Light-emitting substrate, display panel and display device

Abstract

The utility model provides a light emitting substrate, a display panel and a display device. The light-emitting substrate comprises: a substrate; the flat layer is arranged on one side of the substrate; the light-emitting layer is arranged on the side, away from the substrate, of the flat layer, the flat layer comprises N sub flat layers which are arranged in a stacked mode, each sub flat layer comprises a first surface which is away from the side of the substrate, the first surfaces of at least two sub flat layers comprise a plurality of concave surfaces, and N is a positive integer larger than or equal to 2.

Description

Technical Field

[0001] The utility model relates to the technical field of display, and particularly relates to a light-emitting substrate, a display panel and a display device. Background Art

[0002] At present, as a new type of light-emitting device, OLED (Organic Light-Emitting Diode) has shown great application potential in the fields of display and lighting, and thus has received strong attention from the industry. In the field of display, OLED has the advantages of self-luminescence, fast response, wide viewing angle, high brightness, thin and light, etc., and is regarded as the next-generation display technology. However, due to factors such as waveguide effect and interface total reflection, the light extraction efficiency of OLED light-emitting devices is relatively low. Therefore, how to improve the light extraction efficiency of OLED light-emitting devices is one of the important research topics for those skilled in the art.

[0003] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present utility model, and thus may include information that does not constitute the prior art known to those skilled in the art. Summary of the Utility Model

[0004] In one aspect, a light-emitting substrate is provided, which includes:

[0005] A substrate;

[0006] A planarization layer disposed on one side of the substrate; and

[0007] A light-emitting layer disposed on the side of the planarization layer away from the substrate,

[0008] wherein, the planarization layer includes N sub-planarization layers stacked, the sub-planarization layer includes a first surface on the side away from the substrate, and the first surfaces of at least two of the sub-planarization layers include a plurality of concave surfaces, and N is a positive integer greater than or equal to 2.

[0009] According to some exemplary embodiments, the N sub-planarization layers include an i-th sub-planarization layer and an (i + 1)-th sub-planarization layer, and the (i + 1)-th sub-planarization layer is located on the side of the i-th sub-planarization layer away from the substrate,

[0010] wherein, the refractive index of the (i + 1)-th sub-planarization layer is greater than or equal to the refractive index of the i-th sub-planarization layer, and i is a positive integer greater than or equal to 1 and less than or equal to N - 1.

[0011] According to some exemplary embodiments, the distribution density of the plurality of concave surfaces on the first surface of the (i + 1)-th sub-planarization layer is less than or equal to the distribution density of the plurality of concave surfaces on the first surface of the i-th sub-planarization layer.

[0012] According to some exemplary embodiments, in a first direction, the positive projection of at least one concave surface in the first surface of the (i + 1)-th sub-flat layer on the substrate has an (i + 1)-th width, and the positive projection of at least one concave surface in the first surface of the i-th sub-flat layer on the substrate has an i-th width, where the (i + 1)-th width is greater than or equal to the i-th width, and the first direction is parallel to the light-emitting surface of the light-emitting substrate.

[0013] According to some exemplary embodiments, the sidewall angle of at least one concave surface in the sub-flat layer is in the range of 30° to 40°.

[0014] According to some exemplary embodiments, the flat layer includes a first sub-flat layer and a second sub-flat layer.

[0015] Wherein, the distribution density of a plurality of concave surfaces in the first surface of the second sub-flat layer is equal to the distribution density of a plurality of concave surfaces in the first surface of the first sub-flat layer; and

[0016] The second width of the positive projection of at least one concave surface in the first surface of the second sub-flat layer on the substrate is equal to the first width of the positive projection of at least one concave surface in the first surface of the first sub-flat layer on the substrate.

[0017] According to some exemplary embodiments, the flat layer further includes a third sub-flat layer.

[0018] Wherein, the distribution density of a plurality of concave surfaces in the first surface of the third sub-flat layer is equal to the distribution density of a plurality of concave surfaces in the first surface of the second sub-flat layer; and

[0019] The third width of the positive projection of at least one concave surface in the first surface of the third sub-flat layer on the substrate is equal to the second width of the positive projection of at least one concave surface in the first surface of the second sub-flat layer on the substrate.

[0020] According to some exemplary embodiments, the flat layer includes a first sub-flat layer and a second sub-flat layer.

[0021] Wherein, the distribution density of a plurality of concave surfaces in the first surface of the second sub-flat layer is less than the distribution density of a plurality of concave surfaces in the first surface of the first sub-flat layer; and

[0022] The second width of the positive projection of at least one concave surface in the first surface of the second sub-flat layer on the substrate is greater than the first width of the positive projection of at least one concave surface in the first surface of the first sub-flat layer on the substrate.

[0023] According to some exemplary embodiments, the planar layer further includes a third sub-planar layer,

[0024] wherein a distribution density of the plurality of concave surfaces in the first surface of the third sub-planar layer is smaller than a distribution density of the plurality of concave surfaces in the first surface of the second sub-planar layer; and

[0025] A third width of an orthographic projection of at least one concave surface in the first surface of the third sub-planar layer on the base substrate is greater than a second width of an orthographic projection of at least one concave surface in the first surface of the second sub-planar layer on the base substrate.

[0026] According to some exemplary embodiments, the refractive index of the planar layer is in a range of 1.4 to 1.9.

[0027] According to some exemplary embodiments, the material of the planar layer includes a combination of one or more of epoxy resin, acrylic and polyimide.

[0028] According to some exemplary embodiments, the i-th sub-planar layer is in direct contact with the (i+1)-th sub-planar layer; and

[0029] The sub-planar layer also includes a second surface close to the substrate side, the second surface of the (i+1)th sub-planar layer includes multiple convex surfaces, and the multiple convex surfaces in the second surface of the (i+1)th sub-planar layer fill the multiple concave surfaces in the first surface of the i-th sub-planar layer.

[0030] According to some exemplary embodiments, the light-emitting layer includes: a first electrode disposed on a side of the planar layer away from the base substrate; a light-emitting functional layer disposed on a side of the first electrode away from the base substrate; and a second electrode disposed on a side of the light-emitting functional layer away from the base substrate.

[0031] Wherein, the first electrode is arranged in contact with the surface of the flat layer away from the base substrate; and

[0032] The surface of the first electrode close to the substrate includes a plurality of convex surfaces; and / or,

[0033] The surface of the light-emitting functional layer close to the base substrate includes a plurality of convex surfaces; and / or,

[0034] A surface of the second electrode close to the base substrate includes a plurality of convex surfaces.

[0035] According to some exemplary embodiments, the light emitting substrate further includes: a driving circuit layer located between the base substrate and the planar layer; and a filter layer located between the driving circuit layer and the planar layer.

[0036] In another aspect, a display panel is provided, wherein the display panel includes the light-emitting substrate described in any one of the above.

[0037] In yet another aspect, a display device is provided, wherein the display device includes the light-emitting substrate described in any one of the above or the display panel described above. Description of the Drawings

[0038] Through the following description of the embodiments of the present invention with reference to the drawings, the above content and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0039] Figure 1 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0040] Figure 2 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0041] Figure 3 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0042] Figure 4 is Figure 3 a partial enlarged view of the area of the dashed box S1 in;

[0043] Figure 5 is a schematic structural diagram of a light-emitting device according to an exemplary embodiment of the present invention;

[0044] Figure 6 is a schematic diagram showing the relationship between the spacing distance between some film layers in a light-emitting functional layer and a second electrode and the light-emitting effect according to an exemplary embodiment of the present invention;

[0045] Figure 7 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0046] Figure 8 is a schematic structural diagram of a planarization layer according to an exemplary embodiment of the present invention;

[0047] Figure 9 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0048] Figure 10 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0049] Figure 11 is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention;

[0050] Figure 12Schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present utility model;

[0051] Figure 13 Block diagram of a display panel according to an embodiment of the present utility model; and

[0052] Figure 14 Block diagram of a display device according to an embodiment of the present utility model.

[0053] It should be noted that, for clarity, in the drawings used to describe the embodiments of the present invention, the dimensions of layers, structures, or regions may be enlarged or reduced, that is, these drawings are not drawn to actual scale. Detailed implementation manners

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the drawings of the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0055] It should be noted that, in the drawings, for the purpose of clarity and / or description, the dimensions of elements may be enlarged and relative dimensions. Thus, the dimensions and relative dimensions of each element do not have to be limited to the dimensions and relative dimensions shown in the drawings. In the description and drawings, the same or similar reference numerals indicate the same or similar components.

[0056] Unless otherwise defined, the technical terms or scientific terms used in the present utility model should have the ordinary meaning understood by those of ordinary skill in the art. The "first", "second", and similar terms used in the present utility model do not indicate any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or items appearing before this term cover the elements or items listed after this term and their equivalents, without excluding other elements or items.

[0057] In this article, unless otherwise specifically stated, directional terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are used to represent the orientation or positional relationship based on the orientation shown in the drawings, and are only for the convenience of describing the present utility model, rather than indicating or implying that the device, element, or component referred to must have a specific orientation, be constructed or operated in a specific orientation. It should be understood that when the absolute position of the object being described changes, the relative positional relationship they represent may also change accordingly. Therefore, these directional terms should not be construed as limitations on the present utility model.

[0058] In this text, terms such as "substantially", "about", "approximate" and other similar terms are used as approximate terms rather than terms of degree, and they are intended to explain the inherent deviations of measured or calculated values that would be recognized by a person of ordinary skill in the art. Considering factors such as process fluctuations, measurement problems, and errors associated with the measurement of a particular quantity (i.e., limitations of the measurement system), as used herein, "about" or "approximate" includes the stated value and represents within an acceptable deviation range for the particular value determined by a person of ordinary skill in the art. For example, "about" may mean within one or more standard deviations, or within ±10% or ±5% of the stated value.

[0059] In this text, the directional expressions "first direction" and "second direction" are used to describe different directions of the light-emitting substrate or the display panel. For example, the light-emitting surface direction of the light-emitting substrate or the normal direction perpendicular to the light-emitting surface. It should be understood that such representations are only exemplary descriptions and not limitations of the present invention.

[0060] As a new type of light-emitting device, OLED light-emitting devices have shown great application potential in the fields of display and lighting, and thus have received strong attention from the academic and industrial communities. In the display field, OLED display devices have the advantages of self-luminescence, fast response, wide viewing angle, high brightness, vivid colors, thin and light, etc. compared with liquid crystal display devices, and are widely used in mobile phones, computers, televisions, and micro-display fields.

[0061] However, due to material limitations and the influence of the light extraction mode, the light extraction efficiency of OLED light-emitting devices is relatively low. Among them, the influence of the light extraction mode mainly includes internal and external waveguide effects and interface total reflection. At present, the light extraction efficiency is mainly improved by reducing non-light-emitting modes and waveguide effects and reducing total reflection. For example, a micro lens array can be used to form a non-planar surface to suppress interface total reflection. At the same time, the micro lens can also increase the light-emitting surface and achieve edge light convergence, thereby improving the light extraction efficiency and the light-emitting brightness.

[0062] In the related art, top-emitting devices mainly form micro lenses on the encapsulation layer by thermal reflow. For example, the light extraction efficiency is improved by designing an external light extraction structure (External Extraction Structure, abbreviated as EES) and a microlens array (Microlens Array, abbreviated as MLA) filled inside the pixel.

[0063] Compared with ordinary OLED devices, WOLED (White Organic Light-Emitting Diode) has been more widely used because of its longer service life and higher luminous efficiency. WOLED usually adopts a bottom-emission design. There are certain process difficulties in forming MLA in the bottom-emission WOLED light-emitting substrate. Usually, pits with a certain curvature are formed on the flat layer within the pixel, but the current MLA structure has limited improvement for the bottom-emission WOLED light-emitting substrate, resulting in a still low light extraction efficiency.

[0064] It should be noted that bottom emission is a light extraction method in OLED display technology, which means that light is emitted from the anode of the device. In this structure, the structure of the device from top to bottom usually includes an opaque metal cathode, an organic functional layer, and a transparent anode. Since light is emitted from the anode, it is called bottom emission.

[0065] An exemplary embodiment of the present invention provides a light-emitting substrate. Specifically, the light-emitting substrate includes: a substrate; a flat layer disposed on one side of the substrate; and a light-emitting layer disposed on the side of the flat layer away from the substrate. Wherein, the flat layer includes N sub-flat layers stacked, and the sub-flat layer includes a first surface on the side away from the substrate, and the first surfaces of at least two sub-flat layers include a plurality of concave surfaces, and N is a positive integer greater than or equal to 2.

[0066] By designing the flat layer to include a plurality of sub-flat layers, and at least two of the plurality of sub-flat layers include a concave surface design, the total number of concave surfaces in the flat layer can be increased. When the light emitted by the light-emitting layer passes through the flat layer and is emitted outward, the distribution density of the concave surfaces increases, which can better suppress the loss of light at the film layer interface, reduce the occurrence probability of the interface total reflection phenomenon, is beneficial to improving the light extraction efficiency of the OLED light-emitting substrate, reducing power consumption, and increasing the brightness of the light-emitting substrate.

[0067] Figure 1 It is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention, Figure 2 It is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention.

[0068] Exemplarily, an embodiment of the present invention provides a light-emitting substrate 100. The light-emitting substrate 100 may include an OLED light-emitting device, for example, including one or more of a red OLED light-emitting device, a green OLED light-emitting device, a blue OLED light-emitting device, and a white OLED light-emitting device.

[0069] Exemplarily, refer to Figure 1, the light-emitting substrate 100 may include a first electrode 51, a light-emitting functional layer 52, and a second electrode 53. For example, the first electrode 51 may be an anode, and the second electrode 53 may be a cathode. When a voltage is applied between the first electrode 51 and the second electrode 53, the light-emitting functional layer 52 can be excited to emit light and radiate outward, forming outgoing light.

[0070] Exemplarily, the light-emitting substrate 100 may further include a substrate 50. The substrate 50 may be located on the side of the first electrode 51 away from the second electrode 53. For example, the substrate 50 may include a glass substrate. The glass substrate has a high transparency, which is conducive to visible light passing through the substrate and radiating outward.

[0071] Exemplarily, the direction of the outgoing light of the light-emitting substrate 100 is related to the transparency of the first electrode 51 and the second electrode 53. For example, if the first electrode 51 has a high transparency and the second electrode 53 is opaque, the light emitted by the light-emitting functional layer 52 mainly radiates outward through the first electrode 51 side.

[0072] Exemplarily, the first electrode 51 may include a transparent conductive material, such as indium tin oxide (ITO). The second electrode 53 may include an opaque conductive material, such as a thick conductive metal layer, such as metals or metal alloys like aluminum, silver, magnesium / silver, etc.

[0073] Due to the different refractive indices of the multiple film layer materials in the light-emitting substrate, the propagation path of light changes when propagating at the interfaces of different film layers. Refer to Figure 1 , when light enters a flat surface with a lower refractive index from a flat surface with a higher refractive index, such as when light is incident from a glass surface to an air interface, light within a certain range of incident angles will undergo total internal reflection at the interface, resulting in being unable to radiate outward, thus reducing the light extraction efficiency of the light-emitting substrate. For example, incident light with an angle greater than θ1 with respect to the normal line L1 of the light-emitting surface will undergo total internal reflection at the interface where the glass substrate intersects with the air, and cannot radiate outward, resulting in a low light extraction efficiency of the light-emitting substrate.

[0074] Exemplarily, refer to Figure 2 , in order to reduce the probability of total internal reflection of the outgoing light at the interface, a plurality of lenses 40 may be designed on the side of the substrate 50 away from the light-emitting functional layer 52, and the plurality of lenses 40 may be arranged in an array. Most of the light emitted by the light-emitting functional layer 52 can enter the lenses 40 after passing through the substrate 50, and then be emitted from the lenses 40 into the air. For example, a part of the incident light with an angle greater than θ1 with respect to the normal line L1 of the light-emitting surface can be refracted by the lenses 40 and then radiate outward from the convex arc surface of the lenses 40. By adjusting the refractive index and the curved surface angle of the lenses 40, the probability of total internal reflection of the outgoing light at the interface can be reduced, thereby improving the light extraction efficiency of the light-emitting substrate 100.

[0075] Figure 3Schematic diagram of the structure of a light-emitting substrate according to an exemplary embodiment of the present invention Figure 4 is Figure 3 a partial enlarged view of the area within the dashed box S1 in Figure 5 Schematic diagram of the structure of a light-emitting device according to an exemplary embodiment of the present invention Figure 6 Schematic diagram of the relationship between the spacing distance between some film layers in the light-emitting functional layer and the second electrode and the light-emitting effect according to an exemplary embodiment of the present invention

[0076] Exemplarily, in an embodiment of the present invention, the light-emitting substrate 100 may include a WOLED light-emitting substrate. The WOLED light-emitting substrate generally adopts a bottom-emission design.

[0077] In the related preparation of WOLED, with reference to Figure 3 and Figure 4 , after the driving circuit layer 2 is prepared on the substrate 1, a planarization layer 4 can be formed on the side of the driving circuit layer 2 away from the substrate 1. By forming a plurality of concave structures on the side of the planarization layer 4 away from the substrate 1, a microlens array structure can be obtained. Further, a light-emitting layer 5 is provided on the side of the planarization layer 4 having the microlens array structure. For example, the light-emitting layer 5 may include a first electrode 51, a light-emitting functional layer 52, and a second electrode 53 that are sequentially arranged away from the planarization layer 4.

[0078] Exemplarily, the light-emitting substrate 100 may further include a filter layer 3 located between the planarization layer 4 and the driving circuit layer 2. For example, the filter layer 3 may include filter films of various colors. The white light emitted by the WOLED light-emitting device can form light of various colors, such as red light, green light, and blue light, after passing through the filter layer 3, thereby realizing color display.

[0079] Exemplarily, the filter layer 3 may further include a black matrix layer, and the black matrix layer can define a plurality of pixel openings.

[0080] In an embodiment of the present invention, by providing a microlens array structure on the side of the planarization layer 4 close to the light-emitting layer 5, the occurrence probability of total reflection of the light emitted by the light-emitting layer within the light-emitting substrate can be reduced, thereby improving the light extraction efficiency of the light-emitting substrate.

[0081] However, since the first electrode 51, the light-emitting functional layer 52, and the second electrode 53 are provided on the side of the planarization layer 4 having the microlens array structure, the morphology of the stacked structure of the first electrode 51, the light-emitting functional layer 52, and the second electrode 53 will be affected by the microlens array structure, that is, it has a plurality of convex regions and a plurality of concave regions. As Figure 4As shown, in the light-emitting layer 5 of the stacked structure, the first electrode 51 and the second electrode 53 are disposed opposite to each other, and the light-emitting functional layer 52 is located between the first electrode 51 and the second electrode 53, and the layer thickness of the light-emitting functional layer 52 is different at different positions in the recessed area. For example, from Figure 4 As can be seen from d1, d2, and d3 shown in Figure 4 , there are obvious differences in the thickness of the light-emitting functional layer 52 at different positions. For example, the light-emitting functional layer 52 may include a main light-emitting region I and an auxiliary light-emitting region II. The thickness of the light-emitting functional layer of the main light-emitting region I located on the sidewall of the recessed area is less than the thickness of the light-emitting functional layer of the auxiliary light-emitting region II located at the bottom of the recessed area. For example, d3 is less than d1. The auxiliary light-emitting region II also includes a partial light-emitting layer located in the protruding area. The thickness of the light-emitting functional layer of the main light-emitting region I located on the sidewall of the recessed area is less than the thickness of the light-emitting functional layer of the auxiliary light-emitting region II located in the protruding area. For example, d3 is less than d2.

[0082] Understandably, due to the difference in the thickness of the light-emitting functional layer 52 between the main light-emitting region I and the auxiliary light-emitting region II, the difference in the thickness of the light-emitting functional layer 52 will affect both the brightness and color of the light emission. For example, Figure 5 Fig. Figure 5 shows the structure of a WOLED light-emitting device, which includes a first electrode 51, a light-emitting functional layer 52, and a second electrode 53. The light-emitting functional layer 52 includes a first sub-light-emitting layer 521, a first charge generation layer 522, a second sub-light-emitting layer 523, a second charge generation layer 524, and a third sub-light-emitting layer 525. For example, the first sub-light-emitting layer 521 includes a blue light-emitting layer, the second sub-light-emitting layer 523 includes a yellow-green light-emitting layer 5231 and a red light-emitting layer 5232, and the third sub-light-emitting layer 525 includes a blue light-emitting layer. The spacing distance between different color sub-light-emitting layers and the second electrode 53 will affect the light-emitting efficiency and the wavelength (or color) of the emitted light of the sub-light-emitting layer. For example, the spacing distance between the first sub-light-emitting layer 521 and the second electrode 53 is H1, the spacing distance between the second sub-light-emitting layer 523 and the second electrode 53 is H2, and the spacing distance between the third sub-light-emitting layer 525 and the second electrode 53 is H3. Due to the difference in the thickness of the light-emitting functional layer 52 between the main light-emitting region I and the auxiliary light-emitting region II, the values of H1, H2, and H3 in different regions will be different.

[0083] Table 1 shows the spacing distances between different sub-light-emitting layers and the second electrode in different regions

[0084]

[0085] As can be seen from Table 1, there are obvious thickness differences in multiple sub-light-emitting layers in both the main light-emitting region and the auxiliary light-emitting region. Among them, the larger the sidewall angle of the lens structure, the more significant the thickness differences in multiple sub-light-emitting layers in the main light-emitting region and the auxiliary light-emitting region.

[0086] It should be noted that the sidewall angle of the lens structure refers to the angle between the tangent of the arc surface of the lens and the horizontal plane.

[0087] Exemplarily, Figure 6 The relationship between the light emission efficiency and wavelength of different sub-light-emitting layers and the spacing distance between the sub-light-emitting layer and the second electrode 53 is shown. The abscissa X1 represents the wavelength of the light emitted by the sub-light-emitting layer, the ordinate Y1 represents the spacing distance between the sub-light-emitting layer and the second electrode, and different color depths represent different light emission intensities. The light emission intensity in the region with a darker color is greater than that in the region with a lighter color. As the spacing distance between the sub-light-emitting layer and the second electrode 53 changes, the light emission efficiency of the sub-light-emitting layer also changes significantly. For example, for the yellow-green light-emitting layer YG2, the spacing distance between the yellow-green light-emitting layer in the S2 region and the second electrode is less than that between the yellow-green light-emitting layer in the S3 region and the second electrode, which results in a higher light emission efficiency of the yellow-green light-emitting layer in the S2 region than that in the S3 region.

[0088] The microlens array in the flat layer causes differences in the thickness of the light-emitting functional layer 52 in different regions. The thickness difference of the light-emitting functional layer 52 causes differences in the brightness and color of the light emitted in different regions, affecting the display effect. To reduce the thickness difference between different regions, generally, the lens curvature / slope in the microlens array is reduced and the inner diameter is increased. For example, it is ensured that most of the sidewall angles of the lens structure are between 20° and 45°, thereby reducing the thickness difference between different regions.

[0089] The inventor has found through research that: in a light-emitting substrate using a flat layer containing a single-layer microlens array, increasing the inner diameter of the lens and reducing the lens curvature / slope will cause a significant decrease in the lens distribution density in the flat layer, thereby reducing the light extraction effect of the microlens array. That is to say, the improvement effect of the flat layer containing a single-layer microlens array on the light extraction efficiency of the light-emitting substrate is still insufficient, and the light extraction efficiency of the light-emitting substrate still needs to be further improved.

[0090] In the embodiment of the present invention, the flat layer may include a plurality of sub-flat layers, and the surfaces of the plurality of sub-flat layers close to the substrate may all include a microlens array structure, thereby increasing the overall lens distribution density in the flat layer and improving the light extraction efficiency. On the other hand, the sidewall angle of the lens on the surface of the sub-flat layer close to the light-emitting layer can be set to be smaller, which can reduce the thickness difference of the light-emitting functional layer in different regions and is beneficial to improving the light-emitting effect.

[0091] Figure 7 It is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention. Figure 8Schematic diagram of the structure of a flat layer according to an exemplary embodiment of the present utility model.

[0092] Exemplarily, in an embodiment of the present utility model, with reference to Figure 7 , a light-emitting substrate 100 is provided. Among them, the light-emitting substrate 100 may include: a substrate substrate 1; a flat layer 4 disposed on one side of the substrate substrate 1; and a light-emitting layer 5 disposed on the side of the flat layer 4 away from the substrate substrate 1.

[0093] Exemplarily, the light-emitting substrate 100 may further include: a driving circuit layer 2 located between the substrate substrate 1 and the flat layer 4; and a filter layer 3 located between the driving circuit layer 2 and the flat layer 4.

[0094] Exemplarily, the flat layer 4 may include N sub-flat layers stacked, and the sub-flat layer includes a first surface on the side away from the substrate substrate 1, and the first surfaces of at least two sub-flat layers include a plurality of concave surfaces, where N is a positive integer greater than or equal to 2. For example, the flat layer 4 may include 2 sub-flat layers stacked, and the first surfaces of the 2 sub-flat layers on the side away from the substrate include a plurality of concave surfaces. For another example, the flat layer 4 may include 3 sub-flat layers stacked, and the first surfaces of the 3 sub-flat layers on the side away from the substrate include a plurality of concave surfaces. In some embodiments, the flat layer 4 may further include more layers of stacked sub-flat layers, such as 4 layers, 5 layers or more layers, and the embodiments of the present utility model do not limit this.

[0095] Through such a design, the overall lens distribution density in the flat layer can be increased, which is beneficial to improving the light extraction efficiency of the light-emitting substrate.

[0096] Exemplarily, with reference to Figure 4 and Figure 7 , the light-emitting layer 5 may include: a first electrode 51 disposed on the side of the flat layer 4 away from the substrate substrate 1; a light-emitting functional layer 52 disposed on the side of the first electrode 51 away from the substrate substrate 1; and a second electrode 53 disposed on the side of the light-emitting functional layer 52 away from the substrate substrate 1. Among them, the first electrode 51 is disposed in contact with the surface 400 of the flat layer 4 on the side away from the substrate substrate 1.

[0097] Exemplarily, the surface of the first electrode 51 close to the substrate substrate 1 includes a plurality of convex surfaces; and / or, the surface of the light-emitting functional layer 52 close to the substrate substrate 1 includes a plurality of convex surfaces; and / or, the surface of the second electrode 53 close to the substrate substrate 1 includes a plurality of convex surfaces. That is to say, the multiple film layers in the light-emitting layer 5 can be formed conformally on the flat layer 4, so that the surfaces of the multiple film layers in the light-emitting layer 5 close to the substrate include a plurality of convex surfaces. The spacing distance between the multiple film layers in the light-emitting layer 5 and the second electrode will be affected by the topography of the surface 400 of the flat layer 4 close to the light-emitting layer 5.

[0098] In order to improve the consistency of the film thickness in different regions of the light-emitting layer and enhance the light-emitting uniformity, the embodiments of the present utility model optimize the sidewall angles of the lens structures in the flat layer.

[0099] Exemplarily, the sidewall angles of at least one concave surface in the sub-flat layer are in the range of 30° to 40°. For example, the sidewall angle α of the concave surface of the sub-flat layer in direct contact with the light-emitting layer 5 is in the range of 30° to 40°.

[0100] Exemplarily, the sidewall angle α of the concave surface of the sub-flat layer in direct contact with the light-emitting layer 5 is in the range of 35° to 38°.

[0101] Through such a design, the thickness difference of the light-emitting functional layers in different regions can be reduced, which is beneficial to improving the light-emitting uniformity and enhancing the display effect.

[0102] Exemplarily, with reference to Figure 7 and Figure 8 , the N sub-flat layers may include the i-th sub-flat layer and the (i + 1)-th sub-flat layer. The (i + 1)-th sub-flat layer is located on the side of the i-th sub-flat layer away from the substrate. Among them, the refractive index of the (i + 1)-th sub-flat layer is greater than or equal to the refractive index of the i-th sub-flat layer, where i is a positive integer greater than or equal to 1 and less than or equal to N - 1.

[0103] Through such a design, a gradually changing refractive index gradient can be formed by multiple sub-flat layers in the flat layer. The light emitted by the light-emitting layer will refract at the interfaces of multiple sub-flat layers in the flat layer. The design of the gradually changing refractive index can avoid too large a refractive index difference at the interfaces of two adjacent film layers, which is beneficial to reducing the occurrence probability of total reflection, and thus can improve the light extraction efficiency of the light-emitting substrate.

[0104] Exemplarily, the refractive index of the flat layer is in the range of 1.4 to 1.9. For example, the refractive index of the (i + 1)-th sub-flat layer is in the range of 1.7 to 1.9, and the refractive index of the i-th sub-flat layer is in the range of 1.4 to 1.7. For another example, the refractive index of the (i + 2)-th sub-flat layer is in the range of 1.8 to 1.9, the refractive index of the (i + 1)-th sub-flat layer is in the range of 1.6 to 1.8, and the refractive index of the i-th sub-flat layer is in the range of 1.4 to 1.6.

[0105] Exemplarily, the material of the flat layer may include a transparent organic material. For example, the material of the flat layer may include one or a combination of epoxy resin, acrylic, and polyimide.

[0106] Exemplarily, multiple concave structures in the flat layer can be formed by imprinting technology.

[0107] Exemplarily, the i-th sub-planar layer is in direct contact with the i+1-th sub-planar layer. That is, the surface of the i+1-th sub-planar layer close to the i-th sub-planar layer may fill the plurality of concave surfaces in the surface of the i-th sub-planar layer close to the i+1-th sub-planar layer. Figure 8 The sub-planar layer also includes a second surface close to the substrate. The second surface 42 of the (i+1)th sub-planar layer i+1 The second surface 42 of the (i+1)th sub-planar layer includes a plurality of convex surfaces. i+1 The plurality of convex surfaces in the i-th sub-planar layer fill the first surface 41 i Multiple concavities in .

[0108] Through such a design, multiple stacked sub-flat layers can be arranged adjacent to each other in sequence without the need for an additional transition layer in between, which simplifies the preparation and helps reduce costs.

[0109] In an exemplary embodiment of the present invention, the first surface 41 of the (i+1)th sub-planar layer i+1 The plurality of concave surfaces 40 i+1 The distribution density is less than or equal to the first surface 41 of the i-th sub-planar layer. i The plurality of concave surfaces 40 i That is, in the same area, the first surface 41 of the i+1th sub-planar layer i+1 The plurality of concave surfaces 40 i+1 The number is less than or equal to the first surface 41 of the i-th sub-planar layer i The plurality of concave surfaces 40 i The number of

[0110] It should be noted that the “distribution density” of the concave surfaces in the embodiments of the present invention refers to the number of concave surfaces per unit area. For example, the distribution density of multiple concave surfaces may include 3 / cm 2 .

[0111] In an exemplary embodiment of the present invention, in the first direction X, the first surface 41 of the (i+1)th sub-planar layer i+1 At least one concave surface 40 i+1 The orthographic projection on the substrate has the i+1th width D i+1 , the first surface 41 of the i-th sub-planar layer i At least one concave surface 40 i The orthographic projection on the substrate has an i-th width D i For example, the i+1th width D i+1 Greater than or equal to the i-th width D i The first direction X is parallel to the light emitting surface of the light emitting substrate. Alternatively, the first direction X is perpendicular to the light emitting direction of the light emitting substrate.

[0112] Through such a design, while increasing the total number of lens structures in the flat layer, it is possible to ensure that the sidewall angle of the concave surface in the sub-flat layer close to the light-emitting layer is small, which is beneficial to improving the uniformity of the film layer thickness in the light-emitting layer and enhancing the light-emitting uniformity.

[0113] Figure 9 It is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention.

[0114] Exemplarily, in some embodiments of the present invention, referring to Figure 9 , the flat layer 4 may include a first sub-flat layer 41 and a second sub-flat layer 42.

[0115] Exemplarily, the distribution density of the plurality of concave surfaces 402 in the first surface 421 of the second sub-flat layer 42 is substantially equal to the distribution density of the plurality of concave surfaces 401 in the first surface 411 of the first sub-flat layer 41.

[0116] Exemplarily, the second width D2 of the orthographic projection of at least one concave surface 402 in the first surface 421 of the second sub-flat layer 42 on the substrate is substantially equal to the first width D1 of the orthographic projection of at least one concave surface 401 in the first surface 411 of the first sub-flat layer 41 on the substrate.

[0117] Exemplarily, the second widths D2 of the plurality of concave surfaces 402 in the first surface 421 of the second sub-flat layer 42 may be respectively equal to the first widths D1 of the plurality of concave surfaces 401 in the first surface 411 of the first sub-flat layer 41.

[0118] It should be noted that "substantially equal" in the embodiments of the present invention means that the ratio of the two is in the range of 0.8 - 1.2.

[0119] Through such a design, on the one hand, while increasing the total number of lens structures in the flat layer, it is possible to ensure that the sidewall angle of the concave surface in the sub-flat layer close to the light-emitting layer is small, which is beneficial to improving the uniformity of the film layer thickness in the light-emitting layer and enhancing the light-emitting uniformity. On the other hand, the concave surface sizes of the first sub-flat layer and the second sub-flat layer are substantially the same, and the same type of imprint template can be used to form them, which is beneficial to simplifying the manufacturing process and reducing the production cost.

[0120] Figure 10 It is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention.

[0121] Exemplarily, in some embodiments of the present invention, referring to Figure 10 , the flat layer 4 may include a first sub-flat layer 41, a second sub-flat layer 42, and a third sub-flat layer 43.

[0122] Exemplarily, the distribution density of the plurality of concave surfaces 403 in the first surface 431 of the third sub-flat layer 43 is substantially equal to the distribution density of the plurality of concave surfaces 402 in the first surface 421 of the second sub-flat layer 42.

[0123] Exemplarily, the third width D3 of the orthographic projection of at least one concave surface 403 in the first surface 431 of the third sub-flat layer 43 on the substrate is substantially equal to the second width D2 of the orthographic projection of at least one concave surface 402 in the first surface 421 of the second sub-flat layer 42 on the substrate.

[0124] Exemplarily, the third widths D3 of the plurality of concave surfaces 403 in the first surface 431 of the third sub-flat layer 43 may be respectively equal to the second widths D2 of the plurality of concave surfaces 402 in the first surface 421 of the second sub-flat layer 42.

[0125] Through such a design, the total number (or distribution density) of the concave surface structures in the flat layer can be further increased, the loss of light at the film layer interface can be better suppressed, the probability of total reflection can be reduced, and the light extraction efficiency of the light-emitting substrate can be improved. At the same time, the third sub-flat layer can also be formed using the same type of imprint template as the first sub-flat layer, which is beneficial to simplifying the manufacturing process and reducing the production cost.

[0126] In some embodiments of the present invention, the concave surface structures in the plurality of sub-flat layers may also adopt different designs. For example, multiple parameters such as the distribution density (or number), sidewall angle, and radius width of the plurality of concave surfaces on the first surface of the different sub-flat layers away from the substrate can be different or partially different.

[0127] Figure 11 It is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention.

[0128] Exemplarily, in some embodiments of the present invention, referring to Figure 11 , the flat layer 4 may include a first sub-flat layer 41 and a second sub-flat layer 42.

[0129] Exemplarily, the distribution density of the plurality of concave surfaces 402 in the first surface 421 of the second sub-flat layer 42 is less than the distribution density of the plurality of concave surfaces 401 in the first surface 411 of the first sub-flat layer 41.

[0130] Exemplarily, the second width D2 of the orthographic projection of at least one concave surface 402 in the first surface 421 of the second sub-flat layer 42 on the substrate is greater than the first width D1 of the orthographic projection of at least one concave surface 401 in the first surface 411 of the first sub-flat layer 41 on the substrate.

[0131] Through such a design, the inner diameter of the concave structure can be reduced in the sub-flat layer (such as the first sub-flat layer 41) that does not directly contact the light-emitting layer, and the distribution density of the plurality of concave surfaces can be increased, so that the number of concave structures in the same area is larger, which is beneficial to better improving the light extraction effect of the flat layer and improving the light extraction efficiency of the light-emitting substrate.

[0132] Figure 12 FIG. is a schematic structural diagram of a light-emitting substrate according to an exemplary embodiment of the present invention.

[0133] Exemplarily, in some embodiments of the present invention, referring to Figure 12 , the flat layer 4 may include a first sub-flat layer 41, a second sub-flat layer 42, and a third sub-flat layer 43.

[0134] Exemplarily, the distribution density of the plurality of concave surfaces 403 in the first surface 431 of the third sub-flat layer 43 is less than the distribution density of the plurality of concave surfaces 402 in the first surface 421 of the second sub-flat layer 42.

[0135] Exemplarily, the third width D3 of the positive projection of at least one concave surface 403 in the first surface 431 of the third sub-flat layer 43 on the substrate is greater than the second width D2 of the positive projection of at least one concave surface 402 in the first surface 421 of the second sub-flat layer 42 on the substrate.

[0136] Through such a design, the distribution density of the concave surfaces in the flat layer can be further increased, which is beneficial to better improving the light extraction effect of the flat layer and improving the light extraction efficiency of the light-emitting substrate.

[0137] Figure 13 FIG. is a structural block diagram of a display panel according to an embodiment of the present invention.

[0138] Optionally, an embodiment of the present invention further provides a display panel. Referring to Figure 13 , the display panel 200 may include the above-mentioned light-emitting substrate 100. It should be understood that the display panel has the same beneficial effects as the light-emitting substrate provided in the foregoing embodiment.

[0139] Figure 14 FIG. is a structural block diagram of a display device according to an embodiment of the present invention.

[0140] Optionally, an embodiment of the present invention further provides a display device. Referring to Figure 14, the display device 300 may include the above-mentioned light-emitting substrate 100 or display panel 200. The display device may include, but is not limited to: any product or component with a display function such as an electronic paper, a mobile phone, a tablet computer, a display, a laptop computer, a digital photo frame, a navigator, etc. It should be understood that the display device has the same beneficial effects as the light-emitting substrate or display panel provided in the foregoing embodiments.

[0141] Although some embodiments of the general concept of the present utility model have been shown and described, those of ordinary skill in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the general disclosure concept. The scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A light-emitting substrate, characterized in that, Comprising: A substrate; A planar layer disposed on one side of the substrate; And A light-emitting layer disposed on the side of the planar layer away from the substrate, wherein the planar layer includes N sub-planar layers stacked, the sub-planar layer includes a first surface on the side away from the substrate, and the first surfaces of at least two of the sub-planar layers include a plurality of concave surfaces, and N is a positive integer greater than or equal to 2.

2. The light-emitting substrate according to claim 1, wherein, The N sub-planar layers include an i-th sub-planar layer and an (i + 1)-th sub-planar layer, and the (i + 1)-th sub-planar layer is located on the side of the i-th sub-planar layer away from the substrate, wherein the refractive index of the (i + 1)-th sub-planar layer is greater than or equal to the refractive index of the i-th sub-planar layer, and i is a positive integer greater than or equal to 1 and less than or equal to N - 1.

3. The light-emitting substrate according to claim 2, wherein, The distribution density of the plurality of concave surfaces in the first surface of the (i + 1)-th sub-planar layer is less than or equal to the distribution density of the plurality of concave surfaces in the first surface of the i-th sub-planar layer.

4. The light-emitting substrate according to claim 2 or 3, wherein In a first direction, the positive projection of at least one concave surface in the first surface of the (i + 1)-th sub-planar layer on the substrate has an (i + 1)-th width, and the positive projection of at least one concave surface in the first surface of the i-th sub-planar layer on the substrate has an i-th width, and the (i + 1)-th width is greater than or equal to the i-th width, wherein the first direction is parallel to the light-emitting surface of the light-emitting substrate.

5. The light-emitting substrate according to any one of claims 1-4, wherein, The sidewall angle of at least one concave surface in the sub-planar layer is in the range of 30° to 40°.

6. The light-emitting substrate according to claim 4, wherein The planar layer includes a first sub-planar layer and a second sub-planar layer, wherein the distribution density of the plurality of concave surfaces in the first surface of the second sub-planar layer is substantially equal to the distribution density of the plurality of concave surfaces in the first surface of the first sub-planar layer; and The second width of the positive projection of at least one concave surface in the first surface of the second sub-planar layer on the substrate is substantially equal to the first width of the positive projection of at least one concave surface in the first surface of the first sub-planar layer on the substrate.

7. The light-emitting substrate according to claim 6, wherein, The planar layer further includes a third sub-planar layer, wherein the distribution density of the plurality of concave surfaces in the first surface of the third sub-planar layer is substantially equal to the distribution density of the plurality of concave surfaces in the first surface of the second sub-planar layer; and The third width of the positive projection of at least one concave surface in the first surface of the third sub-planar layer on the substrate is substantially equal to the second width of the positive projection of at least one concave surface in the first surface of the second sub-planar layer on the substrate.

8. The light-emitting substrate according to claim 4, wherein, The planar layer includes a first sub-planar layer and a second sub-planar layer, wherein the distribution density of the plurality of concave surfaces in the first surface of the second sub-planar layer is less than the distribution density of the plurality of concave surfaces in the first surface of the first sub-planar layer; and The second width of the positive projection of at least one concave surface in the first surface of the second sub-planar layer on the substrate is greater than the first width of the positive projection of at least one concave surface in the first surface of the first sub-planar layer on the substrate.

9. The light-emitting substrate according to claim 8, wherein, The planar layer further includes a third sub-planar layer, Among them, the distribution density of the plurality of concave surfaces in the first surface of the third sub-flat layer is less than the distribution density of the plurality of concave surfaces in the first surface of the second sub-flat layer; and The third width of the positive projection of at least one concave surface in the first surface of the third sub-flat layer on the substrate is greater than the second width of the positive projection of at least one concave surface in the first surface of the second sub-flat layer on the substrate.

10. The light-emitting substrate according to any one of claims 1-9, wherein, The refractive index of the flat layer is in the range of 1.4 to 1.

9.

11. The light-emitting substrate according to claim 1, wherein, The material of the flat layer includes one or a combination of epoxy resin, acrylic, and polyimide.

12. The light-emitting substrate according to any one of claims 2-4, wherein, The i-th sub-flat layer and the (i + 1)-th sub-flat layer are in direct contact; and The sub-flat layer further includes a second surface on the side close to the substrate. The second surface of the (i + 1)-th sub-flat layer includes a plurality of convex surfaces, and the plurality of convex surfaces in the second surface of the (i + 1)-th sub-flat layer fill the plurality of concave surfaces in the first surface of the i-th sub-flat layer.

13. The light-emitting substrate according to claim 1, wherein, The light-emitting layer includes: a first electrode disposed on the side of the flat layer away from the substrate; a light-emitting functional layer disposed on the side of the first electrode away from the substrate; and a second electrode disposed on the side of the light-emitting functional layer away from the substrate, Among them, the first electrode is disposed in contact with the surface of the flat layer on the side away from the substrate; and The surface of the first electrode close to the substrate includes a plurality of convex surfaces; and / or, The surface of the light-emitting functional layer close to the substrate includes a plurality of convex surfaces; and / or, The surface of the second electrode close to the substrate includes a plurality of convex surfaces.

14. The light-emitting substrate according to claim 1, wherein, The light-emitting substrate further includes: a driving circuit layer located between the substrate and the flat layer; and a light-filtering layer located between the driving circuit layer and the flat layer.

15. A display panel, characterized in that, Comprising the light-emitting substrate according to any one of claims 1-14.

16. A display device, characterized in that, Comprising the light-emitting substrate according to any one of claims 1-14 or the display panel according to claim 15.

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