to the base substrate, and the substrate includes a plurality of pixel units, and the plurality of pixel units are positioned on the insulating layer corresponding to the display region. 
     For example, in the preparation method provided by at least one embodiment of the present disclosure, the insulating layer is configured that at least a surface of the insulating layer in the peripheral region has lyophobicity. 
     For example, the preparation method provided by at least one embodiment of the present disclosure further comprises: forming a pixel definition layer, the pixel definition layer including a plurality of pixel openings respectively used for the plurality of pixel units; and forming a light-emitting layer, the light-emitting layer at least covering the plurality of pixel openings, and the light-emitting layer is formed by using an ink-jet printing, spin-coating or spray-coating mode, and at least one portion of the light-emitting layer is formed in the groove. 
     For example, in the preparation method provided by at least one embodiment of the present disclosure, the forming the insulating layer includes: forming a first sub insulating layer, the first sub insulating layer having a first groove portion; and forming a second sub insulating layer on the first sub insulating layer, the second sub insulating layer having an opening communicating with the first groove portion, and the first groove portion and the opening constitute the groove. 
     For example, in the preparation method provided by at least one embodiment of the present disclosure, the second sub insulating layer is formed by adopting a material with lyophobicity, or a surface of the second sub insulating layer which is positioned in the peripheral region is subjected to surface treatment, so that the surface of the second sub insulating layer which is positioned in the peripheral region has lyophobicity. 
     For example, in the preparation method provided by at least one embodiment of the present disclosure, the surface treatment is carried out by adopting plasmas of Ar, N2, CF4 or O2. 
     At least one embodiment of the present disclosure provides a preparation method of the display panel, the preparation method of the display panel comprises: manufacturing the substrate, the substrate being prepared by any of the preparation method as mentioned above; and providing an opposed substrate, and bonding the opposed substrate on the substrate by a sealant, and the sealant covers the groove. 
     At least one embodiment of the present disclosure provides a display device, the display device comprises the display panel as mentioned above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to clearly illustrate the technical solution of the embodiments of the invention, the drawings of the embodiments will be briefly described in the following; it is obvious that the described drawings are only related to some embodiments of the invention and thus are not limitative of the invention. 
         FIG. 1A  is a cross-sectional schematic diagram of a display panel; 
         FIG. 1B  is a plane schematic diagram of a display panel; 
         FIG. 2  is a schematic diagram of an enter path of impurities such as water, oxygen and the like in a display panel; 
         FIG. 3A  is a cross-sectional schematic diagram of another display panel; 
         FIG. 3B  is a plane schematic diagram of another display panel; 
         FIG. 4  is a schematic diagram of an enter path of impurities such as water, oxygen and the like in another display panel; 
         FIG. 5A  is a cross-sectional schematic diagram of a substrate provided by some embodiments of the present disclosure; 
         FIG. 5B  is a cross-sectional schematic diagram of a display panel provided by some embodiments of the present disclosure; 
         FIG. 5C  is a plane schematic diagram of a display panel provided by some embodiments of the present disclosure; 
         FIG. 6  is a plane schematic diagram of another display panel provided by some embodiments of the present disclosure; 
         FIG. 7A  is a cross-sectional schematic diagram of yet another substrate provided by some embodiments of the present disclosure; 
         FIG. 7B  is a cross-sectional schematic diagram of yet another display panel provided by some embodiments of the present disclosure; 
         FIG. 7C  is a plane schematic diagram of yet another display panel provided by some embodiments of the present disclosure; 
         FIGS. 8A to 8D  are cross-sectional schematic diagrams of a display panel in the preparation process, as provided by some embodiments of the present disclosure; 
         FIG. 9  is a plane schematic diagram in which a plurality of display panels are simultaneously formed, as provided by some embodiments of the present disclosure; and 
         FIG. 10  is a schematic diagram of a display device provided by some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In order to make objects, technical details and advantages of the embodiments of the invention apparent, the technical solutions of the embodiment will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the invention. It is obvious that the described embodiments are just a part but not all of the embodiments of the invention. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the invention. 
     Unless otherwise defined, all the technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms, such as “first,” “second,” or the like, which are used in the description and the claims of the present disclosure, are not intended to indicate any sequence, amount or importance, but for distinguishing various components. The terms, such as “comprise/comprising,” “include/including,” or the like are intended to specify that the elements or the objects stated before these terms encompass the elements or the objects and equivalents thereof listed after these terms, but not preclude other elements or objects. The terms, such as “connect/connecting/connected,” “couple/coupling/coupled” or the like, are not limited to a physical connection or mechanical connection, but may include an electrical connection/coupling, directly or indirectly. The terms, “on,” “under,” “left,” “right,” or the like are only used to indicate relative position relationship, and when the position of the object which is described is changed, the relative position relationship may be changed accordingly. 
     Generally speaking, in one type of structure of a display panel, an opposed substrate and an array substrate are bonded with each other by a sealant, so that the opposed substrate and the sealant completely isolate a pixel unit and functional structures such as a driving circuit and the like in a display region of the array substrate from the external environment so as to avoid a case that impurities such as water, oxygen and the like enter the display region, thereby prolonging the working life of the display panel. For example,  FIG. 1A  and  FIG. 1B  show an ideal display panel structure. 
     As shown in  FIG. 1A  and  FIG. 1B , a display panel  1  has a display region  1 A and a peripheral region  1 B for sealing the display region  1 A, the display panel  1  includes an array substrate  17  and an opposed substrate  15 , the array substrate  17  includes a base substrate  11  and a driving circuit  12 , an insulating layer  13  and a light-emitting element layer  14  on the base substrate  11 , and the opposed substrate  15  is bonded on the insulating layer  13  by a sealant  16  so as to be bonded on the array substrate and carry out sealing on the display region  1 A. As shown in  FIG. 1A  and  FIG. 1B , the sealant  16  completely surrounds the light-emitting element layer  14 , and thus, the opposed substrate  15  and the sealant  16  completely isolate the light-emitting element layer  14  from the external environment. 
     According to the structure, as shown in  FIG. 2 , there are routes (shown as arrows on both upper and lower sides of the sealant  16 ) for the impurities such as water, oxygen and the like to enter the display region  1 A only on both the upper and lower sides of the sealant  16  in the display panel  1 , and thus, the display panel  1  has a good packaging effect. 
     However, in an actual preparation process, as shown in  FIG. 3A  and  FIG. 3B , a portion of functional layers of the light-emitting element layer  14  (for example, a light-emitting layer, a common electrode and the like) often adopt a full-surface forming mode, and thus, not only the display region is covered, but also the peripheral region may be covered. At the moment, in some examples, as shown in  FIG. 3B , a plurality of display panels may be formed in a one-time preparation process. For example, the light-emitting element layer  14  includes structures, such as a first electrode  141 , a pixel definition layer  142  with a plurality of pixel openings, a light-emitting layer  143  at least formed in the plurality of pixel openings, a second electrode  144 , a passivation layer  145  and the like. For example, the structures, such as the light-emitting layer  143  and the like, in the light-emitting element layer  14  adopt a full-surface forming mode, as shown in  FIG. 3A , so that the light-emitting layer  143  is also formed in the peripheral region  1 B for sealing, resulting in that when the opposed substrate  15  is formed by adopting the sealant  16  at the later stage, the sealant  16  is formed (for example, coated) on the light-emitting layer  143  without direct contact with the insulating layer  13 . 
     As shown in  FIG. 4 , under the case, routes for the impurities such as water, oxygen and the like to enter the display region  1 A are also formed on the light-emitting layer  143  in the peripheral region  1 B and on both upper and lower sides of the light-emitting layer  143  in the display panel, so that the packaging effect of the display panel is reduced. 
     At least one embodiment of the present disclosure provides a substrate, including a display region and a peripheral region positioned in the periphery of the display region and used for sealing. The substrate includes: a base substrate; an insulating layer, arranged on a side of the base substrate and positioned in the display region and the peripheral region for sealing; and a plurality of pixel units, positioned on the insulating layer corresponding to the display region, wherein in the peripheral region, at least one groove is disposed on a side of the insulating layer, which faces away from the base substrate, a side of the groove, which is away from the base substrate, is open, and a depth direction of the groove is perpendicular to the base substrate. 
     At least one embodiment of the present disclosure provides a preparation method of a substrate. The substrate includes a display region and a peripheral region positioned in the periphery of the display region and used for sealing. The preparation method includes: providing a base substrate; forming an insulating layer in a display region and a peripheral region and on a side of the base substrate; and forming at least one groove in the peripheral region and on a side of the insulating layer, which faces away from the base substrate, a side of the groove, which is away from the base substrate, being open, a depth direction of the groove being perpendicular to the base substrate, wherein the substrate includes a plurality of pixel units, and the plurality of pixel units are positioned on the insulating layer corresponding to the display region. 
     At least one embodiment of the present disclosure provides a display panel, and the display panel includes the above-mentioned substrate. 
     At least one embodiment of the present disclosure provides a display device, and the display device includes the above-mentioned display panel. 
     The substrate and the preparation method thereof, the display panel and the preparation method thereof and the display device of the present disclosure will be illustrated below by several specific embodiments. 
     At least one embodiment of the present disclosure provides a display panel,  FIG. 5A  is a cross-sectional schematic diagram of a substrate  1000 , and  FIG. 5C  is a plane schematic diagram of the display panel, wherein  FIG. 5B  is a cross-sectional schematic diagram of the display panel in  FIG. 5C  along an A-A line. 
     The display panel includes an array substrate and an opposed substrate, the array substrate includes a base substrate, a driving circuit formed on the base substrate, an insulating layer covering the driving circuit and a light-emitting element layer on the insulating layer, and the opposed substrate is bonded on the insulating layer of the array substrate in a peripheral region by a sealant so as to carry out sealing on a display region. The display region includes a plurality of pixel units, and in each pixel unit, the driving circuit includes a pixel driving circuit, the light-emitting element layer includes a light-emitting element, and the pixel driving circuit drives the light-emitting element electrically connected therewith to emit light. 
     As shown in  FIGS. 5B and 5C , the substrate  1000  includes the display region  10  and the peripheral region  11  positioned in the periphery of the display region and used for sealing, and the substrate  1000  includes: the base substrate  101 ; the insulating layer  103 , which is arranged on a side of the base substrate  101  and positioned in the display region and the peripheral region for sealing; and a plurality of pixel units, which are positioned on the insulating layer  103  corresponding to the display region, wherein in the peripheral region, at least one groove  103 A is disposed on a side of the insulating layer, which faces away from the base substrate, a side of the groove  103 A, which is away from the base substrate  101 , is open, and a depth direction of the groove  103 A is perpendicular to the base substrate. 
     For example, in the embodiment, the peripheral region for sealing is a sealant disposing region, and each of the plurality of pixel units (R/G/B) includes: the light-emitting element layer  104 , which is arranged on a side of the insulating layer  103 , which faces away from a base, and includes a light-emitting layer  1043 . 
     For example, in the embodiment, the substrate  1000  further includes a pixel definition layer  1042 , the pixel definition layer  1042  includes a plurality of pixel openings  1042 A respectively used for the plurality of pixel units, the light-emitting layer  1043  at least covers the plurality of pixel openings  1042 A, i.e., the plurality of pixel units share the light-emitting layer  1043 , or the plurality of pixel units are separately provided with the respective light-emitting layers, and the embodiments of the present disclosure do not make any limit to it. For example, corresponding to each pixel unit, the light-emitting element layer  104  further includes a first electrode  1041  and a second electrode  1044  for driving the light-emitting layer  1043  to emit light, i.e., the first electrode  1041 , the second electrode  1044  and the light-emitting layer  1043  sandwiched therebetween constitute a light-emitting element, and the light-emitting layer may be an organic light-emitting layer or a quantum dot light-emitting layer, and thus, the obtained light-emitting element may be an Organic Light-Emitting Diode (OLED) or a Quantum dot Light-Emitting Diode (QLED). Moreover, the light-emitting element layer  104  further may include a passivation layer  1045  covered on the light-emitting layer  1043  so as to form packaging and protection. 
     For example, in this embodiment, an extending direction of the groove is parallel to a plane where the base is positioned, and on a plane perpendicular to the base, a longitudinal cross-section of the groove is of a regular trapezoid or inverted trapezoid shape. 
     For example, the longitudinal cross-section of the groove  103 A may be of a regular trapezoid shape with a narrow upper portion and a wide lower portion (a trapezoid of which a bottom edge is longer than a top edge), so that the groove  103 A can have a high volume. In addition, as shown in  FIG. 5A , the longitudinal cross-section of the groove  103 A also may be of an inverted trapezoid shape with a wide upper portion and a narrow lower portion (a trapezoid of which a bottom edge is shorter than a top edge), so as to benefit to fluid inflow. In some embodiments, the groove  103 A further may be of a shape of a rectangular with the same width of the upper and lower portions and the like, and the embodiments of the present disclosure do not make specific limit to it. 
     For example, in the preparation process of the display panel provided by some embodiments of the present disclosure, the light-emitting layer  1043  is formed by using a full-surface forming mode and for example, by using printing modes of ink-jet printing, spin-coating, spray-coating and the like, and thus, a material of the light-emitting layer  1043  can flow to the peripheral region  11  for sealing, and at the moment, the groove  103 A in the insulating layer  103  may collect the material of the light-emitting layer  1043 , which flows to the peripheral region  11 , so that the material of the light-emitting layer  1043 , which remains on the insulating layer  103  in the peripheral region  11 , is reduced, the material of the light-emitting layer  1043  cannot remain on the insulating layer  103  in the peripheral region  11 , or residual portions of the material of the light-emitting layer  1043  are spaced from each other, and thus, a path for impurities such as water, oxygen and the like to enter the display region  10  is disconnected. It will be illustrated below by taking a case that the material of the light-emitting layer cannot remain on the insulating layer  103  in the peripheral region  11  as an example. At the moment, in some embodiment, the light-emitting layer  1043  at least partially extends into the groove  103 A. 
     For example, in the embodiment, a surface of the insulating layer  103 , which is positioned in the peripheral region  11 , has lyophobicity. For example, the insulating layer  103  is formed by adopting a material with lyophobicity, or the surface of the insulating layer  103 , which is positioned in the peripheral region  11 , is subjected to surface treatment so as to have lyophobicity. At the moment, the surface of the insulating layer  103 , which has lyophobicity, can promote the material of the light-emitting layer  1043  to flow into the groove  103 A, so that the material of the light-emitting layer  1043 , which flows to the peripheral region  11 , sufficiently flows into the groove  103 A and is accommodated in the groove  103 A, thereby ensuring that the material of the light-emitting layer  1043  may not remain on the insulating layer  103  in the peripheral region  11 . 
     For example, in some embodiments, as shown in  FIG. 5C , the groove  103 A and the pixel opening  1042 A are the same in plane shape and size, the plane shape herein refers to a shape of uppermost portions of the groove and the pixel opening, and that is to say, the plane shape and size herein refer to a plane shape and a size of an end of the groove which is away from the substrate and plane shapes and sizes of ends of the plurality of pixel openings which is away from the substrate, that is, a plane shape and a size of upper ends of the groove and the plurality of pixel openings. Or, as shown in  FIG. 6 , the shape of an end of the groove which is away from the base is the same with that of ends of the plurality of pixel openings which are away from the base, the plane size of the groove  103 A is greater than that of the pixel opening  1042 A, and for example, a length and/or a width of the groove  103 A is greater than a length and/or a width of the pixel opening  1042 A. In the embodiments of the present disclosure, the plane shapes of the groove  103 A and the pixel opening  1042 A refer to shapes of the groove  103 A and the pixel opening  1042 A, which are shown in plane diagrams of the groove  103 A and the pixel opening  1042 A, i.e., shapes of the uppermost portions of the groove  103 A and the pixel opening  1042 A, for example, as shown in  FIG. 5B  and  FIG. 6 , the plane shapes of the groove  103 A and the pixel opening  1042 A are rectangles, in other embodiments, the plane shapes of the groove  103 A and the pixel opening  1042 A also may be circles, ovals or irregular shapes and the like, and the embodiments of the present disclosure do not make any specific limit to it. The plane sizes of the groove  103 A and the pixel opening  1042 A refer to sizes (for example, a length, a width and the like) of the shapes of the groove  103 A and the pixel opening  1042 A, which are shown in the plane diagrams of the groove  103 A and the pixel opening  1042 A, i.e., the shapes of the uppermost portions of the groove  103 A and the pixel opening  1042 A, at the same dimension, e.g., the sizes of the length and the width of the rectangle shape or an area of the rectangle shape, as shown in  FIG. 5C  and  FIG. 6 . In this embodiment, the plane shapes and the plane sizes of the groove  103 A and the pixel opening  1042 A may be selected according to actual demands, for example, in some embodiments, the plane size of the groove  103 A also may be smaller than that of the pixel opening  1042 A, and the embodiments of the present disclosure do not make any specific limit to it. 
     For example, in some embodiments, the insulating layer  103  includes a plurality of grooves  103 A in the peripheral region  11 , and the plurality of grooves  103 A are arranged around the display region  10 . The plurality of grooves are the same in an extending direction, the plurality of grooves are arranged into a plurality of rows and a plurality of columns in the periphery of the display region, a row direction of the grooves is the same with that of the plurality of pixel openings, a column direction of the grooves is the same with that of the pixel opening, the shapes of ends of the plurality of grooves which are away from the base are the same and are also the same with those of ends of the plurality of pixel openings which are away from the base, the sizes of the ends of the plurality of grooves which are away from the base are all equal to those of the ends of the plurality of pixel openings which are away from the base, or the sizes of ends of at least one portion of the plurality of grooves which are away from the base are greater than those of the ends of the plurality of pixel openings which are away from the base, and for example, the sizes of one portion are equal to those of the pixel openings, and the sizes of the other portion are greater than or smaller than those of the pixel openings: or all the sizes of the grooves are greater than or smaller than those of the pixel openings; and the sizes of one portion are equal to those of the pixel openings, the sizes of another portion are smaller than those of the pixel openings, and the sizes of the rest portions are greater than those of the pixel openings. 
     For example, as shown in  FIG. 5C , the sizes of the ends of the plurality of grooves which are away from the base are equal to those of the ends of the plurality of pixel openings which are away from the base, i.e., the lengths and the widths of the upper portions of the plurality of grooves are equal to the lengths and the widths of the upper portions of the pixel openings; the plurality of grooves are the same in shape and size; a pitch  10501  of the grooves in a row direction is the same with a pitch  10500  of the pixel openings in the row direction and/or a pitch of the grooves in a column direction is the same with a pitch of the pixel openings the column direction; a pitch of the grooves positioned at edges on both left and right sides of the pixel units may be regarded as a pitch between the groove and the pixel opening, and that is to say, as shown in  FIG. 5C , the plurality of pixel openings  1042 A are arranged in a first array, the plurality of grooves  103 A are arranged in a second array, the first array and the second array have the same arrangement direction and have the same pitch in the arrangement direction, i.e., the plurality of pixel openings  1042 A and the plurality of grooves  103 A adopt the basically same arrangement mode. For example, when the plane shapes of the groove  103 A and the pixel opening  1042 A are rectangles, the rectangles are the same in a length extending direction and a width extending direction, a spacing between the adjacent grooves  103 A is basically the same with that between the adjacent pixel opening  1042 A, the spacing herein refers to a distance between edges of the adjacent grooves in the row direction or the column direction, and the pitch refers to a distance between centers of the adjacent grooves in the row direction or the column direction. Viewing from the plane diagram, the groove and the pixel opening constitute the array together, the groove and the pixel opening constitute an unit of the array together, and pitches between the units are the same. Viewing from the plane diagram, the pitch of the grooves are the same with those of the pixel openings, so that an apparatus parameters and a process parameter, e.g., a step pitch, a nozzle pitch and the like, of the light emitting layer and other light-emitting functional layers do not need to be transformed, and the light-emitting layer in the sealant set region can all fall into the groove, thereby achieving an excellent sealing effect. 
     Optionally, it may be that the pitch, shape and size of a portion of the grooves are the same with those of the pixel openings, so that a portion of the light-emitting layer in the sealant set region can all fall into the groove, the sealing effect also can be improved, and the embodiments of the present disclosure do not make any limit to it. 
     Optionally, the size and the shape of a random position of the groove may be equal to the sizes and the shapes of corresponding positions of the plurality of pixel openings, for example, the size and the shape of a middle depth position of the groove is equal to the size and the shape of the middle depth position of the pixel opening, and those skilled in the art may set as required. 
     For further example, as shown in  FIG. 6 , the second array formed by the plurality of grooves  103 A is different from the first array formed by the plurality of pixel openings  1042 A, the plane size of the groove  103 A is different from that of the pixel opening  1042 A, and the pitch of the array also may be different. The plurality of grooves are divided into two groups according to the length, the widths of the plurality of grooves are equal to that of the pixel opening, the lengths of the grooves of one of the two groups are equal to or slightly smaller than a sum of the pitches of the plurality of pixel openings along the column direction, the one group of grooves are arranged on both sides of the display region along the row direction of the pixel opening, the lengths of the grooves of the other group of the two groups are equal to or greater than those of the plurality of pixel openings, the other group of grooves are arranged on both sides of the display region in the column direction, the pitch of the plurality of grooves along the row direction is the same with that of the plurality of pixel openings along the row direction, and herein, the pitch of the grooves positioned at edges of both the left and right sides of the pixel units may be regarded as the pitch between the groove and the pixel opening. 
     Optionally, in the second array including the plurality of grooves  103 A, the plurality of grooves  103 A may be arranged in an irregular row and column mode, and for example, the grooves  103 A in the adjacent rows are staggered with each other by half the length in the row direction. 
     Under the above-mentioned setting, when the light-emitting layer  1043  is formed in the pixel opening  1042 A, the groove  103 A in the peripheral region  11  can collect the material of the light-emitting layer  1043  formed on the insulating layer  103  in the peripheral region  11  so as to avoid or reduce the material of the light-emitting layer  1043 , which remains on the insulating layer  103  in the peripheral region  11 . 
     For example, in the embodiments of the present disclosure, a material of the insulating layer  103  includes inorganic materials such as SiOx, SiNx, Al 2 O 3  and the like, or includes organic materials such as polyimide (PI), polyacrylate or phenolic resin and the like, and the embodiments of the present disclosure do not make any specific limit to it. 
     As shown in  FIG. 5A , for example, the substrate provided by the embodiments of the present disclosure further includes the base substrate  101  and the driving circuit  102 . The base substrate  101  is used for supporting structures and members in the display region  10  and the peripheral region  11 ; and the driving circuit  102  is positioned on the base substrate  101  and used for driving a plurality of pixel units. For example, the driving circuit  102  includes the pixel driving circuit for the pixel unit, the pixel driving circuit includes structures such as a thin film transistor, a capacitor and the like, may be formed in a form of 2T1C (i.e., two transistors and one capacitor) and also may be formed in a form of 3T1C and the like, for example, when a light-emitting member of a light-emitting member layer is driven to emit light, functions of compensation, resetting and the like also may be provided, the driving circuit  102  further includes signal lines such as a gate line, a data line and the like, and the embodiments of the present disclosure do not make any limit to it. 
     For example, the insulating layer  103  covers the driving circuit  102  so as to protect the driving circuit  102  and planarize the driving circuit  102 . 
     In the display panel provided by some embodiments of the present disclosure, the insulating layer  103  includes the groove  103 A in the peripheral region  11 , and thus, the groove  103 A can collect the material of the light-emitting layer  1043 . For example, in some embodiments, the second electrode  1044  and the passivation layer  1045  on the light-emitting layer  1043  also may adopt a full-surface forming mode, and thus, there also may be materials of the second electrode  1044  and the passivation layer  1045  in the groove  103 A. Therefore, an undesired material such as the material of the light-emitting layer  1043  and the like cannot remain for example on the insulating layer  103  in the peripheral region  11 , so that the sealant  106  can be directly adhered between the insulating layer  103  and the opposed substrate  105  to form better sealing and bonding effects, and for example, compared to a case that the undesired material remains on the insulating layer  103  in the peripheral region  11  to form a path for the impurities such as water, oxygen and the like to enter the display region, an enter path of water, oxygen and the like can be reduced. In another aspect, the sealant  106  also may be at least partially filled into the groove  103 A, and the formation of the groove  103 A also complicates an entering path of the impurities such as water, oxygen and the like below the sealant  106 , thereby further reinforcing the sealing effect. 
     For example, in some embodiments, in order to increase the volume of the groove, the insulating layer may adopt a double-layer structure, and the groove is formed in the double-layer structure. This setting can further ensure that the undesired material cannot remain for example on the insulating layer in the peripheral region. In another aspect, in a case that a total volume of a plurality of grooves is constant, this setting can reduce the forming number of the grooves. 
     For example, as shown in  FIG. 5B , the display panel provided by some embodiments of the present disclosure includes the substrate  1000 , the opposed substrate  105  and the sealant  106 , the opposed substrate is set to be opposite to the substrate, the sealant  106  is set between the substrate and the opposed substrate and for example, covers the groove  103 A, and in the peripheral region, the opposed substrate  105  and the substrate  1000  are bonded to form the display panel  100  and the sealing is achieved. 
     For example, at least one embodiment of the present disclosure provides a substrate  2000 ,  FIG. 7A  is a cross-sectional schematic diagram of the substrate,  FIG. 7B  is a cross-sectional schematic diagram of a display panel including the substrate, and  FIG. 7C  is a plane schematic diagram of the display panel, wherein  FIG. 7A  is a cross-sectional schematic diagram of the display panel in  FIG. 7C  along a B-B line. 
     As shown in  FIG. 7A ,  FIG. 7B  and  FIG. 7C , the substrate  2000  has a display region  20  and a peripheral region  21  for sealing, and the substrate  2000  includes an insulating layer  203  in the display region  20  and the peripheral region  21 . The insulating layer  203  includes a groove  203 A in the peripheral region  21 , a light-emitting element layer  204  for a plurality of pixel units (R/G/B) is formed in the display region  20  and on the insulating layer  203 , and the light-emitting element layer  204  includes a light-emitting layer  2043 . 
     For example, the insulating layer  203  includes a first sub insulating layer  2031  and a second sub insulating layer  2032  laminated on the first sub insulating layer  2031 . The first sub insulating layer  2031  has a first groove portion  2031 A, the second sub insulating layer  2032  is laminated on the first sub insulating layer  2031  and has an opening  2032 A communicating with the first groove portion  2031 A, and the first groove portion  2031 A and the opening  2032 A constitute the groove  203 A together. For example, a longitudinal cross-section of the first groove portion  2031 A is of a regular trapezoid shape, and a longitudinal cross-section of the opening  2032 A is of an inverted trapezoid or rectangle shape, so that the groove  203 A has a large volume. 
     For example, as shown in  FIG. 7A , the longitudinal cross-section of the opening  2032 A is of an inverted trapezoid shape with a wide upper portion and a narrow lower portion, and the longitudinal cross-section of the first groove portion  2031 A is of a regular trapezoid shape with a narrow upper portion and a wide lower portion. For example, a size of a lower end of the opening  2032 A is basically the same with that of an upper end of the first groove portion  2031 A, and thus, a cross-section of the obtained groove  203 A is of an hourglass shape. In this embodiment, the groove  203 A has a larger volume, and compared to the case shown in  FIG. 5A  for example, an entering path of the impurities such as water, oxygen and the like is more complex. 
     In some embodiments, for example, a material of the first sub insulating layer  2031  includes a negative photoresist material, which benefits for forming the first groove portion  2031 A which has the narrow upper portion and the wide lower portion and has a larger volume in the preparation process. A material of the second sub insulating layer  2032  includes a positive photoresist material or includes an inorganic material. For example, the negative photoresist material includes phenolic resin and the like, the positive photoresist material includes polyimide, polyacrylate and the like, and the inorganic material includes SiOx, SiNx, Al 2 O 3  and the like. When the photoresist material exposes, an exposing amount of a material on a surface layer is larger, and thus, after development, due to different exposure intensities of upper and lower portions, a longitudinal cross-section which is of a trapezoid shape with a bevel edge is formed. 
     For example, in some embodiments of the present disclosure, the substrate further includes a pixel definition layer  2042 , the pixel definition layer  2042  includes a plurality of pixel openings  2042 A respectively used for defining a plurality of pixel units, the light-emitting layer  2043  at least covers the plurality of pixel openings  2042 A. For example, the light-emitting element layer  204  further includes a first electrode  2041  and a second electrode  2044  for driving the light-emitting layer  2043  to emit light, and further includes a passivation layer  2045  which may be covered on the light-emitting layer  2043  so as to form packaging and protection. 
     For example, in the preparation process of the display panel provided by some embodiments of the present disclosure, the light-emitting layer  2043  is formed by using a full-surface forming mode and for example, by using printing modes of ink-jet printing, spin-coating, spray-coating and the like, and thus, a material of the light-emitting layer  2043  can flow into the peripheral region  21  for sealing, and at the moment, the groove  203 A in the insulating layer  203  can collect the material of the light-emitting layer  2043 , which flows into the peripheral region  21 , so that the material of the light-emitting layer  2043  cannot remain for example on the insulating layer  203  in the peripheral region  21 . At the moment, in some embodiment, the light-emitting layer  2043  at least partially extends into the groove  203 A. 
     For example, in some embodiments of the present disclosure, a surface of the insulating layer  203 , which is positioned in the peripheral region  21 , has lyophobicity. For example, the first sub insulating layer  2031  of the insulating layer  203  is formed by adopting a material with lyophobicity, or a surface of the first sub insulating layer  2031 , which is positioned in the peripheral region  21 , is subjected to surface treatment so as to have lyophobicity. At the moment, the surface of the insulating layer  203 , which has lyophobicity, can promote the material of the light-emitting layer  2043  to flow into the groove  203 A, so that the material of the light-emitting layer  2043 , which flows to the peripheral region  21 , sufficiently flows into the groove  203 A, thereby ensuring that the material of the light-emitting layer  2043  cannot remain on the insulating layer  203  in the peripheral region  21 . 
     For example, in some embodiments of the present disclosure, the groove  203 A and the pixel opening  2042 A are the same in plane shape and size, or the plane size of the groove  203 A is greater than that of the pixel opening  2042 A. In this embodiment, the plane shape of the groove  203 A refers to a shape of the second sub insulating layer  2032  in an upper layer of the groove  203 A, which is shown in the plane diagram of the groove  203 A, i.e., a plane shape of the uppermost portion of the second sub insulating layer  2032 , and a plane shape of the pixel opening refers to a shape of the pixel opening shown in the plane diagram of the pixel opening, that is, a shape of the uppermost portion of the pixel opening, for example, as shown in  FIG. 7C , the plane shapes of the groove  203 A and the pixel opening  2042 A are rectangles, and in other embodiments, the plane shapes of the groove  203 A and the pixel opening  2042 A also may be circles, ovals or irregular shapes and the like, and the embodiments of the present disclosure do not make any specific limit to it. The plane size of the groove  203 A refers to an area occupied by the shape of the second sub insulating layer  2032  in the upper layer of the groove  203 A, which is shown in the plane diagram of the groove  203 A, the plane size of the pixel opening  2042 A refers to a size (for example, a length, a width and the like) of the shape of the pixel opening  2042 A, which is shown in the plane diagram of the pixel opening  2042 A, at the same dimension, e.g., the sizes of the length and the width of the rectangle shape or the area of the rectangle shape, as shown in  FIG. 7 . In the embodiments of the present disclosure, the plane shapes and the plane sizes of the groove  203 A and the pixel opening  2042 A may be selected according to actual demands, for example, in some embodiments, the plane size of the groove  203 A also may be smaller than that of the pixel opening  2042 A, and the embodiments of the present disclosure do not make any specific limit to it. 
     For example, in some embodiments, the insulating layer  203  includes a plurality of grooves  203 A in the peripheral region  21 , and the plurality of grooves  203 A are arranged around the display region  20 . For example, the plurality of pixel openings  2042 A are arranged in a first array, the plurality of grooves  203 A are arranged in a second array, the first array and the second array have the same arrangement direction and have the same pitch in the arrangement direction, i.e., the plurality of pixel openings  2042 A and the plurality of grooves  203 A adopt the basically same arrangement mode. For example, when the plane shapes of the groove  203 A and the pixel opening  2042 A are rectangles, an extending direction of an length of the rectangle of the groove  203 A is the same with an extending direction of an length of the rectangle of the pixel opening  2042 A, and an extending direction of a width of the rectangle of the groove  203 A is the same with an extending direction of a width of the rectangle of the pixel opening  2042 A, and a spacing between the adjacent grooves  203 A is basically the same with that between the adjacent pixel opening  2042 A. 
     Under the above-mentioned setting, when the light-emitting layer  2043  is formed in the pixel opening  2042 A, the groove  203 A in the peripheral region  21  can better collect the material of the light-emitting layer  2043  formed on the insulating layer  203  in the peripheral region  21  so as to ensure that the material of the light-emitting layer  2043  cannot remain for example on the insulating layer  203  in the peripheral region  21 . 
     For example, the substrate  2000  provided by this embodiment further includes a base substrate  201  and a driving circuit  202 . The base substrate  201  is used for supporting the display region  20  and the peripheral region  21 ; and the driving circuit  202  is positioned on the base substrate  201  and used for driving a plurality of pixel units. For example, the driving circuit  202  includes a pixel driving circuit for the pixel unit, the driving circuit includes structures such as a thin film transistor, a capacitor and the like and may be formed in a form of 2T1C, 3T1C and the like, and the embodiments of the present disclosure do not make any limit to it. For example, the insulating layer  203  covers the driving circuit  202  so as to protect the driving circuit  202 . For example, the first sub insulating layer  2031  of the insulating layer  203  is positioned on the driving circuit  202  and planarizes the driving circuit  202 , and the second sub insulating layer  2032  is positioned on the first sub insulating layer  2031  for forming the groove  203 A. 
     For example, a display panel  200  provided by some embodiments of the present disclosure includes the substrate  2000 , an opposed substrate  205  and a sealant  206 , the opposed substrate is set to be opposite to the substrate, and the sealant  206  is disposed between the substrate and the opposed substrate and for example, covers the groove  203 A and bonds the substrate  2000  with the opposed substrate  205  together. 
     The first substrate  1000  and the second substrate  2000  are different in the structure of the insulating layer, and are all the same in other members and structures, which are not repeated herein and may refer to related descriptions in the first substrate  1000 . 
     In the substrate and the display panel provided by some embodiments of the present disclosure, the insulating layer  203  includes the groove  203 A with the double-layer structure in the peripheral region  21 , and thus, the groove  203 A can collect the material of the light-emitting layer  2043 . For example, in some embodiments, the second electrode  2044  and the passivation layer  2045  on the light-emitting layer  2043  also may adopt a full-surface forming mode, and thus, there also may be materials of the second electrode  2044  and the passivation layer  2045  in the groove  203 A. Therefore, the undesired material such as the material of the light-emitting layer  2043  and the like cannot remain for example on the insulating layer  203  in the peripheral region  21 , so that the sealant  206  can be directly adhered between the insulating layer  203  and the opposed substrate  205  to form better sealing, and for example, compared to a case that the undesired material remains on the insulating layer  203  in the peripheral region  21 , an enter path of the impurities such as water, oxygen and the like can be reduced. In another aspect, the formation of the groove  203 A also complicates the entering path of the impurities such as water, oxygen and the like below the sealant  206 , thereby further reinforcing the sealing effect. 
     At least one embodiment of the present disclosure provides a preparation method of a display panel. The preparation method includes: forming a display region and a peripheral region for sealing; and the forming the display region and the peripheral region for sealing includes: forming an insulating layer in the display region and the peripheral region, forming a groove in the insulating layer in the peripheral region, and forming a light-emitting element layer for a plurality of pixel units on the insulating layer in the display region, the light-emitting element layer including a light-emitting layer. 
     An embodiment of the present disclosure further provides a preparation method of a substrate. The substrate includes a display region and a peripheral region positioned in the periphery of the display region and used for sealing. The preparation method includes: providing a base substrate; forming an insulating layer in the display region and the peripheral region on a side of the base substrate; and forming at least one groove in the peripheral region and on a side of the insulating layer which faces away from the base substrate, a side of the groove, which is away from the base substrate, being open, a depth direction of the groove being perpendicular to the base substrate, wherein the substrate includes a plurality of pixel units, and the plurality of pixel units are positioned on the insulating layer corresponding to the display region. 
     For example, the insulating layer is configured that at least a surface of the insulating layer in the peripheral region is lyophobic. 
     For example, the preparation method of the substrate further includes: forming a pixel definition layer, the pixel definition layer including a plurality of pixel openings respectively used for the plurality of pixel units; and forming a light-emitting layer, the light-emitting layer at least covering the plurality of pixel openings, wherein the light-emitting layer is formed by using an ink-jet printing, spin-coating or spray-coating mode, and at least one portion of the light-emitting layer is formed in the groove. 
     For example, the forming the insulating layer includes: forming a first sub insulating layer, the first sub insulating layer having a first groove portion; and forming a second sub insulating layer on the first sub insulating layer, the second sub insulating layer having an opening communicating with the first groove portion, wherein the first groove portion and the opening constitute the groove. 
     For example, the second sub insulating layer is formed by adopting a material with lyophobicity, or a surface of the second sub insulating layer, which is positioned in the peripheral region, is subjected to surface treatment, so that the surface of the second sub insulating layer, which is positioned in the peripheral region, has lyophobicity. 
     For example, the surface treatment is carried out by adopting plasmas of Ar, N 2 , CF 4  or O 2 . 
     The preparation provided by this embodiment will be illustrated below by taking the substrate shown in  FIG. 7A  and  FIG. 7C  as an example. 
     For example, as shown in  FIG. 8A , firstly, the base substrate  201  is provided, and then the display region  20  and the peripheral region  21  are formed in different regions of the base substrate  201 . For example, the base substrate  201  adopts a glass substrate, a quartz substrate, a plastic substrate and the like, and the embodiments of the present disclosure do not make any specific limit to it. 
     For example, the driving circuit  202  for a plurality of pixel units in the display region  20  is formed on the base substrate  201 . For example, the driving circuit  202  includes the pixel driving circuit for the pixel unit, the pixel driving circuit includes structures such as a thin film transistor, a capacitor and the like, the driving circuit further may include signal lines such as a gate line, a data line and the like and may be formed by adopting a semiconductor preparation process, and the embodiments of the present disclosure do not make any limit to it. 
     For example, the first sub insulating layer  2031  is formed on the driving circuit  202 , and the step includes: forming a first sub insulation material layer on the driving circuit  202 , and then patterning the first sub insulation material layer so as to form the first groove portion  2031 A. 
     For example, the first sub insulating layer  2031  is formed by adopting a negative photoresist material and for example, adopting phenolic resin and the like. At the moment, the patterning the first sub insulation material layer includes: exposing the first sub insulation material layer by a mask, and then performing development so as to form the first groove portion  2031 A. The first groove portion  2031 A is of a structure with a narrow upper portion and a wide lower portion, and thus has a larger volume. 
     As shown in  FIG. 8B , after the first sub insulating layer  2031  is formed, the second sub insulating layer  2032  may be formed on the first sub insulating layer  2031 , and the step includes: forming a second sub insulation material layer on the first sub insulating layer  2031 , and then patterning the second sub insulation material layer so as to form the opening  2032 A communicating with the first groove portion  2031 A. 
     For example, the second sub insulating layer  2032  is formed by adopting a positive photoresist material or an inorganic material and for example, adopting the positive photoresist material such as polyimide, polyacrylate and the like, or the inorganic materials such as SiOx, SiNx, Al 2 O 3  and the like. For example, when the second sub insulating layer  2032  is formed by adopting the positive photoresist material, the patterning the second sub insulation material layer includes: exposing and developing the second sub insulation material layer by the mask so as to form the opening  2032 A. When the second sub insulating layer  2032  is formed by adopting the inorganic material, the patterning the second sub insulation material layer includes: forming a layer of photoresist on the second sub insulation material layer, then exposing and developing the photoresist by the mask so as to form a photoresist pattern, and then performing etching on the second sub insulation material layer by the photoresist pattern so as to form the opening  2032 A; and the etching, for example, adopts a dry etching or a wet etching, and the embodiments of the present disclosure do not make any limit to it. The first groove portion  2031 A and the opening  2032 A constitute the groove  203 A in the insulating layer  203 . 
     For example, the insulating layer  203  is configured that at least a surface in the peripheral region  21  is lyophobic. At the moment, the second sub insulating layer  2032  positioned at an upper portion of the insulating layer  203  is formed by adopting a material with lyophobicity (for example, the materials illustrated above), or a surface of the second sub insulating layer  2032 , which is positioned in the peripheral region  21 , is subjected to surface treatment, so that the surface of the second sub insulating layer  2032 , which is positioned in the peripheral region  21 , is lyophobic. 
     For example, the surface of the second sub insulating layer  2032 , which is positioned in the peripheral region  21 , may be subjected to a surface treatment by adopting plasmas of Ar, N 2 , CF 4  or O 2 , so that the surface of the second sub insulating layer  2032 , which is positioned in the peripheral region  21 , is lyophobic. For example, when the second sub insulating layer  2032  is formed by adopting the material with lyophobicity, different materials with lyophobicity have different lyophobic degrees for different fluids formed thereon, and thus, the corresponding materials may be selected as required; or, the surface of the second sub insulating layer  2032  formed by adopting the material with lyophobicity also may be subjected to lyophobic treatment so as to further improve lyophobicity of the surface of the second sub insulating layer  2032 . 
     As shown in  FIG. 8C , the light-emitting element layer  204  is formed on a portion of the insulating layer  203 , which is positioned in the display region  20 . For example, firstly, the first electrode  2041  is formed, the first electrode  2041  includes a plurality of sub electrodes corresponding to a plurality of pixel units; and then the pixel definition layer  2042  is formed, the pixel definition layer  2042  includes a plurality of pixel openings  2042 A respectively used for a plurality of pixel units, the plurality of pixel openings  2042 A respectively expose a plurality of sub electrodes of the first electrode  2041 , and the light-emitting layer  2043  is configured to at least cover a plurality of pixel openings  2042 A; and then the second electrode  2043  and the passivation layer  2044  are formed on the light-emitting layer  2043 . 
     For example, the first electrode  2041  and the pixel definition layer  2042  may be formed by adopting the patterning process, a material of the first electrode  2041 , for example, includes metal oxide such as ITO, IZO and the like or metal such as Ag, Al, Mo and the like or alloy thereof, and a material of the pixel definition layer  2042 , for example, includes an organic material such as polyimide and the like or an inorganic material such as silicon oxide, silicon nitride and the like. 
     For example, the light-emitting layer  2043  may be formed by using a printing mode such as ink-jet printing, spin-coating or spray-coating and the like, and due to fluidity of printed ink, the material of the printed light-emitting layer  2043  also extends into the groove  203 A. The material of the light-emitting layer  2043  is correspondingly selected according to a type of a to-be-formed light-emitting element. For example, when an OLED is to be formed, an organic light-emitting material is used, and the light-emitting layer may be a composite layer and for example, includes an electron injection sub layer, an electron transport sub layer, a light-emitting sub layer, a hole transport sub layer, a hole injection sub layer and the like; and for further example, when the QLED is to be formed, a quantum dot light-emitting material is used. The embodiments of the present disclosure do not make any limit to the material of the light-emitting layer. For example, the second electrode  2044  and the passivation layer  2045  may be formed by the mask respectively in modes of evaporation, sputtering or deposition and the like. For example, a material of the second electrode  2044  includes metal such as Mg, Ca, Li or Al and the like or alloy thereof, or an inorganic material with conductivity, such as IZO, ZTO and the like, or an organic material with conductivity, such as (poly 3,4-ethylenedioxythiophene/polystyrene sulfonate) (PEDOT/PSS) and the like, and a material of the passivation layer  2045  includes an organic material such as polyimide and the like or an inorganic material such as silicon oxide, silicon nitride and the like. 
     Further, an embodiment of the present disclosure further provides a preparation method of a display panel, including: manufacturing the substrate, the substrate being prepared by any one of the above-mentioned preparation methods; and providing an opposed substrate, and bonding the opposed substrate on the display panel by a sealant, wherein the sealant covers the groove. For example, the preparation method is described with reference to the drawing, and as shown in  FIG. 8D , after the light-emitting element layer  204  is formed, the preparation method of the display panel, after the preparation method of the substrate, further includes: providing the opposed substrate  205 , and bonding the opposed substrate  205  on the substrate by the sealant  206 ; for example, the sealant  206  is coated in the peripheral region according to a preset pattern and covers the groove  203 A so as to be at least partially filled into and cover the groove  203 A; and for example, according to a type of the sealant, the sealant may be subjected to ultraviolet lighting curing or thermocuring. For example, a material of the opposed substrate  205  includes a glass plate, a plastic plate or a plastic film, for example, a plastic material may adopt a transparent material such as polyethylene terephthalate (PET) or polyimide (PI) and the like, and the material of the sealant  206  includes a material being adhesive, such as resin and the like. 
     In some embodiments of the present disclosure, the groove  203 A of the insulating layer  203 , which is positioned in the peripheral region  21 , can collect the material of the light-emitting layer  2043  formed in the peripheral region  21  when the light-emitting element layer  204  is formed, and thus, for example, the undesired material cannot remain for example on a portion of the insulating layer  203 , which is positioned in the peripheral region  21 , and at the moment, the sealant  206  may directly bond the opposed substrate  205  with the insulating layer  203  so as to have a better packaging effect. 
     For example, in some embodiments, the second electrode  2044  and/or the passivation layer  2045  also may be formed into one whole surface in modes of evaporation, sputtering or deposition and the like, and at the moment, there is also a forming material of the second electrode  2044  and/or the passivation layer  2045  in the groove  203 A. 
     In some embodiments of the present disclosure, a portion of the insulating layer  203 , which is positioned in the peripheral region  21 , has the groove  203 A, and thus, the groove  203 A can collect the undesired material formed on a portion of the insulating layer  203 , which is positioned in the peripheral region  21 . As shown in  FIG. 9 , the preparation method may be used for using one mother board and simultaneously preparing a plurality of display panels by the mother board, those display panels may be of the same shape or different shapes, and then those display panels may be separated from each other by a cutting process. For example, in  FIG. 9 , three display panels are prepared on the same mother board, and include an oval display panel on an upper side and two rectangular display panels on a lower side. In each display panel, the sealant  206  surrounds the display region  20  and covers the groove in the peripheral region. For example, in some embodiments, the display panel also may be of an irregular shape, and at the moment, even though one whole surface of functional layer, such as the light-emitting layer  2043  and the like, is formed, due to a collection effect of the groove  203 A, the material of the functional layer such as the light-emitting layer  2043  and the like, for example, also cannot remain on a portion of the insulating layer  203 , which is positioned in the peripheral region  21 , so as not to influence the packaging effect of the sealant  206 . Therefore, the display panel prepared by the preparation method provided by the embodiments of the present disclosure has a better packaging effect, and a plurality of display panels can be simultaneously formed by utilizing the preparation method, thereby improving production efficiency. 
     At least one embodiment of the present disclosure further provides a display device. As shown in  FIG. 10 , a display device  300  includes any one of the display panels provided by the embodiments of the present disclosure, and a display panel  200  is shown in the drawing. The display device  300  may be any product or part with a display function, such as a mobile phone, a tablet personal computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like, and the embodiments of the present do not make any limit to it. 
     The following statements should be noted: 
     (1) The accompanying drawings involve only the structure(s) in connection with the embodiment(s) of the present disclosure, and other structure(s) can be referred to common design(s). 
     (2) For the purpose of clarity only, in accompanying drawings for illustrating the embodiment(s) of the present disclosure, the thickness of a layer or a region may be enlarged or reduced, that is, the accompanying drawings are not drawn according to the actual scale. 
     (3) In case of no conflict, features in one embodiment or in different embodiments can be combined to obtain a new embodiment. 
     What are described above is related to the specific embodiments of the disclosure only and not limitative to the scope of the disclosure. The protection scope of the disclosure shall be based on the protection scope of the claims. 
     This application claims priority to Chinese Patent Application No. 201811496810.5 filed Dec. 7, 2018, the disclosure of which is incorporated herein by reference as part of the application.